The Changing Environmental Factors Affecting Hatching Success in Tree Swallows
Mentor 1
Peter Dunn
Start Date
16-4-2021 12:00 AM
Description
Birds that eat flying insects (aerial insectivores), such as swallows, are declining at the fastest rates in North America. One prominent hypothesis for this decline is that climate change is leading to declines in their food supply (aerial insects) and this is resulting in lower reproductive success. We examined this hypothesis using long-term data on the reproductive success of tree swallows at the UWM Field Station from 2000-2020. Data on weather and food abundance were also collected daily. Two different traps were used to catch insects: 1) malaise trap, a large tent-like structure that funnels insects into a collecting vessel, and 2) a suction trap. We predicted that rain and cold temperatures would lead to lower food supply and reduced hatching success of eggs, however they did not have a significant effect. Rather, female mass was the most significant factor in chick mortality. Chicks hatched earlier in the season had a higher success rate of later fledging and the overall hatching success had increased since this study began, as has average female body mass.
The Changing Environmental Factors Affecting Hatching Success in Tree Swallows
Birds that eat flying insects (aerial insectivores), such as swallows, are declining at the fastest rates in North America. One prominent hypothesis for this decline is that climate change is leading to declines in their food supply (aerial insects) and this is resulting in lower reproductive success. We examined this hypothesis using long-term data on the reproductive success of tree swallows at the UWM Field Station from 2000-2020. Data on weather and food abundance were also collected daily. Two different traps were used to catch insects: 1) malaise trap, a large tent-like structure that funnels insects into a collecting vessel, and 2) a suction trap. We predicted that rain and cold temperatures would lead to lower food supply and reduced hatching success of eggs, however they did not have a significant effect. Rather, female mass was the most significant factor in chick mortality. Chicks hatched earlier in the season had a higher success rate of later fledging and the overall hatching success had increased since this study began, as has average female body mass.
