AMERICAN KESTRELS IN AGROECOSYSTEMS: EFFECTS OF EXTREME TEMPERATURE AND LAND-USE ON RESOURCE SELECTION AND NESTLING DIET | |||
| Mary E Badger; UC Davis; mebadger@ucdavis.edu; Robyn Boothby, Ryan Bourbour, Breanna Martinico | |||
Extreme heat driven by climate change poses a significant threat to many avian species, particularly those nesting in agricultural landscapes. Recent research has shown that high temperatures and agricultural land-use interact to erode nest success for habitat generalist birds, highlighting the compounding effects of climate and land-use change on reproductive outcomes. The reduction in naturally shaded micro-refugia, such as trees and hedgerows, may hinder thermoregulation for farmland avian species, particularly during extreme heat events. These conditions can negatively affect fitness and reproduction, as increased energy expenditure and stress may reduce foraging efficiency. American Kestrels (Falco sparverius) are one such species vulnerable to the impacts of rising temperatures in agroecosystems during the breeding season. Agricultural lands may act as ecological traps for American Kestrels, where rapid changes in habitat quality mislead individuals when selecting nesting sites, potentially furthering population declines. We examined whether diversified landscapes buffer breeding American Kestrels from heat stress while improving nestling diet quality in California agroecosystems. We monitored over 130 nest boxes across three counties and tracked parental movement and provisioning rate in relation to nestling diet, temperature, and land cover on a subset of active nests. We hypothesize that American Kestrels in more diverse farming systems will have greater access to nutrient-rich prey, whereas those in simplified landscapes may face greater thermal stress and lower quality diets. | |||
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