Whytock R.C.,Ebo Forest Research Project |
Whytock R.C.,University of Stirling |
Buij R.,Wageningen University |
Virani M.Z.,Peregrine Fund |
Morgan B.J.,Institute for Conservation Research
ORYX | Year: 2016
The commercial bushmeat trade threatens numerous species in the forests of West and Central Africa. Hunters shoot and trap animals, which are transported to rural and urban markets for sale. Village-based surveys of hunter offtake and surveys of bushmeat markets have shown that mammals and reptiles are affected most, followed by birds. However, hunters also consume some animals in forest camps and these may have been overlooked in surveys that have focused on bushmeat extracted from the forest. A number of studies have used indirect methods, such as hunter diaries, to quantify this additional offtake but results can be difficult to verify. We examined discarded animal remains at 13 semi-permanent hunting camps in the Ebo Forest, Cameroon, over 272 days. Twenty-one species were identified from 49 carcasses, of which birds constituted 55%, mammals 43% and other taxa 2%. The mammals identified were typical of those recorded in previous bushmeat studies but we recorded several species of birds rarely recorded elsewhere. Offtake of bird species increased with mean body mass. We extrapolated our results to the 34 known hunting camps in the Ebo Forest and estimated that a minimum of 97 birds are hunted annually in a catchment area of c. 479 km2. We conclude that some bird species may be hunted more frequently than previous research suggests and this has important conservation implications for larger-bodied species such as raptors and hornbills. Copyright © Fauna & Flora International 2014.
Ogada D.L.,Peregrine Fund |
Kibuthu P.M.,Raptor Working Group of Nature Kenya
Journal of Raptor Research | Year: 2012
African owls are relatively little known and studying them is difficult due to negative effects of cultural beliefs and consumptive uses of owls. Over a 5-yr period from 2004-08, we studied the breeding ecology of 13 pairs of Mackinder's Eagle-Owls (Bubo capensis mackinderi), a subspecies of the Cape Eagle-Owl (B. capensis), inhabiting a densely populated farming community in central Kenya. Mean owl density was 0.24 pairs/km2 and mean nearest neighbor distance averaged over all years was 1.9 km. Most nests (65%) were located in a cave or on a covered ledge, and mean nest site elevation was 2191 m asl. Nests were located close to farms and grasslands, but far from forests. Initiation of breeding was associated with rainfall patterns. Mean breeding success was 51% and reproductive rate was 1.36 young fledged per successful pair. Increased reproductive success was associated with breeding after the long rainy season, nesting on cliffs or covered ledges, and nesting close to grasslands and human habitation. The majority (59%) of recorded owl deaths were caused by human activities and poisoning was the most common source of mortality. Compared to other populations of Bubo spp., the birds in our study area had a high breeding density but a low reproductive output. Human-induced mortality may be negatively affecting productivity in this population. © 2012 The Raptor Research Foundation, Inc.
Virani M.Z.,Peregrine Fund |
Monadjem A.,University of Swaziland |
Thomsett S.,Ornithology Section |
Kendall C.,Ornithology Section |
Kendall C.,Princeton University
Bird Conservation International | Year: 2012
Vulture populations have been declining globally and regionally within Africa. Rüppell's Vulture Gyps rueppellii is currently listed as Near Threatened' and numbers of the species, along with African White-backed Vultures G. africanus, have declined by 52% in and around the Mara-Serengeti ecosystem. A large breeding colony of Rüppell's Vulture at Kwenia, southern Kenya, was monitored between 2002 and 2009. Around 150-200 adults were present on each visit, with up to 64 simultaneously active nests. The date of egg-laying differed considerably between years, with two discrete breeding attempts in some years. Nests were not positioned randomly across the cliff face and the number of active nests was related to rainfall in the previous year. The large ungulate migration of the Mara-Serengeti provides a vital foraging ground for the species. Conservation implications of the loss of vultures are discussed. © Copyright Â(c) BirdLife International 2012.
Ibarra J.T.,University of British Columbia |
Ibarra J.T.,Environment Canada |
Martin K.,University of British Columbia |
Altamirano T.A.,University of Chile |
And 2 more authors.
Journal of Wildlife Management | Year: 2014
Owls occur at relatively low densities and are cryptic; thus, monitoring programs that estimate variation in detectability will improve inferences about their presence. We investigated temporal and abiotic sources of variation associated with detection probabilities of rufous-legged owls (Strix rufipes), a threatened forest specialist, and austral pygmy-owls (Glaucidium nana), a habitat generalist, in temperate forests of southern Chile. We also assessed whether detection of 1 species was related to the detection of the other species. During 2011-2013, we conducted 1,145 broadcast surveys at 101 sampling units established along an elevational gradient located inside and outside protected areas. We used a multi-season occupancy framework for modeling occupancy (ψ) and detection (p), and ranked models using an information-theoretic approach. We recorded 292 detections of rufous-legged owls and 334 detections of austral pygmy-owls. Occupancy was positively associated with elevation for rufous-legged owls but constant (i.e., did not vary with covariates) for pygmy-owls. Detectability for both owls increased with greater moonlight and decreased with environmental noise, and for pygmy-owls greater wind speed decreased detectability. The probability of detecting pygmy-owls increased nonlinearly with number of days since the start of surveys and peaked during the latest surveys of the season (23 Jan-7 Feb). Detection of both species was positively correlated with the detection of the other species. We suggest both species should be surveyed simultaneously for a minimum of 3-4 times during a season, survey stations should be located away from noise, and observers should record the moon phase and weather conditions for each survey. © 2014 The Wildlife Society. © The Wildlife Society, 2014.
Smallie J.,Wildlife and Energy Programme |
Virani M.Z.,Peregrine Fund
Scopus | Year: 2010
A rapid risk assessment of the interactions between Kenya's large birds and electrical infrastructure was conducted around Magadi and Naivasha in Kenya in January 2009. Six out of the seven <132 kV distribution pole designs assessed pose an electrocution risk to medium and large-sized birds. Several sites of high bird collision risk were identified. Several of the observed >132 kV transmission tower structures were vulnerable to electrical faulting caused by birds. Of approximately 24 relevant bird species that are of conservation concern in Kenya, 17 (71 %) face a high risk of direct interactions with electrical infrastructure. Priority species for attention include the Egyptian Vulture Neophron percnopterus, White-headed Vulture Trigonoceps occipitalis, Lappet-faced Vulture Torgos tracheliotos, Grey-crowned Crane Balearica regulorum, Lesser Flamingo Phoeniconaias minor, White-backed Vulture Gyps africanus, Rüppell's Vulture Gyps rueppellii, Martial Eagle Polemaetus bellicosus, White Stork Ciconia ciconia, Secretarybird Sagittarius serpentarius, and various sit-and-wait raptors. These preliminary findings have national relevance given plans (already underway) for a rapid expansion of electrical infrastructure in Kenya; recommendations are made for a national response to this matter.
Bingham A.M.,University of South Florida |
Burkett-Cadena N.D.,University of Florida |
Hassan H.K.,University of South Florida |
McClure C.J.W.,Peregrine Fund |
Unnasch T.R.,University of South Florida
American Journal of Tropical Medicine and Hygiene | Year: 2014
Studies investigating winter transmission of Eastern equine encephalitis virus (EEEV) were conducted in Hillsborough County, Florida. The virus was detected in Culiseta melanura and Anopheles quadrimaculatus in February 2012 and 2013, respectively. During the winter months, herons were the most important avian hosts for all mosquito species encountered. In collections carried out in the summer of 2011, blood meals taken from herons were still common, but less frequently encountered than in winter, with an increased frequency of mammalian- and reptile-derived meals observed in the summer. Four wading bird species (Black-crowned Night Heron [Nycticorax nycticorax], Yellow-crowned Night Heron [Nyctanassa violacea], Anhinga [Anhinga anhinga], and Great Blue Heron [Ardea herodias]) were most frequently fed upon by Cs. melanura and Culex erraticus, suggesting that these species may participate in maintaining EEEV during the winter in Florida. Copyright © 2014 by The American Society of Tropical Medicine and Hygiene.
Otieno P.O.,Maseno University |
Lalah J.O.,Maseno University |
Virani M.,Peregrine Fund |
Jondiko I.O.,Maseno University |
Schramm K.-W.,Helmholtz Center for Environmental Research
Bulletin of Environmental Contamination and Toxicology | Year: 2010
Forensic analysis of carbofuran residues in weathered tissue samples for evidence of Furadan exposure in vultures (Gps africanus) by HPLC gave concentration (mg/Kg dry tissue weight) ranges of bdl - 0.07(carbofuran), bdl - 0.499 (3-ketocarbofuran) and 0.013-0.147 (3-hydroxycarbofuran) in beaks, bdl-0.65 (carbofuran), 0.024-0.190 (3-ketocarbofuran) and 0.017-0.098 (3-hydroxycarbofuran) in feet, 0.179-0.219 (3-ketocarbofuran) and 0.081-0.093 (3-hydroxycarbofuran) in crop content, 0.078-0.082 (3-ketocarbofuran) and 0.091-0.101 (3-hydroxycarbofuran) in muscle of a laced carcass and 0.006-0.014 (carbofuran), 0(3-ketocarbofuran) and 0.017-0.098 (3-hydroxycarbofuran) in feet, 0.179-0.219 (3-ketocarbofuran) and 0.081-0.093 (3-hydroxycarbofuran) in crop content, 0.078-0.082 (3-ketocarbofuran) and 0.091-0.101 (3-hydroxycarbofuran) in muscle of a laced carcass and 0.006-0.014 (carbofuran), 0), 0.590-1.010 (3-ketocarbofuran) and 0.095-0.135 (3-hydroxycarbofuran) in soil sampled from a poisoning site. These compounds were confirmed by GC-MS. The results showed that HPLC combined with GC-MS is suitable for forensic analysis of carbofuran residues in bird tissue samples and that forensic investigation should include its two toxic metabolites, 3-hydroxycarbofuran and 3-ketocarbofuran. © Springer Science+Business Media, LLC 2010.
Chaudhry M.J.I.,WWF Pakistan |
Chaudhry M.J.I.,Quaid-i-Azam University |
Ogada D.L.,Quaid-i-Azam University |
Malik R.N.,Peregrine Fund |
And 2 more authors.
Bird Conservation International | Year: 2012
The cliff-nesting Long-billed Vulture Gyps indicus is one of four critically endangered Asian Vultures. In India, this species has declined catastrophically, but in Pakistan only small population declines have been recorded. Mortality of this species has been linked to poisoning by veterinary diclofenac, which was banned throughout south Asia in 2006. Between 2003 and 2012 we measured abundance of adult, sub-adult, juvenile, and dead vultures, and nest occupancy and productivity at the largest known Long-billed Vulture colony in Pakistan. We compared population parameters from before (2003-2006) and after (2007-2012) the ban on veterinary diclofenac. Our data and models indicate that vulture abundance, nest occupancy, and nest productivity declined 61%, 73%, and 95%, respectively, in the three years before the diclofenac ban, and then increased 1-2 years after the ban by 55%, 52%, and 95%. Furthermore, we observed 87% of total vulture mortalities prior to the diclofenac ban. Our results demonstrate for the first time since the onset of the Asian vulture crisis that the ban on veterinary diclofenac is an effective management tool for reversing Long-billed Vulture population declines. © 2011 BirdLife International.
De J. Vargas Gonzalez J.,Peregrine Fund |
Vargas F.H.,Peregrine Fund
Journal of Raptor Research | Year: 2011
Between October 2000 and December 2006, we located 30 nests of 25 breeding pairs of Harpy Eagle (Harpia harpyja) in the province of Darien, Panama. Most nests were in primary tropical rain forest at a mean altitude of 132 m (range = 50-305 m). Applying the Polygon and the Maximum Packed Nest Density (MPN) methods, we estimated nest densities of 4 and 6 nests/100 km 2, with each breeding pair occupying 24 and 16 km 2 of forest, respectively. This nesting density is the highest reported for the species throughout its breeding range. Although most nests (n = 25) were in primary forest, the average distance from small parcels (<2 ha) of agricultural fields was 2.5 km. By extrapolating the nesting density results from the selected study area in Darien to the entire area of Panama with suitable forest cover at altitudes below 350 m, we estimated that the Harpy Eagle population size could range between 806 and 1208 pairs. Greater conservation effort should be placed on potentially suitable Harpy Eagle habitat. We also suggest that educational outreach measures should be an important part of conservation efforts throughout Panama. © 2011 The Raptor Research Foundation, Inc.
Hunt W.G.,Peregrine Fund
Journal of Raptor Research | Year: 2012
The high incidence of lead exposure being reported in avian scavengers is not surprising, considering the frequency with which lead ammunition residues occur in the remains of gun-killed animals. Population impacts likely are underestimated because of latency of effect, low probability of carcass discovery, and the difficulty of detecting the health manifestations of sublethal lead burdens. There are good reasons to expect that sublethal lead is harmful, especially in view of the considerable body of human health literature providing evidence of multiple adverse effects associated with very small amounts of lead, together with the implication that lead physiology is broadly similar among vertebrates. A detailed experimental study of growth and behavior involving dosing and controls in developing Herring Gulls (Larus argentatus), and reports of morphological and physiological responses in other species, offer insight into the implications of sublethal lead exposure on wild populations. Further studies of lead's sublethal effects on avian scavengers are therefore warranted and may benefit from advancements in bone-lead measurement and feather analysis, particularly where lead burdens can be benignly assessed among live birds in the field. © 2012 The Raptor Research Foundation, Inc.