Home-Range Size and Space Use of Territorial Bonelli’s Eagles (Aquila fasciata) Tracked by High-Resolution GPS/GSM Telemetry

Diversity, Journal Year: 2022, Volume and Issue: 14(12), P. 1082 - 1082

Published: Dec. 8, 2022

High-resolution GPS/GSM dataloggers provide spatial information of the highest quality, which outperform previous tracking methods, such as Argos telemetry or conventional VHF ground-tracking. As a result, this has improved our knowledge home-range behavior and ecology many species, including large raptors. In paper, we use high-resolution to assess size role sex, season (breeding non-breeding season), breeding status (reproductive non-reproductive individuals) on space Bonelli’s eagle (Aquila fasciata). To end, 51 territorial individuals (25 females 26 males) were equipped with transmitters tracked over 7 years (2015–2021) in eastern Spain. Overall, recorded 4,791,080 fixes that analyzed through kernel density methods (50%, 75%, 95% fixed kernels). The average individual according 95%, 50% kernels was 54.84 ± 20.78 km2, 24.30 10.18 11.17 4.90 respectively. occupying same territory similar, mainly due cooperative hunting exhibited by species. We did not find interannual differences (95% kernel) majority individuals, showing strong fidelity pairs. general, females’ slightly smaller than males’ decrease activity result laying, incubation, chick attendance at nests. No seasonal variation found, but it found 75% kernels. regard status, higher individuals. Moreover, low neighbor overlap among territories (4.18% 3.06%), evidences high level intraspecific competition eagle. Finally, study highlights advantages accurate improve understanding endangered eagle, ultimately will serve better inform management actions for its conservation.

Language: Английский

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Laying date depends on territorial breeders’ age, climatic conditions and previous breeding success: a long-term study (2004–2021) with Bonelli’s eagle in Spain

Journal of Ornithology, Journal Year: 2024, Volume and Issue: 165(3), P. 725 - 735

Published: March 22, 2024

Abstract Adjustment of reproductive timing within the annual cycle is a crucial issue for both offspring and parents’ survival, breeding success. Early laying date closely related to successful outcome better survival. Obtaining long datasets on threatened long-lived species’ performance can contribute their conservation. Using field observations telemetry information, here we analyse how an endangered raptor varies with nest characteristics, individual factors climatic variables during 18-year (2004–2021) study period in eastern Spain. To this end, estimated environmental affect date. Our results showed that average our area took place February 17th. Laying no trend period. Nests placed higher elevations delayed dates. Territories occupied by adults previous experience high brood size earlier Current year was highly correlated Colder territories minimum temperature December were negatively highlight importance experienced birds able adjust reproduction maximise biological fitness. High adult mortality allows sub-adults settle as breeders jeopardises persistence. Therefore, reduction territorial outmost improve conservation status declining species such Bonelli’s eagle ( Aquila fasciata ).

Language: Английский

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Breeders’ age, nest-site characteristics and climatic conditions but not density-dependent effects determine Bonelli’s Eagle breeding performance: A long-term study (2002–2021)

Ornithological Applications, Journal Year: 2023, Volume and Issue: 126(1)

Published: Sept. 11, 2023

Abstract The conservation of endangered species is a crucial topic in biology due to the important ecological roles these play their respective ecosystems. Top predators are particularly vulnerable variation environmental conditions. Bonelli’s Eagle (Aquila fasciata) long-lived bird prey that fulfills its role as top predator Mediterranean ecosystems, but overall population has declined Iberian Peninsula recent decades. As with other species, reaches maximum fitness at maturity, highlighting importance assessing how intrinsic and extrinsic factors affect dynamics over time. In this study, we conducted annual surveys subpopulation eastern from 2002 2021. Our results indicate large decline observed number occupied territories, fledged chicks, successful pairs not negative density-dependent effects rather influenced by various demographic factors. These include breeders’ age, nest-site characteristics, climatic conditions, previous breeding costs. We found productivity was higher territories high winter precipitation temperatures, well coastal areas, leading earlier laying dates. Additionally, presence subadult individuals pair decreased performance. Interestingly, variability fledglings each territory driven Prioritizing efforts mitigate adult mortality conserve suitable habitats becomes imperative halt ongoing also enhance productivity, ultimately facilitating restoration levels.

Language: Английский

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Experimental food subsidies keep eagles inside protected areas: implications for conservation and resource management

Biological Conservation, Journal Year: 2023, Volume and Issue: 286, P. 110259 - 110259

Published: Sept. 8, 2023

The conservation and management of mobile species, populations dynamic habitats, presents significant challenges since such species face diverse threats during various stages their life cycle. Protected areas (PAs) are essential tools in efforts, aiming to preserve native habitats. However, larger animals, as the Bonelli's eagle (Aquila fasciata), may require much outside PAs for moments, including foraging, resting, wintering. As a result, efficacy conserving be questionable. We designed an experiment eastern Spain PA that is home nesting eagles determine if increasing food availability through experimental feeding within could result effective reduction space use protected area by lead reduce death risk. Over period 2016 2021, we tracked 10 from six different territories using GPS-GSM transmitters. evaluated before, during, after experiment. Our results indicate restricted eagles' movement, resulting higher concentration locations inside PAs. spent less time when they were fed highly human-dominated Consequently, this reduced mortality risks findings suggest decisions aimed at PAs, critical endangered Mediterranean landscapes.

Language: Английский

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Potential negative effects of the installation of video surveillance cameras in raptors’ nests

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

Published: Dec. 20, 2022

Abstract Video surveillance cameras installed on birds’ nests are a cost-effective tool to study many aspects of ecology and behaviour that would otherwise be practically impossible obtain. However, although most studies report neutral effects birds, very few analyse in detail the potential negative their use, particularly raptors. Here, using long-term database population Bonelli’s eagle ( Aquila fasciata ) collected from 2000 2022, I show how inappropriate use video could result reproduction threatened species through before-and-after control-impact design. Pairs under showed lower productivity, breeding success unusual delayed laying dates. The installation close date, coinciding with mating phase individuals, them subadult inexperienced birds; combination reiteration visits once were check system, during incubation period early stages breeding; particular area subject constant human disturbance, might explain these results. Potential management actions mitigate effect should include need plan intervention dates, testing systems beforehand controlled conditions adequate post-installation monitoring avoid unnecessary disturbance animals. Finally, urge scientific community observed studies, especially if target extinction.

Language: Английский

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Ranging Behavior of Non-Breeding and Breeding Adult White-Tailed Eagles

Diversity, Journal Year: 2023, Volume and Issue: 15(12), P. 1208 - 1208

Published: Dec. 8, 2023

Space utilization by animals is vital for species ecology but also a valuable predictor of habitat conditions and environment capacity given species. We investigated the ranging behavior white-tailed eagle, an apex predator experiencing significant population increase saturation. Comparing five adult floaters two breeding males tracked with GPS loggers in Poland 1–5 years, we observed substantial differences space utilization. Breeding occupied approximately 63 to 122 km2 (using 90% kernel density), while ranged over roughly 6000 60,000 km2. expanded their home ranges during successful breeding, one male frequently flying 29 km foraging site when raising chicks hardly doing so other seasons. Both revisited nests more April May (up seven times daily, typically four), exhibiting distinct seasonal daily movement patterns. Floaters had slightly higher rates weak pattern. conclude that males’ depended on proximity optimal sites, engaged prolonged wandering.

Language: Английский

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A new view of territoriality in large eagles: the territory pre‐exists regardless of their occupants

Journal of Zoology, Journal Year: 2024, Volume and Issue: 323(3), P. 177 - 186

Published: May 6, 2024

Abstract Knowledge of vertebrate territoriality and spatial use is a topic great interest in the study animal behaviour conservation biology. Investigating plasticity territory boundaries, shape territories how can be modified depending on their owners important to deepen our knowledge territorial species. We analysed variation tested similarity distribution area individuals from same between 2015 2021, using data 51 Bonelli's eagles ( Aquila fasciata ) 22 different territories, tagged with GPS/GSM transmitters eastern Spain. calculated percentage overlap individual years 95% kernel density estimator. also changes size following replacement either by single or whole pair. Our results show that retain extent regardless occupying members, boundaries change little over time. Identifying maintaining large eagle owners, therefore key ensuring long‐term recovery these threatened

Language: Английский

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Widespread use of anticoagulant rodenticides in agricultural and urban environments. A menace to the viability of the endangered Bonelli's eagle (Aquila fasciata) populations

Environmental Pollution, Journal Year: 2024, Volume and Issue: 358, P. 124530 - 124530

Published: July 14, 2024

Anticoagulant rodenticides (ARs) are one of the most toxic groups compounds currently used worldwide for rodent pest control. Toxic baits often, directly or indirectly, ingested by non-target animals, resulting in secondary poisoning and frequently affecting apex predators. Their presence many species raptors is quite common, particularly scavenger species, with some these acting as sentinels substances environment. However, there less data on ARs Bonelli's eagle, endangered eagle Spain which experiencing a negative population trend Europe. This medium-sized feeds predominantly live rarely consumes carrion. In this study, 17 carcasses eagles from Eastern were necropsied. Both first second generation their livers analyzed HPLC-MS-TOF revealing that all studied had been exposed to at least 5 ARs, out total 10 analyzed, 7 being highest number detected sample. Second prevalent, bromadiolone brodifacoum, concentrations 94% cases. More than third presented liver concentration greater 200 ng/g suggesting AR poisoning. The elevated could be new cause mortality explain other causes death, such increased power lines, should taken into account conservation. At same time, environment also represents risk public health, frequent diet (rabbits partridges) hunted consumed hunters families.

Language: Английский

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Similar post-fledging behavior observed in wild and reintroduced juvenile Bonelli’s Eagle in two Mediterranean islands

Ornithological Applications, Journal Year: 2023, Volume and Issue: 125(4)

Published: Aug. 8, 2023

Abstract Reintroduction projects are gaining popularity; however, their relatively elevated cost and chance of failure make them debatable, hence assessing effectiveness is essential. Within the early stages raptors, post-fledging dependency period (PFDP) one in which individuals must face dangers without having completely developed skills. Thereby, comparing PFDP patterns concerning reintroduced wild major interest as it would help to plan improve future conservation actions. We analyzed behavior 38 juvenile Bonelli’s Eagles (Aquila fasciata) (15 23 wild) tracked through GPS telemetry, tagged nestlings two insular environments. The study encompassed 9-yr movement data from chicks Mallorca (Spain) Sicily (Italy). Movement parameters (i.e., age first flight, dispersal, length PFDP, revisits natal or release area, residence time them) were together with for individuals. Similar obtained both origins, although revisited site more often dispersed earlier. Behavior was also similar, though varied throughout observing a abrupt progress an earlier development travelling hunting behaviors. Observed differences probably related food availability, can body condition thus delay onset parental presence, prompt ending by encouraging independence. In conclusion, our provides valuable insights into during how compares counterparts. Our results suggest that successfully adapt environment behave similarly These findings aid planning improvement reintroduction actions this endangered species.

Language: Английский

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Home-Range Size and Space Use of Territorial Bonelli’s Eagles (Aquila fasciata) Tracked by High-Resolution GPS/GSM Telemetry

Published: Dec. 14, 2022

High-resolution GPS/GSM dataloggers provide spatial information of the highest quality, which outperform previous tracking methods, such as Argos telemetry or conventional VHF ground-tracking. As a result, this has improved our knowledge home-range behavior and ecology many species, including large raptors. In paper, we use high-resolution to assess size role sex, season (breeding non-breeding season), breeding status (reproductive non-reproductive individuals) on space Bonelli’s eagle (Aquila fasciata). To end, 51 territorial individuals (25 females 26 males) were equipped with transmitters tracked over 7 years (2015–2021) in eastern Spain. Overall, recorded 4,791,080 fixes that analyzed through kernel density methods (50%, 75%, 95% fixed kernels). The average individual according 95%, 50% kernels was 54.84 ± 20.78 km2, 24.30 10.18 11.17 4.90 respectively. occupying same territory similar, mainly due cooperative hunting exhibited by species. We did not find interannual differences (95% kernel) majority individuals, showing strong fidelity pairs. general, females’ slightly smaller than males’ decrease activity result laying, incubation, chick attendance at nests. No seasonal variation found, but it found 75% kernels. regard status, higher individuals. Moreover, low neighbor overlap among territories (4.18% 3.06%), evidences high level intraspecific competition eagle. Finally, study highlights advantages accurate improve understanding endangered eagle, ultimately will serve better inform management actions for its conservation.

Language: Английский

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