Tuesday, 29 May 2012

A primer on conservation design

You might remember that I recently wrote about conservation design, an emerging field focused on translating scientists' recommendations into physical products and solutions addressing conservation problems; it is a discipline that aims to promote "reconciliation ecology," or the joint use of habitats by humans and wildlife. After reading my previous post, an Anthrophysis reader alerted me to an earlier, and more introductory, paper on the same topic. Although it's now a couple years old, I've decided to break with tradition and summarize it here because a) it contains some interesting ideas that b) do not seem to have not been updated in subsequent scientific literature, suggesting that conservation design is a technique that has yet to gain traction among conservationists.

 (One example of a successful conservation design: wood duck nest boxes)

The paper, written by Meredith Root-Bernstein and Richard Ladle, appeared in Conservation Biology back in 2010, prior to the authors' subsequent work with South American sea lions (Otaria flavescens) in Valdivia, Chile. According to the authors, conservation design is only one of many tools that can be used to try to fix the "global biodiversity crisis;" however, unlike most of those other tools, this field relies on interdisciplinary work by experts in anthropology, history, political geography, environmental psychology, design, engineering, and more. In the case of conservation design, the goal is to "devise innovative solutions that allow species to thrive in human-dominated habitats" in a manner that is both useful and pleasing to all parties involved--not an easy task.

Root-Bernstein and Ladle list four key benefits of collaborations between designers and conservationists. First, designers are generally more familiar with the process of taking an abstract idea--or a set of parameters/constraints--and turning it into a physical product. This helps streamline the process of creation and avoid potential obstacles in the path of desired outcomes. Second, designers might be aware of certain materials or techniques that are unknown to researchers. Thus, they may be in a better position to figure out how to, say, work with recycled or biodegradable materials, or utilize renewable energy sources. Third, designers have a long history of working with customers and stakeholders in order to produce something that reflects everyone's needs and desires. This expertise may help managers "harmonize conservation products with local values." Finally, the authors believe that conservation design will promote the development of "psychological biomimesis"--or creating something based on a knowledge of how animals perceive and interact with their environments, rather than simply trying to copy physical structures observed in nature. This technique has been successful in the design of products for use among humans, so it likely would have benefits when applied to wildlife, as well.

(Another example of a conservation design: enrichment aviaries for captive birds)

While conservation products may benefit from the input of designers from a variety of fields, the authors suggest that industrial designers are particularly well positioned to offer assistance. This field frequently deals with the urban environment, and is focused on creating products in which utility and aesthetics are balanced; designs may ultimately be mass-produced, one-of-a-kind, or anywhere in between. Industrial designers have experience creating products that can be used by a large audience, or only a particular subset (such as children, the elderly, or patients); they hope to "generate new and desirable interactions among product, user, and environment" and "participate in the making of new ways of living, thinking, and feeling." In other words, industrial designers are a very innovative group, and are used to coming up with novel items and solutions.

That said, people from other fields may also have much to contribute. For instance, researchers interested in creating a corridor facilitating the movement of bats from one habitat patch to another might work not only with industrial designers who would develop the optimal roost box design, but also with landscape designers who might suggest which dimensions would make the corridor most functional. Experts in animal welfare should also be consulted in order to provide information on which products and settings will be safest and most comfortable; likewise, animal behaviorists will understand the ways in which animals are likely to respond to novel items and environments. Collaborations among all these individuals, as well as community members who will be impacted by the management schemes, should help "blend human needs, desires, and preferences with those of the wildlife that conservation seeks to protect."

(A very simple conservation design: corrugated metal sheets used to provide shelter for reptiles)

The authors report that many conservation design projects have already yielded beneficial results. In Wisconsin, for instance, loons (Gavia immer) were happy to utilize artificial nesting platforms, and, when they did, experienced higher nesting success than their counterparts breeding on natural platforms; likewise, endangered iguanas (Cyclura lewisi) living on Gran Cayman island were quick to move in to artificial nests and retreats supplied by conservationists. One of the many other conservation problems that might be solved by conservation design is the capture of native birds in Indonesia, for use as song tutors for pet birds that will be entered into singing contests. The authors suggest that designers might come up with an automated training system that could teach captive-bred birds new songs in the absence of wild-caught individuals.

In order to facilitate this sort of interdisciplinary collaboration, Root-Bernstein and Ladle suggest that it would be useful to develop education programs that merge conservation and design goals earlier on. This would help ensure that conservationists and designers are on the same page--or at least in the same book--when collaborations begin. Even something as simple as agreeing on definitions can be helpful: Recently, a survey conducted among design students revealed that they defined "conservation" as "separation of wildlife from humanity," whereas, in many cases, conservationists might seek "better integration of humans and wildlife." The paper trail associated with each project would also have educational benefits if made available to other conservationists and designers. This could give later research teams a boost and allow them to avoid making the same mistakes that have been made before.

(Pingers--a conservation design that works better on some species than on others)

The authors also recommend extensive testing and comparison of products in order to ensure that only useful designs make the final transition from prototype to deployable and/or marketable product. This would prevent the distribution of, say, containment fences that can be breached, or nest boxes that will be invaded by non-target species. According to the authors, one of the best examples of a non-functioning conservation design is the pingers used to scare off dugongs (Dugong dugon) in Australia; as it turns out, the dugongs aren't much bothered by the noise and so continue about their business in areas where they are not wanted. One other important consideration is where the results of these tests should be published. Currently, many findings are published only in the gray literature and are therefore difficult for other researchers to locate; by targeting more mainstream publications, authors can present their results to a larger audience.

Although conservationists and designers come from very different worlds, the authors feel that interdisciplinary collaborations between these groups will be fruitful and rewarding. A learning period may be required during which everyone learns to speak the same language, but ultimately Root-Bernstein and Ladle believe the field of conservation design is poised to help take the recommendations of conservationists off the page and into nature.

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Root-Bernstein, M. and Ladle, R.J. 2012. Conservation by design. Conservation Biology 24(5):1205-1211.

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Friday, 25 May 2012

Are anthropogenic pressures increasing the speed of bacterial evolution?

It wasn't so long ago that antibacterial products, from soaps to hand gels to wipes for your kitchen counter, became ubiquitous in our grocery stores and our daily lives. Not long afterwards, though, we started hearing reports that these products and their even more powerful cousins, antibiotic prescriptions, were actually doing more harm than good--by facilitating the evolution of bacterial resistance to antimicrobials. As it turns out, that may be just be one evolutionary side effect of exposing bacteria to strongly selective anthropogenic pressures. An even more fundamentally important one is the ability to evolve rapidly, quickly incorporating genetic changes in order to display a different phenotype--in this case, increased or more comprehensive robustness in the face of antimicrobial treatments. This means that our struggles to deal with antibiotic-resistant strains, such as the dreaded methicillin-resistant Stapholococcus aureus (MRSA), are only just the tip of the iceberg.

(Methicillin-resistant Stapholococcus aureus, otherwise known as MRSA)

The question of whether humans are increasing bacterial "evolvability" is addressed by two Australian researchers in a review article published in the latest issue of Trends in Ecology and Evolution. They define "evolvability" as "an increased potential for evolution," which can be driven by characteristics such as basal mutation rate, recombination rates, protection against the incorporation of foreign DNA into the genome, and propensity for lateral gene transfer (or acquiring genes from a source other than a "parent"). All of these traits "affect the rate at which genetic variation can be generated"--and some of this variation could very well confer resistance.

Interestingly, many antibiotics were originally isolated from soil bacteria, which probably developed these compounds for use in signalling or competition with neighbors. For cells to survive in these potentially toxic environments, they had to evolve resistance genes alongside those producing poison, and so the terrestrial environment is probably already teeming with genetic elements offering protection from various man-made drugs. Once our antibiotic runoff reaches these environments, bacteria without the genes die off, while those with them will survive, passing on the resistance not only to their "offspring" but also, potentially, to their neighbors. Cells with higher levels of evolvability will become resistant more quickly; in other words, exposure to antibiotics leads not only to the selection of resistance, but also of the ability to develop it. This process works so well that the number of antibiotic-resistant genetic elements has increased significantly over the years. Many such elements are located in wild animals or environments not directly exposed to antibiotics, strongly suggesting that resistance has spread along a bacterial supply chain that begins in anthropogenic environments and extends even into those otherwise considered "pristine."

The authors point out that evolvability is not always a useful characteristic for bacteria to possess. For instance, while some mutations can be advantageous, others can impair functionality or even remove it altogether; likewise, incorporation of DNA from an unrelated bacterium might result in the transcription of a useful protein, but it also could generate something that is ultimately toxic. Thus, we should expect evolvability to be high only in systems where it's a gamble that, more often than not, pays off. This describes the current state of affairs in both terrestrial and aquatic ecosystems, into which humans dump vast quantities of antibiotics each year--especially in the form of waste water. The exact amounts are difficult to measure, but are likely to be large if they are even a small portion of the millions of metric tons produced annually.

(Acinetobacter baumannii, a gram-negative bacterium that is sometimes known as "Iraqibacter" because of its prevalence among US soldiers wounded to Iraq.)

One particularly frightening aspect of the spread of resistance is how it can often involve whole suites of genes rather than just one. Acinetobacter baumannii, for instance, now possesses a "resistance island" containing 45 genes for antibiotic/antimicrobial resistance, as well as resistance to heavy metals such as mercury and arsenic. As a result, A. baumannii infections have become a much greater threat to human health over the last several decades; additionally, these bacteria have given rise to a number of new hybrids and variants that are also likely to cause trouble in the future. Indeed, higher levels of evolvability are likely not only to increase the threat from current pathogens, but also "stimulate the emergence of new disease agents" from organisms that used to be our friendly neighbors.

As mentioned earlier, however, evolvability should be found at relatively lower levels in systems where it leads to more harm than good--for instance, places where there is limited exposure to novel antibiotic products. It is unlikely that we will be able to easily remove current contamination, but we can limit the amount introduced in the future by minimizing unnecessary use of antimicrobials and by disposing of them in a more eco-friendly way. This won't stop bacteria from developing defenses against our drugs and disinfectants, but it might help reduce the speed with which they do so.

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Gillings, M.R., and Stokes, H.W. 2012. Are humans increasing bacterial evolvability? Trends in Ecology and Evolution, 27(6): online advance publication.

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Wednesday, 23 May 2012

Different personalities in urban and rural house sparrows

Late last year, I described evidence suggesting that urban and rural song sparrows (Melospiza melodia) have different "personalities," or suites of behaviors that show repeatability within individuals. Recently, similar patterns were found for an Old World relative, the house sparrow (Passer domesticus), providing further support for the hypothesis that rural and urban habitats select for different types of individuals.

(A male house sparrow, Passer domesticus, guarding his nest cavity in a man-made wall.)

The current study was conducted by a team of Hungarian and Polish scientists who reported their findings in the academic journal PLoS ONE. They examined four major behavioral traits: fear of new objects, fear of new foods, risk-taking, and total activity levels. Lower levels of the first three behaviors, and higher levels of the fourth, have previously been associated with an increased likelihood of colonizing, and thriving in, anthropogenic habitats. Thus, the researchers expected to find that urban birds would be less fearful of novel objects (or "neophobic"), but take greater risks and be more active, than their rural counterparts. If urban house sparrows have personalities that are distinct from those of rural sparrows, correlations between these diverse behaviors should be different in the two types of environment; further, there might be different levels of personality variation within city and country populations.

To explore these possibilities, the researchers collected sparrows from four populations living along an urban gradient in Hungary--in Budapest, Veszprém, Nemesvámos, and Dóramajor, to be specific. Birds caught at the first two sites (at a train/bus station and fast food restaurant, respectively) were considered "urban," while birds from the latter two (a dairy farm and horse/cattle breeding farm, respectively) were considered "rural." Each bird participated in five trials: a control consisting of a normal daily routine, exposure to a novel object, exposure to a novel food item, exposure to a "friendly" heterospecific (a stuffed collared dove, Streptopelia decaocto), and exposure to a "predatorial" heterospecific (a stuffed sparrowhawk, Accipiter nisus). During each trial, researchers observed the focal bird's feeding activity--in particular, its latency to feed after the treatment had commenced, and the total number of hops it made throughout the trial (i.e., its activity level).

 (A house sparrow visiting a cafe in order to take advantage of crumbs left by messy diners.)

Surprisingly, urban and rural birds had similar feeding latencies in all treatments. However, a population-by-population analysis revealed significant differences along the urban gradient: between the two rural populations during the novel food trial, and between Nemesvámos (rural) sparrows and all others during the predator trial. These analyses revealed that Nemesvámos birds have lower levels of food neophobia, and higher levels of boldness, than other individuals; this is exactly the opposite of the predicted pattern. In fact, an abundance of bold individuals and a scarcity of shy individuals caused the Nemesvámos population to have unexpectedly high and low levels of inter-individual behavioral variation in the food neophobia and raptor tests, respectively. The total number of hops was similar for both urban and rural birds, and across all trials--with the exception of the novel food trial, during which all birds were more active.

In both urban and rural populations, the different types of behavior were highly correlated with each other, indicating that both urban and rural sparrow display "personalities." However, personality types varied according to habitat. In urban birds, moderate levels of object neophobia and risk taking were associated with very low activity levels; food neophobia was not a characteristic of city birds' behavioral syndromes. In rural birds, however, high levels of object and food neophobia were associated with moderate levels of risk taking and low levels of activity. Thus, not only are different traits included in the syndromes, but the relative contributions of those traits vary depending on population.

(A female house sparrow walking along a table in the outdoor portion of a cafe)

The presence of habitat-specific behavioral syndromes suggests that urban and rural environments place different selection pressures on their inhabitants. The variations observed across the 4 sites examined here indicates that these pressures are strongest at moderate levels of urbanization, though this may be an artifact of the sampling methods used in the current study; testing of more individuals from additional sites along the urban gradient would be needed to clarify this issue. Sampling of sites in various stages of urbanization might be helpful for determining whether successful colonization of urban habitats is associated with one suite of behavioral traits, while continued success is facilitated by another; there is currently little research directly addressing this potential multi-stage process. 

Another unanswered question is whether urbanization itself affects bird personalities, or whether individuals are responding to habitat features, such as fluctuations in food distribution or risk of predation, associated with urban environments. The authors hope that a better understanding of these details will help explain the "dynamics of animals' behavioral adaptation to urban life," thus allowing us to better predict the impacts of continued human expansion, and, in general, improve our understanding of how animals adapt to changing environments.

Bókony, V., Kulcsár, A., Tóth, Z., and Liker, A. 2012. Personality traits and behavioral syndromes in differently urbanized populations of house sparrows (Passer domesticus). PLoS ONE 7(5): e36639.

Thursday, 17 May 2012

How effective is the endangered species act?

In an attempt to evaluate the efficacy of the U.S. Endangered Species Act (ESA)--arguably one of North America's most crucial conservation tools--a pair of researchers from the University of Ottawa has sifted through decades of congressional reports outlining the recovery progress of threatened species. Their final assessment? Either the ESA is not nearly as effective as scientists and legislators once thought, or we simply don't have enough species recovery data in order to make a thorough and accurate evaluation of the bill's impacts.

(A Delmarva Peninsula Fox Squirrel, Sciurus niger cinereus, one of the first species to be placed on the endangered species list.)

Passed in 1973, the ESA outlines several major tools for reducing extinction of species and degradation of their habitats, including: protection from take (including harassment, harm, and killing), section 7 consultation (whereby federal agencies consult with the Fish and Wildlife Service to ensure that proposed activities will not threaten listed species), provision of funding (for research, enforcement, and the purchase of threatened areas), design and implementation of recovery plans, and recognition of critical areas (needed for both current habitat requirements and those that may arise in the future). Although these are the most commonly implemented elements of the ESA, not all species recovery plans involve each of these measures, and there are also other tools that are used on a case-by-case basis. The authors of the current report reasoned that variations in tool use might relate to variations in recovery, such that the most effective techniques would yield the biggest improvements in species numbers.

They are not the first researchers to look for this sort of relationship between ESA activities and conservation success. Several previous studies have investigated the effects of various tools--especially funding, recovery plan development, and critical habitat designation--on species recovery. However, findings of that research have been contradictory. Perhaps more importantly, the authors of those studies were looking for the presence/absence of an effect rather than attempting to measure the effect size. For instance, while researchers have reported that amount of funding is significantly related to species status, they did not focus on the strength of that relationship (e.g., the quantity of variation in status explained by variation in funding), or compare it to those found for other conservation tools--important analyses to perform if you are interested in identifying which of several influential tools is likely to have the greatest impact on conservation outcomes.

(Whooping crane, Grus americana, and chick. This is another of the first species to be placed on the endangered list. One dubious benefit of this "honor" is that this species was able to avoid the average 11-year wait associated with the listing process.)

In the current study, researchers evaluated the recovery status for all species listed prior to 2003. Recovery was measured in two ways: number of recovery objectives achieved (as evaluated on a scale of 1-4), and population trends (e.g., declining, stable, or increasing). In order to determine which factors had the greatest impact on recovery, the researchers also noted the length of time each species had been officially listed, the length of time a recovery plan had been in place, the length of time critical habitat had been designated, and the amount of federal funding provided for the recovery effort. Data on all of these factors were extracted from biennial species recovery status reports submitted to Congress between 1988 and 2006. The scientists also hypothesized that another important predictor of recovery might be the amount of published literature available on each species, since knowledge can improve recovery efforts and also since funding facilitates research. Information on this variable was obtained by searching an academic database for papers on each species.

Ultimately, the scientists were able to include 1179 species in their study--61% plants, 14% invertebrates, 9% fish, 6% birds, 5% mammals, 3% reptiles, and 2% amphibians. Cumulatively, conservation progress trends did not look very promising; over the study period, populations tended to remain stable or trend towards a slight decline, and, on average, less than a quarter of recovery objectives were achieved for most species.

(A Texas blind salamander, Typhlomolge rathbuni, another endangered species list pioneer.)

The proportion of recovery objectives achieved was significantly related to proportion of requested funding provided, amount of peer-reviewed literature published, and both length of time listed and length of time with a recovery plan. However, despite the clear statistical significance of these factors, cumulatively they only explained 13% of the variation in recovery patterns observed across all species--suggesting that no one conservation tool was having a particularly strong effect on population trends. Similar results were obtained from an analysis on change in population status; in this case, number of years listed and proportion of requested funding provided were both associated with population improvements, but together these variables explained less than 10% of variation in recovery.

Interestingly, patterns varied according to taxonomic group, with birds, mammals, and fish displaying higher recovery rates than plants, amphibians, and invertebrates. In fact, when the researchers repeated their analysis within each group, rather than across all groups, as much as ~40% of variation in their data was explained. In birds, for instance, number of years listed explained ~21% of variation in population status, while proportional funding and critical habitat designation together explained 39.9% of variation in mammals.

Birds and mammals are two of the most intensively studied groups of organisms, which suggests that it is not a coincidence that these are the two taxa with the strongest patterns. Species status was only provided an average of 68% of the time across all the congressional reports, and data were most common for birds and fish, but least common for plants. Further, the likelihood that species status was known was strongly related to the amount of peer-reviewed literature available on that species. Taken together, these results suggest that there are many species for whom there are not sufficient data on which to base an estimate of population status, and potentially many more species in which the given status may not be representative of conditions on the ground.

(The shortnose sturgeon, Acipenser brevirostrum, is an early-listed species whose stocks were depleted in some areas of the US by the mid-20th century.)

Thus, the authors feel that the seeming low efficacy of the ESA tools examined here--listing, recovery plan development, critical habitat designation, and funding--may not actually result from a flaw in the methods so much as a flaw in our ability to gauge how well those methods are working. They take some consolation from the fact that the "best among the weak predictors of recovery" is the number of years a species has been listed, implying that protection from take and section 7 consultation do provide benefits, even if they are not huge.

Two of the major problems associated with current species recovery reports are the use of qualitative data--with species recovery patterns often described relative to previous reports--and a lack of peer review, such that some reports merely reflect staff opinions rather than statistically supported results. An emphasis on quantitative data and rigorous analysis should help improve accuracy and make the reports more scientifically useful in the future. Unfortunately, this may require more time and money, or, at the very least, a redistribution of current resources. However, the authors point out that efforts to address these problems should benefit ESA efforts as a whole, as well as potentially helping the species protected by the bill.

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Gibbs, K.E., and Currie, D.J. 2012. Protecting endangered species: Do the main legislative tools work? PLoS ONE 7(5):e35730.

Thanks to the following websites for providing the images used in this post:

Tuesday, 15 May 2012

Triatomines and street lamps: Like moths to a flame?

If you have ever left your porch light aglow during a late-night outing, you are probably familiar with the cloud of insect life through which you will have to pass once you get home at the end of the evening. In most places this is merely an inconvenience, but in areas where insects can carry dangerous diseases, their attraction to anthropogenic illumination can pose a serious threat to human health.

(Adult Triatoma demidiata)

This was recently found to be true in Mexico's Yucatan peninsula, where street lights attract a group of insects called triatomines, also known as kissing bugs, conenose bugs, and assassin bugs. Triatomines are "hematophagous," meaning that they feed on vertebrate blood. As they do so, they may leave behind droppings infested with Trypanosoma cruzi, the parasite responsible for Chagas disease. If the parasite comes into contact with victims' blood streams--via the open bite wounds, for instance--it can cause an infection that has a treatable acute form, but a chronic form that may not appear for 10-20 years and can eventually lead to death via heart failure.

Light traps have long been used to capture triatomines in the wild, suggesting that the insects are attracted to artificial sources of illumination. Further, managers have previously noticed that these bugs are nonrandomly distributed in villages, and quickly re-infest houses after the application of pesticides. Cumulatively, these patterns suggested that the triatomines might cue in on street lamps and porch lights, preferentially infesting homes nearest these features.

This was the hypothesis tested by an international team of collaborators who utilized both observational and experimental methods to explore the dispersal of one triatomine, Triatoma dimidiata, in the Mexican villages of Bokoba, Teya, and Sudzal. Residents of the villages were asked to bring their insect invaders to the local health center, allowing the researchers to create a map of which homes were infested. Maps also included data on locations of public street lights and "peridomestic lights," or those illuminating porches and/or yards. Further, the researchers visited each home at night in order to measure the intensity of each light source. These data allowed them to investigate the differences in brightness between the two sources of light, and to evaluate whether infestation could be predicted by proximity to artificial illumination.

(Trypanosoma cruzi, the parasite responsible for Chagas disease)

Cumulatively, a total of 1466 houses were surveyed across the 3 villages, and only 214 of these (or 14.6%) were infested by T. dimidiata. Anthropogenic light sources were more commonly public (135-228 per village) than private (229 houses total), and both types of lighting had similar intensities (22-23 lux). The presence of peridomicile lighting only predicted infestation patterns in one village (Bokoba); however, infested houses were significantly closer to public lights in all three study sites. Specifically, more than 50% of infested houses were located near a public light, and the critical proximity appeared to be ~18 m.

In order to verify these patterns experimentally, the scientists caught both adult and nymph triatomines in order to perform a choice chamber experiment. Each bug was placed in the center of a chamber at either end of which was a different light treatment: The triatomines could choose to crawl through a tunnel leading to darkness or one leading towards light. Nymphs did not seem to display any preferences, but adults of both sex chose the lit end of the chamber significantly more often than the dark end; this dispersal activity was particularly high between 1 and 4 AM. The researchers then performed a second choice chamber experiment in which they investigated preferences for different components of the white light treatment--blue, yellow, or red wavelengths. Triatomines showed strong attraction to blue light, but only mild attraction to yellow, and none at all to red. In other words, the insects appeared to prefer shorter wavelengths over longer ones.

The authors of the study acknowledge that the data collection period for the field portion of their study was relatively brief. Despite this, they found a consistent relationship between public lighting and infestation across all 3 villages, regardless of local variations in potential confounding factors such as heat, weather, and vegetation. Further, these patterns were consistent with the results of their experimental study. Taken together, these findings suggest that triatomines cue in on public lights and, once they are in the neighborhood, make their way into the homes of residents unlucky enough to live in the glow of nearby street lamps.

(Feeding assassin bug)

Given the strong effect of public lighting, the researchers were surprised that peridomicile lights did not also seem to relate to infestation. One potential reason for this pattern is the time frame in which these different light sources are used; while street lamps are on all night--including during the 1-4 AM period when triatomine movement is greatest--porch and yard lights are often turned off around 10-11 PM when homeowners go to bed. Additionally, public lights are taller and often located in more open areas of the habitat, which means they may be visible to a larger portion of the local insect population.

One way of reducing triatomine infestation may be to dim or turn off street lights during the critical 1-4 AM time slot, or ensure that lights are not installed closer than ~20 m to nearby houses. Additionally, the researchers found that triatomines consistently migrated towards white light over yellow light when given a choice between the two; thus, use of yellow bulbs might be a good compromise in T. dimidiata-infested areas. This could be particularly true if white light traps are erected nearby, distracting the bugs away from street lamps and neighboring houses.

The authors also point out the utility of their geospatial analysis technique for predicting triatomine infestations. Although this method was employed here on only one species, they suggest that it is likely to be useful for other (vector-carrying) varieties of triatomine, as well. The resulting maps should aid in the detection of sites where infestation is so low that residents are unaware of the triatomines, but where there is still a very real risk of being bitten.

Pacheco-Tucuch, F.S., Ramirez-Sierra, M.J., Gourbiere, S., and Dumonteil, E. 2012. Public street lights increase house infestation by the Chagas disease vector Triatoma dimidiata. PLoS ONE 7(4):e36207.

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Tuesday, 8 May 2012

An introduction to urban endocrine ecology

One of the most common topics here on Anthrophysis is urbanization, a process that influences, among other things, habitat structure, resource availability, temperatures and other microclimate variables, species interactions, animal behavior, biodiversity, and reproductive success. Urban environments tend to have fewer vertebrate species and greater levels of homogeneity. In birds--one of the best-studied groups in this context--it appears that urban areas favor generalist species, those with a broad environmental tolerance, and those with a larger relative brain size.

Despite our growing understanding of these general patterns, we have yet to uncover the reason why they exist--or, in other words, the mechanism(s) linking the urban environment with variations in behavior and biodiversity of birds (or any other taxa, for that matter). One of the most likely candidates is the endocrine system, which plays a vital "role in mediating an organism's physiological and behavioral responses to novel environments." This possibility was the focus of a recent review paper,  published in the academic journal Hormones and Behavior, by Frances Bonier of Queen's University. In particular, the paper focuses on two key endocrine axes that are likely to mediate avian responses to urban environments: the hypothalamic-pituitary-adrenal (HPA) axis, which is responsible for regulating processes related to metabolism, and the hypothalamic-pituitary-gonadal (HPG) axis, which is responsible for reproductive processes. Hormones associated with these axes, including glucocorticoids, estradiol, and testosterone, can be used as indicators of physiological responses to the stresses of city life.

(A curve-billed thrasher, Toxostoma curvirostre. Urban thrashers have lower baseline glucocorticoid levels than desert-dwelling thrashers, but only during the non-breeding and molting stages of their life histories; during the breeding season, glucocorticoid levels are similar in urban and non-urban birds.)

Bonier identifies three major questions that researchers have sought to answer by measuring these and other hormones. The first is associated with "allostatic load," or the "current and predicted energetic demands facing an organism." Several studies have investigated whether the allostatic loads of urban birds are different from those found in rural counterparts. There are a variety of factors that can influence allostatic load, including an individual's exposure to certain disturbances, its perception of the environment, and its ability to access and utilize resources. To put that in more specific terms, each animal's response will vary depending on the number of house cats it has to dodge, ambient noise levels in its territory, whether it is able to supplement its diet at a bird feeder, and so on. Each of these factors may, in turn, be influenced by species identity, sex, and life history stage (for instance, whether the animal is currently breeding or not). Perhaps unsurprisingly, the handful of studies that have been conducted on this to date have yielded conflicting results; thus, it is hard to draw any general conclusions at this stage of the game.

The second question commonly asked by researchers is whether urban birds respond differently to "acute" challenges--those that go above and beyond the daily background dose of disturbance that animals are used to experiencing. According to Bonier, endocrine responses "to acute perturbations...can reveal how the urban environment shapes the responsiveness of the HPA axis or selects for particular endocrine phenotypes." Variations in these responses may explain why some urban birds differ from their rural counterparts in terms of flight initiation distance, neophobia, use of foraging innovations, and boldness.

(Florida scrub-jay, Aphelocoma coerulescens. Suburban jays have lower baseline glucocorticoid levels than nonurban jays, and this difference may partly be driven by high levels of supplemental food available in more anthropogenic habitats.)

Finally, Bonier examines work exploring differences in reproduction between urban and non-urban birds. As with allostatic load, there are many factors other than location, per se, that can influence this aspect of the endocrine system--including migratory behavior, the availability of resources such as food and nesting materials, and microclimate. Urban environments might be particularly hard on animals of certain age (and therefore reproductive) categories, which could alter the extent to which different individuals invest in breeding efforts. Such demographic responses to urbanization may be the key to successful reproduction in cities, both for particular individuals and entire species. Thus, Bonier hypothesizes that, in order to thrive in urban environments, animals may need to be "physiologically flexible enough to adjust their phenology and life history in response to urban conditions." Indeed, though there have only been a few urban reproduction studies to date, their results indicate that variations between urban and nonurban birds may stem from plasticity rather than heritable responses.

After sifting through the evidence, Bonier concludes that the "nascent field of urban endocrine ecology has not yet revealed any strong, consistent patterns." Further, although there have been a handful of observational studies asking how endocrine traits vary according to urbanization levels, there is a need for experimental studies that will more clearly demonstrate why the observed patterns occur. Of the many potential questions that can be asked, the author feels it would be particularly interesting to focus on whether endocrine traits "differentiate species that do and do not tolerate urban habitats"--specifically, to ask whether "certain endocrine traits differ among urban avoiders, urban adapters, and urban exploiters." Consistent variations in particular hormones would facilitate their use as proxies for fitness, potentially enabling researchers to more quickly characterize the health of local bird populations.

(European blackbird, Turdus merula. In the wild, levels of luteinizing hormone are similar in urban and nonurban female birds, but are higher in urban males than in nonurban individuals. These same patterns do not hold true for nestlings of these species raised in captivity, indicating that endocrine responses in these birds may be plastic, depending strongly on environmental conditions.)

Bonier also points out the need to generate enough data to permit meta-analyses and comparative studies. The current trend of studying one species in a single urban-nonurban site pairing (e.g. house sparrows, Passer domesticus, in and near Phoenix, AZ) makes it difficult to draw general conclusions about the effects of urbanization around the world. For one thing, variations in resident birds could be driven by habitat variables, such as humidity or local rainfall, that are influenced by degree of urbanization, rather than by urbanization itself. So far, there is only one study in which one or more species has been examined across multiple cities; there are also few projects examining multiple species in a single place. Multi-city studies will help researchers determine whether the effects of urbanization differ according to larger landscape and environmental patterns--for instance, because of a city's location in a desert environment (as in Phoenix) rather than a tropical one (such as Miami).

Other major suggestions include coupling field and captive studies and exploring different data collection techniques that may more accurately measure endocrine responses to urban challenges. Bonier also emphasizes the importance of placing endocrinological patterns within a broader context;
this can be done by utilizing "classical ecology" quantitative tools to measure things such as population density, degree of urbanization, and animal behavior. Together, these data should allow the field of urban endocrine ecology "to make important advances in our understanding of how rapidly expanding urbanization will impact organisms worldwide."

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Bonier, F. 2012. Hormones in the city: endocrine ecology of urban birds. Hormones and Behavior 61:763-772.

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Saturday, 5 May 2012

Combating depression with green care therapies

Depression is thought to affect approximately 3-4% of the global population each year, and while traditional therapies can improve the mental health of many people, others find that these offer no relief. Thus, researchers have long explored alternative or complementary treatments that might benefit these patients, but the efficacy of many such techniques has not yet been rigorously tested.

One example of a promising but under-studied therapy is "green care" or "care farming," a type of intervention that uses "nature and the natural environment to improve or promote health and well-being." Participants in green care programs are offered the opportunity to spend time volunteering on farms, where they learn new skills, interact with other workers, and come into contact with farm animals. These sorts of experiences, which can improve mood and outlook by increasing self-efficacy and self-esteem, are known to be individually beneficial in the treatment of depression, and so may have a positive synergistic effect as well.

(image courtesy of http://www.welcome-to-lancaster-county.com/)

In the only previous randomized control study of a green care program, researchers found no immediate differences in the mental health of patients engaged in this "alternative" therapy and those given more traditional treatments. However, green pare participants did seem to be doing better at the six-month follow-up period, suggesting that further research on this therapy might yield interesting results. Improvements were particularly marked among individuals with affective disorders, indicating that green care might be especially beneficial for patients with depression.

These findings inspired a team of Norwegian scientists to perform a new study examining the effects of a 12-week animal-assisted intervention on clinically depressed patients. The study ultimately included 27 individuals, 16 of whom participated in green care activities and the other 13 of whom received traditional therapy. People in the former group visited one of 11 participating dairy farms for 1.5-3 hours twice weekly over a 12-week period. Because interactions with animals are known to improve mental health, participants were directed towards activities associated directly with dairy cows; despite this constraint, each individual could decide the exact form that interactions would take--for instance, grooming, mucking, feeding, caring for calves, or milking.

 (Cow grooming)

Over the course of the intervention, the researchers distributed questionnaires aimed at assessing severity of depression (the Beck Depression Inventory, or BDI), anxiety (the State-Trait Anxiety Inventory-State Subscale, or STAISS), and self-efficacy (the Generalized Self-Efficacy Scale, or GSES). Participants filled out all questionnaires at recruitment, the beginning of the intervention period, and at a three-month follow-up; they also filled out the BDI and GSE at four and eight weeks into the therapy.

Individuals in both groups experienced "positive developments in all assessments." However, similar to the previous green care study, the current work did not reveal any significant differences in mental health between the green care and traditional therapy groups, both during the intervention period and at the three-month follow-up. Interestingly, though, depression levels declined significantly between two time points (recruitment and the end of the intervention) in green care participants, and then remained steady thereafter; self-efficacy was also found to markedly improve over the study period. A similar intensity of change was not observed among control individuals. Further, the official criteria for clinical improvement were met in nine of the green care individuals, but only three of the control participants; likewise, while six green care patients returned to "normal" levels on a scale of clinical depression, this was only true for one control individual. Thus, the alternative therapy appeared to be slightly more beneficial, and aid a larger number of people.

(Previous research has indicated that people can form bonds with farm animals as well as more "traditional" pets, and that these relationships can help alleviate depression.)

The researchers hypothesize that one of the main benefits of the dairy farm experience is an increase in self-efficacy, facilitated by the opportunity to learn new skills and adapt to a new environment; this likely combated feelings of "diminished self-worth and self-esteem" typical of many people with clinical depression. The green care experience probably also reduced inactivity, withdrawal, and avoidance of others--three other common characteristics (or even causes) of depression. Additionally, as found previously in other studies, interactions with animals seemed to have a soothing effect; many participants reported feeling calmer when in the presence of cows.

Although this study again failed to find any significant difference between traditional and green care treatments, the authors suggest that the latter are still worthy of additional attention. Their sample size was fairly low, and their treatment period relatively short; additionally, each participants could engage in a number of different farm activities rather than following one consistent farming routine. Thus, further work might not just aim to include additional individuals and examine their improvements over a longer period of time, but also standardize their routines or even explore more "complex and challenging" work tasks. This sort of information might enable therapists to tailor green care treatments for people with different characteristics or interests. Even if further studies are not pursued, green care appears to achieve, at worst, similar improvements to those derived from traditional treatments. Thus, this therapy may be a suitable substitute for patients for whom traditional treatments are not feasible or desirable.

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Pedersen, I., Martinsen, E.W., Berget, B., and Braastad, B.O. 2012. Farm animal-assisted intervention for people with clinical depression: a randomized controlled trial. Anthrozoos 25(2):149-160.

Friday, 4 May 2012

Human perceptions of animal cognition

Anyone who has spent much time watching animal behavior has probably, at some point or another, wondered what goes on inside (non-human) animals' brains--Are they thinking, or just acting intuitively? Do they have minds, or just a collection of neural matter? Although the answers to these questions may not immediately seem to have any practical purpose, human perceptions of animal cognition actually play an important role in determining our attitudes towards animals and animal use. As a result, these issues may have serious implications for policies related to medical testing, scientific research, husbandry practices, and the pet trade, to name a few examples.

Attitudes about animal cognition are also likely to influence the receptiveness of lay audiences to scientific results on this topic--not only in terms of people's overall willingness to learn about animal thought, but also their interest in one subset of cognitive research over another--with implications for the funding of, and progress in, these fields. Thus, it is useful to understand "what people think about animal thinking" in order to develop education tools such as classroom curricula or museum exhibits.

(Alex the parrot, who, at the time of his death, had an English vocabulary of 100+ words. Here, he is demonstrating his ability to distinguish between different numbers--or the shapes thereof--and colors.)

The latter of these outputs was the goal of three collaborators from the City University of New York and Edgewater, Maryland's Institute for Learning Innovation. In order to optimize their product, they first sought to better understand how people perceive animal thinking. To this end, they developed a two-part study utilizing surveys that explored several topics: human attitudes towards the idea of animal thinking, which animals are perceived to be thoughtful, what different types of intelligence (if any) animals are thought to display, and whether public perception of these issues aligns with the results of scientific research on animal cognition.

After perusing the academic literature, the researchers identified four main dimensions of animal cognition that have received attention from scientists: learning and memory, communication, numerosity (e.g., an understanding of numbers), and awareness. Subjects' familiarity with these dimensions was explored in the first survey, which was conducted among visitors at the New York Hall of Science and the Staten Island Zoo.

The majority of survey participants indicated that they had previously pondered animal thinking, and many were familiar with animal cognition topics either from popular media presentations or from their own previous experience--especially with pets. Survey responses suggested that most people perceived a "cognitive hierarchy" topped by humans;  pet species such as dogs and cats, and charismatic social animals such as dolphins also seemed to rank highly. The researchers noted that many survey responses were disconnected from one another, and that few respondents summarized across multiple animals in order to offer a generalized theory of animal cognition.

(Blue tit, Parus caeruleus, drinking from a milk bottle. This feeding technique rapidly spread through tit populations in England after observant individuals copied the behavior of successful pioneer bottle-raiders.)

Answers to questions about the cognitive dimensions revealed that most people were vaguely familiar with certain mental abilities of animals, but could not offer many details about how these abilities develop, why/when they might be applied, or the many varieties that can be seen within and among species. For instance, although people readily agreed that animals could remember things, few answers described memory capacity or differentiated between varieties of memory; further, while most participants recognized that animals communicate, people commonly focused on conspecific signaling and ignored information transfer between species.

The researchers used these results to design a second, online survey that could a subset of these issues in greater detail; they were particularly interested in understanding whether the public is likely to attribute certain mental abilities to some species rather than others, and why this might be. Since familiar domestic animals had repeatedly been mentioned during the first survey, the researchers also wanted to contrast attitudes about these animals with attitudes about wild species, and, further, to investigate whether pets were perceived differently than other types of domestics (such as animals destined to become food). To this end, the survey consisted of a series of statements (such as "Animals cannot draw on their memory to plan for the future" and "When a dog protects its owner it is just responding to training") to which respondents could agree or disagree along a six-point scale.

The survey was distributed to over 500 participants who indicated they had recently visited some type of science/nature exhibit. Somewhat surprisingly, most answers had a mean value of 3-4, indicating that respondents were neutral, and did not strongly agree or disagree with the statements. The strongest responses were to the questions "Birds do not use meaningful calls to intentionally communicate with each other" and "Elephants can multiply and divide;" although most people appear to recognize the importance (and, potentially, the intricacy) of avian vocalizations, few are willing to believe that elephants can do math.

(A young police dog, which will go to school to learn a variety of skills such as identifying illegal substances, finding injured people, and bringing down criminals without causing lasting damage.)

Given the results of the previous survey, it was not surprising to find that lay people do not seem to conceptualize animal cognition in the same way that scientists do. Specifically, the average person tends to think of an animal as either being intelligent or not; there is no recognition of the four dimensions of intelligence perceived by researchers. Further, most individuals do not seem to have opinions on the mechanisms behind animal thought.

As anticipated, attitudes about animal cognition varied depending on the species identified. Wild animals, cats, dogs, and "higher" mammals were perceived as being more intelligent than farm animals; in general, there seemed to be a tendency for people to rank animals according to phylogeny, though this issue requires further exploration. Respondents readily agreed that many animals possessed "survival-based abilities" such as escaping from a predator or obtaining food, but seemed to regard these as instinctual behaviors rather than indications of thoughtfulness.

Based on this final result, the researchers suggest that animal cognition exhibits might be most palatable if they emphasize animal thinking in a survival context.  Additionally, the authors believe that it would be valuable to focus on how/why cognition developed in wild species that later became domesticated. This would provide an evolutionary context to animal thinking and highlight the fact that animal intelligence goes beyond an ability to learn how to do tricks and solve puzzles while in captivity.

(Many primates, such as these Allen's swamp monkeys, Allenopithecus nigroviridis, use tools to acquire or process food items.)

Because so many of the survey responses were neutral, the researchers feel that the public is "likely to be open to considering evidence that animals have higher-order thinking abilities." This is further supported by the overwhelmingly positive feedback supplied by most participants, indicating that people generally enjoyed contemplating these ideas. Thus, the authors conclude that "popular media and museum exhibitions have the potential to build stronger connections between humans and other animals by helping people develop an understanding of the numerous and varied findings from scientific studies on how other species think."

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Maust-Mohl, M., Fraser, J., and Morrison, R. 2012. Wild minds: what people think about animal thinking. Anthrozoos 25(2):133-147.

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Thursday, 3 May 2012

Mammals and meat: Does carnivory impact weaning?

Why do our closest primate cousins spend more time suckling their young than we typically spend nursing ours? This question has been heavily debated over the past several decades, but to date there is more information on the implications of our relatively short lactation periods than on their causes. One reason it has been difficult to address this question empirically is that there is not much variation in large-brained primates in some of the traits that are hypothesized to impact suckling behaviors; thus, it is difficult to explore how these characteristics could affect lactation and parenting. However, a team of European scientists has sidestepped this issue by analyzing suckling patterns--or, to be more specific, time to weaning (TTW)--across all mammals, while simultaneously taking into consideration other important life history characteristics such as brain size. This allowed them to examine data from a large and phylogenetically diverse group of animals--67 species from 67 genera across 12 mammalian orders. The results of their analysis led them to conclude that human weaning patterns are driven by our carnivory, a practice that was first begun by our early hominid ancestors 2.6-2.0 million years ago.

(A chimpanzee, Pan troglodytes, mother suckling her offspring)

For each of the 67 species examined in the current study, the researchers collected a variety of data allowing them to explore several different potential drivers and correlates of TTW. First, they considered two measures of mass: brain mass, which impacts the length of time it takes for an offspring to mature, and female body mass, which could influence lactation by imposing metabolic limits on mothers. It turned out that brain mass was a better predictor of time to weaning, though both variables accounted for a fair amount of variation in TTW. Interestingly, the researchers found stronger relationships when looking at time to weaning post-conception rather than post-birth, despite the fact that the latter metric is more commonly used. The relationship between brain mass and TTW remained significant even after body mass was controlled for, providing support for the theory that weaning patterns have developed as a result of offspring need rather than female limitations.

The second variable of interest was limb biomechanics. A recent comprehensive study found that animals that locomote with the entire sole of each foot on the ground--i.e., in the "plantigrade" posture, as seen in humans, raccoons, bears, and rabbits--take significantly longer to take their first steps when young. This is an important developmental milestone that the researchers hypothesized might be related to other developmental events such as weaning. Indeed, it turns out that "plantigrade animals" take longer to wean, even after differences in brain mass are accounted for.

(A sow, Sus scrofa domesticus, suckling her piglets)

Finally, the authors explored the effects of diet--carnivory, omnivory, or herbivory--on TTW. Here, following the suggestion of RA Foley, species were defined as "carnivorous" if they displayed a "shift from 10% to 20% of food from meat;" this reflects the difference in diet between chimpanzees (5% meat) and hunter-gatherers in environments like those of our early human ancestors (20-50% meat). Carnivores were found to wean earlier than both omnivores and herbivores, the latter two of which weaned in similar time frames. Using the patterns found for actual species, the researchers predicted TTW for a hypothetical carnivore and non-carnivore with a human-like brain mass; this value was then compared to weaning times observed in 46 human "natural fertility societies" (i.e. those in which birth control use does not skew reproductive patterns). There was a much better match between the expected and observed values when the predictor diet was carnivory rather than omnivory/herbivory, and in fact the mean predicted value of a 1162-day TTW was surprisingly similar to the observed mean of 1129 days.

In addition to investigating each of these TTW predictors separately, the researchers also compiled a full model which simultaneously explored the effects of brain mass, limb biomechanics, and dietary profile on TTW. Cumulatively, these three variables accounted for 89% of variance observed across the mammals examined here; 75.5% of this could be attributed to brain mass, 10.3% to limb biomechanics, and 3.4% to diet. Given the similarities in brain mass and limb biomechanics between humans and primates, the authors conclude that a (or even the) major factor driving differences in TTW between humans and other primates is our carnivorous diet: "...dietary profile has had a profound evolutionary effect on weaning in mammals," and "carnivory per se may provide not only a necessary but also a sufficient explanation for the difference between humans and great apes with respect to the timing of weaning."

 (A lioness, Panthera leo, suckles her cubs)

The researchers admit that cultural factors, such as cooking and help with child care from other family members, are also likely to impact weaning, but suggest that these are more likely to explain the relatively minor variations among societies rather than the major variations observed between humans and other primates. Increases in meat consumption could have fueled the generation of more nutritious milk, allowing mothers to shorten the period of time over which they lactate and suckle young. This, in turn, would have decreased interbirth intervals and therefore increased rates of reproduction, thereby facilitating an expansion of the human population. As the authors state, this would have "affected [hominid] population dynamics profoundly." Thus, these findings support previous theories that at least some aspects of hominid evolution were associated with dietary changes.

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Psouni, E., Janke, A., and Garwicz, M. 2012. Impact of carnivory on human development and evolution revealed by a new unifying model of weaning in mammals. PLoS ONE: 7(4):e32452.

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Wednesday, 2 May 2012

A decision theory approach to conservation fencing

"In a conservation funding climate that is characterized by insufficient resources, and where donors...are increasingly demanding that return on investment be demonstrated, conservation fencing decisions cannot continue to be based solely on ecological intuition." This is the assessment of a group of Australian collaborators seeking a practical method of identifying the best sites for erecting conservation fences. Fences may not sound like the most exciting or innovative management technique, but in fact they are often a vital component of reintroduction schemes, the success of which is often dependent on the exclusion of potential predators such as foxes (Vulpes vulpes), cats (Felix catus), feral dogs (Canis lupus familiaris), and dingoes (Canis lupus dingo); fences can also be used to limit the activity of exotic herbivores that compete with the natives for vegetative resources.

(An example of conservation fencing)

According to the Australian research group, there has been a fair amount of research on how to design useful fences, but not much work on how to choose places in which to erect them. A variety of local features can influence habitat suitability, including vegetation, management history, distance from infrastructure or boundaries, and cultural significance; expenses associated with construction and maintenance will also be important. This large number of variables can make fencing seem "a costly and uncertain action," which is why the researchers have used decision theory to develop a method of selecting--and defending, if necessary--fencing locations. They have also field-tested their recommendations in a conservation site in Western Australia in order to examine the efficacy of their plan.

The selection process involves four steps, the first of which is to state a specific conservation objective and then select a metric (a "benefit function") that can be used to measure how well a particular plan achieves this goal. For instance, the collaborators were tasked with creating an exclusion site (or sites) in the planned Lorna Glen Conservation Reserve; there, locally extinct mammal species could be reintroduced as part of the Operation Rangelands Restoration project. The failure of previous "hard introductions" indicated that many species would benefit from a "soft introduction" that would allow them to acclimate to their new habitat. Thus, the objective in Lorna Glen was to set aside as large a predator-free area as possible in which these reintroduced mammals could live and breed; size of site would therefore be an accurate indication of a plan's suitability.

(One area of the Lorna Glen Conservation Reserve, or Matuwa)

The second step is to collect data on spatial features that could impact the benefit function. These may be ecological, economic, social, or even political. In the case of Lorna Glen, for instance, the  managers collected information on the vegetation in, and underlying geology of, preserve land; land management history (particularly in association with pastoral activities), and the cultural significance of certain areas to local Aboriginal residents. Collection of these data should allow researchers to identify all potential fencing locations within a larger site. Once this list is compiled, researchers can move on to the third step: identifying constraints associated with the project. Cost is likely to be a major constraint, and managers should be sure to consider not only the initial outlay but also expenses that will be required for maintenance. Each project will likely also have a number of other constraints associated with the spatial feature data collection previously. For instance, conservationists in Lorna Glen wanted to avoid land degraded by cattle stockading, utilize existing clearings (in order to minimize costs associated with fence erection), incorporate a particular type of habitat (sand dunes/plains with spinifex) and underlying geology (calcrete) preferred by the mammals they were reintroducing, and stay away from areas of Aboriginal significance.

Each of these constraints can then be used as a filter to remove potential fencing sites from the list. If a site doesn't meet any one of the requirements, it cannot be included on the final consideration list, so the order in which the filters are applied is unimportant. However, progress will be much quicker if managers start with the filters they expect to be most stringent, as this will more speedily trim the list to a more workable number of options. The results of the filtering process can be dramatic; whereas the Lorna Glen project started with an infinite number of possibilities, the list was ultimately reduced to just 32 options. The final phase of the evaluation process involves assessing the benefit function associated with each potential choice in order to see which maximizes the desired output. The Lorna Glen managers used an equation that calculated the maximum amount of undegraded land that could be set aside by fencing in one or more of the areas that had made it through all of their filters. The calculation indicated one clear solution that was head and shoulders above the rest; this fencing scheme would protect 560 ha of non-culturally significant land, incorporate appropriate habitat features, and provide maintenance staff with easy access to its boundaries, all while staying within both short- and long-term budgetary constraints.

(A boodie, Bettongia lesueur, one of the native mammals that has been successfully introduced into the new exclosure at Lorna Glen)

The main goals of the decision theory method was to provide managers with a defensible way of choosing fence location. However, one beneficial side effect is that this process improves the ability of managers to logically consider what might otherwise be an overwhelming amount of information. According to the authors, people who are confronted with a large number of choices will often ignore many of them and then use oversimplified rules for making a selection; unsurprisingly, this method of choosing something that is "good enough," rather than "optimal," often does not facilitate the best conservation or management plans. By following a pre-established list of steps, such as those outlined here, managers are more likely to select an appropriate course of action. Further, by keeping detailed notes on each step of the process, they can make their methodology transparent--providing information not only to funding bodies, but also to other managers who may face similar issues.

The authors do admit, however, that their "flexible decision-support tool" is not perfect. During installation of the Lorna Glen fencing, for instance, they ran into several problems resulting from inaccurate or missing data; clearly, some amount of ground-truthing would have been useful to ensure that all ecological and spatial information used in the analyses was up-to-date. The collaborators are quick to point out that all methods are associated with uncertainty, however, and emphasize that their optimal site remained the first choice even after the updated data had been included in their analyses. Thus, the system appears to be robust, and may become even more so as future modifications are made to account for uncertainty more explicitly.

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Bode, M., Brennan, K.E.C., Morris, K., Burrows, N., and Hague, N. 2012. Choosing cost-effective locations for conservation fences in the local landscape. Wildlife Research 39:192-201.

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Brainstorming new methods of scientific outreach

Teachers of all grades often struggle to find memorable, useful, and affordable techniques for exposing their students to science; students often long for an innovative, hands-on way to learn about science without sitting through a tedious series of lectures. A group of educators from the Los Angeles area have created a program, Project Brainstorm, to solve both of these problems, while simultaneously improving relationships between academic institutions and local communities.

Writing in the Community Page section of PLoS Biology, the collaborators describe their 5-year-old creation, which has already involved >100 undergrads, >60 classrooms across 30 different local schools, and >1900 schoolchildren. The lynchpin of the project is student teaching; specifically, university undergraduates work together in two- or three-person groups to create a 45-minute presentation that will be delivered to local students. When they enroll in the course, the undergrads are given an outline of the material they should understand, but it is up to them to do research on these topics and then use their new-found knowledge to design a lesson plan appropriate for their target audience. Their final product is field-tested in front of fellow students and a panel of other academics so that it can be perfected before taken into local classrooms.

Figure 1 (courtesy of PLoS Biology). UCLA neuroscience undergraduate students teaching local school children about the brain. (A) Explaining how the water in a jar protects an egg from breaking in much the same way that the cerebrospinal fluid protects the brain from damage. (B) School children look at healthy and diseased human brains wrapped in plastic. (C) Undergraduate neuroscience student introduces the brain to a classroom of seventh grade students. (D) Classroom of fifth grade students learn the gross anatomy of the brain from an undergraduate student holding a model human brain. All participants in this study (legal guardians of school children, undergraduate and graduate students) provided signed consent to publication of their likeness as part of this project.

Although Project Brainstorm focuses on neuroscience, the authors write that its format could easily be altered to accommodate other fields of scientific research. In a classroom where students are all neuroscience novices, a typical presentation would begin with a 5-minute introduction of the nervous system (covering basics such as the structure/function of neurons, and overall brain anatomy), proceed to a 10-minute discussion of a "brain-in-perspective" topic (such as how people learn, gender differences in brain function, or the impact of drugs), and then end with a 30-minute hands-on practical where students break out into small groups and work their way through stations allowing them to compare brain specimens from different species, examine sections of injured brains, and engage in other (student-developed) activities. At the end of the Project Brainstorm class, undergrads hand in brief lesson plans detailing their presentations. These are compiled by the course instructors and can be accessed by primary and secondary teachers for use in their own classrooms.

The creators of Project Brainstorm developed it with the goal of improving the lives of everyone involved in the course. Schoolchildren get the chance to learn about neuroscience, a topic that they will often not explore in great detail until they are undergraduates; further, they can use their contact with current university students to learn more about tertiary education, potential scientific careers, and the specific institutions with which the guest lecturers are affiliated. The undergrads themselves will get experience teaching, which is not only a useful thing to put on their CVs but also a potential eye-opener to a career they might not previously have considered. Education studies have also shown that individuals tend to learn information more completely when they are required to teach it to others; group learning has a similar effect. Thus, Project Brainstorm students may retain more details than they would if they had simply sat in neuroscience lectures all semester. Throughout the class, graduate students also help guide and inform course participants, which means that these older students will also benefit from the opportunity to gain experience with teaching.

A very important by-product of Project Brainstorm is the facilitation of positive relationships between academic institutions and the local community; hopefully, it also fosters goodwill towards, and acceptance of, science in general. In a time when the public seems to be losing faith in the power of scientific thinking and research, this sort of outreach may help convince people that science--and even scientists themselves--can be approachable, interesting, useful, and fun.

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Romero-Calderon, R., O'Hare, E.D., Suthana, N.A., Scott-Van Zeeland, A.A., Rizk-Jackson, A., Attar, A., Madsen, S.K., Ghiani, C.A., Evans, C.J., and Watson, J.B. 2012. Project Brainstorm: using neuroscience to connect college students with local schools. PLoS Biology 10(4):e1001310.