20 research outputs found
Using the spatial population abundance dynamics engine for conservation management
1. An explicit spatial understanding of population dynamics is often critical for effective management of wild populations.
Sophisticated approaches are available to simulate these dynamics, but are largely either spatially homogeneous or agentbased,
and thus best suited to small spatial or temporal scales. These approaches also often ignore financial decisions crucial to
choosing management approaches on the basis of cost-effectiveness.
2. We created a user-friendly and flexible modelling framework for simulating these population issues at large spatial scales â
the Spatial Population Abundance Dynamics Engine (SPADE). SPADE is based on the STAR model (McMahon et al. 2010) and
uses a reaction-diffusion approach to model population trajectories and a cost-benefit analysis technique to calculate optimal
management strategies over long periods and across broad spatial scales. It expands on STAR by incorporating species
interactions and multiple concurrent management strategies, and by allowing full user control of functional forms and
parameters.
3. We used SPADE to simulate the eradication of feral domestic cats Felis catus on sub-Antarctic Marion Island (Bester et al.
2002) and compared modelled outputs to observed data. The parameters of the best-fitting model reflected the conditions of
the management programme, and the model successfully simulated the observed movement of the cat population to the
southern and eastern portion of the island under hunting pressure. We further demonstrated that none of the management
strategies would likely have been successful within a reasonable timeframe if performed in isolation. 4. SPADE is applicable to a wide range of population management problems, and allows easy generation, modification and
analysis of management scenarios. It is a useful tool for the planning, evaluation and optimisation of the management of wild
populations, and can be used without specialised training.Appendix S1. SPADE manual.Appendix S2. Details of algorithms used in SPADE.Appendix S3. Details of statistical models.Appendix S4. Source code for SPADE package.Appendix S5. Description of potential issues in using STAR.The development of SPADE was aided extensively by input from the Australian Alps National Parks Cooperative Management
Programmeâs Feral Horse Working Group, including participants from Parks Victoria, the NSW National Parks and Wildlife
Service, the ACT Parks and Conservation Service and Forestry Corporation NSW.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)2041-210Xhb2017Mammal Research Institut
Circumpolar habitat use in the southern elephant seal : implications for foraging success and population trajectories
In the Southern Ocean, wide-ranging predators offer the opportunity to quantify how animals respond to differences in the environment because their behavior and population trends are an integrated signal of prevailing conditions within multiple marine habitats. Southern elephant seals in particular, can provide useful insights due to their circumpolar distribution, their long and distant migrations and their performance of extended bouts of deep diving. Furthermore, across their range, elephant seal populations have very different population trends. In this study, we present a data set from the International Polar Year project; Marine Mammals Exploring the Oceans Pole to Pole for southern elephant seals, in which a large number of instruments (N = 287) deployed on animals, encompassing a broad circum-Antarctic geographic extent, collected in situ ocean data and at-sea foraging metrics that explicitly link foraging behavior and habitat structure in time and space. Broadly speaking, the seals foraged in two habitats, the relatively shallow waters of the Antarctic continental shelf and the Kerguelen Plateau and deep open water regions. Animals of both sexes were more likely to exhibit area-restricted search (ARS) behavior rather than transit in shelf habitats. While Antarctic shelf waters can be regarded as prime habitat for both sexes, female seals tend to move northwards with the advance of sea ice in the late autumn or early winter. The water masses used by the seals also influenced their behavioral mode, with female ARS behavior being most likely in modified Circumpolar Deepwater or northerly Modified Shelf Water, both of which tend to be associated with the outer reaches of the Antarctic Continental Shelf. The combined effects of (1) the differing habitat quality, (2) differing responses to encroaching ice as the winter progresses among colonies, (3) differing distances between breeding and haul-out sites and high quality habitats, and (4) differing long-term regional trends in sea ice extent can explain the differing population trends observed among elephant seal colonies.Publisher PDFPeer reviewe
A global cline in a colour polymorphism suggests a limited contribution of gene flow towards the recovery of a heavily exploited marine mammal
Evaluating how populations are connected by migration is
important for understanding species resilience because gene
flow can facilitate recovery from demographic declines. We
therefore investigated the extent to which migration may
have contributed to the global recovery of the Antarctic fur
seal (Arctocephalus gazella), a circumpolar distributed marine mammal that was brought to the brink of extinction by the sealing industry in the eighteenth and
nineteenth centuries. It is widely believed that animals emigrating from South Georgia, where a
relict population escaped sealing, contributed to the re-establishment of formerly occupied
breeding colonies across the geographical range of the species. To investigate this, we interrogated
a genetic polymorphism (S291F) in the melanocortin 1 receptor gene, which is responsible for a
cream-coloured phenotype that is relatively abundant at South Georgia and which appears to have
recently spread to localities as far afield as Marion Island in the sub-Antarctic Indian Ocean. By
sequencing a short region of this gene in 1492 pups from eight breeding colonies, we showed that
S291F frequency rapidly declines with increasing geographical distance from South Georgia,
consistent with locally restricted gene flow from South Georgia mainly to the South Shetland
Islands and BouvetĂžya. The S291F allele was not detected farther afield, suggesting that although
emigrants from South Georgia may have been locally important, they are unlikely to have played a
major role in the recovery of geographically more distant populations.J.I.H., E.B., A.J.P., E.H., L.M.B., C.K., F.C., N.K., B.F. and A.M. were funded by Deutsche
Forschungsgemeinschaft (DFG) standard grant no. (HO 5122/3-1) and this research was also partly funded by the
DFG as part of the SFB TRR 212 (NC3, project A01). A.C.C., C.L., K.M.K. and A.L. were funded by projects from
the Norwegian Antarctic Research Expeditions. The Department of Science and Technology of South Africa
provided funding through the National Research Foundation (NRF) for Marion Island research. Support for the
publication fee was provided by the DFG and the Open Access Publication Funds of Bielefeld University.http://rsos.royalsocietypublishing.orgam2019Mammal Research InstituteZoology and Entomolog
The retrospective analysis of Antarctic tracking data project
The Retrospective Analysis of Antarctic Tracking Data (RAATD) is a Scientific Committee for Antarctic Research project led jointly by the Expert Groups on Birds and Marine Mammals and Antarctic Biodiversity Informatics, and endorsed by the Commission for the Conservation of Antarctic Marine Living Resources. RAATD consolidated tracking data for multiple species of Antarctic meso- and top-predators to identify Areas of Ecological Significance. These datasets and accompanying syntheses provide a greater understanding of fundamental ecosystem processes in the Southern Ocean, support modelling of predator distributions under future climate scenarios and create inputs that can be incorporated into decision making processes by management authorities. In this data paper, we present the compiled tracking data from research groups that have worked in the Antarctic since the 1990s. The data are publicly available through biodiversity.aq and the Ocean Biogeographic Information
System. The archive includes tracking data from over 70 contributors across 12 national Antarctic programs, and includes data from 17 predator species, 4060 individual animals, and over 2.9 million observed locations
The retrospective analysis of Antarctic tracking data project
The Retrospective Analysis of Antarctic Tracking Data (RAATD) is a Scientific Committee for
Antarctic Research project led jointly by the Expert Groups on Birds and Marine Mammals and
Antarctic Biodiversity Informatics, and endorsed by the Commission for the Conservation of
Antarctic Marine Living Resources. RAATD consolidated tracking data for multiple species
of Antarctic meso- and top-predators to identify Areas of Ecological Significance. These
datasets and accompanying syntheses provide a greater understanding of fundamental
ecosystem processes in the Southern Ocean, support modelling of predator distributions
under future climate scenarios and create inputs that can be incorporated into decision
making processes by management authorities. In this data paper, we present the compiled
tracking data from research groups that have worked in the Antarctic since the 1990s. The
data are publicly available through biodiversity.aq and the Ocean Biogeographic Information
System. The archive includes tracking data from over 70 contributors across 12 national
Antarctic programs, and includes data from 17 predator species, 4060 individual animals, and
over 2.9 million observed locations.Supplementary Figure S1: Filtered location data (black) and tag deployment locations (red) for each species.
Maps are Lambert Azimuthal projections extending from 90° S to 20° S.Supplementary Table S1: Names and coordinates of the major study sites in the Southern Ocean and on the Antarctic Continent where tracking devices were deployed on the selected species (indicated by their 4-letter codes in the last column).Online Table 1: Description of fields (column names) in the metadata and data files.Supranational committees and organisations including the Scientific Committee on Antarctic Research Life Science Group and BirdLife International. National institutions and foundations, including but not limited to Argentina (DirecciĂłn Nacional del AntĂĄrtico), Australia (Australian Antarctic program; Australian Research Council; Sea World Research and Rescue Foundation Inc., IMOS is a national collaborative research infrastructure, supported by the Australian Government and operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent), Belgium (Belgian Science Policy Office, EU Lifewatch ERIC), Brazil (Brazilian Antarctic Programme; Brazilian National Research Council (CNPq/MCTI) and CAPES), France (Agence Nationale de la Recherche; Centre National dâEtudes Spatiales; Centre National de la Recherche Scientifique; the French Foundation for Research on Biodiversity (FRB; www.fondationbiodiversite.fr) in the context of the CESAB project âRAATDâ; Fondation Total; Institut Paul-Emile Victor; Programme Zone Atelier de Recherches sur lâEnvironnement Antarctique et Subantarctique; Terres Australes et Antarctiques Françaises), Germany (Deutsche Forschungsgemeinschaft, Hanse-Wissenschaftskolleg - Institute for Advanced Study), Italy (Italian National Antarctic Research Program; Ministry for Education University and Research), Japan (Japanese Antarctic Research Expedition; JSPS Kakenhi grant), Monaco (Fondation Prince Albert II de Monaco), New Zealand (Ministry for Primary Industries - BRAG; Pew Charitable Trusts), Norway (Norwegian Antarctic Research Expeditions; Norwegian Research Council), Portugal (Foundation for Science and Technology), South Africa (Department of Environmental Affairs; National Research Foundation; South African National Antarctic Programme), UK (Darwin Plus; Ecosystems Programme at the British Antarctic Survey; Natural Environment Research Council; WWF), and USA (U.S. AMLR Program of NOAA Fisheries; US Office of Polar Programs).http://www.nature.com/sdataam2021Mammal Research Institut
The functional morphology of the kidney of the Cape fur seal, Arctocephalus pusillus (Schreber)
Thesis (M. Sc.) -- University of Stellenbosch, 1974.Full text to be digitised and attached to bibliographic record
The ontogeny of at-sea behaviour in male southern elephant seals (Mirounga leonina) at Marion Island
DATA AVAILABILITY : Data will be made available on request.Megafauna, such as southern elephant seals (SESs) (Mirounga leonina, Linn.), forage in diverse, seemingly limitless habitats. In pelagic settings, their behaviour is more likely to be limited by physiological ability and prey distribution, than physical barriers. For elephant seals, their rapid growth in body size corresponds to changing physiological abilities. These changes are most pronounced for male elephant seals. While most studies have compared male and female SESs in terms of changing body size and physiological ability, few studies have compared the influence of changing body size on behaviour of male SESs from the same population using long term satellite tracking data. We describe age-related differences in movement and diving behaviour for male SESs from Marion Island. We analysed satellite tracking data collected from 23 male SESs seals fitted with Sea Mammal Research Unit Satellite Relay Data Loggers at Marion Island between 2005 and 2011. Each dive was assigned a behavioural mode, either âsearchingâ or âtransitâ, using state-space modelling. We used mixed-effects models to quantify the influence of age and behavioural mode on dive duration, surface duration, dive depth and number of daily dives. Younger seals travelled significantly further from Marion Island and spent most of their dives in transit mode, whereas older seals stayed closer to the island but were in searching mode for most of their tracks. When searching, older seals dived more frequently, displayed longer dive and surface durations, and reached greater depths than younger seals. These differences in diving behaviour seem to reflect changing physiological ability. For male SESs, changes in physiological ability necessitate behavioural plasticity, which may be the key to survival and future breeding success. Robust males are more likely to breed and must therefore, maintain their body size by adapting to local oceanic conditions.The Alfred Wegener Institute for Polar and Marine Research (Germany), the Department of Science and Innovation through the National Research Foundation (South Africa), the Department of Forestry, Fisheries and the Environment via the South African National Antarctic Programme, the Australian Antarctic Division and Hubbs-SeaWorld Research Institute. The âArcGISâ software was funded by the University of Pretoria, Pretoria, South Africa.https://www.elsevier.com/locate/jembe2023-11-22hj2023Mammal Research InstituteZoology and Entomolog
Using the Spatial Population Abundance Dynamics Engine for conservation management
Appendix S1. SPADE manual.Appendix S2. Details of algorithms used in SPADE.Appendix S3. Details of statistical models.Appendix S4. Source code for SPADE package.Appendix S5. Description of potential issues in using STAR.1. An explicit spatial understanding of population dynamics is often critical for effective management of wild populations.
Sophisticated approaches are available to simulate these dynamics, but are largely either spatially homogeneous or agentbased,
and thus best suited to small spatial or temporal scales. These approaches also often ignore financial decisions crucial to
choosing management approaches on the basis of cost-effectiveness.
2. We created a user-friendly and flexible modelling framework for simulating these population issues at large spatial scales â
the Spatial Population Abundance Dynamics Engine (SPADE). SPADE is based on the STAR model (McMahon et al. 2010) and
uses a reaction-diffusion approach to model population trajectories and a cost-benefit analysis technique to calculate optimal
management strategies over long periods and across broad spatial scales. It expands on STAR by incorporating species
interactions and multiple concurrent management strategies, and by allowing full user control of functional forms and
parameters.
3. We used SPADE to simulate the eradication of feral domestic cats Felis catus on sub-Antarctic Marion Island (Bester et al.
2002) and compared modelled outputs to observed data. The parameters of the best-fitting model reflected the conditions of
the management programme, and the model successfully simulated the observed movement of the cat population to the
southern and eastern portion of the island under hunting pressure. We further demonstrated that none of the management
strategies would likely have been successful within a reasonable timeframe if performed in isolation. 4. SPADE is applicable to a wide range of population management problems, and allows easy generation, modification and
analysis of management scenarios. It is a useful tool for the planning, evaluation and optimisation of the management of wild
populations, and can be used without specialised training.The development of SPADE was aided extensively by input from the Australian Alps National Parks Cooperative Management
Programmeâs Feral Horse Working Group, including participants from Parks Victoria, the NSW National Parks and Wildlife
Service, the ACT Parks and Conservation Service and Forestry Corporation NSW.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)2041-210Xhb2017Mammal Research Institut
Data from: Population differentiation in the context of Holocene climate change for a migratory marine species, the southern elephant seal
Understanding observed patterns of connectivity requires an understanding of the evolutionary processes that determine genetic structure among populations, with the most common models being associated with isolation by distance, allopatry or vicariance. Pinnipeds are annual breeders with the capacity for extensive range overlap during seasonal migrations, establishing the potential for the evolution of isolation by distance. Here we assess the pattern of differentiation among six breeding colonies of the southern elephant seal, Mirounga leonina, based on mtDNA and 15 neutral microsatellite DNA markers, and consider measures of their demography and connectivity. We show that all breeding colonies are genetically divergent and that connectivity in this highly mobile pinniped is not strongly associated with geographic distance, but more likely linked to Holocene climate change and demographic processes. Estimates of divergence times between populations were all after the Last Glacial Maximum, and there was evidence for directional migration in a clockwise pattern (with the prevailing current) around the Antarctic. We discuss the mechanisms by which climate change may have contributed to the contemporary genetic structure of southern elephant seal populations and the broader implications
Median pupping date, pup mortality and sex ratio of fur seals at Marion Island
Modelling fur seal populations requires the accurate assessment of demographic parameters such as age-specific mortality. Owing to the highly variable mortality rates that pups are subject to, mortality of this age class is perhaps the most important factor determining the number of surviving individuals within each cohort. Early pup mortality,sex ratio and median pupping date were determined for sympatric populations of Subantarctic fur seals (Arctocephalus tropicalis) and Antarctic fur seals (A. gazella) at Marion Island, Southern Ocean. Mortality for this species was density dependent, varying from 0.8% at low density sites to 10.9% at high density sites. More accurate methods employed at low-density sites showed a substantially higher pup mortality at three weeks of 1.3-3.4% for Subantarctic fur seals. The same method yielded a mortality estimate at four weeks of age of 1.1-5.1% for Antarctic fur seals. Despite the underestimate inherent in island-wide counts for Subantarctic fur seals, these estimates are still useful for observing temporal and spatial patterns. Sex ratios were at parity for newborns of both species. The sex ratio of eightweek-old Subantarctic fur seal pups was also at parity, which is unusual for fur seal populations. The median pupping dates determined for Subantarctic fur seals and Antarctic fur seals did not differ substantially from previous estimates