A three-decade review of telemetry studies on vultures and condors

Abstract

Telemetry-based movement research has become central for learning about the behavior, ecology and conservation of wide-ranging species. Particularly, early telemetry studies were conducted on vultures and condors due to three main reasons: i) these birds capture the curiosity of humans, ii) their large body size allows researchers to deploy large telemetry units, and iii) they are of high conservation concern. This has resulted in a great number of scientific articles that remain scattered throughout the literature. To achieve a more cohesive view of vultures and condors movement behavior, we review all telemetry studies published up to 2017. We first present a descriptive summary of the technical and design characteristics of these studies (e.g. target species, tagging location, number of individuals tagged) and go on to discuss them under a common conceptual framework; the Movement Ecology Paradigm. The articles found (N = 97) were mainly published in the last decade and based on the tagging of individuals from 14 species (61% of the extant species) and 24 countries. Foraging was the most in-depth investigated movement phase (25 studies), with studies covering several species, using both phenomenological and mechanistic approaches and tackling the role of different drivers of movement. In contrast, commuting and natal dispersal phases were only superficially investigated (3 and 8 studies, respectively). Finally, studies dealing with the conservation and management also comprised a large portion of the reviewed articles (24 studies). Telemetry studies have revealed relevant details of vultures and condors movements, with highly accurate measurements of flight energetics and a better understanding of the morphological, physiological and context-dependent drivers that underlie the movement decisions of these birds. However, we also detected several information gaps. We expect this review helps researchers to focus their efforts and funds where more information is needed.Electronic supplementary materialThe online version of this article (10.1186/s40462-018-0133-5) contains supplementary material, which is available to authorized users.

Spatial and Temporal Variability in Migration of a Soaring Raptor Across Three Continents

“…The study of long-distance migration has benefitted from a rapid growth in individual-based tracking data with increasing spatial and temporal resolution, enabling more detailed investigation of variability and flexibility of migratory movements (López-López, 2016). Large soaring birds have been the subjects of many tracking studies, partly because their large size enabled the attachment of transmitters since early technical development (Shamoun-Baranes et al, 2003;Alarcón and Lambertucci, 2018;Sergio et al, 2019). However, while migratory patterns have been assessed for individuals from the same or proximate populations (Sergio et al, 2014;Vardanis et al, 2016;Schlaich et al, 2017;Vansteelant et al, 2017), and migratory connectivity has been evaluated for some raptor species (Martell et al, 2014;Trierweiler et al, 2014;Finch et al, 2017), relatively few studies have analyzed these patterns across large portions of a species' distribution (Mandel et al, 2011;Dodge et al, 2014;Monti et al, 2018).…”

Applying circuit theory and landscape linkage maps to reintroduction planning for California Condors

“…Future efforts to develop landscape conductance surfaces could explore this finer-scale habitat selection by: (1) using a hierarchical approach [63] with a smaller spatial grain; (2) including environmental covariates on seasonal or real-time wind direction and speed in relation to topographic features; (3) including seasonal or real-time meteorological conditions; and, (4) including direct measures of terrestrial and marine food availability. In addition, separating occurrence points into categories of movement (e.g., linear soaring, gliding, and circular soaring), or specific parts of a species’ life cycle [64], might also improve our ability to make finer-scale predictions [51, 65–67].…”

Winter movement patterns of a globally endangered avian scavenger in south-western Europe

“…The spatial ecology of the Egyptian Vulture ( Neophron percnopterus ) is still poorly known 34 , and most of the studies have focused on pure migrant or pure resident (i.e., insular) populations 26 , 31 . In this study, we describe for the first time the spatial ecology and resource use of a unique Egyptian Vulture population which, contrary to the commonest migratory pattern, winters in south-west Europe (instead of migrating to the Sahel region of Africa), by means of the combination of field surveys and telemetry information.…”