Population monitoring of small and declining brush-tailed rock wallaby (Petrogale penicillata) colonies at the extreme of their range using faecal DNA sampling

2018 ◽  
Vol 40 (1) ◽  
pp. 58
Author(s):  
Maxine P. Piggott ◽  
Birgita Hansen ◽  
Todd Soderquist ◽  
Mark D. B. Eldridge ◽  
Andrea C. Taylor
Keyword(s):  
Genetic Diversity ◽  
Population Monitoring ◽  
Evolutionary Significance ◽  
Faecal Dna ◽  
Non Invasive ◽  
Management Actions ◽  
South Wales ◽  
Probable Loss ◽  
Declining Populations ◽  
Minimum Number

Obtaining much-needed information on population parameters such as abundance and genetic diversity can be difficult for small and declining populations. The brush-tailed rock-wallaby (Petrogale penicillata) is an endangered and cryptic species with many colonies in decline. The Warrumbungle National Park (NP) in New South Wales contains a declining metapopulation of P. penicillata at the western (inland) extreme of the species’ current range. Loss of these colonies would cause substantial range contraction and probable loss of regional genetic diversity in the Central Evolutionary Significance Unit (ESU). We used non-invasive genetic methods to identify individuals from faecal DNA from five colonies in the Warrumbungle NP. We identified a minimum of 21 individuals, with the largest colony containing seven individuals. The Warrumbungle NP colonies showed significant intercolony structuring and we were able to detect a single dispersal event. Comparison of genetic diversity to other Central ESU colonies shows that loss of the Warrumbungle NP population will result in loss of unique diversity from this region. The minimum number of animals and genetic diversity information obtained in this study was used to support management actions of herbivore control and translocation in the Warrumbungle NP population.

scholarly journals Population genetics of the school shark (Galeorhinus galeus) in New Zealand, Australian and Chilean waters

2021 ◽  
Author(s):  
◽  
Sebastián Ignacio Hernández Muñoz
Keyword(s):  
Genetic Diversity ◽  
New Zealand ◽  
Dna Markers ◽  
Microsatellite Dna ◽  
Multiple Paternity ◽  
Shark Species ◽  
Microsatellite Dna Markers ◽  
Minimum Number ◽  
Galeorhinus Galeus ◽  
Shark Fisheries

<p>The school shark (Galeorhinus galeus) is a coastal bentho-pelagic species that is highly migratory and has a widespread distribution in temperate waters. This species matures late, has a relatively low fecundity and is slow growing, which makes it vulnerable to overfishing. They are commercially fished throughout their distribution, and some global stocks have been under pressure because of poor management. In Australia, longline and gillnet fisheries targeted pregnant females and juveniles around Victorian and Tasmanian nursery grounds, resulting in loss of historical inshore nursery habitat. School shark tagging programmes have reported migration between Australian and New Zealand stocks, but preliminary genetic studies have suggested that there are slight genetic differences between the stocks. Currently, the Australian and New Zealand school shark fisheries are assessed and managed as separate stocks. However, the question of whether this species is comprised of a single population or multiple sub-populations in the South Pacific remains unresolved. Given the commercial importance of the school shark fisheries and the concern about stock levels on the regional and trans-Tasman scales, knowledge of stock structure is essential for effective management. The aim of this thesis research was to determine the levels of genetic diversity and population structure of G. galeus in New Zealand and Australia, and compare these to a population in Chile, using mitochondrial DNA (mtDNA) sequencing and microsatellite DNA markers.  The DNA sequence of an 893 base pair region of the mtDNA control region (CR) was determined using 475 school shark samples and nine microsatellite DNA loci were genotyped in 239 individuals. Analyses of the data revealed strong evidence of genetic differentiation between G. galeus populations in Australasia and Chile, suggesting restricted gene flow among populations in the western and eastern areas of the Pacific Ocean. The FST values ranged from 0.188 to 0.300 for CR mtDNA, and 0.195 to 0.247 for microsatellite DNA in G. galeus. However, there was no evidence of stock differentiation among New Zealand/Australian sample sites for either mtDNA or microsatellite DNA data. These results support the model of a single panmictic stock across the Tasman Sea. The similarity of the results obtained from the maternally inherited mtDNA and biparental inherited microsatellite loci did not support the suggestion of sex-biased dispersal of G. galeus in the New Zealand/Australia region and it was concluded that females and males had similar patterns of dispersal.  Sharks can be either monogamous or polygamous, which is important when considering stock assessments and harvesting models. Multiple paternity has been reported in several shark species, however, the number of sires per litter varies considerably among species. An investigation of multiple paternity (MP) was conducted in G. galeus by assessing the levels of relatedness within progeny arrays using six polymorphic microsatellite DNA markers. Five “families” (mother and litters) were sampled from the North Island of New Zealand and a parentage analysis was conducted. The minimum number of males contributing to each progeny array was estimated by identifying the putative paternal alleles by allele counting and reconstructing multilocus genotypes method. The analysis showed the occurrence of genetic polyandry in G. galeus; two of five litters showing multiple sires involved in the progeny arrays (40%). The minimum number of sires per litter ranged from one to four. Although MP was only detected in two litters, this finding is consistent with the known reproductive characteristics of G. galeus. It can potentially store sperm for long periods of time and has a specific mating season when males and females typically mix on the edge of the continental shelf. Detecting MP within a litter has highlighted the importance of the post-copulatory selective processes in the G. galeus mating system, and this has implications for the management and conservation of genetic diversity.</p>

scholarly journals Genetic diversity of African clawless otters (Aonyx capensis) occurring in urbanised areas of Gauteng, South Africa

2019 ◽  
Vol 115 (7/8) ◽  
Author(s):  
Damian W. Ponsonby ◽  
M. Thabang Madisha ◽  
Schwaibold Schwaibold ◽  
Desiré L. Dalton
Keyword(s):  
South Africa ◽  
Genetic Diversity ◽  
Gene Flow ◽  
Environmental Changes ◽  
Urban Expansion ◽  
Evolutionary Potential ◽  
Non Invasive ◽  
Faecal Samples ◽  
Physical Barriers ◽  
High Gene

Genetic diversity is the basis of the evolutionary potential of species to respond to environmental changes. However, restricting the movement of species can result in populations becoming less connected which can reduce gene flow and can subsequently result in a loss of genetic diversity. Urban expansion can lead to the fragmentation of habitats which affects the ability of species to move freely between areas. In this study, the genetic diversity of the African clawless otter (Aonyx capensis) in Gauteng (South Africa) was assessed using non-invasive sampling techniques. DNA was extracted from spraint (faecal) samples collected along nine rivers and genotyped using 10 microsatellites to assess population structure and genetic diversity. Samples were grouped based on locality and by catchment to determine whether isolated subpopulations exist. Genetic diversity of A. capensis in Gauteng was found to be low (mean observed heterozygosity (Ho)=0.309). Analysis of genetic structure provides support for the otter populations being panmictic with high gene flow between populations from different rivers. Results from the study indicate that the movement of A. capensis is not affected by physical barriers in urbanised areas. However, because the genetic diversity of the species in the study area is low, these animals may not be able to cope with future environmental changes.

Urban edge effects in the Blue Mountains, New South Wales: implications for design of buffers to protect significant habitats

2010 ◽  
Vol 16 (2) ◽  
pp. 92 ◽  
Author(s):  
Peter Smith ◽  
Judy Smith
Keyword(s):  
Edge Effects ◽  
Major Influence ◽  
Weed Invasion ◽  
Native Flora ◽  
Blue Mountains ◽  
The Road ◽  
Management Actions ◽  
Urban Edge ◽  
South Wales ◽  
Local Residents

Urban edge effects can have an adverse impact on native flora and fauna in the adjoining bushland. We surveyed edge effects at sites in the Blue Mountains where the urban area is separated from bushland by a perimeter road. Common edge effects included weed invasion, physical disturbance of the vegetation and soil, incidental rubbish, dumped rubbish, dumped plant material, tree felling/lopping/ringbarking and visits from domestic dogs. Uncommon edge effects included recent hazard reduction burns, bushrock collection, and poor tree health (dieback not associated with fires). The maximum extent of obvious edge effects (all types combined) varied between sites, from 9 m to 60 m from the edge of the road. At most sites (77%), edge effects were restricted to distances of 40 m or less into the bushland, but a significant number of sites (23%) had more extensive edge effects. Sites with extensive weed invasion were associated with older housing, suggesting that weed invasion will increase over time at sites adjacent to younger housing. Weed invasion frequently extended further than 60 m into the bushland along drainage lines and tracks, especially the former, but these were not included in the measurements. Edge effects were more extensive on flatter topography than downslope of housing, apparently because the former is subject to more intensive use by local residents. The actions of local residents have a major influence on edge effects, and are responsible for much of the variability observed between sites. The findings of this study are consistent with previous studies of edge effects around Sydney and elsewhere. Based on the results of the study, we recommend that a buffer of native vegetation at least 60 m wide should be retained around significant flora and fauna habitats to protect them from edge effects. Additional management actions are required to control vegetation degradation along drainage lines.

scholarly journals Validation of a noninvasive technique to quantify stress in northern bobwhite (Colinus virginianus)

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jessica L Mohlman ◽  
Kristen J Navara ◽  
Michael J Sheriff ◽  
Theron M Terhune ◽  
James A Martin
Keyword(s):  
Colinus Virginianus ◽  
Population Decline ◽  
Endocrine System ◽  
Northern Bobwhite ◽  
Noninvasive Technique ◽  
Acth Challenge ◽  
Non Invasive ◽  
Management Actions ◽  
Hunting Dog ◽  
Corticosterone Metabolites

Abstract Examination of the endocrine system through non-invasive fecal sampling may improve population management more than using demographic indicators alone. By addressing the physiological mechanisms that are influencing fitness, management actions can be proactively developed to alleviate stressors. Proactive determination of vulnerable populations is critical for species of concern, such as the Northern Bobwhite (Colinus virginianus), which have suffered decades of population decline. We validated an assay to noninvasively measure the adrenocortical response of captive reared bobwhite through fecal corticosterone metabolites (FCM). All individuals received three sequential 48-hour treatments in which samples were collected every 4 hours, including a reference period, an adrenocorticotropic hormone (ACTH) challenge and a biological stressor (exposure to a hunting dog). Reference FCM values had a mean concentration of 16.75 pg/mg (95% CrI: 13.68, 19.91) with adrenocortical activity increasing by 73% for the duration of the ACTH challenge (29.00 pg/mg; CrI: 25.01, 33.78). FCM concentrations remained similar to that of the reference levels during the biological stressor (16.56 pg/mg; CrI: 13.33, 19.92). Our study validates the use of feces to detect changes in FCM levels in our subject species but also demonstrates the complexity of FCM and the importance of both physiological and biological validation prior to field implementation.

Using ecological studies to understand the conservation needs of the squirrel glider in Brisbane?s urban forest-remnants.

2006 ◽  
Vol 28 (2) ◽  
pp. 173 ◽  
Author(s):  
R. L. Goldingay ◽  
D. J. Sharpe ◽  
G. L. Beyer ◽  
M. Dobson
Keyword(s):  
Urban Forest ◽  
Field Work ◽  
Future Research ◽  
Parameter Estimates ◽  
Nest Boxes ◽  
Management Actions ◽  
Forest Remnants ◽  
Minimum Number ◽  
Squirrel Glider ◽  
Urban Matrix

This paper provides an overview of our current ecological research on squirrel gliders (Petaurus norfolcensis) living in forest-remnants within an urban matrix in south-east Queensland. We have conducted population censuses and behavioural observations primarily in one 60-ha remnant. The number of tagged gliders (minimum number known alive) in this remnant varied from 75 in 2002 when flowering trees were abundant, to 33 the following year when flowering was poor. Poor flowering led to a delay in breeding and a decline in the probability of glider survival. Feeding observations on gliders in the year of abundant flowering revealed that almost 50% of the diet was comprised of nectar and pollen derived from 10 tree species. A more detailed focus on flowering and its influence on population dynamics at several sites would be of considerable value in understanding the population ecology of this species. We assessed the viability of the subpopulations of P. norfolcensis distributed across the various remnants to allow identification of management actions that may improve viability. Viability analyses under various scenarios suggest that our focal metapopulation will have a high likelihood of extinction within the next 100 years. Predictions of population viability are sensitive to changes in life history parameter estimates. Thus, current field-work has been directed by the need for more precise empirical values. The remnants containing our metapopulation need to be functionally linked to larger nearby remnants to enable glider dispersal among sites. We need a better understanding of glider dispersal behaviour and how permeable the urban matrix might be for P. norfolcensis. Arterial roads and freeways sever connections between many remnants, requiring novel approaches to corridor provision. Future research should examine how habitat quality of the remnants changes over time due to tree die-back and wind-throw. We are investigating the potential role of nest boxes to facilitate glider dispersal and to supplement the availability of den trees. The findings of our studies should contribute to a greater understanding of the general conservation requirements of P. norfolcensis.

The genetic diversity and distinctiveness of the Yellow-footed Rock-wallaby Petrogale xanthopus (Gray, 1854) in New South Wales

1998 ◽  
Vol 4 (2) ◽  
pp. 164 ◽  
Author(s):  
Lisa C. Pope ◽  
Andy Sharp ◽  
Craig Moritz
Keyword(s):  
Genetic Diversity ◽  
Threatened Species ◽  
New South ◽  
New South Wales ◽  
Species Conservation ◽  
Habitat Disturbance ◽  
European Settlement ◽  
South Wales ◽  
Feral Animals ◽  
Species Being

Yellow-footed Rock-wallabies (YFRW) Petrogale xanthopus have declined in numbers since European settlement from past hunting for skins, habitat disturbance and predation and competition with feral animals (Gordon et al. 1978, 1993; Copley 1983; Henzell 1990). This has led to the species being classed as potentially vulnerable to extinction in Australia (Kennedy 1992), and endangered in New South Wales (Schedule 1, Threatened Species Conservation Act, 1995).

Are vegetation interfaces important to foraging insectivorous bats in endangered coastal saltmarsh on the Central Coast of New South Wales?

2012 ◽  
Vol 18 (4) ◽  
pp. 282 ◽  
Author(s):  
Leroy Gonsalves ◽  
Bradley Law ◽  
Cameron Webb ◽  
Vaughan Monamy
Keyword(s):  
New South ◽  
Individual Species ◽  
Microhabitat Use ◽  
Central Coast ◽  
Insectivorous Bats ◽  
Insect Abundance ◽  
Bat Activity ◽  
Management Actions ◽  
South Wales ◽  
Linear Elements

Conservation of insectivorous bats and their habitats is of increasing concern in Australia and linear elements in the landscape form important foraging habitats for many species. Only recently has use of endangered coastal saltmarsh habitat by bats been documented. Vegetation adjoining saltmarsh provides echolocating bats with linear elements that may be used while foraging and commuting to patches of high insect abundance. We used acoustic detectors to investigate whether individual species and total bat activity along seaward and landward saltmarsh edges was different to the interior of the saltmarsh. Four taxa accounted for greater than 80 % of all bat activity in each zone with similar taxa recorded in both edge and interior zones. However, significantly more bat activity was recorded in edge zones. While differences in microhabitat use by individual species were also found, bat morphology did not account for the observed differences. Conservation managers of saltmarsh and adjoining habitats should consider potential impacts of management actions on foraging bats and their prey. Retention of strips of edge vegetation may help to balance the conservation requirements of endangered coastal saltmarsh habitats and the foraging insectivorous bat populations they sustain.

The decline, response to fire, status and management of the Eastern Bristlebird

1997 ◽  
Vol 3 (3) ◽  
pp. 235 ◽  
Author(s):  
Jack Baker
Keyword(s):  
Nature Reserve ◽  
New South ◽  
Population Monitoring ◽  
Average Density ◽  
Disjunct Distribution ◽  
Habitat Manipulation ◽  
Southeastern Australia ◽  
South Wales ◽  
Western Victoria ◽  
Barren Grounds

The Eastern Bristlebird Dasyornis brachypterus is a threatened passerine, endemic to southeastern Australia. It is a cryptic, ground dwelling, semi-flightless inhabitant of dense, fire-prone vegetation and is usually only detected by its calls. The disjunct distribution suggests that they were once more numerous and their population continuous from southern Queensland to western Victoria. Their decline has been documented in historic and recent times. Habitat loss, nest desertion and fire have been implicated in the decline and extinction of local populations. Strongholds for the species are Barren Grounds Nature Reserve and Bherwerre Peninsula, 100 and 150 km south of Sydney respectively. At Barren Grounds, in the absence of recent fire, there were significant increases in the population between 1992 and 1996. There was a trend of increasing Eastern Bristlebird density with increasing fire-age of habitat and average density plateauing at two birds per 5 ha, 10 years after fire. At Nadgee, a coastal Nature Reserve on the New South Wales/Victorian border, the population appears to be recovering very slowly from severe wildfires in 1972 and 1980. At the beginning of 1996 there were less than 2 000 individual Eastern Bristlebirds occupying an area of approximately 100 km2. For the management of Eastern Bristlebirds, habitat manipulation using prescribed fire should not be undertaken unless site-specific population monitoring data demonstrate that it would be beneficial. Concentrations of Eastern Bristlebirds and potential fire refuges should be protected from unplanned fire. For prescription burns, potential escape routes need to be planned for Eastern Bristlebirds. The threatened status should be changed from Vulnerable to Endangered.

scholarly journals A new non-invasive in situ underwater DNA sampling method for estimating genetic diversity

2020 ◽  
Vol 34 (4) ◽  
pp. 633-644
Author(s):  
Gergely Balázs ◽  
Judit Vörös ◽  
Brian Lewarne ◽  
Gábor Herczeg
Keyword(s):  
Genetic Diversity ◽  
Sampling Method ◽  
Non Invasive ◽  
Dna Sampling

scholarly journals Defining intraspecific conservation units in the endemic Cuban Rock Iguanas (Cyclura nubila nubila)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kyle J. Shaney ◽  
L. Grisell Diaz-Ramirez ◽  
Sayra Espindola ◽  
Susette Castañeda-Rico ◽  
Vicente Berovides-Álvarez ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Effective Population ◽  
Conservation Units ◽  
Declining Populations ◽  
Nuclear Microsatellite ◽  
Geographic Separation ◽  
Negative Impacts ◽  
Time Of Divergence ◽  
East West

AbstractDefining conservation units is an important step in species management and requires interpretation of the genetic diversity and ecological function of the taxon being considered. We used the endemic Cuban Rock Iguanas (Cyclura nubila nubila) as a model to highlight this challenge and examined patterns of its intraspecific genetic diversity across Cuba. We evaluated nuclear (microsatellite loci) and mitochondrial diversity across eight populations from the island and its off-shore cays, and applied the population genetics results for assignment of Management Unit (MU) status and Evolutionary Significant Units (ESUs) based on phylogeographic and time of divergence information. We identified at least six distinct Cuban Rock Iguana MUs, encompassing demographically isolated and genetically differentiated populations across Cuba, most with low effective population size, declining populations, and with high risk of inbreeding and genetic drift. Hence, each MU should be considered of urgent conservation priority. Given the key ecological seed dispersal role of C. n. nubila, the disappearance of any MU could trigger the loss of local ecological functional diversity and major negative impacts on their ecosystems. Two divergent ESUs were also identified, exhibiting an historical east–west geographic separation on Cuba. Based on a Caribbean phylogeographic assessment, our findings strengthen the conclusion that all geographically and evolutionarily differentiated Cyclura species and subspecies across the archipelago warrant ESU distinction.

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