Problem crocodiles, Crocodylus porosus, at Nhulunbuy, Northern Territory: an assessment of relocation as a mangaement strategy

1993 ◽  
Vol 20 (1) ◽  
pp. 127 ◽  
Author(s):  
B Walsh ◽  
PJ Whitehead
Keyword(s):  
Carrying Capacity ◽  
Northern Territory ◽  
Effective Strategy ◽  
Wet Season ◽  
Rates Of Return ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus ◽  
Remote Sites ◽  
Total Capture ◽  
Capture Rates

Since 1986 the Conservation Commission of the Northern Territory has operated a programme to remove 'problem' saltwater crocodiles from waters in and adjoining the township of Nhulunbuy. Over a period of five years, 52 different saltwater crocodiles (44 male) were captured. Most (48) were released at remote sites designated by the traditional Aboriginal owners of the surrounding lands. Release distances from the township varied from 17 to 282 km (by coastline). Many crocodiles (47.9%), including those released at the most distant sites, returned to, and were subsequently recaptured at, the township. Total capture rates (initial captures and recaptures pooled) varied seasonally, with fewer crocodiles being caught in the cooler dry season. During the wet season capture rates remained high, but relatively fewer 'new' crocodiles were caught. Probability of recapture could not be related to distance and direction of release from the township, nor size and sex of the released crocodile. Frequency of capture of individual crocodiles (1-8 times) was also unrelated to these variables. The high rates of return indicate that relocation is unlikely to be an effective strategy for managing humancrocodile interactions, at least in areas where potential release sites already support saltwater crocodile populations near carrying capacity.

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.

Factors affecting the success rate of traps for catching feral pigs in a tropical habitat

1994 ◽  
Vol 21 (3) ◽  
pp. 287 ◽  
Author(s):  
P Caley
Keyword(s):  
Success Rate ◽  
Vegetation Type ◽  
Northern Territory ◽  
Trap Site ◽  
Wet Season ◽  
Factors Affecting ◽  
Feral Pigs ◽  
Time Of Year ◽  
Open Woodland ◽  
Capture Rates

Factors affecting the success rate of traps for catching feral pigs inhabiting a tropical habitat in the Northern Territory, Australia, were identified by constructing a generalised linear model relating capture rates of pigs to environmental variables. Capture rates were influenced most significantly by time of year, being highest during the late dry season and lowest during the late wet season. The next-most important variables were the presence of fresh pig-tracks at the trap site before construction, and vegetation type, with capture rates higher in closed forest, open forest and woodland habitats than in open woodland and low open woodland habitats. Other variables that significantly influenced capture rates were whether pigs had previously eaten bait at the trap site, presence of rooting, bait type, and distance from water. The model developed here provides a useful framework of planning and conducting feral pig trapping programmes in the Northern Territory and other similar tropical habitats.

Timoniella absita n.sp. (Digenea: Cryptogonimidae) from the saltwater crocodile (Crocodylus porosus Schneider) from Australia

1988 ◽  
Vol 66 (8) ◽  
pp. 1763-1766
Author(s):  
D. Blair ◽  
D. R. Brooks ◽  
J. Purdie ◽  
L. Melville
Keyword(s):  
New Species ◽  
Oral Sucker ◽  
Seminal Receptacle ◽  
Northern Territory ◽  
Australian Region ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus

Timoniella absita n.sp. is described from the intestine of the saltwater crocodile (Crocodylus porosus Schneider) from the Northern Territory of Australia. Timoniella absita is closest to Timoniella unami and Timoniella loossi, but can be distinguished from them by the number of oral spines and the posterior extent and arrangement of vitelline follicles, and possibly by the ratio of oral sucker width to pharynx width and the form of the seminal receptacle. The new species is the first representative of Timoniella to be described from the Indo-Malaysian – Australian region.

Mitochondrial DNA analyses of the saltwater crocodile (Crocodylus porosus) from the Northern Territory of Australia

2012 ◽  
Vol 60 (1) ◽  
pp. 18 ◽  
Author(s):  
Naomi L. Luck ◽  
Kristen C. Thomas ◽  
Victoria E. Morin-Adeline ◽  
Sophie Barwick ◽  
Amanda Y. Chong ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Control Region ◽  
Unknown Origin ◽  
Mitochondrial Control Region ◽  
River Basins ◽  
Northern Territory ◽  
Phylogeographic Pattern ◽  
Control Region Sequences ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus

The saltwater crocodile is distributed throughout south-east Asia and Australia. In Australia, it is most abundant in the Northern Territory and Queensland, where it is sustainably farmed for its skins and meat. The aim of this study was to elucidate the relationships and genetic structure among saltwater crocodiles from the Northern Territory of Australia using mitochondrial control region sequences from 61 individuals, representing nine river basins and six of unknown origin, as well as published sequences from other regions. Eight mitochondrial control region haplotypes were identified among both published and novel sequences. Three of the haplotypes appear to be restricted to specimens from northern Australia, with a single haplotype being the most widely dispersed across all river basins. Although Analysis of Molecular Variance provides some support for differentiation among river basins, the frequency of shared haplotypes among these geographical units and median-joining network analysis do not support a clear genetic structure or phylogeographic pattern for saltwater crocodiles in the Northern Territory. The results of this study will assist in furthering our understanding of the genetic diversity of wild saltwater crocodile populations used for ranching in the Northern Territory, as well as providing a framework for assessing the origin of unknown specimens in the future.

The assessment of sperm DNA fragmentation in the saltwater crocodile (Crocodylus porosus)

2017 ◽  
Vol 29 (3) ◽  
pp. 630 ◽  
Author(s):  
S. D. Johnston ◽  
C. López-Fernández ◽  
F. Arroyo ◽  
J. L. Fernández ◽  
J. Gosálvez
Keyword(s):  
Dna Damage ◽  
Dna Fragmentation ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Fragmented Dna ◽  
Sperm Dna ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus ◽  
Dispersion Test ◽  
Sperm Nuclei

Herein we report a method of assessing DNA fragmentation in the saltwater crocodile using the sperm chromatin dispersion test (SCDt) after including frozen–thawed spermatozoa in a microgel (Halomax; Halotech DNA, Madrid, Spain). Following controlled protein depletion, which included a reducing agent, sperm nuclei with fragmented DNA showed a homogeneous and larger halo of chromatin dispersion with a corresponding reduced nucleoid core compared with sperm with non-fragmented DNA. The presence of DNA damage was confirmed directly by incorporation of modified nucleotides using in situ nick translation (ISNT) and indirectly by studying the correlation of the SCDt with the results of DNA damage visualisation using a two-tailed comet assay (r = 0.90; P = 0.037). Results of the SCDt immediately following thawing and after 5 h incubation at 37°C in order to induce a range of DNA damage revealed individual crocodile differences in both the baseline level of DNA damage and DNA longevity.

Standardized Reference Ideogram for Physical Mapping in the Saltwater Crocodile (Crocodylus porosus)

2009 ◽  
Vol 127 (2-4) ◽  
pp. 204-212 ◽  
Author(s):  
P. Dalzell ◽  
L.G. Miles ◽  
S.R. Isberg ◽  
T.C. Glenn ◽  
C. King ◽  
...  
Keyword(s):  
Physical Mapping ◽  
Saltwater Crocodile ◽  
Crocodylus Porosus
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