Event Title

What Environmental Factors Influence Hatching Success of Tree Swallows?

Mentor 1

Peter Dunn

Location

Union 250

Start Date

28-4-2017 12:20 PM

Description

The importance of my study on Tree Swallows, with the help of Professor Peter Dunn, was to monitor and test environmental factors on the hatching success of Tree Swallows at the UW-Milwaukee Field Station. This study on hatching success was conducted due to declining populations of Tree Swallows on the east coast of the United States. We wanted to see if populations in the Midwest were declining, or if we could find a reason for depleted hatching success to help enlighten the issues on the east coast. To conduct this study, we measured abiotic environmental conditions, insect biomass, female fitness, and hatching success of individual nests. Environmental conditions like temperature, wind, and precipitation were monitored using sensory equipment at the field station. To measure insect biomass, we caught flying insects in a suction trap, sorted them by their groupings, and averaged the weight of each batch based on previous weight measurements. Female fitness was measured by using previous year averaged weights. Lastly, hatching success was measured by monitoring each nest, and seeing what percentage of the eggs laid, actually hatched. While conducting bivariate analyses, female fitness (mass) positively correlated to hatching success, while temperature 10 days previous from hatching negatively correlated to hatching success. We also conducted a multivariate analysis including insect biomass availability, female fitness, Julian lay date, and wind, rain, temperature, solar irradiance, and soil temperature variables 10 days before hatch. We found that insect biomass availability and female fitness were significant to the hatching success of Tree Swallows, but the analysis only explained 1.7% of the variance over a 482 bird sample. Both the multivariate and bivariate analyses were based on available data on nests since 1997. Overall, our studies found that female fitness and environmental conditions don't affect hatching success of Tree Swallows.

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Apr 28th, 12:20 PM

What Environmental Factors Influence Hatching Success of Tree Swallows?

Union 250

The importance of my study on Tree Swallows, with the help of Professor Peter Dunn, was to monitor and test environmental factors on the hatching success of Tree Swallows at the UW-Milwaukee Field Station. This study on hatching success was conducted due to declining populations of Tree Swallows on the east coast of the United States. We wanted to see if populations in the Midwest were declining, or if we could find a reason for depleted hatching success to help enlighten the issues on the east coast. To conduct this study, we measured abiotic environmental conditions, insect biomass, female fitness, and hatching success of individual nests. Environmental conditions like temperature, wind, and precipitation were monitored using sensory equipment at the field station. To measure insect biomass, we caught flying insects in a suction trap, sorted them by their groupings, and averaged the weight of each batch based on previous weight measurements. Female fitness was measured by using previous year averaged weights. Lastly, hatching success was measured by monitoring each nest, and seeing what percentage of the eggs laid, actually hatched. While conducting bivariate analyses, female fitness (mass) positively correlated to hatching success, while temperature 10 days previous from hatching negatively correlated to hatching success. We also conducted a multivariate analysis including insect biomass availability, female fitness, Julian lay date, and wind, rain, temperature, solar irradiance, and soil temperature variables 10 days before hatch. We found that insect biomass availability and female fitness were significant to the hatching success of Tree Swallows, but the analysis only explained 1.7% of the variance over a 482 bird sample. Both the multivariate and bivariate analyses were based on available data on nests since 1997. Overall, our studies found that female fitness and environmental conditions don't affect hatching success of Tree Swallows.