Pilfering passerines? Inter-Class Competition: A New Direction in Foraging Ecology, Shenandoah Valley, VA
Faculty Advisor Name
Katrina Gobetz
Department
Department of Biology
Description
Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews have lived in this space for millions of years, carving out an existence in harsh habitats around the world, ranging from the tropics to subarctic boreal tundra. Two shrew species that inhabit the Shenandoah Valley of Virginia are the least shrew (Cryptotis parva) and northern short-tailed shrew (Blarina brevicauda). Shrews make epigeal foraging trails while they continually forage for food, and caching is a way to save this food for times of low and sporadic food availability. Foraging trails and caches for these species are found, mapped, and marked for both species, and for the first time in the case of the least shrew. In addition, the Animal Monitoring Station (AMS), patented at the start of this study, is used to obtain non-invasive data on these mammals. Of further interest is how the caches of shrews fare when they are stored along foraging trails. Some bird and small mammal species are cachers and will in turn pilfer the caches of members of their own taxa. What has not been studied, is whether songbirds pilfer the caches of small mammals. This possibility may heavily impact the ability of shrews to survive considering their high metabolic rates. Using the AMS, time-averaged weight and coat condition are used to ID individuals and species. Seven sites are used, three treatment and four control. Treatment sites include a supplemental feeding platform while controls do not. Image data is used to observe what bird species are visiting and where they are seen foraging. Birds that are ground feeders and cachers are the most prolific visitors and are the species most often seen near foraging trails and caches, treatment sites having more instances than control sites. The information presented here provides a much-needed foundation for future studies focused on foraging interactions across taxa.
Pilfering passerines? Inter-Class Competition: A New Direction in Foraging Ecology, Shenandoah Valley, VA
Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews have lived in this space for millions of years, carving out an existence in harsh habitats around the world, ranging from the tropics to subarctic boreal tundra. Two shrew species that inhabit the Shenandoah Valley of Virginia are the least shrew (Cryptotis parva) and northern short-tailed shrew (Blarina brevicauda). Shrews make epigeal foraging trails while they continually forage for food, and caching is a way to save this food for times of low and sporadic food availability. Foraging trails and caches for these species are found, mapped, and marked for both species, and for the first time in the case of the least shrew. In addition, the Animal Monitoring Station (AMS), patented at the start of this study, is used to obtain non-invasive data on these mammals. Of further interest is how the caches of shrews fare when they are stored along foraging trails. Some bird and small mammal species are cachers and will in turn pilfer the caches of members of their own taxa. What has not been studied, is whether songbirds pilfer the caches of small mammals. This possibility may heavily impact the ability of shrews to survive considering their high metabolic rates. Using the AMS, time-averaged weight and coat condition are used to ID individuals and species. Seven sites are used, three treatment and four control. Treatment sites include a supplemental feeding platform while controls do not. Image data is used to observe what bird species are visiting and where they are seen foraging. Birds that are ground feeders and cachers are the most prolific visitors and are the species most often seen near foraging trails and caches, treatment sites having more instances than control sites. The information presented here provides a much-needed foundation for future studies focused on foraging interactions across taxa.
