Population decline of the White-fronted Chat (Epthianura albifrons) in New South Wales, Australia

2011 ◽  
Vol 111 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Ben Jenner ◽  
Kris French ◽  
Katherine Oxenham ◽  
Richard E. Major
Keyword(s):  
New South ◽  
Population Decline ◽  
New South Wales ◽  
South Wales

Interpreting patterns of population change in koalas from long-term datasets in Coffs Harbour on the north coast of New South Wales

2016 ◽  
Vol 38 (1) ◽  
pp. 29 ◽  
Author(s):  
Daniel Lunney ◽  
Martin Predavec ◽  
Indrie Miller ◽  
Ian Shannon ◽  
Mark Fisher ◽  
...  
Keyword(s):  
Population Change ◽  
New South ◽  
Survey Methods ◽  
Population Decline ◽  
New South Wales ◽  
North Coast ◽  
Common View ◽  
The North ◽  
South Wales

We examined a long-term, repeat dataset for the koala population within Coffs Harbour Local Government Area. Analyses of these data have led to the conclusion that, following a perceived population decline in the 1980s, the koala population of Coffs Harbour has endured between 1990 and 2011 and showed no evidence of a precipitous decline during this period. Rather, the population change is best characterised as stable to slowly declining. This conclusion appears to contradict a common view of recent koala population declines on the north coast of New South Wales. There are four possible explanations for the population’s apparent stability: that conservation efforts and planning regulations have been effective; that surviving adults are persisting in existing home ranges in remnant habitat; that the broader Coffs Harbour population is operating as a ‘source and sink’ metapopulation; and/or that the standard survey methods employed are not sufficiently sensitive to detect small population changes. These findings do not mean there is no need for future conservation efforts aimed at koalas in Coffs Harbour; however, such efforts will need to better understand and account for a koala population that can be considered to be stable to slowly declining.

The Survival and Population Response to Frequent Fires of Two Woody Resprouters Banksia serrata and Isopogon anemonifolius

1988 ◽  
Vol 36 (4) ◽  
pp. 415 ◽  
Author(s):  
RA Bradstock ◽  
PJ Myerscough
Keyword(s):  
High Intensity ◽  
New South ◽  
Population Decline ◽  
New South Wales ◽  
Fire Regimes ◽  
Small Tree ◽  
Population Response ◽  
South Wales ◽  
In Fire

Plants of B. serrata and I. Anemonifolius resprout after fire, although the species differ in morphology (single-stemmed small tree, multistemmed low shrub respectively). If fires occur before newly established plants are fire-tolerant, populations will decline. The age of first fire tolerance was found to be lower in B. serrata (6 years) than in I. Anemonifolius (about 13 years). Rates of survival between and during fires were measured in the field along with rates of stem regrowth in fire-tolerant B. serrata juveniles. These results were used to predict rates of population decline under repeated fires sufficiently closely spaced to prevent the survival of newly established genets. In both species, juveniles were more prone to death than adults in fires and high-intensity fires caused most deaths. In B. serrata, adult stems (>2.0 cm d.b.h.) are mostly fire-tolerant, but fires less than 10 years apart can prevent many juveniles which survive from reaching adulthood. This restriction is less likely in I. Anemonifolius. As a result stands of B. serrata may decline more rapidly than I. Anemonifolius under 5-year fire cycles. I. Anemonifolius populations, however, may be more prone to decline when the interval between fires is slightly longer (e.g. 10 years) because lignotubers in young juveniles develop at a slower rate than in B. serrata. Extinction or substantial depletions of adult numbers may be approached in stands of either species after 50 years under some repeated 5- or 10-year fire cycles. The rate of such declines will depend directly on the structure of populations (proportions of adults and juveniles). Declines in populations of these resprouters may be likely under current fire regimes within the Sydney region of New South Wales, although these species are more likely to persist through long runs of frequent fire (<lo year interval) than some cohabiting species of obligate seeders.

No evidence of protracted population decline across 17 years in an unmanaged population of the green and golden bell frog in north-eastern New South Wales

2017 ◽  
Vol 65 (2) ◽  
pp. 87
Author(s):  
Ross L. Goldingay ◽  
Jonathan Parkyn ◽  
David A. Newell
Keyword(s):  
New South ◽  
Population Decline ◽  
New South Wales ◽  
Common Species ◽  
Population Models ◽  
Litoria Aurea ◽  
South Wales ◽  
Eastern Australia ◽  
North Eastern ◽  
Management And Conservation

Describing the population trends of threatened species over time is central to their management and conservation. The green and golden bell frog (Litoria aurea) is a formerly common species of south-eastern Australia that has declined to ~40 populations in New South Wales, and experienced a substantial contraction of its geographic range. We aimed to determine whether an unmanaged population at the northern end of its range had declined across a 17-year period. We estimated population size at the beginning and end of this period, using several population models to fully characterise this population. Different modelling approaches gave different population estimates. Based on a similar number of survey occasions the adult male segment of the population was estimated using the Popan model at 112.0 (±13.5, s.e.; 95% CI: 85.5–138.8) in 1998/99 and 95.2 (±17.6; 60.8–129.7) in 2015/16. With the inclusion of maturing subadults following the practice of earlier studies, the population was estimated at 163.6 (±25.9; 112.8–214.5) males in 2015/16. These estimates represent an index of a larger population because the largest wetland was subsampled. Our data provide no evidence of a declining population. Our study highlights the need to understand the implications of using different population models and two age-classes to estimate population parameters.

'From These Youth Has Gone': Population Decline in the Lachlan Region of New South Wales, 1920-1947

2015 ◽  
pp. 50-68
Author(s):  
Robert Tierney ◽  
Kevin Parton
Keyword(s):  
Population Change ◽  
New South ◽  
Population Decline ◽  
New South Wales ◽  
The State ◽  
South Wales ◽  
Underlying Causes ◽  
Substantial Change ◽  
Second World

This article analyses major events during the 1920s, 1930s, and 1940s affecting the Lachlan region, in New South Wales, in order to assess their relative impact on population change. The analysis juxtaposes the demographic changes taking place against the economic context of the time. The Lachlan region is compared with the four other wheatsheep regions of New South Wales and with the State generally. The paper demonstrates that population decline in the Lachlan region in the 1930s and 1940s was substantially greater than that of other wheat-sheep regions and of the State of New South Wales generally, and sets out to explain this anomaly. The Depression, the Second World War, drought over a sequence of years, and changing technology are shown, in combination, to be the underlying causes of substantial change that heralded the long-term drift of population from regional and rural NSW; especially so in the Lachlan region.

Historical changes in the distribution of hairy-nosed wombats (Lasiorhinus spp.): a review

2017 ◽  
Vol 39 (1) ◽  
pp. 1 ◽  
Author(s):  
Michael J. Swinbourne ◽  
David A. Taggart ◽  
David Peacock ◽  
Bertram Ostendorf
Keyword(s):  
New South ◽  
Population Decline ◽  
New South Wales ◽  
South Australia ◽  
European Settlement ◽  
South Wales ◽  
Western Group ◽  
Murray River ◽  
And Control ◽  
Abundant Population

We conducted a search of the historical records for any mention of hairy-nosed wombats in order to establish their likely distribution at the time of European settlement. The evidence suggests that there were two main groups of southern hairy-nosed wombats (Lasiorhinus latifrons) that were separated by Spencer Gulf in South Australia. The western group extended to Balladonia in Western Australia, while the eastern group extended along the Murray River to Euston in New South Wales. The Queensland population of northern hairy-nosed wombats (Lasiorhinus krefftii) was geographically large but highly patchy, and there was an abundant population in the New South Wales Riverina. Both species experienced a population decline between 1870 and 1920, with the main influences thought to be competition from rabbits and control actions by landholders. Our findings suggest that the ongoing control of rabbits via methods that do not harm wombats is critical for wombat conservation today. We also suggest that hairy-nosed wombats may be sensitive to climate change, and recommend more research on this topic.

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