Springing forward : Migrating songbirds catch up with the start of spring in North America

© 2023 The Authors. Journal of Animal Ecology © 2023 British Ecological Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA..

In temperate regions, the annual pattern of spring onset can be envisioned as a 'green wave' of emerging vegetation that moves across continents from low to high latitudes, signifying increasing food availability for consumers. Many herbivorous migrants 'surf' such resource waves, timing their movements to exploit peak vegetation resources in early spring. Although less well studied at the individual level, secondary consumers such as insectivorous songbirds can track vegetation phenology during migration as well. We hypothesized that four species of ground-foraging songbirds in eastern North America-two warblers and two thrushes-time their spring migrations to coincide with later phases of vegetation phenology, corresponding to increased arthropod prey, and predicted they would match their migration rate to the green wave but trail behind it rather than surfing its leading edge. We further hypothesized that the rate at which spring onset progresses across the continent influences bird migration rates, such that individuals adjust migration timing within North America to phenological conditions they experience en route. To test our hypotheses, we used a continent-wide automated radio telemetry network to track individual songbirds on spring migration between the U.S. Gulf Coast region and northern locations closer to their breeding grounds. We measured vegetation phenology using two metrics of spring onset, the spring index first leaf date and the normalized difference vegetation index (NDVI), then calculated the rate and timing of spring onset relative to bird detections. All individuals arrived in the southeastern United States well after local spring onset. Counter to our expectations, we found that songbirds exhibited a 'catching up' pattern: Individuals migrated faster than the green wave of spring onset, effectively closing in on the start of spring as they approached breeding areas. While surfing of resource waves is a well-documented migration strategy for herbivorous waterfowl and ungulates, individual songbirds in our study migrated faster than the green wave and increasingly caught up to its leading edge en route. Consequently, songbirds experience a range of vegetation phenophases while migrating through North America, suggesting flexibility in their capacity to exploit variable resources in spring.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:93

Enthalten in:

The Journal of animal ecology - 93(2024), 3 vom: 27. März, Seite 294-306

Sprache:

Englisch

Beteiligte Personen:

Nemes, Claire E [VerfasserIn]
Marra, Peter P [VerfasserIn]
Zenzal, Theodore J [VerfasserIn]
Collins, Samantha A [VerfasserIn]
Dossman, Bryant C [VerfasserIn]
Gerson, Alexander R [VerfasserIn]
Gómez, Camila [VerfasserIn]
González, Ana M [VerfasserIn]
Gutierrez Ramirez, Mariamar [VerfasserIn]
Hamer, Sarah A [VerfasserIn]
Marty, Joseph [VerfasserIn]
Vasseur, Phillip L [VerfasserIn]
Cohen, Emily B [VerfasserIn]

Links:

Volltext

Themen:

Animal migration
Automated radio telemetry
Green wave
Journal Article
Migration rate
Motus
Phenology
Research Support, Non-U.S. Gov't
Songbird
Spring onset

Anmerkungen:

Date Completed 07.03.2024

Date Revised 27.03.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/1365-2656.14025

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM364622202