Olfactory Enrichment in California Sea Lions (\u3ci\u3eZalophus californianus\u3c/i\u3e): An Effective Tool for Captive Welfare?

In the wild, California sea lions (Zalophus californianus) are exposed to a wide variety of sensory information, which cannot be replicated in captive environments. Therefore, unique procedures are necessary for maintaining physiological and psychological health in nonhuman animals in captivity. The effects of introducing natural scents to captive enclosures have been investigated in a variety of species, yet they have not been examined in marine mammals. This project explored the behavioral effect of scent added to the environment, with the goal of improving the welfare of sea lions in captivity. Two scent types were introduced: (a) natural scents, found in their native environment, and (b) non-natural scents, not found in their native environment. This study examined not only scent enrichment but also the possible evolutionary underpinnings of pinniped olfaction. Scent enrichment was found to significantly impact sea lion behavior as demonstrated by a reduction in pattern swimming, an increase in habitat utilization, and a reduction in stereotypical behavior. However, there were no differences in behavior between natural and non-natural scent conditions

Climatic breadth of calling behaviour in two widespread Neotropical frogs: insights from humidity extremes

Climate change is severely altering precipitation regimes at local and global scales, yet the capacity of species to cope with these changes has been insufficiently examined. Amphibians are globally endangered and particularly sensitive to moisture conditions. For mating, most amphibian species rely on calling behaviour, which is a key weather‐dependent trait. Using passive acoustics, we monitored the calling behaviour of two widely distributed Neotropical frogs in 12 populations located at the humidity extremes but thermal mean of the species distribution. Based on 2,554 hours of recordings over a breeding season, we found that both the arboreal species Boana raniceps and the aquatic species Pseudis paradoxa exhibited calling behaviour at a wide range of relative humidity. Calling humidity was significantly lower in conspecific populations subjected to drier conditions, while calling temperature did not differ between populations or species. Overall, no variation in climatic breadth was observed between large and small choruses, and calling behaviour was scarcely detected during the driest, hottest and coldest potential periods of breeding. Our results showed that calling humidity of the studied species varies according to the precipitation regime, suggesting that widespread Neotropical anurans may have the capacity to exhibit sexual displays in different climatic environments. Regardless of the underlying mechanism (plasticity or local adaptation), which should be determined by common garden experiments, a wide and population‐specific climatic breadth of calling behaviour may assist species to deal with changing humidity conditions. To our knowledge, this is the first study to explore the response capacity of anurans to perform calling behaviour under contrasting precipitation regimes

Conserving imperiled species: a comparison of the IUCN Red List and U.S. Endangered Species Act

The United States conserves imperiled species with the Endangered Species Act (ESA). No studies have evaluated the ESA's coverage of species on the International Union for Conservation of Nature (IUCN) Red List, which is an accepted standard for imperiled species classification. We assessed the ESA's coverage of IUCN-listed birds, mammals, amphibians, gastropods, crustaceans, and insects, and studied the listing histories of three bird species and Pacific salmonids in more detail. We found that 40.3% of IUCN-listed U.S. birds are not listed by the ESA, and most other groups are underrecognized by >80%. Species with higher IUCN threat levels are more frequently recognized by the ESA. Our avian case studies highlight differences in the objectives, constraints, and listing protocols of the two institutions, and the salmonids example shows an alternative situation where agencies were effective in evaluating and listing multiple (related) species. Vague definitions of endangered and threatened, an inadequate ESA budget, and the existence of the warranted but precluded category likely contribute to the classification gap we observed. © 2011 Wiley Periodicals, Inc.J. Berton C. Harris, J. Leighton Reid, Brett R. Scheffers, Thomas C. Wanger, Navjot S. Sodhi, Damien A. Fordham & Barry W. Broo