The Effect of Urbanization on Starling Egg Size and Parental Investment
Disciplines
Behavior and Ethology
Abstract (300 words maximum)
Urban habitats can have lower abundances of food, negatively impacting wildlife. We studied whether birds inhabiting urban habitats show negative consequences via their investment in breeding. European starlings (Sturnus vulgaris) can inhabit a variety of habitats, from rural to peri-urban, making them an ideal study system for this research. In addition, their eggs fall along a wide range of mass and volume such that we can examine whether habitat type shapes investment in egg size. Once the eggs hatch, starlings provide important parental care—such as sitting on the chicks for warmth, which is called brooding. We analyzed whether egg mass and brooding behavior differed for starlings from a range of habitat types, as well as whether starlings laying bigger eggs also provided more offspring care behavior. We found a significant difference in the amount of brooding behavior expressed by adults depending on their environment, indicating that habitat does play a role. In urban environments, female brooding was observed 3.3 percent of the time, while in rural environments, it was observed 8.6 percent of the time. We also found that egg size was greater in rural habitats than urban ones. However, there is no significant correlation between egg size and parental care investment. Together, these results suggest that urban habitats cause parents to decrease their investment in brooding at both the egg and chick stages of development. This research offers valuable information that can inform how we consider the effects of urbanization on starlings and other birds.
Academic department under which the project should be listed
CSM - Ecology, Evolution, and Organismal Biology
Primary Investigator (PI) Name
Sarah Guindre-Parker
The Effect of Urbanization on Starling Egg Size and Parental Investment
Urban habitats can have lower abundances of food, negatively impacting wildlife. We studied whether birds inhabiting urban habitats show negative consequences via their investment in breeding. European starlings (Sturnus vulgaris) can inhabit a variety of habitats, from rural to peri-urban, making them an ideal study system for this research. In addition, their eggs fall along a wide range of mass and volume such that we can examine whether habitat type shapes investment in egg size. Once the eggs hatch, starlings provide important parental care—such as sitting on the chicks for warmth, which is called brooding. We analyzed whether egg mass and brooding behavior differed for starlings from a range of habitat types, as well as whether starlings laying bigger eggs also provided more offspring care behavior. We found a significant difference in the amount of brooding behavior expressed by adults depending on their environment, indicating that habitat does play a role. In urban environments, female brooding was observed 3.3 percent of the time, while in rural environments, it was observed 8.6 percent of the time. We also found that egg size was greater in rural habitats than urban ones. However, there is no significant correlation between egg size and parental care investment. Together, these results suggest that urban habitats cause parents to decrease their investment in brooding at both the egg and chick stages of development. This research offers valuable information that can inform how we consider the effects of urbanization on starlings and other birds.