ABSTRACT
Vultures provide the key ecosystem service of quickly removing carrion, so they have recently been assumed to be top scavengers. To challenge the concept of top scavenger (i.e. the most influential in the scavenging community and process), between 2012 and 2019, we recorded the consumption of 45 equine carcasses available for two different avian scavenger guilds in the Tropical Andes; each guild included the Andean Condor, the alleged top scavenger. The carcasses eaten by Andean Condors were consumed, on average, 1.75 times faster than those they did not eat. Furthermore, the greater abundance of feeding condors shortened carcass consumption time more than a greater abundance of any other species by 1.65 to 5.96 times, on average. These findings support the hypothesis that the Andean Condor significantly drives scavenging dynamics and is, therefore, an unrestricted top scavenger. Additionally, we established a gradient of tolerance of avian scavengers to domestic dog disturbance at carcasses, from highest to lowest: vultures > caracaras > condors. Our study framework holds great potential for advancing in food webs' comprehension through quantifying the relative functional role of scavenging communities' members and for guiding efforts to weigh up the ecological contributions of top scavengers and foster their conservation.
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.
ABSTRACT
Exposure to residues of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac present in livestock carcasses has caused extensive declines in 3 Gyps vulture species across Asia. The carcass of a wild Eurasian Griffon Vulture (Gyps fulvus) was found in 2012 on an Andalucian (Spain) game hunting reserve and examined forensically. The bird had severe visceral gout, a finding consistent with Gyps vultures from Asia that have been poisoned by diclofenac. Liver and kidney samples from this Eurasian Griffon Vulture contained elevated flunixin (an NSAID) levels (median = 2.70 and 6.50 mg/kg, respectively). This is the first reported case of a wild vulture being exposed to and apparently killed by an NSAID outside Asia. It is also the first reported instance of mortality in the wild resulting from environmental exposure to an NSAID other than diclofenac.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/poisoning , Clonixin/analogs & derivatives , Environmental Exposure , Environmental Pollutants/poisoning , Falconiformes , Animals , Clonixin/poisoning , Drug Combinations , Ferrous Compounds , Mucins , SpainABSTRACT
Descreve-se a interação e o uso do espaço entre espécimes de urubus-pretos (C. atratus) no consumo de um recurso limitado na forma de uma fonte de água temporária, em uma área do nordeste do Brasil, em época de seca. As aves mostraram uma frequência de agressividade elevada pelo aumento do número de indivíduos realizando o comportamento de beber água, e uma distribuição dos indivíduos aparentemente hierárquica no acesso ao recurso.
The interaction and space use among the specimens of Black Vultures (C. atratus) consuming a limited resource in the form of a temporary water source, during drought period, at one site in northeastern Brazil is described. The birds showed an aggressiveness frequency elevated by the increase of the number of individuals accomplishing behavior of drinking water, and a distribution of the individuals apparently hierarchic in the access to the resource.
Subject(s)
Animals , Birds , Drinking , Feeding BehaviorABSTRACT
Descreve-se a interação e o uso do espaço entre espécimes de urubus-pretos (C. atratus) no consumo de um recurso limitado na forma de uma fonte de água temporária, em uma área do nordeste do Brasil, em época de seca. As aves mostraram uma frequência de agressividade elevada pelo aumento do número de indivíduos realizando o comportamento de beber água, e uma distribuição dos indivíduos aparentemente hierárquica no acesso ao recurso.(AU)
The interaction and space use among the specimens of Black Vultures (C. atratus) consuming a limited resource in the form of a temporary water source, during drought period, at one site in northeastern Brazil is described. The birds showed an aggressiveness frequency elevated by the increase of the number of individuals accomplishing behavior of drinking water, and a distribution of the individuals apparently hierarchic in the access to the resource.(AU)