Overexploitation of Wildlife

Trade and Consumption of Freshwater Turtles in the Urban Areas of the Brazilian Amazon

Across the globe, people are increasingly moving out of rural areas and into urban areas to improve their access to resources and financial opportunity. Our researchers are investigating what this mass migration may mean for biodiversity, particularly looking at how rural-to-urban migration influences the consumption of wild meat (i.e. meat from wild animals, sometimes called bushmeat). Current research focuses on endangered freshwater turtles in the Brazilian state of Amazonas, where urban consumption rates total more than 2 million turtles per year. Our results so far show that rural-to-urban migrants consume more turtles than non-migrants do, and that consumption decreases with the size of the city. Our researchers work closely with local decision-makers to inform public policy related to conservation of freshwater turtles.

Consumption of wild meat is illegal in most cases in Brazil, making people less willing to share information about their consumption habits. To study this practice, our researchers are using innovative interview approaches originally developed by statisticians to assess sensitive behaviors. These techniques protect the responses of participants by not connecting their answers to an illegal behavior while still permitting a valid analysis of the behavior. Such methods have been applied in fields such as criminology and health sciences, but only more recently have they been deployed for conservation purposes.

Using randomized response techniques (RRT) we can gain more accurate estimates of turtle consumption in the Amazon and compare these estimates to estimates obtained by traditional direct questioning (“do you eat turtles?”). Preliminary results indicate that RRT reveals higher rates of consumption than do direct methods, and the difference in accuracy between the two methods increases with size of the urban area. The two methods also point to different explanations for why people consume turtles in urban areas. Thus, in addition to helping us develop conservation measures for turtles, our work will provide important insights into the use of RRT and direct questioning to assess sensitive behaviors such as the consumption of wild animals These approaches can them be deployed in other places to benefit other species.

Researcher: Willandia Chaves

The Impacts of Hunting and Bycatch on Shorebird Populations in China

Globally, migratory shorebirds are experiencing massive population declines, often caused by human-induced changes to their habitats and stopover points. Bird populations that migrate along the East Asia-Australasia Flyway (EAAF) are experiencing the steepest declines, and, consequently, a high proportion of these shorebird species are listed as threatened or near threated by the IUCN Red List. The well-documented threats include habitat loss and habitat degradation, especially of the intertidal mudflats along the Yellow Sea. However, a significant source of bird mortality may be due to intentional hunting as well as unintentional capture of birds in tidal fishing nets – factors largely ignored to date.

Our field-based study investigates the combined effects of hunting and bycatch on shorebird populations across the entirety of China’s coast. By determining the density of mist nets, decoys, and tidal fishing nets and by monitoring the mortality rates of shorebirds in randomly selected stopover sites, we are able to estimate the magnitude of hunting and bycatch. Then, by developing population models, we can then quantify the effects of hunting and bycatch on shorebird populations. Our research will provide information critical to protecting declining populations of migratory shorebirds.  

Researcher: Dan Liang