Wildlife Databases Research Articles

Species Composition, Distribution and Habitat Types of Odonata in the iSimangaliso Wetland Park, KwaZulu-Natal, South Africa and the Associated Conservation Implications

Maputaland–Pondoland–Albany, South Africa has been identified as a biodiversity hotspot and centre for endemism. Odonata make good indicators of freshwater ecosystem health. Consequently we compiled a list of Odonata species recorded to date in the iSimangaliso Wetland Park. We then detailed important species in terms of endemism, conservation status, and potential as indicator species. Finally, we compared Odonata assemblages of different sites sampled within the park to illustrate habitat importance. Species identified during two formal surveys and incidental observations made during the study period were combined with an existing database to compile an accurate and up to date species list for the iSimangaliso Wetland Park. Data from this study were then analyzed to determine which water bodies had the most similar species composition. The Dragonfly Biotic Index (DBI) value of each study area was also determined. We recorded 68 odonate species in the iSimangaliso Wetland Park, adding 13 species to the Ezemvelo KwaZulu-Natal Wildlife database for the area. This brings the total number of Odonata species for the iSimangaliso Wetland Park to 86. Eight species are red-listed, 12 are restricted in South Africa to the coastal plains of northern KwaZulu-Natal, and the remainder occurs widely across the southern African savanna. Analyses indicate that species odonate assemblages were most similar in water bodies with comparable habitats. iSimangaliso Wetland Park is identified as an important area for Odonata diversity and endemism, a trend also reflected by the DBI values. Shifts in the existing species assemblages would indicate changes within the ecosystem and thus this species account provides necessary baseline data for the area. Species Conservation efforts should thus target water bodies of varying habitat types to protect greater species diversity.

Extinction in Eden: identifying the role of climate change in the decline of the koala in south-eastern NSW

Context Reviews of climate change in Australia have identified that it is imposing additional stresses on biodiversity, which is already under threat from multiple human impacts. Aims The present study aimed to determine the contributions of several factors to the demise of the koala in the Eden region in south-eastern New South Wales and, in particular, to establish to what extent climate change may have exacerbated the decline. Methods The study built on several community-based koala surveys in the Eden region since 1986, verified through interviews with survey respondents. Historical records as far back as the late 19th century, wildlife databases and field-based surveys were used to independently validate the community survey data and form a reliable picture of changes in the Eden koala population. Analysis of the community survey data used a logistic model to assess the contribution of known threats to koalas, including habitat loss measured as changes in foliage projective cover, fire, increases in the human population and climate change in the form of changes in temperature and rainfall, to the regional decline of this species. Key results We found a marked, long-term shrinkage in the distribution of the koala across the Eden region. Our modelling demonstrated that a succession of multiple threats to koalas from land use (human population growth and habitat loss) and environmental change (temperature increase and drought) were significant contributors to this decline. Conclusions Climate change, particularly drought and rising temperatures, has been a hitherto hidden factor that has been a major driver of the decline of the koala in the Eden region. Implications Development of strategies to help fauna adapt to the changing climate is of paramount importance, particularly at a local scale.

Latitudinal range shifts in Australian flying‐foxes: A re‐evaluation

AbstractRecent range shifts towards higher latitudes have been reported for many animals and plants in the northern hemisphere, and are commonly attributed to changes in climate. Relatively little is known about such changes in the southern hemisphere, although it has been suggested that latitudinal distributions of the fruit‐batsPteropus alectoandPteropus poliocephaluschanged during the 20th century in response to climate change in eastern Australia. However, historical changes in these species distributions have not been examined systematically. In this study we obtained historical locality records from a wide range of sources (including banding and museum records, government wildlife databases and unpublished records), and filtered them for reliability and spatial accuracy. The latitudinal distribution of each species was compared between eight time‐periods (1843–1920, 1921–1950, five 10‐year intervals between 1950 and 2000, and 2001–2007), using analyses of both the filtered point data (P. alecto870 records,P. poliocephalus2506) and presence/absence data within 50 × 50 km grid cells. The results do not support the hypothesis that either species range is shifting in a manner driven by climate change. First, neither the northern or southern range limits ofP. poliocephalus(Mackay, Queensland and Melbourne, Victoria respectively) changed over time. Second,P. alecto's range limit extended southward by 1168 km (approximately 10.5 degrees latitude) during the twentieth century (from approximately Rockhampton, Queensland to Sydney, New South Wales). Within this zone of southward expansion (25–29°S), the percentage of total records that wereP. alectoincreased from 8% prior to 1950 to 49% in the early 2000s, and local count data showed that its abundance increased from several hundred to more than 10 000 individuals at specific roost sites, as range expansion progressed.Pteropus alectoexpanded southward at about 100 km/decade, compared with the 10–26 km/decade rate of isotherm change, and analyses of historical weather data show that the species consequently moved into recently‐colder regions than it had previously occupied. Neither climate change nor habitat change could provide simple explanations to explainP. alecto's observed rapid range shift. More generally, climate change should not be uncritically inferred as a primary driver of species range shifts without careful quantitative analyses.

The response of herpetofauna to urbanization: Inferring patterns of persistence from wildlife databases

AbstractUrbanization involves the conversion of natural habitats into human‐modified ecosystems and is known to reduce the diversity and abundance of indigenous plant and animal communities. Urbanization may lead to the extinction of indigenous species or facilitate the establishment of non‐indigenous communities in cities and towns. We analysed sighting records held in wildlife databases to infer the probability of persistence of reptiles and amphibians (‘herpetofauna’) within Melbourne, Victoria, Australia. Throughout greater Melbourne, 81% (13) of the 16 frog species recorded had ≥95% probability of being extant in 2006, compared with 56% (22) of the 39 species of reptiles recorded. The number of frog species that had ≥95% probability of being extant in inner local government areas (LGAs) within 10 km of the centre of Melbourne was higher (86%) than in the outer LGAs (69%). Conversely, only 46% of reptile species had ≥95% probability of being extant in inner and outer LGAs. The proportion of reptile species with <50% probability of being extant in inner LGAs was higher than for frog species (25% and 7%, respectively), suggesting that reptiles have been negatively affected by urbanization to a much greater extent than frogs. Based on the probability of species being extant, frogs and reptiles exhibited variations in their response to urbanization between species that persisted (urban‐adapters) and species that did not (urban‐sensitive or urban‐avoiders). These differences in response were likely related to individual species' life‐history and their requirements for habitat, space and dispersal. To conserve herpetofauna in urban areas we need to maintain structural complexity in remnant habitat patches, and implement strategic policies and management actions that protect habitat remnants and habitat corridors.

Comprehensive, integrated database of elements contributing to bottom and volume clutter.

Multiple components within and at the bottom of the water column can scatter acoustic signals, resulting in decreased sonar performance and compromised tactical decision making. Many of the biological organisms that contribute to acoustic clutter are also protected or managed species, integral to a fully functional marine ecosystem. In order to understand, predict, and model bottom and volume scattering, detailed descriptions of the spatial, spectral, and temporal variability of clutter elements are needed, along with reliable estimates of backscattering strength. All of these necessary components are dependent on marine wildlife databases. Efforts by several organizations have resulted in databases that provide pieces of the overall puzzle. Databases of distribution and abundance (Census of Marine Life’s OBIS‐SEAMAP), two‐dimensional movement (Census of Marine Life’s Tagging of Pacific Pelagics), and diving and movement behavior (Marine Wildlife Behavior Database) are examples of current, but disparate, ...

Red fox population decrease in hungary: Competition or carrying capacity limitation?

In the last two decades the Hungarian red fox (Vulpes vulpes) population (POP) has grown significantly. The growing trend was broken in 2002. We tested two hypotheses: (1) the POP falling due to a fox POP size that is above the carrying capacity (CC) that initiates internal control mechanisms (H1); or (2) a fall in the POP due to competition from the expanding golden jackal POP (H2). Data was collected in one of three ways: (1) voluntary questionnaire survey from Game Management Units regarding estimated (EST) fox POP size; (2) country and countywide hunting (HUNT) bag data from the National Wildlife Database; and (3) POP dynamics (DYN) data obtained from 1,352 dissected fox carcasses. For H1, the pop density was calculated from the EST fox POP size, the hunt mortality (MORT) was calculated from the hunt bag data, and the natural mortality was calculated from the difference between the following year’s EST POP size and the average litter size and stock of the current year. For H2 we examined data from three counties (Baranya, Bacs-Kiskun, Somogy) where a considerable breeding golden jackal POP exists. The county data have been compared with each other and with data for the whole of Hungary. The average POP DYN parameters have increased significantly from 1998 to 2002. In 2002, density was 9.47 sp/1,000 hectares, HUNT MORT was 8.2 sp/1,000 hectares, litter size was 7.1 sp, the reproductive (REP) rate for bitches was 55.14%, and the overall reproductive rate was 22.04 sp/1,000 hectares (the natural MORT rate was 15.36). In 2002, the natural mortality rate was nearly two times the HUNT bag rate. The Bacs-Kiskun county data parallels the average country’s data. Some differences in Baranya county’s data were noticeable when compared to the country’s data POP DYN parameters were of larger magnitude. In 2002 the POP density was 19.23 sp/1,000 hectares, the HUNT MORT was 9.8 sp/1,000 hectares, the REP rate was 44.77 sp/1,000 hectares, and the natural MORT rate was 42.96 in Baranya county. H1 seems to be supported by our results. POP size was above carrying capacity and internal control mechanisms were at work. The rodent POP decline in 2003 may have assisted in Dogs and other canines in the wild 63

Occupancy of Random Plots by White‐Tailed and Gunnison's Prairie Dogs

ABSTRACT Areas occupied by white‐tailed prairie dogs (WTPD; Cynomys leucurus) and Gunnison's prairie dogs (GPD; C. gunnisoni) are not well‐known in Colorado (USA) and elsewhere. Suitable methodology for monitoring changes in populations of WTPD and GPD over broad areas also has not been well established. We evaluated occupancy modeling methodology to establish baseline occupancy rates for WTPD and GPD in Colorado. We estimated that WTPD occupied 24.1% (SE = 12.8) of 47,710 0.25‐km2 plots and GPD occupied 7.5% (SE = 1.3) of 158,225 0.25‐km2 plots in Colorado during 2004 and 2005. Areas reported as colonies in the Colorado Division of Wildlife's database were not good predictors of WTPD and GPD occupancy. Occupancy rates were highest for GPD at intermediate elevations. We estimated detection probabilities for surveys from the ground of 0.760 (SE = 0.042) for WTPD and 0.786 (SE = 0.060) for GPD. Probability of detection for WTPD improved with lower temperature and earlier Julian date, whereas no covariates improved detection rates for GPD. We recommend that wildlife managers use occupancy monitoring to establish status and trends in populations of WTPD and GPD across their range.

Review of the past distribution and decline of the Southern Bell FrogLitoria raniformisin New South Wales

The Southern Bell Frog Litoria raniformis was formally widespread throughout south eastern Australia. Poor knowledge of the past and present distribution of populations and the pattern of decline currently limits our ability to plan conservation measures. The past and present distribution of L raniformis in New South Wales (NSW) is described through the use of museum records, wildlife databases, reports and surveys. Survey identified a further 10 populations, all in lower Murrumbidgee floodplain (Lowbidgee), and confirmed the absence of L raniformis in past habitats along the middle reaches of the Murrumbidgee River. Based on past records, L raniformis declines have been substantial. The eastern edge of the geographic range has shifted approximately 500 km west from the South Eastern Highlands, and the northern edge of its range has shifted 200 km south from the most northerly population in Willandra National Park. Litoria raniformis is currently restricted to the semi-arid zone of NSW with populations oc...

The distribution of the greater broad-nose bat Scoteanax rueppellii (Microchiroptera: Vespertilionidae) in relation to climate and topography.

Concepts of the distribution of the greater broad-nose bat (Scoteanax rueppellii) have changed significantly as occurrence records have accumulated over the years. Early accounts of the species' distribution suggested that it was restricted to the heavily timbered areas of eastern Australia, and occurred over a wide range of altitudes. However, recent summaries of the distribution of the species differ significantly from these early accounts. To reconcile these discrepancies, I collated records from museum collections and wildlife databases. These data clearly indicate that stated altitudinal limits for the species are not correct. The currently known southern limit of the species is near Eden, New South Wales (NSW). The distribution of the species was modelled using the DOMAIN climate matching algorithm. The model indicates that S. rueppellii may occur in East Gippsland, Victoria, suggests its likely occurrence in inland Queensland and northern NSW, but a low likelihood of occurrence in inland southern NSW. However, the data show strong spatial and temporal biases that restrict the confidence that may be placed in the model. It is argued that species distributions must be regarded as open and evolving hypotheses.

Predicting the local dynamics of epizootic rabies among raccoons in the United States.

Mathematical models have been developed to explore the population dynamics of viral diseases among wildlife. However, assessing the predictions stemming from these models with wildlife databases adequate in size and temporal duration is uncommon. An epizootic of raccoon rabies that began in the mid-Atlantic region of the United States in the late 1970s has developed into one of the largest and most extensive in the history of wildlife rabies. We analyzed the dynamics of local epizootics at the county level by examining a database spanning more than 20 years and including 35,387 rabid raccoons. The size, number, and periodicity of rabies epizootics among raccoons were compared with predictions derived from a susceptible, exposed, infectious, and recovered model of raccoon rabies [Coyne, J., Smith, G. & McAllister, F. E. (1989) Am. J. Vet. Res. 50, 2148-2154]. After our methods for defining epizootics were applied to solutions of the model, the time series revealed recurrent epizootics in some counties, with a median first epizootic period of 48 months. Successive epizootics declined in size and the epizootic period progressively decreased. Our reanalysis of the model predicted the initial-epizootic period of 4-5 years, with a progressive dampening of epizootic size and progressive decrease in epizootic period. The best quantitative agreement between data and model assumed low levels of immunity (1-5%) within raccoon populations, suggesting that raccoons develop little or no rabies immune class. These results encourage the use of data obtained through wildlife surveillance in assessing and refining epidemic models for wildlife diseases.