Pilfering passerines? Inter-Class competition: A new direction in foraging ecology
Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews (Soricidae, 1910) have foraged in this microhabitat 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 th...
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JMU Scholarly Commons
2022
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| Online Access: | https://commons.lib.jmu.edu/masters202029/154 https://commons.lib.jmu.edu/context/masters202029/article/1158/viewcontent/auto_convert.pdf |
| Summary: | Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews (Soricidae, 1910) have foraged in this microhabitat 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, the least shrew (Cryptotis parva) and northern short-tailed shrew (Blarina brevicauda), were the focus of this study. 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 were found, mapped, and marked for both species, and for the first time in the case of the least shrew. A computer-controlled monitoring station, patented at the start of this study, was used to attract shrews and non-invasively obtain weight and morphological data. Also of interest was fate of invertebrate caches that shrews leave along their foraging trails. Some bird and small mammal species are cachers and will in turn pilfer the caches of members of their own taxa. However, inter-Class pilfering behavior between birds and mammals remains unstudied. This possibility may heavily impact the ability of shrews to survive considering their high metabolic rates. This study was conducted in the JMU arboretum and treatment sites included a supplemental feeding platform for birds while controls did not. Cameras were used to observe visiting bird species and whether they foraged in shrew trails or at caches. Treatment shrews of both species weighed less on average than control shrews, although this finding was not significant. Ground-feeding and caching birds were the most prolific visitors (p = |
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