Appalachian-breeding Vermivora chrysoptera (Golden-winged Warbler) occur at very low densities in mid-elevation forests and agroforestry systems throughout the Andes and isolated massifs of northern Colombia

Vermivora chrysoptera (Golden-winged Warbler) is one of the most striking but also one of the most vulnerable migratory warblers on Earth. To understand its non-breeding ecology in northern South America, where the steeply declining Appalachian breeding population is known to spend the non-breeding season, we conducted 2,534 surveys between 2018 and 2023 in isolated massifs and the Andes of Colombia. Our goal was to evaluate the distribution, detection rates, elevational range, habitat preferences and microhabitat associations of the species. We obtained 54 detections, with a very low detection rate (2.13%) compared to rates reported from Central America (~10%). Detections covered a wide range of elevations (634 – 2,551 m a.s.l.), with support for a mid-elevation peak at around 1,750 m a.s.l. Importantly, detection elevation was negatively correlated with latitude such that peak abundances occurred at higher elevations closer to the equator. Most detections were in mature or secondary f..., Distribution and timing of surveys
We conducted surveys for Vermivora chrysoptera in Colombia during five nonbreeding seasons in 2018 – 2023 across a broad elevation gradient (350 – 2,650 m a.s.l.). Survey locations were established in six biogeographic regions: Magdalena Valley – departments of Santander and Tolima; Cauca Valley – departments of Caldas, Quindío, Antioquia, Valle del Cauca and Risaralda; Sierra Nevada de Santa Marta – department of Magdalena; Pacific slope – Antioquia, Chocó, Risaralda and Valle del Cauca; Serranía de Perijá – Cesar; and Orinoco-Amazonas – Boyacá (Figure 1). Locations within biogeographic regions were selected to maximize coverage of likely nonbreeding areas, however, certain regions could not be surveyed due Colombia´s internal conflict, including parts of northern Antioquia and eastern Norte de Santander. In any given season, surveys were conducted between November 10 and March 20 in order to avoid the main post-breeding and pre-breeding migration pe..., , # Appalachian-breeding Vermivora chrysoptera (Golden-winged Warbler) occur at very low densities in mid-elevation forests and agroforestry systems throughout the Andes and isolated massifs of northern Colombia

[https://doi.org/10.5061/dryad.5dv41nsh0](https://doi.org/10.5061/dryad.5dv41nsh0)

## Description of the data and file structure

The data contained in these files are the result of 2534 surveys being carried out across 1324 unique points located in the Andes and isolated massifs of Colombia. The surveys were carried out to understand the distribution, elevation use, habitat preferences and microhabitat associations of the Golden-winged Warbler (Vermivora chrysoptera). During surveys all migratory birds were recorded and are therefore included in the file entitled \"León et al. 2025 - Raw point count data\".

### Files and variables

#### File: León\_et\_al.*2025*-\_Raw\_point\_count\_data.xlsx

**Description:** Raw point count data based on 2534 surveys carried out at 1324 unique...,