The breeding status and colony dynamics of Cape Vulture <i>Gyps
coprotheres</i> in Botswana

Borello, Wendy D.; Borello, Remigio M.

doi:10.1017/s0959270902002058

Cited by 33 publications

(39 citation statements)

References 5 publications

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“…2), breeding cliffs inside two protected areas were regularly used as roost sites by three adults and one immature, confirming that protected areas are important for reducing anthropogenic disturbance at nest and roost sites [13], [15], [21], [22], [57]. The most intensively used areas by the vultures were located in a south-westerly direction from the Kransberg colony (Marakele NP) on private and communal farmland, and rarely included protected wildlife reserves.…”

Section: Discussionmentioning

confidence: 81%

Do Power Lines and Protected Areas Present a Catch-22 Situation for Cape Vultures (Gyps coprotheres)?

Phipps

Wolter²,

Michael

et al. 2013

PLoS ONE

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Cape vulture Gyps coprotheres populations have declined across their range due to multiple anthropogenic threats. Their susceptibility to fatal collisions with the expanding power line network and the prevalence of carcasses contaminated with illegal poisons and other threats outside protected areas are thought to be the primary drivers of declines in southern Africa. We used GPS-GSM units to track the movements and delineate the home ranges of five adult (mean ±SD minimum convex polygon area = 121,655±90,845 km2) and four immature (mean ±SD minimum convex polygon area = 492,300±259,427 km2) Cape vultures to investigate the influence of power lines and their use of protected areas. The vultures travelled more than 1,000 km from the capture site and collectively entered five different countries in southern Africa. Their movement patterns and core foraging ranges were closely associated with the spatial distribution of transmission power lines and we present evidence that the construction of power lines has allowed the species to extend its range to areas previously devoid of suitable perches. The distribution of locations of known Cape vulture mortalities caused by interactions with power lines corresponded to the core ranges of the tracked vultures. Although some of the vultures regularly roosted at breeding colonies located inside protected areas the majority of foraging activity took place on unprotected farmland. Their ability to travel vast distances very quickly and the high proportion of time they spend in the vicinity of power lines and outside protected areas make Cape vultures especially vulnerable to negative interactions with the expanding power line network and the full range of threats across the region. Co-ordinated cross-border conservation strategies beyond the protected area network will therefore be necessary to ensure the future survival of threatened vultures in Africa.

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Section: Discussionmentioning

confidence: 81%

Do Power Lines and Protected Areas Present a Catch-22 Situation for Cape Vultures (Gyps coprotheres)?

Phipps

Wolter²,

Michael

et al. 2013

PLoS ONE

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“…Breeding in a colony may enhance foraging efficiency and thus aid breeding success by increased food provisioning rates (Ward & Zahavi 1973, Krause & Ruxton 2002, Dermody et al 2011. some water birds and kestrels), links between nest density and cliff characteristics in vulture breeding success remain unclear (Harris et al 1997, Borello & Borello 2002, Franco et al 2005, Anushiravani et al 2016, Brussee et al 2016. Certain individuals may be forced to occupy sub-optimal sites, such as the periphery of the colony, and therefore may suffer from increased predation and be removed from the social network of food patch knowledge (Forster & Phillips 2009).…”

mentioning

confidence: 99%

“…Unfortunately, in recent years, entire vulture breeding colonies have gone extinct because of human disturbance or reductions in carrion availability (Ogada et al 2015). Thus, the southern African endemic Cape Vulture has seen a severe range contraction in recent years (Boshoff & Vernon 1980, Borello & Borello 2002, Bamford et al 2007. In the 1960s, vultures bred at 32 known breeding colonies in South Africa, but by 2015, only 11 of the 32 colonies supported breeding pairs (Allan 2015).…”

mentioning

confidence: 99%

Cliff characteristics, neighbour requirements and breeding success of the colonial Cape VultureGyps coprotheres

Pfeiffer

Venter

Downs

2016

Ibis

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The breeding success of endangered colonial nesting species is important for their conservation. Many species of Gyps vultures form large breeding colonies that are the foci of conservation efforts. The Cape Vulture is a globally threatened species that is endemic to southern Africa and has seen a major reduction in its population size (≥ 50% over 48 years). There is evidence that breeding colonies are prone to desertion as a result of human disturbance. Factors that influence the occupancy and breeding success of individual nest‐sites is not fully understood for any African vulture species. We investigated cliff characteristics and neighbour requirements of the Msikaba Cape Vulture colony, a major breeding colony in the southern node of the population in the Eastern Cape, South Africa, together with their nest‐site occupation and breeding success over 13 years. In total, 1767 breeding attempts were recorded. Nest‐sites that had a higher elevation, smaller ledge depth, greater total productivity and were surrounded by conspecifics were more likely to be occupied, although the amount of overhang above the nest was not an important predictor of occupancy. In accordance with occupation, nest‐sites with a smaller ledge depth had higher breeding success; however, nests with a greater overhang were also more successful and height of the nest‐site was not an important predictor of breeding success. The breeding success of a nest‐site in a given year was positively influenced by the number of direct nest neighbours, and nests in the middle of high‐density areas had greater breeding success. This suggests that maintaining a high nest density may be an important consideration if declines of reproducing adults continue. Breeding success declined over the study period, highlighting the effects of a temporal variation or observer bias. Our results identified optimal nest‐site locations (ledge depths of 1 m, at a height of 180 m) and their effects on breeding success. This information can be used for planning reintroduction efforts of the endangered Cape Vulture and for their ongoing conservation.

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“…The cause of ''colony switching'' (Piper 2004) frequently remains unclear as sometimes optimal sites may be abandoned whereas others with low breeding success may be occupied (Borello and Borello 2002). In some cases the phenomenon has been attributed to human disturbance (Mundy 1983), although it could have resulted by breeding adults that change colonies after nest failures (Sarrazin et al 1996).…”

Section: Colony Occupancymentioning

confidence: 99%

Status and structure of the griffon vulture (Gyps fulvus) population in Crete

Xirouchakis

Mylonas

2005

Eur J Wildl Res

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Griffon vulture (Gyps fulvus) population surveys were conducted during 1996-2002 in the island of Crete (Greece) to document population status and structure. Fieldwork was carried out during the breeding period when birds could be monitored in their colonies. Total population size was estimated at 379 individuals (range = 341-417) with adult birds comprising 63%. The breeding population was estimated at 141 pairs, which were distributed on an average in 23 colonies per year (range = 16-30) while the mean number of breeding pairs that laid eggs was 98 (range= 64-126). Crete thus supports the largest insular population of the species in the world and hosts 70-80% of the breeding population of the species in Greece. Population density was estimated at 6.9 individuals/100 km 2 , 2.6 breeding pairs/100 km 2 and 1.8 nesting pairs/100 km 2 . The average home range of an occupied colony (i.e., breeding group) was estimated at ca. 204 km 2 producing a theoretical foraging range of 8 km radius around the breeding cliff. No trends in the total number of individuals and breeding pairs appeared to exist, although significant differences in population size of individual colonies occurred between the years. The majority of the population was concentrated in small-sized colonies, which showed a low occupancy rate. The number of abandoned sites and the colonization of new ones could represent a shift of breeding pairs to alternative colonies provoked by local food abundance and conspesific attraction.

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The breeding status and colony dynamics of Cape Vulture Gyps coprotheres in Botswana

Cited by 33 publications

References 5 publications

Do Power Lines and Protected Areas Present a Catch-22 Situation for Cape Vultures (Gyps coprotheres)?

Do Power Lines and Protected Areas Present a Catch-22 Situation for Cape Vultures (Gyps coprotheres)?

Cliff characteristics, neighbour requirements and breeding success of the colonial Cape VultureGyps coprotheres

Status and structure of the griffon vulture (Gyps fulvus) population in Crete

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