# The Fragile First Year: GPS Tracking Identifies Post‐Release Survival Risks in Migratory Geese

## TL;DR

This study uses GPS tracking to identify factors affecting the first-year survival of migratory geese after release, including behavior, weather, and tracking device type.

## Contribution

The study reveals how device type, behavior, and weather influence survival rates in migratory geese during their first year post-release.

## Key findings

- First-year survival probability is significantly affected by average daily activity levels and wind speed.
- Neckband tracking devices outperformed backpack tags in influencing survival outcomes.
- Geographic clusters did not show consistent survival times across study cohorts.

## Abstract

Migratory birds play a critical role as sentinels of ecosystem health, serving as key indicator species for monitoring biodiversity changes and environmental conditions. The survival of migratory birds has always been a focus of attention, and the first year following post‐release represents a critical period for establishing stable survival outcomes. However, it is difficult to track the life status of migratory birds, because some drivers affecting their survivorship may be hard to identify. Here, we investigated the survival and adaptation of Tundra Bean Geese (Anser serrirostris serrirostris) and Greater White‐fronted Geese (
A. albifrons
) by using GPS tracking data in order to systematically assess how study design parameters, key behavioral traits, and environmental conditions influence the first‐year survival rates of migratory geese from post‐release to spring migration onset. We found that the first‐year survival probability was significantly affected by factors such as average daily activity levels and weather conditions, particularly wind speed. Notably, tracking device type also significantly influenced survival outcomes, with neckband tag units demonstrating superior performance compared to backpack tags. Contrary to expectations, geographic clusters showed no consistent survival times across study cohorts. These findings highlight the influences of study design parameters (particularly device selection), individual behavior, and local weather conditions on waterfowl survival time. Our results provide operational guidelines for GPS tracking deployment in geese conservation and are crucial for developing effective conservation strategies and management measures.

This study investigates how factors such as behavior, weather conditions, and other variables influence the first‐year survival of Bean Geese and Greater White‐fronted Geese after release. We found that the average daily activity level from release to migration onset and local weather conditions before migration, especially wind speed, significantly affected the first‐year survival rate. Our findings provide insights into the adaptive strategies of migratory birds and the impact of environmental factors on their survival.