Extreme drought increased home range sizes and space use of Aquila chrysaetos (Golden Eagles) in coastal southern California

Aquila chrysaetos (Golden Eagles) are long-lived top predators, vulnerable to a variety of threats. There is increasing concern about the declining population in coastal southern California, which has largely coincided with habitat loss due to urbanization of the region. This Mediterranean-type ecosystem is also experiencing more prolonged and intense droughts, which can reduce the abundance of key prey species, such as jackrabbits (Lepus californicus) and ground squirrels (Otospermophilus beecheyi). However, the impact of drought on Golden Eagles is poorly understood. Here, we used high-resolution GPS tracking data to calculate eagle home ranges and hypothesized that home range size would be influenced by drought such that home ranges would be larger to meet their resource needs with worsening drought severity. Fifty individuals were captured over seven breeding seasons, spanning the time both during and after a historic drought. We also compared space use for different stages of the b..., , # Extreme drought increased home range sizes and space use of Aquila chrysaetos (Golden Eagles) in coastal southern California

Dataset DOI: [10.5061/dryad.h9w0vt4vm](10.5061/dryad.h9w0vt4vm)

## Description of the data and file structure

Seasonal home range sizes of Golden Eagles in southern California 2014-2022

### Files and variables

#### File: thomsen\_etal\_06242025\_GOEAdrought\_homerangesizes.csv

**Description:** 

##### Variables

* eagleID: individual eagle ID
* sex: sex of eagle
* age: age category (\"adult\" or \"subadult\")
* season: \"winter\" (Nov-Jan) \"spring\" (Feb-Apr) \"summer\" (May-Jul) \"fall\" (Aug-Oct)
* nestyear: breeding season year that begins the previous winter in Nov and ends in Oct; calendar year during spring season is used to label the nestyear
* ldistmove: category for individuals that remained in the local study area (\"local\") versus those that moved beyond outside of the local study area (\"ldist\") during that season
* floater: category for adults with territ...,