Targeted sampling successfully detects the cryptic and declining arboreal marsupial (Phascogale pirata) in northern Australia

2020 ◽  
Vol 26 (4) ◽  
pp. 395
Author(s):  
Hayley M. Geyle ◽  
Leigh-Ann Woolley ◽  
Hugh F. Davies ◽  
John C. Z. Woinarski ◽  
Brett P. Murphy

The threatened northern brush-tailed phascogale (Phascogale pirata) is one of the most poorly known mammals in Australia. While the few available records indicate a decline in its distribution and abundance, it has not previously been subject to intensive targeted survey. Here, we trialled a specifically tailored methodology for detection of P. pirata, with the aim of informing ongoing survey and monitoring of this species. We deployed 50 motion-sensor cameras (spaced closely together in a grid 500×1000m) on Melville Island (Northern Territory, Australia), between June 2018 and May 2019. Cameras were baited and secured to trees ~3m above the ground on a bracket facing the trunk. We selected for large (>30cm diameter at breast height [DBH]) trunks of the dominant tree species (Eucalyptus miniata, E. tetrodonta and Corymbia nesophila). We detected P. pirata 16 times on eight cameras over the duration of the study, finding that detection was most likely on large (DBH >41.5cm) E. tetrodonta trees during the wet season. Our results indicate that survey effort for this species should be seasonally targeted and focussed on large trees. However, the efficacy of additional methods (nest boxes, Elliott traps) and a comparison between detections on arboreal versus ground-based cameras requires further investigation. We highlight the importance of conducting additional work on this species, as little is known about its ecology, population trends and threats, making it difficult to assess its conservation status. Without more targeted work, P. pirata is at risk of slipping into extinction unnoticed.

1990 ◽  
Vol 6 (2) ◽  
pp. 219-230 ◽  
Author(s):  
G. J. Flanagan ◽  
C. G. Wilson ◽  
J. D. Gillett

ABSTRACTA monospecific stand of the alien shrub Mimosa pigra (Mimosaceae) was examined weekly for 14 months from March 1984. A total of 44 phytophagous insect species were found on M. pigra. The five most abundant of these made up 74% of the total community. This insect community in general showed a distinct seasonal cycle of abundance with maximum numbers during the wet season. However, a few species had a completely different pattern.Two species, Mictis profana (Hemiptera: Coreidae) and Platymopsis humeralis (Coleoptera: Cerambycidae), were observed to cause substantial damage to M. pigra. When compared with the fauna of M. pigra from its native region, Central America, that of the Northern Territory is low in leaf and flower-feeding insects. It is suggested that these types of insects be sought as future biocontrol agents to complement those native insects causing damage and those biocontrol agents already released.


1991 ◽  
Vol 18 (6) ◽  
pp. 761 ◽  
Author(s):  
DMJS Bowman ◽  
L Mcdonough

A grid of 447 cells (each 50x50 m) was set up in a wet monsoon rain forest on a gradual slope above the Adelaide River floodplain in the Australian Northern Territory. Surveys of pig (Sus scrofa) rooting were carried out at approximately 3-month intervals from November 1988 to September 1989. The pigs had only limited effects on the forest in both the wet and dry seasons. The seasonally flooded swamp communities (Melaleuca forest and sedgeland) were primarily exploited in the dry season; dryland communities ([Eucalyptus] and Lophostemon forests) were exploited during the wet season. Rainfall during the previous wet season may have influenced the pattern of rooting in the dryland forests. Rooting and ground cover were weakly positively related in 3 out of the 4 surveys.


1986 ◽  
Vol 7 (2) ◽  
pp. 1-3
Author(s):  
Harry Allen

The northern part of North Australia is not far from Java and Timor. There are great numbers of influences in the North Western part of Australia from Indonesian region. The coast alligator river area is 200 kilometres east of Darwin, Northern Territory is now 60 kilometres from the coast to the mountain area. The plain area is flat and the water is salty, being tidal on the coast. Further inland the river is fresh water. To day there are few mangroves in this area, but there is evidence that mangroves were more widespread between 6.000 - 3.000 BP. During the wet season the coastal plain is flooded.


1979 ◽  
Vol 6 (3) ◽  
pp. 347 ◽  
Author(s):  
JA Taylor

Stomach contents were studied for 289 live young crocodiles (Crocodylus porosus) less than 180 cm long, collected from coast, river and swamp of Arnhem Land, Melville Island and Grant Island, Northern Territory, Australia; the crocodiles were then released. Tables give orders and families and some generic and specific names for prey or carrion eaten and for 3 parasites on the crocodiles, for a dry and a wet season in 1975-76. Between crocodiles 50 to 120 cm long and those smaller or larger there was no significant difference in the proportion of crocodiles having eaten crabs, shrimps, fish or insects or with empty stomachs, but only the larger crocodiles ate mammals or birds. Frequency of different foods eaten differed significantly with type of habitat or with salinity. Weight of food or incidence of empty stomachs did not differ between seasons, habitats or salinities. Condition of the crocodiles was significantly poorer for those from freshwater swamps than for those from lower mangrove or flood plains, and highest for those from upper mangrove. Main foods in both seasons were crustaceans, mainly crabs of subfamily Sesarminae and shrimps of genus Macrobrachium. The only fish eaten regularly was Pseudogobius sp., a slow-moving fish found by the water's edge. Amphibians were not found in the stomach.


2014 ◽  
Vol 41 (1) ◽  
pp. 35 ◽  
Author(s):  
Carol Palmer ◽  
Lyndon Brooks ◽  
Guido J. Parra ◽  
Tracey Rogers ◽  
Debra Glasgow ◽  
...  

Context Three dolphin species occur in coastal waters of monsoonal northern Australia: the Australian snubfin (Orcaella heinsohni), humpback (Sousa sp.) and the bottlenose (Tursiops sp.). Their overall population size and trends are poorly known, and their conservation status has been difficult to resolve, but can be expected to deteriorate with likely increased development pressures. Aims We sought to provide an estimate of abundance, and apparent survival, of the three dolphin species at the largely undeveloped harbour of Port Essington (325 km2), Northern Territory, with repeated sampling over a 2.9-year period. Given increasing obligations to undertake population assessments for impact studies at proposed development sites, we assess the strengths and limitations of a systematic sampling program. Methods We used photo-identification data collected during systematic boat-based transect surveys undertaken from 2008 to 2010 and Pollock’s robust capture–recapture design model. Key results Total abundance estimates for the three species were variable across different sampling periods. The estimated number of individuals in the sampled area varied per sampling episode from 136 (s.e. 62) to 222 (s.e. 48) for snubfin, from 48 (s.e. 7) to 207 (s.e. 14) for humpbacks and from 34 (s.e. 6) to 75 (s.e. 9) for bottlenose dolphins. Apparent survival was estimated for snubfin at 0.81 (s.e. 0.11), humpbacks at 0.59 (s.e. 0.12) and bottlenose at 0.51 (s.e. 0.17) per annum. Key conclusions (1) The values derived here provide some of the only estimates of local population size for these species across monsoonal northern Australia; (2) population-size estimates varied considerably among seasons or sampling episodes; (3) the low apparent survival probabilities indicated that many individuals may move at scales larger than the study area; (4) density of snubfin and humpback dolphins in the present study area exceeded the few other estimates available for these species elsewhere in Australia. Implications The present study provided the first baseline estimates of abundance and apparent survival for three coastal dolphin species in monsoonal northern Australia. Such information is becoming increasingly important as development pressures intensify in coastal areas. Sampling protocols for future monitoring and impact assessment need an enhanced consideration of seasonality and scale issues.


2001 ◽  
Vol 23 (2) ◽  
pp. 185 ◽  
Author(s):  
S Murphy

THE bare-rumped sheathtailed bat Saccolaimus saccolaimus is a poorly understood species that has a wide distribution covering parts of India, Sri Lanka, Thailand, Myanmar, Malaya, Indonesia, New Guinea, the Solomon Islands and Northern Australia (Bonaccorso 1998). First collected in Australia by De Vis near Cardwell, the current known distribution in Queensland (Qld) extends from Bowen to Cooktown with one isolated specimen collected near Coen on Cape York Peninsula (Hall 1995; Duncan et al. 1999). It has also been recorded in the Alligator River area in the Northern Territory (McKean et al. 1981). The conservation status of S. saccolaimus in Qld has recently been defined as ?Critically Endangered?, and the species has not been recorded anywhere in Australia for at least 18 years (Duncan et al. 1999; Menkhorst and Knight 2001). The likely reasons for the apparent decline are unclear, but may involve land-clearing and changed fire regimes in the coastal zone where it is thought to occur (Duncan et al. 1999). In contrast, Bonaccorso (1998) considers S. saccolaimus to be secure, albeit also poorly known in Papua New Guinea.


2006 ◽  
Vol 54 (7) ◽  
pp. 641 ◽  
Author(s):  
Beth Crase ◽  
Ian D. Cowie ◽  
Carrie R. Michell

Targeted searches of approximately 150 km of cliff lines for two rare sandstone shrubs, Melaleuca triumphalis Craven and Stenostegia congesta A.R.Bean, thought to be restricted to the Victoria River gorge system within Gregory National Park, increased the number of known populations from 3 and 6 to 31 and 37, respectively. Both species occur predominantly in rocky and often fire-protected niches on sandstone cliffs and scree slopes, and are frequently associated with permanent drip-lines and seepage areas. Although their broad habitat requirements are similar, the two species do occur in slightly different niches. The data presented here suggest that M. triumphalis is reasonably fire tolerant, whereas S. congesta appears to be more fire sensitive. Weeds and introduced animals are not thought to pose a threat to these rare species. Models developed using remotely sensed and landscape-scale data (digital elevation models, radiometrics, geology and distance to rivers and streams) suggest that these species may also occur outside Gregory National Park in other areas of the Northern Territory such as on Bullo River and Bradshaw stations and in Keep River National Park. It is suggested that both species be regarded as Vulnerable under the IUCN guidelines.


2000 ◽  
Vol 48 (5) ◽  
pp. 629 ◽  
Author(s):  
A. P. O'Grady ◽  
X. Chen ◽  
D. Eamus ◽  
L. B. Hutley

Savanna communities dominate the wet–dry tropical regions of the world and are an important community type in monsoonal northern Australia. As such they have a significant impact on the water and carbon balance of this region. Above the 1200-mm isohyet, savanna’s are dominated by Eucalyptus miniata–E. tetrodonta open forests. We have described in detail the composition and structure as well as seasonal patterns of leaf area index and above-ground biomass in the E. miniata–E. tetrodonta open forests of the Gunn Point region near Darwin in the Northern Territory of Australia. In all, 29 tree species from four phenological guilds were recorded in these forests. Stand structure suggests that the forests were still recovering from the impacts of cyclone Tracy and subsequent frequent fires. Eucalyptus miniata and E. tetrodonta were significant contributors to overstorey leaf area index and standing biomass (>70%), and both leaf area index and biomass were strongly correlated to basal area. Leaf area index was at a maximum (about 1.0) at the end of the wet season and declined over the dry season by about 30–40%. There were proportionally greater changes in the understorey reflecting the greater contribution of deciduous and semi-deciduous species in this strata. Standing biomass was about 55 t ha –1 . Detailed descriptions of leaf area index and biomass are important inputs into the development of a water and carbon balance for the savanna’s of northern Australia.


1996 ◽  
Vol 6 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Sonia C. Tidemann

SummaryPopulations of Gouldian Finch Erythrura gouldiae, an estrildid endemic to northern Australia, declined markedly during the last two or three decades. A survey revealed the species in two areas of Northern Territory, with an estimated 2,000 individuals, including juveniles. Recaptures were low either because of mortality or dispersal. Gouldian Finches eat predominantly Sorghum spp. seeds, but consume other seeds before Sorghum ripens. Other finches declined as cattle increased. Gouldian Finches breed in tree hollows of predominantly two species of eucalypts that grow on rocky slopes. They require water within about 4 km of the nest site. There was no shortage of nesting hollows at the known breeding sites. Fires in the early to mid-dry season allow birds access to seed without damaging trees, but later fires can destroy trees with nest hollows and remove shade. Average clutch-size is 5.2. About 72% of eggs laid, and 63% of nests, fledged young. Pairs lay up to three clutches in a season (February-August), the length of which may depend on rainfall during the preceding wet season. Air-sac mite (Sternostoma tracheacolum), found in 62% of Gouldian Finches sampled, may be preventing the species recovering to former numbers. New colonies of Gouldian Finches should be identified, populations monitored, and habitat managed by effecting patchy burns by low-intensity fires early in the dry season.


1997 ◽  
Vol 37 (3) ◽  
pp. 279 ◽  
Author(s):  
R. M. Sullivan ◽  
P. K. O'Rourke

Summary. In northern Australia, many cows conceive only after their calves are weaned. The subsequent calves are born in the late wet or early dry season. Where producers wean once a year these late calves stay with the cows with resultant increased risk of cow mortality. A second weaning may reduce this risk. From June 1985 to June 1990 we recorded cow liveweights, mortalities and reproductive rates from a herd of 500 Bos indicus-Bos taurus-cross cows at Kidman Springs, Northern Territory. The herd grazed native pastures, and was continuously mated and unsupplemented. Calves were weaned if they weighed 100 kg or more at muster in June (W1) or in either of June and October (W2). In both groups (W1 and W2), 75% of calves were weaned at the June muster, and a further 14% were weaned at the October muster (W2 group). There was no difference in liveweight change, mortality or branding rates between the 2 groups. Overall productivity was low, probably due to poor nutrition during both dry and wet seasons. For example, average branding and mortality rates were 51.8 and 11.8%. Forty-seven percent of all cows were pregnant at the June muster but a quarter of these failed to rear a calf. The low proportion of calves suitable for weaning in October indicated that the weaning times were too close together, and did not allow enough late calves to reach the target liveweight for weaning. Consequently, the benefit of the second weaning was reduced. Weaning times for continuously mated herds should be determined by the time taken for calves born late in the wet season to reach target liveweights for weaning at the second weaning round. Effectively, this means the first weaning should be earlier, perhaps in April, since high temperatures and the increased likelihood of rain make mustering after October difficult.


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