Category Archives: Uncategorized

The Society for Conservation Biology recently completed a major overhaul of the SCB website.

The new website provides a wealth of information on recent issues in conservation policy. You can access regular updates on conservation policy news by subscribing to the Policy RSS feed.

Other sections of the website provide information on SCB’s regional sections and working groups. The most popular section of the website is the board listing job openings in the field of conservation biology.

A new study published in Science by Brosi and Biber compares species listed under the US Endangered Species Act (ESA) in response to citizen petitions versus initiatives from within the agencies (FWS and NMFS). The authors asked whether citizen involvement, as some claim, diverts scarce conservation resources to species which are at lower risk than those identified by the agencies. The authors found, on the contrary, that species listed in response to citizen petitions were at least as threatened as those proposed by the agencies. These findings support the wisdom of the drafters of the ESA, who included the ability of citizens to petition for species’ listing to help ensure that species are not overlooked in the listing process due to political concerns or other reasons.

As the New York Times notes, “These impressive statistical results also help restate — and re-ratify — the reason the authors of the Endangered Species Act included the public in the first place. There are a lot more of us than there are Fish and Wildlife Service scientists. And the petitioning public isn’t merely an amorphous cross section of Americans. It includes scientists, local specialists, committed conservationists and passionate defenders of nature, who, in many cases, can keep a closer eye on the ground than the Fish and Wildlife Service.”

Science Daily also noted “The public brings diffuse and specialized expertise to the table, from devoted nature enthusiasts to scientists who have spent their whole careers studying one particular animal, insect or plant. Public involvement can also help counter the political pressure inherent in large development projects. The FWS, however, is unlikely to approve the listing of a species that is not truly threatened or endangered, so some petitions are filtered out. “You could compare it to the trend of crowdsourcing that the Internet has spawned,” Brosi says. “It’s sort of like crowdsourcing what species need to be protected.”

A new paper by Levi and Wilmers in the journal Ecology uses a 30-year time series of wolf, coyote, and fox relative abundance from the state of Minnesota, USA, to show that wolves suppress coyote populations, which in turn releases foxes from top-down control by coyotes. The authors conclude “Mesopredator release theory has often considered the consequence of top predator removal in a three species interaction chain (i.e., coyote–fox–prey) where the coyote was considered the top predator (Ritchie and Johnson 2009). However, the historical interaction chain before the extirpation of wolves had four links. In a four-link system, the top predator releases the smaller predator. The implication is that a world where prey species are heavily predated by abundant small predators (mesopredator release) may be similar to the historical ecosystem.” The study’s findings suggest that “among-guild interaction chains with even numbers of species will result in the smallest competitor being suppressed while among-guild interaction chains with odd numbers of species will result in the smallest competitor being released.” These findings have important implications for efforts to predict the consequences of removal or restoration of top predators.
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Conservation biologists have long debated whether and how it is appropriate for scientists to influence policy decisions. A pair of essays in the journal Conservation Biology (one published, another in press) asks whether it’s appropriate for scientists to review and critique recovery goals for endangered species. Wilhere (2012) argues that because recovery criteria are inherently normative (values driven), scientists are engaging in “inadvertent advocacy” when they criticize such criteria. In a response, myself and coauthors agree with Wilhere that recovery criteria represent an interaction of science and values, but provide a different view on the appropriate role of individual scientists and scientific societies in reviewing recovery criteria and recovery plans. This debate is central to recovery planning for many species, and we suggest a way forward for the agencies to more clearly separate the normative and scientific elements of recovery criteria. We call on the agencies to develop an explicit decision framework that would provide the flexibility needed to address the unique biological circumstances faced by different species but would limit the abuse of discretion that has allowed political interference to drive many listing and recovery decisions.
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A new paper in the journal Nature Climate Change finds evidence that declining snowfall in the southwestern US indirectly influences plants and associated birds by allowing greater over-winter herbivory by elk. Abundances of deciduous trees and associated songbirds have declined with decreasing snowfall over 22 years of study in montane Arizona. The researchers experimentally tested the hypothesis that declining snowfall indirectly influences plants and associated birds by allowing greater over-winter herbivory by elk, by excluding elk from one of two paired snowmelt drainages and replicating this paired experiment across three distant canyons. Over six years, the exclosures reversed multi-decade declines in plant and bird populations by experimentally inhibiting heavy winter herbivory associated with declining snowfall. Predation rates on songbird nests decreased in exclosures, despite higher abundances of nest predators, demonstrating the over-riding importance of habitat quality to avian recruitment.
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The Connectivity Analysis Toolkit is a software interface that provides conservation planners with tools for both linkage mapping and landscape-level ‘centrality’ analysis. 450 people from around the world have downloaded the CAT since it became available in 2010.
We have just released Version 1.2 with the following changes:

• Approximate shortest-path betweenness centrality allows faster computation of this metric
• Approximate current flow betweenness centrality allows faster computation of this metric; function also uses sparse matrices for lower RAM requirements
• Network flow functions updated to LEMON version 1.2.2
• Updates to manual and tutorial dataset

These are major updates which speed computation in some cases by an order of magnitude. Thanks to Aric Hagberg for his work adding these new functions to NetworkX and thus making them available for the CAT.

The software is freely available at www.connectivitytools.org (a link is also posted on this blog site).

Two new articles published in the Proceedings of the National Academy of Sciences discuss whether management can push forests and other ecosystems into ‘landscape traps’ which may be difficult to restore to former conditions. The ‘landscape trap’ concept resembles previous research on alternate stable ecosystem states, but recognizes the importance of spatial dynamics in maintaining a landscape in a degraded state. Continue reading →

A new report titled “Assessment & Planning for Ecological Connectivity: A Practical Guide” has been produced by a team of scientists convened by the Wildlife Conservation Society’s North America Program. The report can be downloaded here.

A new paper in the Journal Science by Chen and colleagues finds that species ranges are moving upward in elevation and towards the poles faster than has been expected from previous studies. Species’ ranges have climbed an average of 11 meters higher and 16.9 km closer to the poles per decade, with species in areas experiencing the greatest climate shift also showing the greatest range movement. Continue reading →

A new paper in Science by Jim Estes and colleagues reviews contemporary findings on the consequences of removing large apex consumers (e.g., top predators) from nature—a process they term trophic downgrading.
The authors highlight the ecological theory that predicts trophic downgrading, consider why these effects have been difficult to observe, and summarize the key empirical evidence for trophic downgrading. The paper concludes Continue reading →