Environmental conditions and individual characteristics influence movement patterns of juvenile Passerculus sandwichensis (Savannah sparrow) throughout the post-fledging period

Movements in the post-fledging period, an important first stage of natal dispersal that occurs after juveniles fledge from the nest but before they depart for fall migration, have important implications for survival. However, relatively little is known about movements during this vulnerable period. Here, we used daily radio telemetry data from 137 juvenile Passerculus sandwichensis (Savannah sparrows) between 2022-2024 and hierarchical generalized additive models to examine the relationship between movement and age across a 90-day period. We evaluated how movement—distance from the nest and between consecutive daily locations—was influenced by age post-fledging, sex, brood number, year, age at fledging, local nest density, nestling mass, and weather variables. Both the distance of fledglings from their natal nest and distance moved between days increased with age post-fledging, most steeply when fledglings became independent, then remained steady for the remainder of the post-fledging p..., , # Data from: Environmental conditions and individual characteristics influence movement patterns of juvenile Passerculus sandwichensis (Savannah sparrow) throughout the post-fledging period

Dataset DOI: [10.5061/dryad.44j0zpcrj](10.5061/dryad.44j0zpcrj)

## Description of the data and file structure

We used radio telemetry data from 137 juvenile Savannah sparrows in a population breeding on Kent island, NB, Canada, between 2022 and 2024 to evaluate the ecological and individual factors influencing movement behavior: the distance individuals travelled from their natal nests and the distances travelled between consecutive daily locations. Juveniles were located once per day using radio telemetry and their fate (alive, dead, or unknown) noted.

All individuals breeding within the study area and all nestlings that received radio transmitters were marked with a unique combination of color bands and a USFWS aluminum band. Nestlings without radio transmitters were marked with one color band ...,