Legacy Effects of Habitat Degradation by Lesser Snow Geese on Ground-Nesting Savannah Sparrows along the Hudson Bay Lowlands
Little is known of the direct and indirect legacy of Lesser Snow Goose (LSGO) habitat degradation in northern Canada on the biodiversity of other avian species. It is believed that a human-induced trophic cascade caused in part by agricultural habitat modification along migratory routes and winterin...
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DigitalCommons@USU
2013
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| Online Access: | https://digitalcommons.usu.edu/etd/1455 https://doi.org/10.26076/2819-23a3 https://digitalcommons.usu.edu/context/etd/article/2455/viewcontent/Stevenpeterson.pdf |
| Summary: | Little is known of the direct and indirect legacy of Lesser Snow Goose (LSGO) habitat degradation in northern Canada on the biodiversity of other avian species. It is believed that a human-induced trophic cascade caused in part by agricultural habitat modification along migratory routes and wintering grounds has contributed to the increase in LSGO numbers, which has resulted in increased foraging pressure by LSGO on northern breeding and stopover sites. This habitat degradation may lead to decreased abundance and richness of Arctic / sub-Arctic avian species across landscapes that LSGO utilize and degrade. Here we evaluated the annual change in vegetative cover (graminoids and shrubs) and how that may have influenced the nesting occurrence of the Savannah Sparrow (SAVS), a robust, adaptable ground nester, that relies on intact ground and shrub cover for nesting. Over a 10-year period (1999 to 2010) there was a 10% annual decline in the probability of SAVS nesting occurrence, driven by a loss of over half of the shrub cover, due to increased barren ground, over the same time period. This research will provide information for managers about the broad risks of increasing numbers of LSGO and provide insight into ways to mitigate habitat degradation and trophic impacts on other species. It will also provide critical evaluation of the impacts of habitat degradation by LSGO (a native invasive species) on natural resources, ecosystem services, and threatened and endangered species. |
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