Threats to Migratory Birds
The most vulnerable time in a migratory bird’s life cycle may occur during spring and fall when it is traveling between its breeding and wintering grounds. During migration, birds are under physiological stress and mortality rates may be higher than during stationary periods. Several factors that may contribute to stress and high mortality rates include:
- Loss and or fragmentation of stopover habitat in Great Lakes region due to changes in land use; pace of human alteration may exceed time needed for birds to adapt.
- Collisions with tall structures, especially communication towers, tall buildings, reflective glass on all buildings regardless of height, transmission lines, and wind turbines; certain types of lighting on tall structures may attract birds during adverse weather such as fog.
- Predation by domestic and feral cats; scientists estimate hundreds of millions of birds are killed by cats every year in U.S.
- Invasive plants that replace native plants and either do not provide food or lack appropriate nutrition to support migratory birds.
- Pollution of waterways from urban, municipal, and industrial sources, and pesticides and herbicides from ag practices, golf course practices, and mosquito control.
- Non-consumptive biological resource use, such as jet-skis, picnicking, boating, and off-road vehicles, during the migratory seasons.
- Unleashed dogs causing flight by foraging flocks of shorebirds or waterfowl.
- Modification of natural processes from climate change, grazing or mowing or vegetation manipulations, fire suppression, and altered hydrologic regimes.
Wisconsin Night Guardians for Songbirds
For more information on these topics, please see our Links and Technical Resources pages.
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