scholarly journals Long-term movements and activity patterns of platypus on regulated rivers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tahneal Hawke ◽  
Gilad Bino ◽  
Richard T. Kingsford ◽  
Dion Iervasi ◽  
Kylie Iervasi ◽  
...  

AbstractThe platypus is a semi-aquatic mammal, endemic to freshwater habitats of eastern Australia. There are gaps in the understanding of platypus movement behaviour within river systems, including spatial and temporal organization of individuals. We tracked movements of 12 platypuses on the regulated Snowy and Mitta Mitta Rivers for up to 12-months, the longest continuous tracking of platypus using acoustic telemetry. Platypuses remained relatively localized, occupying 0.73–8.45 km of river over 12 months, consistent with previous tracking studies over shorter periods. Males moved further than females, and larger males had higher cumulative movements, suggesting a possible relationship to metabolic requirements. Platypuses moved greater distances on the Mitta Mitta River, possibly associated with impacts of altered flow regimes to their macroinvertebrate diet. Increased movements and diurnal activity during winter were primarily driven by males, possibly attributable to breeding behaviours, rather than increased costs of winter foraging. Evidence for relatively small movements has implications for declining populations, given areas of localised declines are unlikely to be supplemented by migrating platypuses, especially when dispersal is restricted by dam walls. Understanding platypus movement behaviour is pertinent for their conservation, as water resource development and habitat modification continue to reduce connectivity between populations across their distribution.

Phytotaxa ◽  
2013 ◽  
Vol 133 (1) ◽  
pp. 1 ◽  
Author(s):  
GLENN B. MCGREGOR

This volume provides the first detailed account of the Chroococcales of north-eastern Australia. It provides keys, morphological and ecological data for 6 families, 33 genera and 112 species, and photomicrographs and original illustrations to enable the identification of natural populations based on stable and recognizable characters observable with the aid of light microscopy. Distributional data are based on extensive surveys at 270 sites representing the major freshwater habitats including rivers and streams, palustrine and lacustrine wetlands, thermal springs, and man-made reservoirs in Queensland and the Northern Territory as well as a review of the Australian phycological literature. 


1999 ◽  
Vol 276 (4) ◽  
pp. R1078-R1086 ◽  
Author(s):  
Gabriela Klante ◽  
Karin Secci ◽  
Mireille Masson-Pévet ◽  
Paul Pévet ◽  
Berthe Vivien-Roels ◽  
...  

We investigated the possibility that strain-dependent differences in the diurnal pattern of wheel running activity rhythms are also reflected in the melatonin profiles. The inbred rat strains ACI/Ztm, BH/Ztm, and LEW/Ztm. LEW were examined for diurnal [12:12-h light-dark (LD)] wheel running activity, urinary 6-sulphatoxymelatonin (aMT6s) excretion, melatonin concentrations of plasma and pineal glands, and melatonin receptor density in the suprachiasmatic nuclei (SCN). ACI rats displayed unimodal activity patterns with a high level of activity, whereas BH and LEW rats showed multimodal activity patterns with ultradian components and reduced activity levels. In contrast, the individual daily profiles of aMT6s excretion and mean melatonin synthesis followed a unimodal time pattern in all three strains, suggesting that different output pathways of the SCN are responsible for the temporal organization of locomotor activity and pineal melatonin synthesis. In addition, melatonin synthesis at night and SCN melatonin receptor density at day were significantly higher in BH and LEW rats than in ACI rats. These results support the hypothesis of a long-term stimulating effect of melatonin on its own receptor density in the SCN.


2017 ◽  
Vol 39 (2) ◽  
pp. 169 ◽  
Author(s):  
K. Green ◽  
N. E. Davis ◽  
W. A. Robinson

To understand the recent elevational range expansion of European rabbits (Oryctolagus cuniculus) with declining snow cover and earlier snow thaw we examined their diet in relation to that of long-term residents, common wombats (Vombatus ursinus). The colonisation of eastern Australia by rabbits was effectively completed by 1910 when they reached an elevation of 1500 m (the winter snowline). Rabbits began to penetrate higher elevations only from the 1970s in association with anthropogenic habitat modification. Since 2011, rabbits have occupied elevations to the alpine treeline (~1850 m) throughout the year without the ameliorating presence of infrastructure or anthropogenically modified vegetation. Rabbits and wombats are both grazers preferring grasses (largely inaccessible beneath winter snow) and are spatially restricted in their foraging by their need to return to their burrows. Wombats used a much wider foraging range, enabling them to select preferred food. Rabbits, with a much smaller range, were constrained in their choice of forage mainly to plants that projected above the snow. Unexpectedly, rabbits fed intensively on leaves of eucalypts, food not typically consumed in substantial quantities by this species. These leaves, on stems regenerating after fire, will diminish in availability as stems mature, possibly halting the range expansion of rabbits.


1991 ◽  
Vol 18 (6) ◽  
pp. 677 ◽  
Author(s):  
M Phillips ◽  
PC Catling

Three adult red foxes (Vulpes vulpes) in a 20-km2 wilderness area of coastal south-eastern Australia were studied during pre-denning and denning. Home ranges were defined by geographic featues, but not by roads. The foxes occupied exclusive home ranges, and observations suggest that they were territorial and existed alone or, at most, in mated pairs. Home-range sizes were small (1.2-5.2 km2) compared with those in North America and Europe, but similar to those in England and Wales. During denning the female's activity became almost entirely diurnal. When not active, the vixen was with the cubs. Male activity during denning was nocturnal, but, as found for the female, inactive periods were spent near the suspected den-site in his home range. Habitats that were frequented most by all foxes were those with the highest abundance of either small or medium-sized mammals. Dry sclerophyll forest was used consistently by all foxes but heathland and the beaches were rarely frequented. Small and medium-sized mammals, which were abundant in all habitats except the beach and heathland, made up 52.6% of items in the scats.


2019 ◽  
Vol 101 (1) ◽  
pp. 199-210
Author(s):  
Stephen A Symes ◽  
Richard Klafki ◽  
Roger Packham ◽  
Karl W Larsen

Abstract The North American badger (Taxidea taxus) is a nonhibernating carnivore that occurs in areas with highly seasonal climates, such as in Canada where the animal reaches its northern limits. There, winter climate is harsh and conventional habitat is limited and patchy, possibly leading to additional energetic constraints. Using radiotelemetry and remote cameras, we documented winter activities of 16 badgers (12 females, 4 males) between 2007 and 2011 in British Columbia, at the northwestern periphery of the species’ range. In comparison to their summer ecology, the animals reduced home range sizes by up to 98% and showed fidelity to particular burrows. Burrow fidelity was variable (mean 27 days; range 0–108) and coincided with reduction in body temperatures, suggesting the onset of torpor. Despite lengthy use of the same burrow, badgers emerged frequently and conducted excursions that appeared to represent foraging behavior. Burrow emergence was not related to ambient temperature or snow depth; rather, it was best explained by the amount of days elapsed since the start of winter. Despite these trends, winter activity also was variable among individual badgers. It may be that limited fat reserves and higher energetic costs in northwestern ranges require winter foraging activities.


2020 ◽  
Vol 54 (4) ◽  
pp. 985-999
Author(s):  
Lyndsey M. Vivian ◽  
Joe Greet ◽  
Christopher S. Jones

Abstract River regulation has altered the seasonal timing of flows in many rivers worldwide, impacting the survival and growth of riparian plants. In south-eastern Australia, demand for irrigation water in summer often results in high river flows during a season that would naturally experience low flows. Although unseasonal high summer flows are thought to significantly impact waterways, their effects on vegetation are poorly quantified. We investigated the responses of five grass species commonly occurring in riparian zones to different durations of submergence in summer. We experimentally tested the response of three exotic and two native grasses to four submergence treatments (4 weeks, 8 weeks, 2-week pulses and no submergence), and two levels of shading (no shading and 80% light reduction), over 8 weeks in summer and early autumn. All submergence treatments, including the 2-week pulse, resulted in the death of all plants of three species (Bromus catharticus, Dactylis glomerata and Rytidosperma caespitosum). Lolium perenne exhibited moderate survival rates in the shorter-duration unshaded submergence treatments, while Poa labillardierei largely survived all treatments. Similar responses across species were observed for plant height and biomass, although height generally increased while biomass growth was reduced by shading. These results show that even 2-week periods of summer submergence can reduce growth and cause the death of some riparian grasses. Although some species may survive longer submergence durations, impacts on other aspects of fitness, and ongoing effects of repeated unseasonal submergence, remain uncertain. Our study highlights that the impacts of unseasonal flows require further investigation and careful management.


2020 ◽  
Vol 42 (3) ◽  
pp. 312 ◽  
Author(s):  
Christopher Davies ◽  
Wendy Wright ◽  
Fiona E. Hogan ◽  
Hugh Davies

Introduced sambar deer (Rusa unicolor) are increasing in abundance and distribution across much of south-eastern Australia and causing damage to native ecosystems. However, the current paucity of knowledge surrounding many aspects of sambar deer ecology is limiting our capacity to make informed management decisions, and properly gauge the extent of deer impacts. Here we investigate correlates of sambar deer detectability and describe activity patterns of sambar deer in Baw Baw National Park (BBNP) to inform control operations. Camera traps were deployed in BBNP between October and December 2016. We used an occupancy modelling framework to investigate sambar deer detectability and camera trap record time stamps to determine sambar deer activity patterns. Sambar deer were found to be significantly more detectable near roads and in areas of sparse tree density and displayed strong crepuscular activity patterns. Control operations carried out along roads at dawn and dusk could be effective, at least in the short term. Likewise, aerial culling could be an effective control option for sambar deer populations in BBNP. This study highlights the utility of camera trap data to inform the application of control operations for cryptic invasive species.


1995 ◽  
Vol 22 (2) ◽  
pp. 217 ◽  
Author(s):  
IF Lumsden ◽  
AF Bennet

A total of 2075 captures of 11 taxa of bats was recorded during an extensive survey of the vertebrate fauna of the semi-arid Mallee region of Victoria. A further two species, Pteropus scapulatus and Saccolaimus flaviventris, are known from previous records, thus bringing the total to 13 taxa known from the region. There was a marked seasonality in activity patterns and in reproduction. Activity, as revealed by trap captures, peaked over the spring to early autumn months when daytime temperatures are high and nights are mild. Births occurred from October to December, lactating females were recorded from November to February, and juveniles were trapped between December and late February, with minor variation in timing between species. Morphometric measurements revealed that females were generally larger and heavier than males. There was a high level of overlap of species between broad vegetation types. Woodland habitats, especially Riverine Woodland, tended to have a higher frequency of capture and a greater species richness of bats per trapping event than did Mallee Shrubland. The assemblage of bats in the Mallee region, Victoria, like those in other semi-arid regions of southern Australia, includes species that are widespread in Australia (e.g. Chalinolobus gouldii and Nyctophilus geoffroyi), together with species that primarily occur in semi-arid and arid environments (e.g. N. timoriensis, Scotorepens balstoni and Vespadelus baverstocki). This region, which includes mesic riverine habitats, also supports a group of species that are characteristic of temperate south-eastern Australia (e.g. C. morio, V. regulus and V. vulturnus). In comparison with assemblages from temperate and tropical environmental regions, those from the semi-arid region tend to have a lower species richness with fewer families represented, a higher level of insectivory, and a smaller modal body size. The conservation status of bats from the Mallee region, Victoria, is believed to be secure, although the status of N. timoriensis warrants further attention.


2005 ◽  
Vol 53 (1) ◽  
pp. 1 ◽  
Author(s):  
John Llewelyn ◽  
Richard Shine ◽  
Jonathan K. Webb

Two of the most basic biological attributes for any ectothermic animal are the times of day that it is active and the body temperatures that it exhibits. Published studies on reptile biology display a heavy bias towards diurnal lizards from Northern Hemisphere habitats. To help redress this imbalance, we quantified thermal regimes and activity times in four species of small Australian elapid snakes. Mean selected body temperature in a thermal gradient was affected by the time of testing (i.e. night v. day), with snakes choosing higher body temperatures at night than by day. In outdoor enclosures, whip snakes (Demansia psammophis) were shuttling heliotherms active only during daylight hours at relatively high body temperatures; in a laboratory thermal gradient these animals selected high body temperatures (mean 31.3°C during the day and 33.2°C at night). The other three taxa – golden-crowned snakes (Cacophis squamulosus), small-eyed snakes (Cryptophis nigrescens) and marsh snakes (Hemiaspis signata) – were active mostly at night at relatively low body temperatures, and selected low body temperatures in a thermal gradient (18.1–23.4°C). Thus, mean selected body temperatures differ substantially among sympatric elapid species in south-eastern Australia and are correlated with times of activity.


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