Seasonal and daily activity patterns by Eleonora’s Falcon Falco eleonorae based on GPS telemetry: a contribution to the species’ movement ecology at its breeding grounds

C Kassara,C Barboutis,N Tsiopelas,S Giokas,A Evangelidis

doi:10.1017/s0959270920000714

C Kassara, C Barboutis + Show 3 more

Open Access

https://doi.org/10.1017/s0959270920000714

Copy DOI

Abstract

SummaryEleonora’s Falcon Falco eleonorae is a migratory raptor, well-known for its delayed breeding period. Owing to its great mobility, current information on its distribution pattern during the pre-breeding period is rather sporadic, mainly based on field observations and only one telemetry study. Likewise, the species’ ranging activity during the breeding period has not been thoroughly investigated due to methodological limitations of the approaches implemented in previous studies, again amounting to only two telemetry studies in recent years. In this study we aimed to provide a comprehensive overview of the species’ ranging activity at its breeding grounds based on telemetry. Utilizing GPS data from six adult females originating from the core of the species’ breeding range we explored broad- and fine-scale activity patterns while at their breeding grounds. Our results indicated that during the pre-breeding period the falcons visited high biodiversity areas lying hundreds of kilometres away from their colonies, exhibiting site-fidelity, as shown for falcons from other breeding colonies in the past. During the breeding period the falcons roamed at an average distance of 17 km from their nesting sites, but their ranging activity could be observed up to 130 km. In accordance with the species’ breeding biology, the falcons tended to perform longer trips as the nestlings became more independent. The temporal pattern of ranging activity fitted well with the diurnal variability of the autumn migration flux. Furthermore, nest attendance tended to decrease in windy conditions and as the season progressed, and to increase when southerly winds blew. Despite the low number of tracked falcons, our study set a reference basis for future studies highlighting the importance of specific (protected) areas during the pre-breeding period and providing the first assessment of the movement ecology of the species during the pre-breeding and breeding period in Greece.

Highlights

One of the fundamental topics in ecological research deals with how, why, where and when organisms move
Movement ecology is an extensive field of research that addresses questions related to the distribution pattern of organisms in space and time, the mechanisms involved, and the intrinsic and extrinsic factors underlying the observed patterns, providing insights on the interactions among individuals and their environment that are crucial for wildlife management (Nathan et al 2008)
After excluding ELEF05 and ELEF06 due to the very small sample size (Table S1), we modelled the distance from their nesting sites as a function of day using Generalized Mixed Additive Models (GAMMs) considering the breeding event as random factor

Summary

Introduction

One of the fundamental topics in ecological research deals with how, why, where and when organisms move. Movement ecology is an extensive field of research that addresses questions related to the distribution pattern of organisms in space and time, the mechanisms involved, and the intrinsic and extrinsic factors underlying the observed patterns, providing insights on the interactions among individuals and their environment that are crucial for wildlife management (Nathan et al 2008). Especially migratory species, have been the epicentre during this often-acclaimed golden era for tracking technology (Wilmers et al 2015), that has led to the accumulation of voluminous tracking data through an increasingly large number of studies (Lopez-Lopez 2016). Eleonora’s Falcon Falco eleonorae Gene, 1839 is a fully migratory species that spends half the year (spring–autumn) in the Mediterranean basin, the Atlantic coast of Morocco and the Canary Islands and the other half (winter–spring) in Madagascar and surrounding areas (Walter 1979). Eleonora’s Falcon is classified as ‘Least Concern’ according to the IUCN criteria (BirdLife International 2020) but is included in Annex I of the Birds EU Directive (EEC 2010)

Objectives

Methods

Results

Discussion

Conclusion