Spelling suggestions: "subject:"cervus bicolor"" "subject:"cervus coelicolor""
1 |
The impacts of sambar (Cervus unicolor) in the Yarra Ranges National ParkBennett, Ami January 2008 (has links)
Internationally, the impacts of deer have been widely studied, but little work has been conducted in Australia. Sambar (Cervus unicolor Kerr) were introduced to Victoria in the 1860s from Sri Lanka, and have become established throughout eastern Victoria. This study is located in the Yarra Ranges National Park, 100 km north east of Melbourne. The park primarily consists of three protected water catchments that contribute approximately 50% to Melbourne’s water supply. This study was conducted from 2005 to 2008 in the Upper Yarra and O’Shannassy catchments. Large open areas covered by forbs and grasses periodically form adjacent to the water body of the Upper Yarra reservoir. Sambar are frequently observed at the largest of these areas known as The Flats. The impacts of sambar at this locality and in other areas of the catchments were investigated. / Faecal pellet transect surveys determined that sambar occupancy and density was greatest on open flats, lower on forest edges adjacent to open flats (< 250 m), and significantly less in other forested areas of the catchment. Observations of The Flats revealed that hinds were the main demographic class represented, with a mean group size of 39 individuals, and up to 70. This is the largest aggregation of sambar ever reported anywhere in the world, and equates to an approximate density of 200 km-2 at this site. / Selective exclosures effectively differentiated the offtake of forage by sambar from that of native herbivores. Sambar contributed to the majority of offtake at The Flats, and were able to obtain a substantial proportion of their daily food requirements from this source. A culling program began in the Yarra Ranges National Park in May 2008, to reduce the large numbers of deer in the park. The cull reduced the time spent by sambar on The Flats, as determined by faecal pellet accumulation plots, and significantly reduced faecal pellet load and forage offtake. / Sambar significantly decreased relative foliage cover of shiny nematolepis (Nematolepis wilsonii), a threatened understorey tree, through their antler rubbing activities. Thrashing of shiny nematolepis saplings also significantly decreased relative foliage cover, with sambar selecting saplings with a larger stem diameter from those available. Rubbed trees and thrashed saplings experienced damage to, on average, over half the stem circumference. / Selective exclosures allowed differentiation of sambar and native herbivore browsing on forest understoreys. Browsing by sambar in high densities prevented the vertical growth of plants in the understorey, with branches above 60 cm in height most commonly browsed. Plants in the understorey were more frequently and intensely browsed in areas of high sambar density. Three species were browsed to a significantly greater extent by sambar than native herbivores: hazel pomaderris (Pomaderris aspera), prickly tea-tree (Leptospermum continentale) and prickly bush-pea, (Pultenaea juniperina). Sambar significantly reduced plant biomass in forest understoreys where they occur in high densities. / The presence of large, open herb-rich areas drives the high local densities and associated impacts of sambar within the Yarra Ranges National Park. Future areas of research are identified and management recommendations are outlined. A sustained culling program appears to be the only practical option to reduce sambar density and impacts at this locality.
|
2 |
Doen?a do armazenamento lisossomal causada pela ingest?o espont?nea de Sida carpinifolia em cervos Sambar (Cervus unicolor) cativos no Rio de Janeiro. / Lysosomal storage disease caused by spontaneous ingestion of Sida carpinifolia in captive-Sambar deer (Cervus unicolor) in Rio de Janeiro State, Brazil.Anjos, Bruno Leite dos 17 August 2010 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2018-04-11T13:17:41Z
No. of bitstreams: 1
2010 - Bruno Leite dos Anjos.pdf: 12893665 bytes, checksum: 99b4dd0f8ecdebb1f227aa0522ac061f (MD5) / Made available in DSpace on 2018-04-11T13:17:42Z (GMT). No. of bitstreams: 1
2010 - Bruno Leite dos Anjos.pdf: 12893665 bytes, checksum: 99b4dd0f8ecdebb1f227aa0522ac061f (MD5)
Previous issue date: 2010-08-17 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico, CNPq, Brasil. / Cases of diseases induced by toxic plants in domestic herbivores are well reported throughout
the world and have been studied also in Brazil. However, not much is known about the
epidemiological and pathological aspectos of these conditions in free-living wildlife or bred in
captivity. The risk for developing the toxicoses in captivity has been increasing, since natural
habitats are destroyed by human action, and more centers of wildlife conservation and
zoological comes are created. This study describes the epidemiological, biological and
clinicopathological, lectin-histochemical and ultrastructural aspects of an outbreak of
lysosomal storage disease of oligosaccharides induced by ingestion of Sida carpinifolia in
young Sambar deer (Cervus unicolor) in the Rio-Zoo Foundation in the State of Rio de
Janeiro, Brazil. Nine deer showed neurological signs characterized by motor and
proprioceptive deficits. Then neurological signs were mainly depression, incoordination,
dysmetria, ataxia, broad-based members, muscle tremors, loss of tongue tone, frequent falls
and death. Grossly hematomas were observed secondary to trauma caused by dominant males
of the flock, and whitish striations, especially in the renal cortex. Histologic changes included
marked swelling/cytoplasmic vacuolization especially in neurons, progressing to neuronal
lysis and axonal spheroids, in exocrine pancreas, thyroid follicular cells and renal tubular
epithelial cells. In the lectin-histochemical examination the vacuoles were formed by the
accumulation of oligosaccharides specially marked by the lectins WGA, WGA and Con-A.
Ultrastructurally, the swelling/vacuolation corresponded to intense cytoplasmic distention of
lysosomes, formation of residual bodies or dense granular fragments of membranes and
mielinoides bodies. The study has shown the susceptibility of Cervus unicolor to swainsonine
by ingestion of S. carpinifolia. Possibly poisoning the animals in this study was conducted by
food restriction by the hierarchy among males in the group. It might also determine the
marked similarity between clinical and pathological aspects in Sambar deer with the one
presented by other herbivores. / Casos de doen?as induzidas por plantas t?xicas em herb?voros dom?sticos s?o bastante
relatados por todo o mundo e v?m sendo estudados tamb?m no Brasil. Pouco se sabe,
contudo, sobre os aspectos epidemiol?gicos e patol?gicos dessas condi??es em animais
selvagens de vida livre ou criados em cativeiro. Os riscos de desenvolvimento dessas
toxicoses em cativeiros v?m aumentando, conforme os habitats naturais s?o destru?dos pela
a??o humana, e mais centros de conserva??o de vida silvestre e zool?gicos s?o criados. Nesse
estudo s?o descritos os aspectos epidemiol?gicos, biol?gicos e clinicopatol?gicos, lectinohistoqu?micos
e ultraestruturais de um surto de doen?a do armazenamento lisossomal de
oligossacar?deos induzido pela ingest?o de Sida carpinifolia em cervos Sambar jovens
(Cervus unicolor) no zool?gico da Funda??o Rio-Zoo no Estado do Rio de Janeiro. Nove
cervos apresentaram sinais cl?nicos neurol?gicos caracterizados por d?ficits proprioceptivo e
motor. Os sinais neurol?gicos inclu?ram principalmente depress?o, incoordena??o, dismetria,
ataxia, membros em base ampla, tremores musculares, perda do t?nus lingual, quedas
frequentes e morte. Macroscopicamente foram observados hematomas, secund?rios a traumas
provocados por machos dominantes do rebanho, e estria??es esbranqui?adas, principalmente
no c?rtex renal. As les?es histol?gicas inclu?am acentuada tumefa??o/vacuoliza??o
citoplasm?tica especialmente em neur?nios, p?ncreas ex?crino, c?lulas foliculares da tireoides
e do epit?lio renal, necrose neuronal com evolu??o para lise e esferoides axonais. Pelo exame
lectino-histoqu?mico os vac?olos eram formados por ac?mulo de oligossacar?deos marcado
especialmente pelas lectinas S-WGA, WGA e Con-A. Ultraestruturalmente, a
tumefa??o/vacuoliza??o citoplasm?tica correspondeu ? intensa distens?o de lisossomos,
forma??o de corpos residuais densos ou granulares, fragmentos de membranas e corpos
mielinoides. O estudo demonstrou a suscetibilidade de Cervus unicolor ? swainsonina contida
na S. carpinifolia. Possivelmente, a intoxica??o nos animais deste estudo ocorreu pela
restri??o alimentar sofrida pelos animais mais jovens, decorrente da hierarquia entre machos
no grupo. P?de-se determinar ainda a marcada similaridade do quadro cl?nico e patol?gico
entre os cervos descritos nesse trabalho e outros herb?voros dom?sticos.
|
Page generated in 0.0549 seconds