Food predictability and social status drive individual resource specializations in a territorial vulture

Overveld, Thijs van; García‐Alfonso, Marina; Dingemanse, Niels Jeroen; Bouten, W.; Gangoso, Laura; Riva, Manuel de la; Serrano, David; Donázar, José A.

doi:10.1038/s41598-018-33564-y

Cited by 35 publications

(49 citation statements)

References 45 publications

(47 reference statements)

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“…In 2008, as an additional LIFE measure, a new supplementary feeding station was created in northern Fuerteventura, and it gathered the carcasses that were previously deposited near the neighboring farms. This feeding station shows a much lower degree of use (Van Overveld et al., ). Moreover, livestock numbers have decreased during the last years (see Appendix ).…”

Section: Discussionmentioning

confidence: 99%

Evaluating European LIFE conservation projects: Improvements in survival of an endangered vulture

Badia-Boher

Sanz‐Aguilar

Riva

et al. 2019

Journal of Applied Ecology

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1. Long-lived avian scavengers are threatened worldwide and thus, are common targets of conservation plans. However, scientific evidence of both the factors limiting populations and effectiveness of management actions are greatly needed in order to develop more efficient and successful conservation strategies.2. We assessed the effectiveness of conservation actions applied within a LIFE-Nature project aimed at improving the long-term survival of the critically endangered Canarian Egyptian vulture: including education campaigns for public awareness and control of illegal poisoning and the modification of power lines to reduce the risk of accidents. We formulated a multievent capture-mark-recapture model to obtain estimates of survival for juvenile, subadult and adult birds accounting for probabilities of resight, recovery and losses of metal and colour rings.3. Models supported a substantial enhancement in survival for subadult and adult birds and a moderate improvement for juveniles after the implementation of LIFE actions. Ring loss probabilities became notably high in the middle to long term. 4. Poisoning events became very rare after LIFE was implemented, suggesting a positive effect of environmental education and awareness campaigns. Entanglements and collisions in power lines were also efficiently mitigated. Instead, electrocutions became the most identified cause of death in the post-LIFE stage. Synthesis and applications.Our results highlight the improvement of survival in a threatened island vulture population after the implementation of a European LIFE conservation project. On small islands, with small human populations and few stakeholders, education and awareness campaigns can be especially effective for biodiversity conservation. We also demonstrate the need to complement conservation programmes with long-term monitoring, which is essential to evaluate the effectiveness of actions, especially for long-lived species.

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Section: Discussionmentioning

confidence: 99%

Evaluating European LIFE conservation projects: Improvements in survival of an endangered vulture

Badia-Boher

Sanz‐Aguilar

Riva

et al. 2019

Journal of Applied Ecology

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“…Predictability of food has been shown to drive the foraging dynamics and movements of various avian species, including Egyptian Vultures Neophron percnopterus (Van Overveld et al . 2018), Bald Eagles Haliaeetus leucocephalus (Turrin et al 2015) and White Storks Ciconia ciconia (Flack et al 2016, Rotics et al 2017). We therefore hypothesized that ‘subspecies’ may affect home‐range size of Hooded Vultures.…”

Section: Figurementioning

confidence: 99%

Variation in monthly sizes of home‐ranges of Hooded Vultures Necrosyrtes monachus in western, eastern and southern Africa

Thompson

Barber

Bechard

et al. 2020

Ibis

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Tracking studies are often used to inform conservation plans and actions. However, species have frequently only been tracked in one or a few localities, whereas space use can be remarkably flexible, especially in long‐lived species with advanced learning abilities. We assessed variability in space use in the Critically Endangered Hooded Vulture Necrosyrtes monachus by pooling movement data from three populations across the species’ sub‐Saharan range (in South Africa, Botswana, Ethiopia, Kenya, The Gambia and Mozambique). We estimated minimum convex polygons and kernel density estimators (KDEs) and compared monthly home‐range sizes between breeding and non‐breeding seasons, age‐classes and subspecies, accounting for uneven sampling within groups. Mean (± sd) monthly home‐range sizes (95% KDEs) for adult Hooded Vultures from southern (12 453 ± 21 188 km2, n = 82) and eastern Africa (3735 ± 3652 km2, n = 24) were 103 and 31 times larger than those of conspecifics from western Africa (121 ± 98 km2, n = 48). This may relate partly to subspecific differences, and individuals with small home‐ranges in western Africa and Ethiopia were trapped in urban environments. Regional variation in space use by Hooded Vultures may be linked to flexibility in feeding behaviour (degree of commensalism) which may arise in response to resource availability and persecution in different areas. Age‐class also affected monthly home‐range sizes, with immature birds generally having larger monthly home‐range size estimates than adults. Our results highlight the flexibility of Hooded Vultures in terms of their home‐range sizes and suggest that home‐range sizes differ between populations and individuals, depending on the extent of human commensalism. Our results also reaffirm the importance of international co‐operation in conservation efforts aimed at protecting this wide‐ranging, non‐migratory species.

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“…Moreover, sex was also a key factor in Andean condors 30 . However, the situation of European vultures could differ since, unlike Andean condors, they have a moderately reversed sexual dimorphism (i. e. females are slightly larger than males 43 ), so females could increase their competitiveness against males following the global pattern of positive dominance related to body size 60 .…”

Section: Relationships Between Hierarchies and Feeding Behaviormentioning

confidence: 99%

Larger size and older age confer competitive advantage: dominance hierarchy within European vulture guild

Moreno-Opo

Trujillano²,

Margalida

2020

Sci Rep

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competition for limiting natural resources generates complex networks of relationships between individuals, both at the intra-and interspecific levels, establishing hierarchical scenarios among different population groups. Within obligate scavengers, and especially in vultures, the coevolutionary mechanisms operating during carrion exploitation are highly specialized and determined in part by agonistic behavior resulting in intra-guild hierarchies. This paper revisits the behavioral and hierarchical organization within the guild of European vultures, on the basis of their agonistic activities during carrion exploitation. We used a dataset distilled from high-quality videorecordings of competitive interactions among the four European vulture species during feeding events. We found a despotic dominance gradient from the larger species to smaller ones, and from the adults to subadults and juveniles, following an age and body size-based linear pattern. The four studied species, and to some extent age classes, show despotic dominance and organization of their guild exerting differential selection to different parts of the carrion. The abundance of these parts could ultimately condition the level of agonistic interactions. We discuss the behavioral organization and the relationship of hierarchies according to the feeding behavior and prey selection, by comparing with other scavenger guilds.Competition for naturally limited resources generates complex networks of relationships between individuals, based on evolutionary, morphological and behavioral adaptations of different species and populations 1,2 . These competitive relationships at the intra-and interspecific levels may result in: (1) the establishment of dominance hierarchies between competing groups disputing a particular resource 3,4 ; (2) resource partitioning, both in the means of obtaining the disputed resource and in resource selection 5 ; and (3) differing energetic efficiencies obtained from different parts of a shared resource 6,7 .In obligate scavenging animals, the coevolutionary behavioral mechanisms established within this guild are highly specialized in both competitive and facilitatory aspects 4,8-11 . This particular specialization in feeding demeanor is a result of the type of resource being exploited. Carrion is a pulsed food source which is unpredictable and usually limited in occurrence in space and time, which offers highly nutritive biomass [12][13][14][15] . In addition to ecomorphological adaptations (i.e. robust beaks, head without long feathers, accurate visual ability, digestive tracts tolerant to potential pathogens in carrion), obligate scavengers have developed behavioral adaptations to optimize carrion exploitation [16][17][18] , including various agonistic behaviors. Individuals exhibit aggressive activities to exclude competitors (con-or heterospecific) from disputed resources 19 . Such aggressive behaviors are common in many animal species 20 , although they are especially vigorous in terms of display and duration in predators and...

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Food predictability and social status drive individual resource specializations in a territorial vulture

Cited by 35 publications

References 45 publications

Evaluating European LIFE conservation projects: Improvements in survival of an endangered vulture

Evaluating European LIFE conservation projects: Improvements in survival of an endangered vulture

Variation in monthly sizes of home‐ranges of Hooded Vultures Necrosyrtes monachus in western, eastern and southern Africa

Larger size and older age confer competitive advantage: dominance hierarchy within European vulture guild

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