Food predictability determines space use of endangered vultures: implications for management of supplementary feeding

Ecological Applications, Journal Year: 2013, Volume and Issue: 24(5), P. 938 - 949

Published: Dec. 16, 2013

Understanding space use of free-living endangered animals is key to informing management decisions for conservation planning. Like most scavengers, vultures have evolved under a context unpredictability food resources (i.e., exploiting scattered carcasses that are intermittently available). However, the role predictable sources in shaping spatial ecology has seldom been studied detail. Here, we quantify home range Egyptian Vulture (Neophron percnopterus), long-lived raptor experienced severe population decline throughout its and qualified as worldwide. To this end, six adults were tracked by satellite telemetry Spain during breeding season, from 2007 2012, recording 10360 GPS locations. Using Resource Utilization Functions, assessed topology Distribution, three-dimensional measure shows probability finding an animal within range. Our results showed how availability, principally, predictability, determines ranging behavior species. Vultures consistent site fidelity across years, measured two- overlap their ranges. Space varied considerably remarkably, places located far nesting sites used more frequently than some areas closer. Therefore, traditional measures based on establishing restrictive rules fixed radius around could be biologically meaningless if other not protected too. Finally, our emphasize importance anthropogenic (mainly vulture restaurants) which agreement with recent findings. Hence, aimed at ensuring availability essential preserve vulture, especially present limiting carrion dumping field due sanitary regulations according European legislation.

Language: Английский

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Mixed strategies of griffon vultures’ (Gyps fulvus) response to food deprivation lead to a hump-shaped movement pattern

Movement Ecology, Journal Year: 2013, Volume and Issue: 1(1)

Published: July 5, 2013

The need to obtain food is a critical proximate driver of an organism's movement that shapes the foraging and survival individual animals. Consequently, relationship between hunger has received considerable attention, leading common conception primarily enhances "food-intake maximization" (FIMax) strategy intensive search. A complementary explanation, however, suggests trade-off with precautions taken reduce risk physiological collapse from starvation, under we denote as "energy-expenditure minimization" (EEMin). FImax-EEmin may interact forager's level shape complex (non-monotonic) response pattern increasing hunger. Yet, this important rarely been investigated, particularly in free-ranging wild We explored how affects movements adult griffon vultures (Gyps fulvus) southern Israel. Transmitters combining GPS accelerometers provided high-resolution data on vultures' behavior, enabling identification feeding events estimation deprivation periods (FDPs, measured days), which used proxy for hunger.Data 47 vultures, tracked 339 ± 36 days, reveal high variability FDPs. While flight speed, straightness proportion active flights were invariant relation deprivation, clear hump-shaped was found daily distances, maximal displacements elevation. These characteristics increased during first five days FDP sequence decreased following days. also differed short FDPs up four longer sequences. results suggest switch FIMax EEMin strategies along sequence. They indicate affected eventual duration FDP. During winter (the incubation period characterized by unfavorable soaring meteorological conditions), less resulted starvation periods, while, summer, more shorter FDPs.Our show flexible, non-monotonic animals levels, reflecting motivation find starvation. proposed offers unifying perspective apparently contradictory or case-specific empirical findings.

Language: Английский

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Decision-making by a soaring bird: time, energy and risk considerations at different spatio-temporal scales

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2016, Volume and Issue: 371(1704), P. 20150397 - 20150397

Published: Aug. 16, 2016

Natural selection theory suggests that mobile animals trade off time, energy and risk costs with food, safety other pay-offs obtained by movement. We examined how birds make movement decisions integrating aspects of flight biomechanics, ecology behaviour in a hierarchical framework investigating track variation across several spatio-temporal scales. Using extensive global positioning system accelerometer data from Eurasian griffon vultures ( Gyps fulvus ) Israel France, we soaring–gliding decision-making comparing inbound versus outbound flights (to or central roost, respectively), these (and other) home-range foraging movements (up to 300 km) long-range (longer than km). found have similar features compared their counterparts: individuals reduced journey time performing more efficient flight, expenditure flapping less were risk-prone gliding steeply between thermals. Age, breeding status, wind conditions altitude (but not sex) affected prioritization during flights. therefore suggest facing trade-offs broad range ecological contexts spatial scales, presumably owing similarity the uncertainty about outcomes. This article is part themed issue ‘Moving moving medium: new perspectives on flight’.

Language: Английский

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Effects of decreased anthropogenic food availability on an opportunistic gull: evidence for a size‐mediated response in breeding females

Ibis, Journal Year: 2015, Volume and Issue: 157(3), P. 439 - 448

Published: Feb. 13, 2015

Some opportunistic vertebrates exploit, and may largely rely upon, food generated by human activities. Better understanding the influence of this additional anthropogenic on species' ecology would inform sustainable waste management. In Balearic Archipelago Spain, closure an open‐air landfill site provided experimental setting to measure effect removing average body mass, breeding parameters condition Yellow‐legged Gulls Larus michahellis . After there was a significant decline in mass females males (−10.4 −7.8%, respectively), egg volume (−4.8%), shift modal clutch size from three two eggs. Body decreased after both sexes. females, drop weight greater for birds with low index. The differential response reduction between small large suggests that origin contributes tempering effects natural selection, making long‐term demographic changes supply difficult predict.

Language: Английский

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Manipulating size, amount and appearance of food inputs to optimize supplementary feeding programs for European vultures

Biological Conservation, Journal Year: 2014, Volume and Issue: 181, P. 27 - 35

Published: Nov. 14, 2014

Language: Английский

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The energy landscape predicts flight height and wind turbine collision hazard in three species of large soaring raptor

Journal of Applied Ecology, Journal Year: 2017, Volume and Issue: 54(6), P. 1895 - 1906

Published: March 27, 2017

Summary Collisions of large soaring raptors with wind turbines and other infrastructures represent a growing conservation concern. We describe way to leverage knowledge about raptor behaviour forecast the probability that fly in rotor‐swept zone. Soaring are theoretically expected select energy sources (uplift) optimally, making their flight height dependent on uplift conditions. This approach can be used collision hazard when planning or operating farms. Empirical investigations factors influencing have, however, so far been hindered by observation error. propose two‐pronged approach. First, we fitted state‐space models z ‐axis GPS tracking data filter heavy‐tailed error estimate relationship between vertical movement parameters weather variables describing landscape (thermal orographic potential). Second, mechanistic model above ground based aerodynamics resource selection theories. The was replicated for five GPS‐tracked Andean condors Vultur gryphus , eight griffon vultures Gyps fulvus six golden eagles Aquila chrysaetos . In all individuals, correlated thermal potential direction. species, lowest high values. Species specificities presence peak medium values could explained differences wing loading aspect ratio. Synthesis applications Our convert potential) into prediction (probability zone), it possible prioritize different development projects respect relative they would pose raptors. However, our should combined post‐construction monitoring document, eventually account turbine avoidance behaviours rate predictions.

Language: Английский

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Spatial and temporal movements in Pyrenean bearded vultures (Gypaetus barbatus): Integrating movement ecology into conservation practice

Scientific Reports, Journal Year: 2016, Volume and Issue: 6(1)

Published: Oct. 25, 2016

Abstract Understanding the movement of threatened species is important if we are to optimize management and conservation actions. Here, describe age sex specific spatial temporal ranging patterns 19 bearded vultures Gypaetus barbatus tracked with GPS technology. Our findings suggest that asymmetries a consequence breeding status age-classes. Territorial individuals exploited home ranges about 50 km 2 , while non-territorial birds used areas around 10 000 (with no seasonal differences). Mean daily movements differed between territorial (23.8 km) (46.1 km), differences were also found sexes in birds. Daily maximum distances travelled per day (8.2 (26.5 km). females moved greater (12 than males (6.6 Taking into account high-use core (K20), Supplementary Feeding Sites (SFS) do not seem play an role use space by vultures. For individuals, 54% 46% their (K90), respectively, outside protected areas. will help develop guidelines for establishing priority based on use, actions this species.

Language: Английский

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Large birds travel farther in homogeneous environments

Global Ecology and Biogeography, Journal Year: 2019, Volume and Issue: 28(5), P. 576 - 587

Published: Jan. 11, 2019

Abstract Aim Animal movement is an important determinant of individual survival, population dynamics and ecosystem structure function. Nonetheless, it still unclear how local movements are related to resource availability the spatial arrangement resources. Using resident bird species migratory outside period, we examined distribution resources affects patterns both large terrestrial birds (e.g., raptors, bustards hornbills) waterbirds cranes, storks, ducks, geese flamingos). Location Global. Time period 2003–2015. Major taxa studied Birds. Methods We compiled GPS tracking data for 386 individuals across 36 species. calculated straight‐line distance between locations each at 1‐hr 10‐day time‐scales. For time‐scale, median 0.95 quantile displacement. used linear mixed‐effects models examine effect resources, measured as enhanced vegetation index homogeneity, on avian movements, while accounting mean availability, body mass, diet, flight type, status taxonomy autocorrelation. Results found a significant On average, were seven times longer in environments with homogeneously distributed compared areas low homogeneity. Contrary previous work, no or mass non‐migratory birds. Main conclusions suggest that homogeneous might reflect need different habitat types associated foraging reproduction. This highlights importance landscape complementarity, where patches within include range different, yet complementary As homogenization increases, force travel increasingly distances meet their diverse needs.

Language: Английский

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Apex scavengers from different European populations converge at threatened savannah landscapes

Scientific Reports, Journal Year: 2022, Volume and Issue: 12(1)

Published: Feb. 15, 2022

Abstract Over millennia, human intervention has transformed European habitats mainly through extensive livestock grazing. “Dehesas/Montados” are an Iberian savannah-like ecosystem dominated by oak-trees, bushes and grass species that subject to agricultural uses. They a good example of how large-scale, low intensive transformations can maintain high biodiversity levels as well socio-economic cultural values. However, the role these human-modified play for individuals or living beyond their borders is unknown. Here, using dataset 106 adult GPS-tagged Eurasian griffon vultures ( Gyps fulvus ) monitored over seven years, we show breeding in western populations from Northern, Central, Southern Spain, France made long-range forays (LRFs) up 800 km converge threatened “dehesas” forage. There, wild ungulates provide large amounts carcasses, which available scavengers traditional exploitations rewilding processes. Our results highlight maintaining critical not only local but also long-term conservation services provided avian across continent.

Language: Английский

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Moving beyond Curve Fitting: Using Complementary Data to Assess Alternative Explanations for Long Movements of Three Vulture Species

The American Naturalist, Journal Year: 2015, Volume and Issue: 185(2), P. E44 - E54

Published: Jan. 9, 2015

Animal movements exhibit an almost universal pattern of fat-tailed step-size distributions, mixing short and very long steps. The Lévy flight foraging hypothesis (LFFH) suggests a single optimal food search strategy to explain this pattern, yet mixed movement distributions are biologically more plausible often convincingly fit data. To confront alternative explanations for these patterns, we tracked vultures three species in two different ecosystems using high-resolution global positioning system/accelerometer tags accompanied by behavioral, genetic, morphological distribution fitted the data sets reasonably well, matching expectations based on their sparsely distributed resources; models was considerably better, suggesting distinct modes operating at scales. Specifically, long-range forays (LRFs)—rare, short-term, large-scale circular journeys that greatly exceed typical range contribute tail-fatness all species—do not match suggested LFFH. We also found no support preferred weather conditions or population genetic structure as explanations, so LRFs represent failed breeding dispersal attempts find mates remains our most explanation time. conclude inference about mechanisms underlying animal should be confronted with complementary data, suggest behavioral likely commonly observed distributions.

Language: Английский

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