Macropus Giganteus Research Articles

A set of highly polymorphic microsatellite markers developed for the eastern grey kangaroo (Macropus giganteus)

AbstractThe eastern grey kangaroo (Macropus giganteus) has increased in numbers leading to over‐abundant populations in areas of eastern Australia. We have developed nine highly polymorphic microsatellite loci to investigate their population structure and mating systems to manage this species more effectively. These loci show high levels of allelic diversity with the numbers of alleles ranging from 8 to 19 and with observed heterozygosities of 0.750–0.958. Null alleles or allelic dropouts were not detected when comparing animals of known pedigree.

Marsupial, Insectivore, and Chiropteran Anesthesia

This article covers the manual restraint and anesthesia of marsupials, insectivores, and chiroptera. Marsupials commonly kept as pets in the U.S. [e.g., eastern gray kangaroos (Macropus giganteus), Bennett's wallabies (Macropus rufogriseus), and sugar gliders (Petaurus breviceps)] are covered in detail. Marsupial species kept in zoological parks [e.g., Tasmanian devils, koalas (Phascolarctos cinereus), and common wombats (Vombatus ursinus)] are covered in less detail. Of the insectivores, only the African hedgehog (Atelerix albiventris) and the European hedgehog (Erinaceus europaeus) are commonly kept as pets and, consequently, the insectivore section concentrates on discussing these two species. The section on chiropteran anesthesia is divided into two broad categories: the megachiropterans (flying foxes and fruit bats) and the microchiropterans (insectivorous bats). Most of the information on the species covered in this article is anecdotal, and this should be kept in mind when using the anesthesia protocols described.

Stomatogenesis in the ciliate genus MacropodiniumDehority, 1996 (Litostomatea: Macropodiniidae)

Stomatogenesis and the cell division cycle was investigated for Macropodinium yalanbense Dehority, 1996 from Macropus giganteus using light and electron microscopy. Macropodinium spp. are endosymbiotic ciliates found only in the stomachs of macropodid marsupials. Stomatogenesis proceeds through 4 stages: initial formation of a transverse division suture; formation of the preoral field and formation of vestibular kineties in an internal pouch; extension of vestibulum posteriorly and external formation of new adoral kineties; and extension of somatic and adoral kineties accompanying dorsal and ventral constriction of the cell. Karyokinesis and formation of the new cytoproct occur immediately prior to cytokinesis. Comparison with other litostome ciliates shows that the formation of new vestibular kineties is most similar to that of the entodiniomorphs, formation of adoral kineties is most similar to that of the haptorians and formation of the somatic kineties to that of the vestibuliferans. The phylogenetic affinities of Macropodinium are thus difficult to infer from the ontogeny of organelle systems. Stomatogenesis of the adoral kineties is either epiapokinetal or a new type of cryptotelokinetal whereas the vestibular kineties are formed by either endoapokinetal or cryptotelokinetal processes. No other ciliate has been observed to utilise 2 types of stomatogenesis in its division cycle.

Predation by red foxes limits recruitment in populations of eastern grey kangaroos

AbstractWe investigated the impact of red fox (Vulpes vulpes Linnaeus 1758) predation on juvenile eastern grey kangaroos (Macropus giganteus Shaw 1790) using a replicated predator removal experiment. In two sites in Namadgi National Park, south‐eastern Australia, a persistent 1080 poisoning campaign over 18 months reduced fox density by more than 85%, and to less than 10% of the fox density in two other sites with no fox baiting. Changes in the mother : young ratios and densities of kangaroo populations were monitored twice monthly along 2‐km transects in each site from July 1993 to February 1995. Compared to nonremoval sites, where foxes were controlled, 25–40% more females retained juveniles over the period when these young became emergent from the pouch. This higher survival of emergent pouch young resulted in a significantly higher proportion of juveniles in kangaroo populations at fox control sites, which resulted in a significantly higher annual growth rate. We conclude that predation upon juveniles is an important limiting factor for kangaroo populations in Namadgi NP.

Predation by red foxes limits recruitment in populations of eastern grey kangaroos

Predation by red foxes limits recruitment in populations of eastern grey kangaroos

Thermoregulation by Kangaroos from Mesic and Arid Habitats: Influence of Temperature on Routes of Heat Loss in Eastern Grey Kangaroos (Macropus giganteus) and Red Kangaroos (Macropus rufus)

We examined thermoregulation in red kangaroos (Macropus rufus) from deserts and in eastern grey kangaroos (Macropus giganteus) from mesic forests/woodlands. Desert kangaroos have complex evaporative heat loss mechanisms, but the relative importance of these mechanisms is unclear. Little is known of the abilities of grey kangaroos. Our detailed study of these kangaroos' thermoregulatory responses at air temperatures (T(a)) from -5 degrees to 45 degrees C showed that, while some differences occur, their abilities are fundamentally similar. Both species show the basic marsupial characteristics of relatively low basal metabolism and body temperature (T(b)). Within the thermoneutral zone, T(b) was 36.3 degrees + or - 0.1 degrees C (X + or - SE) in both species, and except for a small rise at T(a) 45 degrees C, T(b) was stable over a wide range of T(a). Metabolic heat production was 25% higher in red kangaroos at T(a) -5 degrees C. At the highest T(a) (45 degrees C), both species relied on evaporative heat loss (EHL) to maintain T(b); both panting and licking were used. The eastern grey kangaroo utilised panting (76% of EHL) as the principal mode of EHL, and while this was so for red kangaroos, cutaneous evaporative heat loss (CEHL) was significant (40% of EHL). CEHL appeared to be mainly licking, as evidenced from surface temperatures. Both species utilised peripheral vascular adjustments to control heat flow, as indicated by changes in dry conductance (C(dry)). At lower temperatures, C(dry) was minimal, but it increased significantly at T(a) just below T(b) (33 degrees C); in these conditions, the C(dry) of red kangaroos was significantly higher than that of eastern grey kangaroos, indicating a greater reliance on dry heat loss. Under conditions where heat flows into the body from the environment (T(a) 45 degrees C), there was peripheral vasoconstriction to reduce this inflow; C(dry) decreased significantly from the values seen at 33 degrees C in both kangaroos. The results indicated that, while both species have excellent thermoregulatory abilities, the desert red kangaroos may cope better with more extreme temperatures, given that they respond to T(a) 45 degrees C with lower respiratory evaporation than do the eastern grey kangaroos.

Ventilatory accommodation of oxygen demand and respiratory water loss in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus).

We studied ventilation in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus), respectively, within the range of ambient temperatures (T(a)) from -5 degrees to 45 degrees C. At thermoneutral temperatures (Ta=25 degrees C), there were no differences between the species in respiratory frequency, tidal volume, total ventilation, or oxygen extraction. The ventilatory patterns of the kangaroos were markedly different from those predicted from the allometric equation derived for placentals. The kangaroos had low respiratory frequencies and higher tidal volumes, even when adjustment was made for their lower basal metabolism. At Ta>25 degrees C, ventilation was increased in the kangaroos to facilitate respiratory water loss, with percent oxygen extraction being markedly lowered. Ventilation was via the nares; the mouth was closed. Differences in ventilation between the two species occurred at higher temperatures, and at 45 degrees C were associated with differences in respiratory evaporative heat loss, with that of M. giganteus being higher. Panting in kangaroos occurred as a graded increase in respiratory frequency, during which tidal volume was lowered. When panting, the desert red kangaroo had larger tidal volumes and lower respiratory frequencies at equivalent T(a) than the eastern grey kangaroo, which generally inhabits mesic forests. The inference made from this pattern is that the red kangaroo has the potential to increase respiratory evaporative heat loss to a greater level.

Novel isotrichid ciliates endosymbiotic in Australian macropodid marsupials.

Samples of foregut content were collected from 86 macropodid marsupials and examined for the presence of endosymbiotic ciliates. Four host species were examined: Macropus giganteus (eastern grey kangaroo), M. fuliginosus (western grey kangaroo), M. robustus (common wallaroo) and Thylogale billardierii (Tasmanian pademelon). Ciliate morphology was determined by microscopical examination of live and silver-impregnated specimens. Isotrichid ciliates were detected in 51 (59%) of the 86 animals examined. Five new species and one new genus are described. Three of the species belong to the genus Dasytricha Schuberg, 1888; D. dehorityi n. sp. from M. giganteus, D. dogieli n. sp. from M. robustus and D. mundayi n. sp. from T. billardierii. Bitricha n. g. is characterised by the possession of two fields of somatic ciliation, a transverse ventral and a longitudinal dorsal field. B. oblata n. sp. is described from M. giganteus and M. fuliginosus and B. tasmaniensis n. sp. is described from T. billardierii. The occurrence of isotrichid ciliates in both metatherian and eutherian mammals suggests that the family either evolved prior to the divergence of the mammalian lineages or switched hosts from one group to the other following host diversification.

Interspecific variation of zona pellucida glycoconjugates in several species of marsupial.

The zona pellucida glycoconjugate content of several marsupial species was investigated using differential lectin histochemistry. Ovaries from fat-tailed dunnarts, a southern brown bandicoot, grey short-tailed opossums, brushtail possums, ringtail possums, koalas and eastern grey kangaroos were fixed, embedded in paraffin wax, sectioned and stained with ten fluorescein isothiocyanate-conjugated lectins. Sections were also incubated with either neuraminidase or saponified, respectively, before incubation with the lectins to identify saccharide residues masked by sialic acids or O-acetyl groups on sialic acids. The zonae pellucidae surrounding the oocytes of the marsupials demonstrated interspecific variation in glycoconjugate content, with mannose-containing glycoconjugates exhibiting the greatest variation. Some of the zona pellucida glycoconjugates of all species, except those of the opossums, were masked by sialic acid with an increase in fluorescence with lectins from Arachis hypogea (PNA), and Glycine max (SBA), after desialylation. The disaccharide beta-galactose(1-4)N-acetyl-D-glucosamine appeared to be conformationally masked by O-acetyl groups of sialic acids in the zonae pellucidae of all species, with an increase in fluorescence with the lectin from Erythrina cristagalli (ECA), after saponification. Similar intensity and localization of beta-(1-4)-N-acetyl-D-glucosamine, as shown by staining of the lectin from Triticum vulgaris (WGA), to the inner and outer regions of the zona pellucida, were found to those reported in eutherian species. WGA fluorescence became uniform throughout the zonae pellucidae after saponification, indicating differential O-acetylation of sialic acids on the internal compartment of the zonae pellucidae.

Interspecific variation of zona pellucida glycoconjugates in several species of marsupial

The zona pellucida glycoconjugate content of several marsupial species was investigated using differential lectin histochemistry. Ovaries from fat-tailed dunnarts, a southern brown bandicoot, grey short-tailed opossums, brushtail possums, ringtail possums, koalas and eastern grey kangaroos were fixed, embedded in paraffin wax, sectioned and stained with ten fluorescein isothiocyanate-conjugated lectins. Sections were also incubated with either neuraminidase or saponified, respectively, before incubation with the lectins to identify saccharide residues masked by sialic acids or O-acetyl groups on sialic acids. The zonae pellucidae surrounding the oocytes of the marsupials demonstrated interspecific variation in glycoconjugate content, with mannose-containing glycoconjugates exhibiting the greatest variation. Some of the zona pellucida glycoconjugates of all species, except those of the opossums, were masked by sialic acid with an increase in fluorescence with lectins from Arachis hypogea (PNA), and Glycine max (SBA), after desialylation. The disaccharide beta-galactose(1-4)N-acetyl-D-glucosamine appeared to be conformationally masked by O-acetyl groups of sialic acids in the zonae pellucidae of all species, with an increase in fluorescence with the lectin from Erythrina cristagalli (ECA), after saponification. Similar intensity and localization of beta-(1-4)-N-acetyl-D-glucosamine, as shown by staining of the lectin from Triticum vulgaris (WGA), to the inner and outer regions of the zona pellucida, were found to those reported in eutherian species. WGA fluorescence became uniform throughout the zonae pellucidae after saponification, indicating differential O-acetylation of sialic acids on the internal compartment of the zonae pellucidae.

Assessment of the potential for competition between two sympatric herbivores - the northern hairy-nosed wombat, Lasiorhinus krefftii, and the eastern grey kangaroo, Macropus giganteus

The northern hairy-nosed wombat, Lasiorhinus krefftii, is a critically endangered grazing herbivore, restricted to a single population of just 65 individuals in the savanna of central Queensland. Lasiorhinus krefftii shares its habitat with another grazing herbivore of similar body size, the eastern grey kangaroo, Macropus giganteus. This study investigated the potential for M. giganteus to compete with L. krefftii for food. Analysis of faecal residues demonstrated that both herbivores consumed grass almost exclusively, with the exception of small quantities of sedges and dicotyledons. Dietary overlap between M. giganteus and L. krefftii was high, both in the consumption of plant species (90%) and plant parts (99%), suggesting that there is potential for dietary competition. Using the distribution of faecal deposits for both herbivores, analysis of habitat usage by multiple linear regression techniques indicated that M. giganteus exhibits clear associations with some habitat features but proved inconclusive for L. krefftii because of their use of defecation in social marking. However, an examination of the population dynamics of M. giganteus suggested that the densities reported in this study, although highly seasonal, are sufficiently low that competition with L. krefftii for food is currently negligible.

Water metabolism and renal function and structure in eastern grey kangaroos (Macropus giganteus): responses to water deprivation

The eastern grey kangaroo (M. giganteus) is usually found in mesic habitats but in the past 30–40 years it has expanded its range into arid rangelands. A suggested reason for this expansion has been the provision of additional water sites for domestic stock. In this study we examined aspects of kidney function and water metabolism of M. giganteus. This was done during normal hydration and water restriction so that the water-conserving abilities of M. giganteus could be compared with those of the red kangaroo (M. rufus), the habitat of which is arid rangelands and desert. The indices relative medullary thickness (RMT) and medullary to cortical ratio, derived from the morphology of the kidney, are indicators of renal concentrating ability. In M. giganteus both these indices were lower than in M. rufus: the RMT was 5.24 0.15 (mean s.e.) for M. giganteus and 6.00 0.10 for M. rufus. Measured maximal urine concentrations of these species were 2444 59 (M. giganteus) and 3135 165 mosmol kg–1 (M. rufus), with the respective maximum individual concentrations being 2752 and 4054 mosmol kg–1. Kidney function in hydrated and dehydrated M. giganteus was assessed via glomerular filtration rate, urine flow rate and concentration index. As measured by these parameters, M. giganteus had renal water-conserving capacities similar to, or superior to, those of many comparable-sized arid-zone-inhabiting placental mammals, but below those of M. rufus. Water metabolism, as measured by water turnover, showed a similar pattern.

Similarities and differences in activities and agonistic behavior of male Eastern grey kangaroos (Macropus giganteus) in captivity and the wild.

The behavior of free-ranging and captive Eastern grey kangaroos Macropus giganteus, was observed by the same observers, with similar methods and under similar vegetational/climatic conditions in a 4.2-ha enclosure at Neuwied Zoo, Germany and at Grampians National Park, Victoria, Australia. Data were collected from a zoo group of 56 animals and a free-ranging mob of 50 to 60 animals. Males were individually identified and observed: 3 large males, 9 medium males, and 10 small males in the zoo, and 8 large, 9 medium, and approximately 10 small males in the National Park were present. Activities in both situations were very similarly distributed: Feed took up less time in the zoo, resting was almost similar in both situations, alert behavior was significantly different for small and medium males, locomotor activities were similar in large males and females, autogrooming occurred significantly more in the zoo only for females. Frequencies of social interactions were slightly greater for large males and females in the zoo. Agonistic behavior in males was more frequent in the zoo situation, except for ritualized fights. Sequences of agonistic behavior were more predictable in the zoo. No differences in escalation tendencies toward potentially injurious fighting could be found. Zoo Biol 19:529-539, 2000. Copyright 2000 Wiley-Liss, Inc.

Temporal, spatial and individual variation in the diet of red foxes (Vulpes vulpes) in central New South Wales

This study describes temporal, spatial and individual variation in the diet of 255 red foxes (Vulpes vulpes) collected from agricultural land in central New South Wales from July 1994 to November 1996. Rabbits (Oryctolagus cuniculus), sheep (Ovis aries), eastern grey kangaroos (Macropus giganteus) and invertebrates were the most important food items overall. Significant seasonal variations, and sex and age differences between foxes occurred in the consumption of some food types. Some temporal synchrony was also evident, with different individuals often eating similar foods on the same night. This may have been related to moonlight. On full moon nights, foxes ate rabbits and small mammals significantly less often than during other moon phases. The management implications of variation in diet are discussed.

Lamination of the masticatory muscles in the kangaroo according to their innervation.

An analysis of the laminations of the masseteric, zygomaticomandibular and temporalis muscles of the Red Kangaroo (Macropus Rufus) and all of the masticatory muscles of the Eastern Gray Kangaroo (Macropus Giganteus) was carried out based on their innervation. The masseteric muscle was divided into superficial and deep layers; the superficial layer was further subdivided into three laminae from the rostro-lateral portion to caudo-internal portion. The deep layer was divided into lateral, caudo-internal and rostro-internal laminae. The zygomaticomandibular muscle which was located between the masseteric and temporal muscles was divided into lateral, internal and rostral laminae, on the basis of its innervation. The lateral and internal laminae were innervated by the nerve which arises between the masseteric nerve and the posterior deep temporal nerve. A small rostral portion of the muscle was innervated by masseteric nerves, which passed through the internal lamina of the deep layer of the masseteric muscle. The temporalis muscle was innervated by an anterior deep temporal nerve and posterior deep temporal nerve. Only the most rostro-internal lamina of the temporalis muscle was innervated by the anterior deep temporal nerve. The anterior deep temporal nerve and lateral pterygoid nerve had a common trunk. We believe that the rostro-internal lamina was closely related to the lateral pterygoid muscle. The lateral pterygoid muscle displayed one lamina, whereas the medial pterygoid muscle was divided into internal and lateral laminae. The lateral lamina was further divided into rostro-internal and caudo-lateral laminae.

Reactivation of a macropodid herpesvirus from the eastern grey kangaroo ( Macropus giganteus) following corticosteroid treatment

The family Herpesviridae is a large group of viruses which contain double stranded DNA genomes. Biological characteristics, such as host signs, site of replication and site of latency have been used to describe three major subfamilies, Alphaherpesvirinae, Betaherpesvirinae and Gammaherpesvirinae within the family Herpesviridae. Macropodid herpesviruses (MaHV) have been implicated in fatal outbreaks amongst the captive marsupial populations of Australia. These outbreaks have resulted in the isolation of nine MaHV strains which have been classified into two species called macropodid herpesvirus 1 and 2 (MaHV-1 and MaHV-2). Biological characteristics have been used to place MaHV-1 and -2 within the subfamily Alphaherpesvirinae. Molecular phylogenetic reconstructions indicate an unusual position for MaHV-1 and -2 within the alphaherpesviruses. Current isolates of MaHVs have all been obtained from marsupials exhibiting clinical disease. A common biological characteristic of herpesviruses is the establishment of latent infections in nervous tissue. We have determined that MaHV are able to latently infect eastern grey kangaroos through reactivating and isolating a herpesvirus by inducing immunosuppression. We have investigated the possible sites of latency for MaHV-1 using molecular techniques. Detection of herpesvirus DNA in the trigeminal ganglia taken from two naturally infected eastern grey kangaroos indicates dissemination via a respiratory route.

An overview of the Queensland macropod monitoring programme

Four species of macropods are commercially harvested in Queensland, red kangaroos, eastern grey kangaroos, common wallaroos and whiptail wallabies, under the control of the Nature Conservation (Macropod Harvesting) Conservation Plan 1994. Queensland's harvest represents the major portion of the national total, ranging from 55 to 68% for the period 1984 to 1992. Since the introduction of quotas in 1975, systems have been in place to monitor population trends, the size and distribution of both the commercial and non-commercial harvest, non-harvest mortality and reports of damage to primary production. These data provide the basis for monitoring both the population status of each of the commercial macropod species and any effects of harvesting. Direct monitoring in Queensland has involved aerial surveys, using both fixed-wing aircraft and helicopters, and ground surveys, both on foot and using vehicles. Indirect monitoring is achieved through the determination and analysis of harvest parameters including sex...

Repeatability of aerial surveys

In order to monitor population trends through space and time, aerial surveys need to provide density estimates that are a constant proportion of the true population density and are therefore repeatable. Previous work has identified factors that affect the visibility of kangaroos from fixed-wing aircraft and the relative contribution of these factors to the variation in counts. However, this work has relied on repeated surveys of a population of constant size. The development of accurate survey methods using helicopters has allowed the bias in fixed-wing surveys to be determined directly. Bias can therefore be estimated and assessed between areas and over time. Comparisons of kangaroo density estimated by these two aerial survey methods were made over 1991-97 near Blackall in central-western Queensland. Estimates of bias declined with increasing density for red kangaroos Macropus rufus, were relatively constant for eastern grey kangaroos M. giganteus and were highly variable for common wallaroos M. robustu...

Monospecific and Heterospecific Grouping and Feeding Behavior in Grey Kangaroos and Red-Necked Wallabies

Benefits of grouping by conspecifics as an anti-predator strategy also should apply in heterospecific associations if species are similar in their vulnerability to predation. I investigated monospecific and heterospecific grouping by sibling species, eastern (Macropus giganteus) and western grey kangaroos (M. fuliginosus), together with smaller and less social red-necked wallabies (M. rufogriseus). I observed groups feeding in mornings and evenings on a grassy airfield in the Grampians National Park, western Victoria, Australia. Wallabies formed smaller monospecific groups than the kangaroos, maintained a greater nearest-neighbor distance, and moved more while feeding. Monospecific groups of the two kangaroo species were indistinguishable in size, composition, spacing, and feeding rates. The percentage of individual grey kangaroos feeding increased with group size in monospecific groups of up to six. Heterospecific groups of kangaroos formed frequently, and the percentage of individual eastern and western greys feeding was not affected by species composition of groups, suggesting that conspecifics and heterospecifics were equally valuable as feeding partners. By contrast, there were few associations between kangaroos and wallabies.

A nested PCR for the ssrRNA gene detects Trypanosoma binneyi in the platypus and Trypanosoma sp. in wombats and kangaroos in Australia 1

Trypanosome infections in their natural hosts are frequently difficult to detect by microscopy, and culture methods are unreliable and not suitable for all species of Trypanosoma. A nested PCR strategy for detecting and identifying Trypanosoma species, suitable for detecting both known and unknown trypanosomes, is presented. Thirty-two blood samples from 23 species of Australian birds and mammals were screened by a nested PCR for the presence of Trypanosoma sp. ssrRNA. Three infections were detected, one in an eastern grey kangaroo ( Macropus giganteus), one in a common wombat ( Vombatus ursinus) and one in a platypus ( Ornithorhynchus anatinus). The kangaroo and wombat are new host records for Trypanosoma sp.; the platypus parasite was Trypanosoma binneyi. The three parasites could be distinguished by restriction fragment length polymorphisms of the amplified fragment of the ssrRNA gene. The kangaroo and wombat parasites were also isolated in a semi-solid blood agar medium. The culture forms of the kangaroo trypanosome had an expanded flagellar sheath in which structures similar to hemidesmosomes were detected by EM. The nested PCR was at least as sensitive as culture, and analysis of the PCR products gave parasite-specific fingerprints. Therefore this method could be suitable for rapidly screening host animals for the presence of trypanosomes and identifying the infecting strain.