Full Text Available Tree kangaroos (Macropodidae, Dendrolagus are some of Australasia's least known mammals. However, there is sufficient evidence of population decline and local extinctions that all New Guinea tree kangaroos are considered threatened. Understanding spatial requirements is important in conservation and management. Expectations from studies of Australian tree kangaroos and other rainforest macropodids suggest that tree kangaroos should have small discrete home ranges with the potential for high population densities, but there are no published estimates of spatial requirements of any New Guinea tree kangaroo species. Home ranges of 15 Huon tree kangaroos, Dendrolagus matschiei, were measured in upper montane forest on the Huon Peninsula, Papua New Guinea. The home range area was an average of 139.6±26.5 ha (100% MCP; n = 15 or 81.8±28.3 ha (90% harmonic mean; n = 15, and did not differ between males and females. Home ranges of D. matschiei were 40-100 times larger than those of Australian tree kangaroos or other rainforest macropods, possibly due to the impact of hunting reducing density, or low productivity of their high altitude habitat. Huon tree kangaroos had cores of activity within their range at 45% (20.9±4.1 ha and 70% (36.6±7.5 ha harmonic mean isopleths, with little overlap (4.8±2.9%; n = 15 pairs between neighbouring females at the 45% isopleth, but, unlike the Australian species, extensive overlap between females (20.8±5.5%; n = 15 pairs at the complete range (90% harmonic mean. Males overlapped each other and females to a greater extent than did pairs of females. From core areas and overlap, the density of female D. matschiei was one per 19.4 ha. Understanding the cause of this low density is crucial in gaining greater understanding of variations in density of tree kangaroos across the landscape. We consider the potential role of habitat fragmentation, productivity and hunting pressure in limiting tree kangaroo
O'Neill, R J; Eldridge, M D; Toder, R; Ferguson-Smith, M A; O'Brien, P C; Graves, J A
Marsupial mammals show extraordinary karyotype stability, with 2n = 14 considered ancestral. However, macropodid marsupials (kangaroos and wallabies) exhibit a considerable variety of karyotypes, with a hypothesised ancestral karyotype of 2n = 22. Speciation and karyotypic diversity in rock wallabies (Petrogale) is exceptional. We used cross species chromosome painting to examine the chromosome evolution between the tammar wallaby (2n = 16) and three 2n = 22 rock wallaby species groups with the putative ancestral karyotype. Hybridization of chromosome paints prepared from flow sorted chromosomes of the tammar wallaby to Petrogale spp., showed that this ancestral karyotype is largely conserved among 2n = 22 rock wallaby species, and confirmed the identity of ancestral chromosomes which fused to produce the bi-armed chromosomes of the 2n = 16 tammar wallaby. These results illustrate the fission-fusion process of karyotype evolution characteristic of the kangaroo group.
Webster, Koa N; Dawson, Terence J
We examined the structure-function relationships that underlie the aerobic capacities of marsupial mammals that hop. Marsupials have relatively low basal metabolic rates (BMR) and historically were seen as 'low energy' mammals. However, the red kangaroo, Macropus rufus (family Macropodidae), has aerobic capacities equivalent to athletic placentals. It has an extreme aerobic scope (fAS) and its large locomotor muscles feature high mitochondrial and capillary volumes. M. rufus belongs to a modern group of kangaroos and its high fAS is not general for marsupials. However, other hopping marsupials may have elevated aerobic capacities. Bettongia penicillata, a rat-kangaroo (family Potoroidae), is a small (1 kg), active hopper whose fAS is somewhat elevated. We examined the oxygen delivery system in its muscles to ascertain links with hopping. An elevated fAS of 23 provided a relatively high maximal aerobic oxygen consumption ( ) in B. penicillata; associated with this is a skeletal muscle mass of 44% of body mass. Ten muscles were sampled to estimate the total mitochondrial and capillary volume of the locomotor muscles. Values in B. penicillata were similar to those in M. rufus and in athletic placentals. This small hopper had high muscle mitochondrial volume densities (7.1-11.9%) and both a large total capillary volume (6 ml kg(-1) body mass) and total capillary erythrocyte volume (3.2 ml kg(-1)). Apparently, a considerable aerobic capacity is required to achieve the benefits of the extended stride in fast hopping. Of note, the ratio of to total muscle mitochondrial volume in B. penicillata was 4.9 ml O(2) min(-1) ml(-1). Similar values occur in M. rufus and also placental mammals generally, not only athletic species. If such relationships occur in other marsupials, a fundamental structure-function relationship for oxygen delivery to muscles likely originated with or before the earliest mammals.
Sandra Helena Ramiro Corrêa
Full Text Available A Leptospirose é uma doença bacteriana de caráter zoonótico que afeta os animais domésticos, silvestres e o homem. Levantamentos sorológicos têm demonstrado o envolvimento de diferentes espécies sinantrópicas e silvestres na epidemiologia da doença. Com o objetivo de conhecer melhor a epidemiologia da Leptospirose dentro da Fundação Parque Zoológico de São Paulo, foi realizado um estudo sorológico nos animais silvestres mantidos em cativeiro, no período de 1996 a 1999. Foram colhidas amostras de sangue de 302 animais atendidos na rotina da Divisão de Veterinária, das quais 59 apresentaram resultado positivo (19.5% para a prova de Soroaglutinação Microscópica. Os sorovares mais prováveis para o conjunto total de resultados foram : copenhageni (15/59=25.4%, pomona (13/59=22% e castellonis (10/59=16.9%. Entre os animais silvestres examinados os sorovares mais prováveis foram : Família Callithrichidae : castellonis (3/3=100%, Família cebidae : copenhageni : (13/21=65%, grippotyphosa (2/21=9.5% e castellonis (1/21=44.7%. Família felidae : pomona (12/17=70.5%, icterohaemorrhagiae (2/17=11.7% e grippotyphosa (1/17=5.8%, Família canidae : castellonis (2/4=50%, cynopteri (1/4=25% e mini (1/4=25%, Família cervidae : mini (1/1=100%, Família bovidae : copenhageni (2/3=66.6%, pomona (1/3=33.3%, Família dasyproctidae : castellonis (2/3=66.6%, Família macropodidae: sentot (1/1=100%, família giraffidae : castellonis (1/1=100%. Animais de vida livre como ratos (Rattus norvegicus e gambás (Didelphis marsupialis também foram submetidos a prova de soroaglutinação necroscópica e cultura bacteriológica. Foram encontrados testes positivos para o sorovar icterohaemorrhagiae em 42,8% dos ratos e 40% dos gambás estudados. As freqüências de positivos quando analisadas do ponto de vista da localização espacial dos recintos destes animais, permitiram a verificação da existência de áreas críticas para exposição à leptospira