Movement and Dispersal Patterns of Crocodylus porosus in some Rivers of Arnhem Land, Northern Australia

1978 ◽  
Vol 5 (2) ◽  
pp. 263 ◽  
Author(s):  
GJW Webb ◽  
H Messel
Keyword(s):  
Opposite Direction ◽  
Northern Australia ◽  
Dispersal Patterns ◽  
Capture Site ◽  
Arnhem Land ◽  
Crocodylus Porosus

The dispersal of juvenile C. povosus hatched in the Liverpool River is described. Of those initially caught when hatchlings, 1-y-olds and 2–4-y-olds, and recaught 1 year later, 93 %, 73% and 57% respectively were within 10 km of the original capture site. Movements of up to 21 km in one direction in 1 year could be followed by a similar movement in the opposite direction the following year. Relocated C. povosus demonstrated a homing instinct. A possible explanation for the long distances travelled by some juveniles (up to 81 km in a year), is that chance wandering placed them in the mouth of another stream, and attempts to 'home' in the new stream took them further away from their original capture site. The distribution of C. povosus in other rivers can be explained by dispersal patterns similar to those found in the Liverpool River. Some rivers seem to have supported successful C. povosus breeding for a number of years, others seem to have been sporadically successful, and still others unsuccessful. Movement of juveniles from 'successful' to 'unsuccessful' rivers could account for older juveniles found in the latter type of river.

The Foods and Feeding Habits of Subadult Crocodylus Porosus Schneider in Northern Australia.

1979 ◽  
Vol 6 (3) ◽  
pp. 347 ◽  
Author(s):  
JA Taylor
Keyword(s):  
Feeding Habits ◽  
Stomach Contents ◽  
Northern Territory ◽  
Northern Australia ◽  
Wet Season ◽  
Flood Plains ◽  
Significant Difference ◽  
Arnhem Land ◽  
Crocodylus Porosus ◽  
Slow Moving

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.

An Aerial Survey of Potential Nesting Areas of the Saltwater Crocodile, Crocodylus porosus Schneider, on the North Coast of Arnehem Land, Northern Australia

1978 ◽  
Vol 5 (3) ◽  
pp. 401 ◽  
Author(s):  
WE Magnusson ◽  
GC Grigg ◽  
JA Taylor
Keyword(s):  
Coastal Wetlands ◽  
Aerial Survey ◽  
North Coast ◽  
Northern Australia ◽  
National Library ◽  
The North ◽  
Arnhem Land ◽  
Saltwater Crocodile ◽  
Different Types ◽  
Crocodylus Porosus

Results of a study of habitats used by C, povosus for nesting on the Liverpool and Tomkinson Rivers, Arnhem Land, northern Australia, are presented. These were used as the basis of an aerial survey for potential crocodile nesting habitat in coastal wetlands between Smith Point (Cobourg Peninsula) and Gove. General conclusions of the survey are given, and areas in which different types of management could be applied are indicated. Detailed results are lodged with the Australian National Library,Canberra (catalogue No. MS5640).

The Nesting of Crocodylus porosus in Arnhem Land, Northern Australia

Copeia ◽  
1977 ◽  
Vol 1977 (2) ◽  
pp. 238 ◽  
Author(s):  
Grahame J. W. Webb ◽  
Harry Messel ◽  
William Magnusson
Keyword(s):  
Northern Australia ◽  
Arnhem Land ◽  
Crocodylus Porosus

Population-Dynamics and Status of Crocodylus-Porosus in the Tidal Waterways of Northern Australia

1986 ◽  
Vol 13 (1) ◽  
pp. 71 ◽  
Author(s):  
H Messel ◽  
GC Vorlicek
Keyword(s):  
Population Dynamics ◽  
Population Model ◽  
Total Population ◽  
Population Management ◽  
Northern Australia ◽  
Night Time ◽  
Management Implications ◽  
Arnhem Land ◽  
Crocodylus Porosus ◽  
Large Animals

The results of 10 years of systematic, standardized, night-time surveys of C. porosus in c. 100 tidal waterways in northern Australia are presented. One group of waterways in Arnhem Land has been studied intensively, especially over the last 4 years; others have been surveyed at least once and many several times. The results indicate a basically steady total population, with some signs of an increase in the proportion of large animals. As total protection has been accorded C. porosus since 1972, these results are perhaps surprising. The results of our surveys and studies have allowed a picture of C. porosus population dynamics in northern Australia to be developed, and this is presented in some detail. It enables us to account in a consistent fashion for the results of the surveys and to predict results to be expected on future surveys. The results also enable us to make an assessment of the overall status of C. porosus in northern Australia, and of the prospects for recovery of the population. Management implications of the results and population model are also discussed.

Growth Rates of Crocodylus Porosus (Reptilia: Crocodilia) From Arnhem Land, Northern Australia.

1978 ◽  
Vol 5 (3) ◽  
pp. 385 ◽  
Author(s):  
GJW Webb ◽  
H Messel ◽  
J Crawford ◽  
MJ Yerbury
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Curve ◽  
Exponential Growth ◽  
Maximum Size ◽  
Northern Australia ◽  
Wet Season ◽  
Second Growth ◽  
Arnhem Land ◽  
Crocodylus Porosus

In C. porosus < 80 cm SVL (snout-vent length), growth rate decreases as body size increases; males grow faster than females, and both sexes grow faster in the wet season than in the dry season. If the exponential growth curve for specimens < 80cm SVL is extrapolated, it underestimates the maximum size of C. porosus. A second growth curve for specimens > 80cm SVL has been derived separately, and the two curves intersect in the vicinity of 70 cm SVL. The size at which C. porosus cease growing seems quite variable and some data indicate a range of 3.9-6.0 m total length for males. The twocurve growth model is thought to reflect an energetic advantage in feeding on large rather than small prey.

Ecological thresholds and the status of fire-sensitive vegetation in western Arnhem Land, northern Australia: implications for management

2009 ◽  
Vol 18 (2) ◽  
pp. 127 ◽  
Author(s):  
Andrew C. Edwards ◽  
Jeremy Russell-Smith
Keyword(s):  
National Parks ◽  
Fire History ◽  
Fire Management ◽  
Fire Regime ◽  
Vegetation Types ◽  
Northern Australia ◽  
Study Region ◽  
Ecological Thresholds ◽  
Arnhem Land ◽  
The Status

The paper examines the application of the ecological thresholds concept to fire management issues concerning fire-sensitive vegetation types associated with the remote, biodiversity-rich, sandstone Arnhem Plateau, in western Arnhem Land, monsoonal northern Australia. In the absence of detailed assessments of fire regime impacts on component biota such as exist for adjoining Nitmiluk and World Heritage Kakadu National Parks, the paper builds on validated 16-year fire history and vegetation structural mapping products derived principally from Landsat-scale imagery, to apply critical ecological thresholds criteria as defined by fire regime parameters for assessing the status of fire-sensitive habitat and species elements. Assembled data indicate that the 24 000 km2 study region today experiences fire regimes characterised generally by high annual frequencies (mean = 36.6%) of large (>10 km2) fires that occur mostly in the late dry season under severe fire-weather conditions. Collectively, such conditions substantially exceed defined ecological thresholds for significant proportions of fire-sensitive indicator rain forest and heath vegetation types, and the long-lived obligate seeder conifer tree species, Callitris intratropica. Thresholds criteria are recognised as an effective tool for informing ecological fire management in a variety of geographic settings.

45,610–52,160 years of site and landscape occupation at Nawarla Gabarnmang, Arnhem Land plateau (northern Australia)

2019 ◽  
Vol 215 ◽  
pp. 64-85 ◽  
Author(s):  
Bruno David ◽  
Jean-Jacques Delannoy ◽  
Jerome Mialanes ◽  
Christopher Clarkson ◽  
Fiona Petchey ◽  
...  
Keyword(s):  
Northern Australia ◽  
Arnhem Land

Ndjebbana Talking Books

2007 ◽  
pp. 197-199 ◽  
Author(s):  
Glenn Auld
Keyword(s):  
Indigenous Australians ◽  
Northern Australia ◽  
Community Members ◽  
Indigenous Australian ◽  
Arnhem Land

Members of the Kunibídji community are the traditional landowners of the land and seas around Maningrida, a community in Arnhem Land in Northern Australia. With very few exceptions, Ndjébbana is only spoken by the 150 Kunibídji community members of Maningrida, although Maningrida is also home to indigenous Australians who speak other languages. Ndjébbana is the preferred language of communication between members of the Kunibídji community. Ndjébbana is a minority indigenous Australian language.

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