Non-steroidal anti-inflammatory drugs (NSAIDs) as a hidden threat to scavenging raptors beyond Gyps: A call for wider research and surveillance.

ABSTRACT The incidence of hybridization varies across the avian phylogeny. For some bird orders numerous hybrid records have been reported, whereas hybridization seems to be a rare phenomenon in other bird orders. Vultures are an example of a bird group with few hybrid records, raising the question why hybridization is so uncommon in this group of birds. I searched the scientific literature for hybrid records in both Old World Vultures (part of the family Accipitridae) and New World Vultures (family Cathartidae). My search uncovered only three published cases of natural hybrids in the genus Gyps: White-backed Vulture (Gyps africanus) × Cape Vulture (Gyps coprotheres), Rüppell’s Vulture (Gyps rueppelli) × Griffon Vulture (Gyps fulvus), and Rüppell’s Vulture × Cape Vulture. However, these three cases require genetic confirmation before they can be deemed reliable. Several captive hybrids have also been documented in European zoos, but these hybrids probably represent exceptional cases. The rarity of wild vulture hybrids might be related to their relatively old evolutionary age, although the exact relationship between hybridization probability and genetic divergence remains to be determined. In addition, strong prezygotic barriers, such as species-specific aerial displays and strong social bonds, might play a role in preventing the production of hybrids. This exercise showed how collecting and analyzing hybrid records in less hybridization-prone groups can help to understand why hybridization is rare in these bird groups.

Several vulture species are classified as endangered due to their massive global decline in populations. Humans and other species in the ecosystem may suffer because of this decline. Identification of vulture conservation threats, and creation of sustainable wildlife conservation depends on understanding the attitudes and views of local communities. Research on threats, attitudes, and views of local communities towards vulture conservation in Botswana is limited. The current study yields key insights about the perceptions and knowledge of local communities towards vultures in the Manyelanong and Tswapong hills, Botswana which are crucial foraging and breeding habitats for cape vultures Gyps coprotheres. A questionnaire survey was employed, comprising both open-ended and closed-ended questions about respondents’ perceptions of vultures, their knowledge of them, and how frequently they had seen them in their neighbourhoods. The questionnaire was implemented on 120 randomly selected households near the breeding grounds of vultures. Both qualitative and quantitative techniques were used to analyse the data. Some socioeconomic factors, including education level, age, occupation, residence, and favourable attitude towards vultures, showed a significant association. The physical and behavioural traits of the species had an impact on how the locals felt about vultures. Age, education, and participation level of respondents had an impact on their attitudes towards conservation. The ecological significance of vulture species is recognised by communities, who are concerned about their population declines. Therefore, comprehensive awareness-raising campaigns should be encouraged to protect vulture species.

The Cape Vulture (Gyps coprotheres) has the smallest range of any vulture species in Africa, Europe or Asia and is substantially impacted by anthropogenic factors because of their low productivity and long maturation times. Almost year-round presence at breeding colonies makes understanding Cape Vulture breeding behaviour essential for their conservation. Camera traps, a first for this species, were used to investigate the effect of time of day and temperature on the presence and behaviours performed at nest sites. The number of vultures at a nest site was likely to be higher during the early morning and late afternoon when temperatures were lower, with significantly fewer individuals present at higher temperatures in the days before and after laying. Attendance of at least one adult at the nest was recorded for 86.9% and 99.8% of time points in the days before and after laying, respectively. Almost-constant attendance during incubation may also be necessitated by predation pressure, with this study providing observation of possible predation pressure by White-necked Ravens (Corvus albicollis) at the colony. Here, we demonstrate that camera trapping is an effective method of studying Cape Vulture breeding behaviour, which improves understanding and allows more informed conservation measures to be implemented. Cape Vulture nest attendance is affected by temperature, so this species may be vulnerable to climatic changes and subsequent changes in predation pressure.

Numbers of Critically Endangered Hooded Vultures (Necrosyrtes monachus Temminck 1823) are declining across their distribution. The range-edge population in South Africa is one of the smallest populations with only 100-200 mature individuals. In South Africa, Hooded Vultures nest solitarily in loose colonies (mean distance between nests 0.76 km) along water courses. Basic ecological information, such as breeding behaviour, is still lacking for the species. In this study, we examine the relatedness and nest turnover of nesting individuals along the Olifants River and other locations in the Lowveld of South Africa by sampling nests over five consecutive years. A key hypothesis tested is whether communal roosting sites function as information-sharing hubs, a phenomenon that has been seen in Cape Vultures (Gyps coprotheres) and other cliff-nesting vultures. Theory suggests that information sharing occurs more frequently between closely related individuals. If true, we expect distance between nests and genetic relatedness to be positively correlated and individuals to use the same nests over multiple years. Naturally moulted feathers (n = 108) were collected below nests over five consecutive years, and 14 microsatellite loci markers were used to measure genetic relatedness. Mantel tests performed correlating distance between nests to relatedness coefficient estimators TrioML (r = 0.032, R 2 = 0.001, p = 0.224) and LynchRD (r = 0.007, R 2 = 0.00005, p = 0.403), found no statistical correlation. The Mantel test performed using Nei's genetic distance and distance between nests did show a negative correlation (r = -0.108, R 2 = 0.0117, p-value = 0.012), indicating that individuals that were more closely related tended to breed further away. No nest reuse was found in this study. We thus believe that these loose colonies do not act as food-finding hubs, but rather that the Olifants River is an important breeding site for these birds.

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Validation of the Lead Care II System in Cape vultures (Gyps coprotheres) in comparison to ICP-MS using pure standards

Sub-lethal impacts of lead poisoning on blood biochemistry, immune function and delta-aminolevulinic acid dehydratase (δ-ALAD) activity in Cape (Gyps coprotheres) and white-backed (G. africanus) Vulture chicks

Combining trends from disparate monitoring programs to inform Red List assessments: The case of the Cape Vulture (Gyps coprotheres)

Bio-telemetry from small tags attached to animals is one of the principal methods for studying the ecology and behaviour of wildlife. The field has constantly evolved over the last 80 years as technological improvement enabled a diversity of sensors to be integrated into the tags (e.g., GPS, accelerometers, etc.). However, retrieving data from tags on free-ranging animals remains a challenge since satellite and GSM networks are relatively expensive and or power hungry. Recently a new class of low-power communication networks have been developed and deployed worldwide to connect the internet of things (IoT). Here, we evaluated one of these, the Sigfox IoT network, for the potential as a real-time multi-sensor data retrieval and tag commanding system for studying fauna across a diversity of species and ecosystems. We tracked 312 individuals across 30 species (from 25 g bats to 3 t elephants) with seven different device concepts, resulting in more than 177,742 successful transmissions. We found a maximum line of sight communication distance of 280 km (on a flying cape vulture [Gyps coprotheres]), which sets a new documented record for animal-borne digital data transmission using terrestrial infrastructure. The average transmission success rate amounted to 68.3% (SD 22.1) on flying species and 54.1% (SD 27.4) on terrestrial species. In addition to GPS data, we also collected and transmitted data products from accelerometers, barometers, and thermometers. Further, we assessed the performance of Sigfox Atlas Native, a low-power method for positional estimates based on radio signal strengths and found a median accuracy of 12.89 km (MAD 5.17) on animals. We found that robust real-time communication (median message delay of 1.49 s), the extremely small size of the tags (starting at 1.28 g without GPS), and the low power demands (as low as 5.8 µAh per transmitted byte) unlock new possibilities for ecological data collection and global animal observation.

The rapid development of wind energy in southern Africa represents an additional threat to the already fragile populations of African vultures. The distribution of the vulnerable Cape Vulture Gyps coprotheres overlaps considerably with wind energy development areas in South Africa, creating conflicts that can hinder both vulture conservation and sustainable energy development. To help address this conflict and aid in the safe placement of wind energy facilities, we map the utilization distribution (UD) of this species across its distributional range. Using tracking data from 68 Cape Vultures collected over the last 20 years, we develop a spatially explicit habitat use model to estimate the expected UDs around known colonies. Scaling the UDs by the number of vultures expected to use each of the colonies, we estimate the Cape Vulture population utilization distribution (PUD) and determine its exposure to wind farm impacts. To complement our results, we model the probability of a vulture flying within the rotor sweep area of a wind turbine throughout the species range and use this to identify areas that are particularly prone to collisions. Overall, our estimated PUD correlates well with reporting rates of the species from the Southern African Bird Atlas Project, currently used to assess potential overlap between Cape Vultures and wind energy developments, but it adds important benefits, such as providing a spatial gradient of activity estimates over the entire species range. We illustrate the application of our maps by analyzing the exposure of Cape Vultures in the Renewable Energy Development Zones (REDZs) in South Africa. This application is a scalable procedure that can be applied at different planning phases, from strategic, nationwide planning to project-level assessments.

Understanding continent-wide variation in vulture ranging behavior to assess feasibility of Vulture Safe Zones in Africa: Challenges and possibilities

The endangered Cape Vulture (Gyps coprotheres), a southern African endemic, breeds on precipitous cliffs in various habitats. Some colonies of this cliff-nesting species are found in the southeast (Mannyelanong Hill) and east (Tswapong Hills and adjacent complexes) of Botswana. Of six breeding sites studied in the Tswapong Hills complex from 1992 to 1999, only two large colonies near the villages of Goo-Moremi (Bonwalenong site) and Goo-Tau (Manong Yeng site) and one small colony near Lerala (Kukubye site) still hold breeding vultures. In 2017 and 2018 we used direct observations to estimate the breeding population and breeding success of Cape Vultures at the Bonwalenong and Manong Yeng colonies, and we compared our findings with data from the 1990s. We identified 261 nests in 2017 and 362 nests in 2018, and monitored them throughout the breeding season. Breeding success at the two sites differed significantly between the 2 yr of our study (2017 and 2018). However, breeding success at Manong Yeng in 2017–2018 did not differ significantly from that documented in the earlier study (1992–1999). Our results also suggested relatively stable numbers of breeding pairs in the Tswapong Hills between 1992–1999 and 2017–2018. Cape Vultures in the Tswapong Hills require continued monitoring and research to better understand population dynamics and the key factors influencing breeding success and nestling survival.

Background: Two of Lesotho’s protected areas, namely Bokong Nature Reserve and Tšehlanyane National Park, form the core area of the country’s first proposed Biosphere Reserve. Biodiversity is a key aspect needed to justify nomination of a Biosphere Reserve under UNESCO’s Man and the Biosphere Programme. Previously documented biodiversity of the two protected areas is limited in terms of coverage and scope as well as being outdated. The aim of the current study was to conduct a rapid assessment of the biodiversity, including endemism, of the proposed Biosphere Reserve to inform the formal nomination process.Methods: A field survey was undertaken over 112 033 ha in the core, buffer and transition zones of the proposed Biosphere Reserve during which species of both flora and fauna were documented. Purposeful recordings were made during different seasons to incorporate various flowering seasons of the plants, as well as faunal species that may hibernate or migrate seasonally.Results: A total of 380 plant species was recorded, 30 of which are legally protected in the country, 60 endemic to the Drakensberg Mountain Centre, and two species (Aloe polyphylla and Glumicalyx lesuticus) are endemic to Lesotho. The former is the national flower of Lesotho and is under threat due to illegal trade. Sixteen mammal species were recorded, seven of which are legally protected in the country, as well as 53 bird species (including the IUCN Red Listed vulture species, Gyps coprotheres and Gypaetus barbatus). Two fish species were also recorded including Pseudobarbus quathlambae, which is Lesotho’s only known endemic vertebrate species, as well as seven reptile and three amphibian species (two of which are near endemic namely Amietia delalandii and A. vertebralis).Conclusion: This survey has provided valuable baseline information on the biodiversity (particularly regarding the flora and avifauna) of the proposed Biosphere Reserve, which includes two protected areas namely Bokong Nature Reserve and Tšehlanyane National Park. The findings reflect the biodiversity value of the area and will contribute towards its nomination as Lesotho’s first Biosphere Reserve.

BackgroundThe use of tracking technologies is key for the study of animal movement and pivotal to ecological and conservation research. However, the potential effects of devices attached to animals are sometimes neglected. The impact of tagging not only rises welfare concerns, but can also bias the data collected, causing misinterpretation of the observed behaviour which invalidates the comparability of information across individuals and populations. Patagial (wing) tags have been extensively used as a marking method for visual resightings in endangered vulture species, but their effect on the aerodynamics of the birds and their flight behaviour is yet to be investigated. Using GPS backpack mounted devices, we compared the flight performance of 27 captive and wild Cape Vultures (Gyps coprotheres), marked with either patagial tags or coloured leg bands.ResultsIndividuals equipped with patagial tags were less likely to fly, travelled shorter distances and flew slower compared to individuals equipped with leg bands. These effects were also observed in one individual that recovered its flight performance after replacing its patagial tag by a leg band.ConclusionsAlthough we did not measure the effects of patagial tags on body condition or survival, our study strongly suggests that they have severe adverse effects on vultures’ flight behaviour and emphasises the importance of investigating the effects that tagging methods can have on the behaviour and conservation of the study species, as well as on the quality of the scientific results.

Three species of Old World vultures on the Asian peninsula are slowly recovering from the lethal consequences of diclofenac. At present the reason for species sensitivity to diclofenac is unknown. Furthermore, it has since been demonstrated that other Old World vultures like the Cape (Gyps coprotheres; CGV) and griffon (G. fulvus) vultures are also susceptible to diclofenac toxicity. Oddly, the New World Turkey vulture (Cathartes aura) and pied crow (Corvus albus) are not susceptible to diclofenac toxicity. As a result of the latter, we postulate an evolutionary link to toxicity. As a first step in understanding the susceptibility to diclofenac toxicity, we use the CGV as a model species for phylogenetic evaluations, by comparing the relatedness of various raptor species known to be susceptible, non-susceptible and suspected by their relationship to the Cape vulture mitogenome. This was achieved by next generation sequencing and assembly. The Cape vulture mitogenome had a genome size of 16,908 bp. The mitogenome phylogenetic analysis indicated a close evolutionary relationship between Old World vultures and other members of the Accipitridae as indicated by bootstrap value of 100% on the phylogenetic trees. Based on this, we postulate that the other species could also be sensitive to the toxic effects of diclofenac. This warrants further investigations.

SummaryThe ‘Endangered’ Cape VultureGyps coprothereshas been monitored across its range for decades through disparate studies varying in geographical scope and length. Yet, no long-term, range-wide survey exists for the species. Coordinated monitoring across the range of the Cape Vulture would be logistically challenging but provide a holistic view of population dynamics in this long-lived species that forages across much of southern Africa. Here, we report breeding pair counts from seven colonies in the Cape Vulture’s north-eastern breeding region from 2010 to 2019. We used state-space models to assess population growth across time. Manutsa, Soutpansberg, and Nooitgedacht colonies increased significantly over the study period, with three other colonies having positive estimates of population growth, but 95% credible intervals overlapped zero. The smallest colony at Moletjie is declining toward extirpation; only one breeding pair remained in 2019. Our results suggest the north-eastern population has been stable or increasing since 2010 with our 2019 surveys counting 2,241 breeding pairs across all sites. Indeed, there is an 89% chance that the population across the colonies we monitored increased from 2010 to 2019. Coordinated, range-wide, full-cycle monitoring is needed to thoroughly assess conservation status and efficacy of conservation actions taken for this endangered species.

Abstract Following the continual decline of the Cape vulture Gyps coprotheres since the 1960s, captive breeding and rehabilitation programmes have been established to reinforce populations across southern Africa. This study examines the spatial ecology of captive-bred and rehabilitated vultures following release. Our analysis used 253,671 GPS fixes from 20 captive-bred and 13 rehabilitated birds to calculate home range sizes using kernel density estimation. We found that home range size did not differ significantly between captive-bred and rehabilitated birds. The location of home ranges differed: captive-bred birds showed greater site fidelity, remaining close to their release site, whereas rehabilitated birds dispersed more widely across the species' native range. By remaining close to their release site within a protected area, captive-bred birds had a significantly higher per cent of their GPS fixes within protected areas than did rehabilitated birds. Despite fidelity to their release site, captive-bred birds demonstrated innate capabilities for natural foraging behaviours and the same habitat selection strategy as rehabilitated individuals. These findings suggest that captive breeding and reinforcement of populations at declining colonies could provide localized benefits. Future long-term studies should seek to analyse survivorship and identify the breeding behaviour of these captive-bred birds once they reach sexual maturity.

Wind energy is a clean, renewable alternative to fossil fuel-derived energy sources, but many birds are at risk from collisions with wind turbines. We summarise the diversity of birds killed by turbine collisions at 20 wind energy facilities (WEFs) across southwest South Africa. Monitoring from 2014 to 2018 recovered 848 bird carcasses across all WEFs, at a crude rate of 1.0 ± 0.6 birds turbine−1 y−1 at 16 WEFs with at least 12 months of postconstruction monitoring. However, mortality estimates adjusted for detection and scavenger bias were appreciably higher: 4.6 ± 2.9 birds turbine−1 y−1 or 2.0 ± 1.3 birds MW−1 y−1 (n = 14 WEFs with site-specific bias correction factors), which is slightly lower than mean rates reported in the northern hemisphere, but still well within range. A striking result was the high diversity of birds killed: 130 species from 46 families, totalling 30% of bird species recorded at and around WEFs, including some species not recorded by specialist surveys at WEF sites (e.g. flufftails Sarothruridae). Species accumulation models suggest that 184 (±22) species will be killed at these facilities, some 42% of species found in the vicinity of WEFs. This is despite the smaller number of migrants in the study region, compared with the north temperate zone. Diurnal raptors were killed most often (36% of carcasses, 23 species) followed by passerines (30%, 49 species), waterbirds (11%, 24 species), swifts (9%, six species), large terrestrial birds (5%, 10 species), pigeons (4%, six species) and other near passerines (1%, seven species). Species of conservation concern killed include endangered Cape Vultures Gyps coprotheres and Black Harriers Circus maurus, both of which are endemic to southern Africa. Every effort must be made to site wind energy facilities away from important areas for birds, particularly raptors.

Diclofenac has been responsible for the deaths of millions of vultures on the Asian subcontinent. While the pathology of toxicity is well described, the mechanism of toxicity remains elusive. However, it was postulated that toxicity could be related to the unique avian renal vascular structure known as the renal portal valve and that that diclofenac altered valve functionality with subsequent renal ischaemia. While plausible, the valva renalis portalis has only been described in a small number of other bird species such as the chicken (Gallus domesticus), the domestic duck (Anas platyrhynchos domesticus) and ostrich (Struthio camelus) but not a raptor. The aim of this study was to evaluate the renal anatomy and related vasculature of the Cape griffon vulture (Gyps coprotheres) (CGV), a species sensitive to the toxic effects of diclofenac, using gross anatomy, histology and vascular casting. The vasculature of the vulture was found to be almost identical to that of the domestic chicken with the valva renalis portalis present in the v. iliaca externa between the v. renalis renalis cranialis and the v. renalis caudalus. The valve was ring-shaped with finger-like processes and histologically was composed of smooth muscle. The valve was also well vascularized and was associated with a nerve plexus. Based on the findings of this study, the proposed mechanism of toxicity is anatomically possible.