Andover, United Kingdom
Andover, United Kingdom

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Murn C.,Hawk Conservancy Trust | Murn C.,University of Reading | Combrink L.,Endangered Wildlife Trust | Ronaldson G.S.,Endangered Wildlife Trust | And 2 more authors.
Ostrich | Year: 2013

Vultures are globally threatened, yet reliable population data on these birds are few, thus measuring their response to change is difficult. Kruger National Park (KNP) in South Africa is an important stronghold for many avian species, particularly vultures. In this study we generate population estimates for three vulture species in KNP using two plotless density estimators (PDE): a distance estimator based on nearest-neighbour distance and T-square sampling. We flew aerial censuses over large (c. 3 500 km2) sample areas in two ecogeographically separate parts of KNP and counted vulture nests visible within predetermined transects. In total 416 White-backed Vulture Gyps africanus, 22 Lappet-faced Vulture Torgos tracheliotos and 24 White-headed Vulture Trigonoceps occipitalis nests were recorded. The nearest-neighbour distance PDE performed poorly, and we used a T-square PDE calibrated with aerial survey counts to extrapolate across KNP and estimate breeding population sizes. There are an estimated 904 (95% CI±162) pairs of African White-backed Vultures, 78 (95% CI±18) pairs of Lappet-faced Vultures and 60 (95% CI±13) pairs of White-headed Vultures in KNP. These results provide a basis for investigating how large vultures respond to ecosystem change and understanding their resilience within a broader environmental change scenario. © 2013 Copyright NISC (Pty) Ltd.


Cox D.T.C.,University of St. Andrews | Cox D.T.C.,Ap Leventis Ornithological Research Institute | Brandt M.J.,BioConsult SH | Mcgregor R.,Scottish Natural Heritage | And 5 more authors.
Ibis | Year: 2011

Birds in the northern hemisphere usually increase mass reserves in response to seasonal low temperatures and shorter day length that increase foraging unpredictability and so starvation risk. In the lowland tropics, relatively low temperatures and short day lengths are absent and so the risk of starvation may be reduced, leading to much smaller seasonal effects on mass. Nevertheless, other factors such as high temperatures and water and food availability may vary greatly between tropical wet and dry seasons, leading to variable starvation risk and seasonal mass effects. Using data collected from 47 species of birds caught over a 10-year period in a tropical savannah region in West Africa we tested for seasonal variation in mass in response to a predictable, strongly seasonal tropical climate. Many species (91%) showed seasonal variation in mass, and this was often in a clear annual pattern that was constant across the years. Many species (89%) varied their mass in response to seasonally predictable rainfall. Annual variation in mass was also important (45% of species). Relatively few species (13%) had a seasonal pattern of mass variation that varied between years. Feeding guild or migratory status was not found to affect seasonal or annual mass variation. Seasonal mass change was on average 8.1% across the 21 species with a very large sample size and was comparable with both northern and southern temperate species. Our study showed that biologically significant consistent seasonal mass variation is common in tropical savannah bird species, and this is most likely in response to changing resource availability brought about by seasonal rainfall and the interrupted foraging response due to the constraints of breeding. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union.


Martin G.R.,University of Birmingham | Portugal S.J.,Lane College | Murn C.P.,Hawk Conservancy Trust
Ibis | Year: 2012

The visual fields of vultures contain a small binocular region and large blind areas above, below and behind the head. Head positions typically adopted by foraging vultures suggest that these visual fields provide comprehensive visual coverage of the ground below, prohibit the eyes from imaging the sun and provide extensive visual coverage laterally. However, vultures will often be blind in the direction of travel. We conclude that by erecting structures such as wind turbines, which extend into open airspace, humans have provided a perceptual challenge that the vision of foraging vultures cannot overcome. © 2012 The Authors Ibis. © 2012 British Ornithologists' Union.


Chi J.F.,Anglia | Lawson B.,UK Institute of Zoology | Durrant C.,UK Institute of Zoology | Beckmann K.,UK Institute of Zoology | And 6 more authors.
Parasitology | Year: 2013

Avian trichomonosis, caused by the flagellated protozoan Trichomonas gallinae, is a recently emerged infectious disease of British passerines. The aetiological agent, a clonal epidemic strain of the parasite, has caused unprecedented finch mortality and population-level declines in Britain and has since spread to continental Europe. To better understand the potential origin of this epidemic and to further investigate its host range, T. gallinae DNA extracts were collected from parasite culture and tissue samples from a range of avian species in Britain. Sequence typing at the ITS1/5.8S rRNA/ITS2 region resolved three distinct ITS region types circulating in free-ranging British birds. Subtyping by sequence analyses at the Fe-hydrogenase gene demonstrated further strain variation within these ITS region types. The UK finch epidemic strain was preponderant amongst columbids sampled, however, wide strain diversity was encountered in isolates from a relatively small number of pigeons, suggesting further strains present in columbid populations across the UK are yet to be identified. Fe-hydrogenase gene sequence data in isolates from birds of prey with disease were predominantly identical to the UK finch epidemic strain, demonstrating its presence as a virulent strain in UK birds of prey since at least 2009.


Griffiths R.,West Hatch Wildlife Center | Murn C.,Hawk Conservancy Trust | Clubb R.,RSPCA
Avian Biology Research | Year: 2010

We investigated the survival of 57 rehabilitated juvenile Tawny Owls (Strix aluco) that were 'hard released' (without the provision of a release aviary or support food) by means of radio tracking. The birds were released in the month of August in three consecutive years: 2005, 2006 and 2007, in the counties of Somerset and Hampshire, United Kingdom. Tracking of the owls was successfully carried out for between three and 160 days. Mortality was recorded for 16 birds (28%). The transmitter was shed by 24 (42%) owls, the signal was lost for 12 (21%) and tracking was ceased for five (9%) owls. Survival of the owls was compared with results from previous studies on wild Tawny Owls and also rehabilitated 'soft released' Tawny Owls (released with provision of food and shelter after release) and found to be similar. This study suggests that employing costly and time-consuming soft release techniques may be unnecessary for juvenile Tawny Owls as their survival is not significantly reduced using hard-release methods. Measuring post-release success of rehabilitated birds of prey is discussed in relation to benchmarks used in previous studies.


PubMed | Anglia, UK Institute of Zoology and Hawk Conservancy Trust
Type: Journal Article | Journal: Parasitology | Year: 2014

Avian trichomonosis, caused by the flagellated protozoan Trichomonas gallinae, is a recently emerged infectious disease of British passerines. The aetiological agent, a clonal epidemic strain of the parasite, has caused unprecedented finch mortality and population-level declines in Britain and has since spread to continental Europe. To better understand the potential origin of this epidemic and to further investigate its host range, T. gallinae DNA extracts were collected from parasite culture and tissue samples from a range of avian species in Britain. Sequence typing at the ITS1/5.8S rRNA/ITS2 region resolved three distinct ITS region types circulating in free-ranging British birds. Subtyping by sequence analyses at the Fe-hydrogenase gene demonstrated further strain variation within these ITS region types. The UK finch epidemic strain was preponderant amongst columbids sampled, however, wide strain diversity was encountered in isolates from a relatively small number of pigeons, suggesting further strains present in columbid populations across the UK are yet to be identified. Fe-hydrogenase gene sequence data in isolates from birds of prey with disease were predominantly identical to the UK finch epidemic strain, demonstrating its presence as a virulent strain in UK birds of prey since at least 2009.


A team of scientists from Royal Holloway, University of London, the Royal Veterinary College and the Hawk Conservancy Trust have discovered Secretary Birds can kick with 195 Newtons, which is equivalent to five times their own body weight, when they attack and kill their prey. And the contact time between the bird's feet and the snake is delivered extremely quickly - on average just 15 milliseconds. The study, published today (25 January) in the journal Current Biology, focuses on a captive male Secretary Bird called Madeleine, held at the Hawk Conservancy Trust, Hampshire. Madeleine was trained to attack a rubber snake to demonstrate the hunting techniques of this type of bird. The scientists measured Madeleine's kicks by putting a force plate (hidden under artificial grass) in the bird's enclosure and pulling the rubber snake across the force plate. As Secretary Birds hunt venomous snakes, a missed strike could have deadly consequences so the birds are capable of delivering fast, forceful and accurate foot strikes that are sufficient to stun and kill prey. Dr Steve Portugal from the School of Biological Sciences at Royal Holloway, University of London, said: "The exceptionally rapid strike contact duration is 1/10th of the time it takes to blink an eye – which takes around 150 ms. "Such rapid time, coupled with the exceptionally long legs, means the birds can't be using proprioreception – the sixth sense we use to sense our position and movement. Therefore, they are using visual targeting and feed-forward motor control – (pre-planned movements) - during strike events. This means the birds can only correct for a missed strike in the next kick – once they've started a kick, they can't adapt it, and they have to wait for the next strike." Dr Monica Daley, a Senior Lecturer at the Royal Veterinary College, explains: "There are interesting potential technological applications in 'biologically inspired' control of exceptionally fast movement in robots and prosthetics. A comparable task might be playing baseball with a prosthetic arm, which requires very fast, forceful and accurate arm movements for pitching and batting." Dr Daley, adds: "Despite their very unusual appearance with exceptionally long legs, the secretary bird's striding gait is remarkably similar to of ground birds such as pheasants, turkeys and ostriches. This suggest that specialisation for their remarkable kick-hunting technique has not unduly compromised their locomotor abilities." Explore further: Study of birds' sense of smell reveals important clues for behavior and adaptation More information: Steven J. Portugal et al. The fast and forceful kicking strike of the secretary bird, Current Biology (2016). DOI: 10.1016/j.cub.2015.12.004

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