Diet of Two Freshwater Turtles, Chelodina rugosa and Elseya dentata (Testudines: Chelidae) from the Wet-Dry Tropics of Northern Australia

Copeia ◽  
1996 ◽  
Vol 1996 (2) ◽  
pp. 409 ◽  
Author(s):  
Rod Kennett ◽  
Oswald Tory
Keyword(s):  
Freshwater Turtles ◽  
Northern Australia ◽  
Dry Tropics

Resource partitioning among five sympatric species of freshwater turtles from the wet–dry tropics of northern Australia

2017 ◽  
Vol 44 (3) ◽  
pp. 219 ◽  
Author(s):  
Michael A. Welsh ◽  
J. Sean Doody ◽  
Arthur Georges
Keyword(s):  
Resource Partitioning ◽  
Niche Overlap ◽  
Sympatric Species ◽  
Dry Season ◽  
Gut Contents ◽  
Microhabitat Use ◽  
Freshwater Turtles ◽  
Northern Australia ◽  
Dietary Shift ◽  
Dry Tropics

Context Resource partitioning of diet and microhabitat was examined for five sympatric species of freshwater turtles in the Daly River in the northern end of Northern Territory (Top End) in Australia. The Daly River supports a high diversity of freshwater turtles, making it the ideal place to study a freshwater turtle community. Aims To determine the dry-season diet and microhabitat use of Carettochelys insculpta, Elseya dentata, Chelodina oblonga, Emydura victoriae and Emydura subglobosa worrelli and examine intraspecific and interspecific niche overlap and ontogenetic dietary shift. Methods Gut contents were collected by stomach flushing, and microhabitat use was determined by recording where each turtle was first seen before capture. Diet and microhabitat use were compared using an index of relative importance. Niche overlap was measured with Horn’s overlap index. Key results Carettochelys insculpta is an opportunistic omnivore that feeds mostly on ribbonweed (Vallisneria spiralis) and aquatic snails. Elseya dentata is herbivorous, feeding primarily on aquatic algae. The diets of C. insculpta and E. dentata overlapped moderately, but the overall niche overlap was low because they occupied different microhabitats within the river. Chelodina oblonga fed very little, and may use the Daly River as a dry-season refuge. Emydura victoriae is molluscivorous, consuming more molluscs as it grows. This ontogenetic dietary shift was associated with megacephaly (extreme broadly expanded head that is too large to fit into the carapace) and expanded triturating surfaces. This specialisation allows adult E. victoriae to feed exclusively on molluscs and so their diet overlapped little with other species. Emydura subglobosa worrelli was omnivorous, consuming mostly freshwater sponge and apparently preferring more lentic water. Conclusions The freshwater turtles of the wet–dry tropics are usually reported as being heavily reliant on the seeds, fruits and leaves of riparian vegetation; however, the present study showed that the dry-season diet in perennial rivers is primarily of aquatic origin. Implications The study suggested that populations of C. insculpta, E. dentata and E. victoriae could be threatened by broad-scale development in northern Australia if there were substantive impacts on aquatic macrophytes and molluscs in the Daly River system.

The use of regional and alluvial groundwater by riparian trees in the wet‐dry tropics of northern Australia.

2021 ◽  
Author(s):  
Caroline A. Canham ◽  
Clément Duvert ◽  
Leah S. Beesley ◽  
Michael M. Douglas ◽  
Samantha A. Setterfield ◽  
...  
Keyword(s):  
Northern Australia ◽  
Dry Tropics ◽  
Riparian Trees ◽  
Alluvial Groundwater

Does Dingo Predation or Buffalo Competition Regulate Feral Pig Populations in the Australian Wet-Dry Tropics? An Experimental Study.

1995 ◽  
Vol 22 (1) ◽  
pp. 65 ◽  
Author(s):  
L Corbett
Keyword(s):  
Experimental Study ◽  
Sus Scrofa ◽  
Interference Competition ◽  
Fold Increase ◽  
Bubalus Bubalis ◽  
Northern Australia ◽  
Dry Tropics ◽  
Swamp Buffalo ◽  
And Control ◽  
The Relationship

Dingo (Canis farniliaris dingo) predation on feral pigs (Sus scrofa) in response to experimental changes in prey populations was measured over seven years in the seasonally wet-dry tropics of northern Australia. Following the removal of feral swamp buffalo (Bubalus bubalis) from half of the 614-km*2 study area, the number of pigs doubled and there was a 3-fold increase of pig in dingo diet. The relationship between the functional response of the dingo and pig abundance was negative and significant for both the treatment and control areas. This indicated that dingoes were not regulating the pig population. Instead, dingo predation probably acted in concert with interference competition by buffalo which decreased access to critical subterranean food for pigs during the dry season and thus limited population growth in pigs.

A study of soil erosion rates using 239Pu, in the wet-dry tropics of northern Australia

2020 ◽  
Vol 211 ◽  
pp. 106085
Author(s):  
R. Lal ◽  
L.K. Fifield ◽  
S.G. Tims ◽  
R.J. Wasson ◽  
D. Howe
Keyword(s):  
Soil Erosion ◽  
Northern Australia ◽  
Erosion Rates ◽  
Dry Tropics ◽  
Soil Erosion Rates

scholarly journals Comparative water use by the riparian trees Melaleuca argentea and Corymbia bella in the wet-dry tropics of northern Australia

2006 ◽  
Vol 26 (2) ◽  
pp. 219-228 ◽  
Author(s):  
A. P. O'Grady ◽  
D. Eamus ◽  
P. G. Cook ◽  
S. Lamontagne
Keyword(s):  
Water Use ◽  
Northern Australia ◽  
Dry Tropics ◽  
Riparian Trees

Relationship Between Climate and Provenance Variation in Eucalyptus Camaldulensis Dehnh.

1995 ◽  
Vol 22 (3) ◽  
pp. 453 ◽  
Author(s):  
A Gibson ◽  
EP Bachelard ◽  
KT Hubick
Keyword(s):  
Dry Matter ◽  
Eucalyptus Camaldulensis ◽  
Humid Tropics ◽  
The Other ◽  
Northern Australia ◽  
Axillary Shoots ◽  
Dry Tropics ◽  
Temperature Ranges ◽  
Eucalyptus Camaldulensis Dehnh ◽  
Semi Arid

The morphology and physiology of Eucalyptus camaldulensis seedlings grown from seed collected from two locations in the dry tropics, two in the humid tropics and two in semi-arid Northern Australia were compared in phytotron growth cabinets under well-watered and water-limited conditions and diurnal temperature ranges of 30-25 and 22-15�C. Seedlings from the two locations in each climate resembled each other more closely than they resembled seedlings from the other climates across the range of conditions tested. When water-limited, seedlings from the dry tropical and semi-arid climates had a higher allocation of dry matter to roots than seedlings from the humid tropics. However, those from the dry tropics shed their lower leaves and initiated small-leaved axillary shoots while those from the semi-arid climate retained their leaves and did not produce axillary shoots. In contrast, seedlings from the humid tropics responded by reduced gas (CO2 and H2O) exchange without changes in morphology or allocation of dry matter. These responses are appropriate for growth in each climate and are consistent with observations made on wild trees in the field, on trees in plantations overseas and also with data from seedlings grown in earlier glasshouse experiments.

Evaluation of risks for two native mammal species from feral cat baiting in monsoonal tropical northern Australia

2018 ◽  
Vol 45 (6) ◽  
pp. 518 ◽  
Author(s):  
Jaime Heiniger ◽  
Skye F. Cameron ◽  
Graeme Gillespie
Keyword(s):  
Rhodamine B ◽  
Native Species ◽  
Field Trials ◽  
Camera Traps ◽  
Northern Australia ◽  
Target Species ◽  
Mammal Species ◽  
Feral Cat ◽  
Feral Cats ◽  
Dry Tropics

Context Feral cats are a significant threat to native wildlife and broad-scale control is required to reduce their impacts. Two toxic baits developed for feral cats, Curiosity® and Hisstory®, have been designed to reduce the risk of baiting to certain non-target species. These baits involve encapsulating the toxin within a hard-shelled delivery vehicle (HSDV) and placing it within a meat attractant. Native animals that chew their food more thoroughly are predicted to avoid poisoning by eating around the HSDV. This prediction has not been tested on wild native mammals in the monsoonal wet–dry tropics of the Northern Territory. Aim The aim of this research was to determine whether northern quolls (Dasyurus hallucatus) and northern brown bandicoots (Isoodon macrourus) would take feral cat baits and ingest the HSDV under natural conditions on Groote Eylandt. Methods We hand-deployed 120 non-toxic baits with a HSDV that contained a biomarker, Rhodamine B, which stains animal whiskers when ingested. The species responsible for bait removal was determined with camera traps, and HSDV ingestion was measured by evaluating Rhodamine B in whiskers removed from animals trapped after baiting. Key results During field trials, 95% of baits were removed within 5 days. Using camera-trap images, we identified the species responsible for taking baits on 65 occasions. All 65 confirmed takes were by native species, with northern quolls taking 42 baits and northern brown bandicoots taking 17. No quolls and only one bandicoot ingested the HSDV. Conclusion The use of the HSDV reduces the potential for quolls and bandicoots to ingest a toxin when they consume feral cat baits. However, high bait uptake by non-target species may reduce the efficacy of cat baiting in some areas. Implications The present study highlighted that in the monsoonal wet–dry tropics, encapsulated baits are likely to minimise poisoning risk to certain native species that would otherwise eat meat baits. However, further research may be required to evaluate risks to other non-target species. Given the threat to biodiversity from feral cats, we see it as critical to continue testing Hisstory® and Curiosity® in live-baiting trials in northern Australia.

scholarly journals Productivity is negatively related to shoot growth across five mango cultivars in the seasonally wet-dry tropics of northern Australia

Fruits ◽  
2013 ◽  
Vol 68 (4) ◽  
pp. 279-289 ◽  
Author(s):  
Ping Lu ◽  
Elias K. Chacko ◽  
Sean L. Bithell ◽  
Heinz Schaper ◽  
Josef Wiebel ◽  
...  
Keyword(s):  
Shoot Growth ◽  
Northern Australia ◽  
Dry Tropics
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