Monitoring and population estimation of the European badger (Meles meles) in Northern Ireland

The estimation of animal abundance has a central role in wildlife management and research, including the role of badgers Meles meles in bovine tuberculosis transmission to cattle. This is the first study to examine temporal change in the badger population of Northern Ireland over amedium- to long-term time frame of 14-18 years by repeating a national survey first conducted during 1990-1993. A total of 212 1-km2 squares were surveyed during 2007-2008 and the number, type and activity of setts therein recorded. Badgers were widespread with 75% of squares containing at least one sett. The mean density of activemain setts,which was equivalent to badger social group density, was 0.56 (95%CI: 0.46-0.67) active main setts per km2 during 2007-2008. Social group density varied significantly among landclass groups and counties. The total number of social groups was estimated at 7,600 (95%CI: 6,200-9,000) and, not withstanding probable sources of error in estimating social group size, the total abundance of badgers was estimated to be 34,100 (95% CI: 26,200-42,000). There was no significant change in the badger population from that recorded during 1990-1993. A resource selection model provided a relative probability of sett construction at a spatial scale of 25m. Sett locations were negatively associated with elevation and positively associated with slope, aspect, soil sand content, the presence of cover, and the area of improved grassland and arable agriculture within 300 m.

Ecogeography of roe deer: relation with other ungulates in sympatry

Understanding the spatial distribution of organisms is a central topic in ecology. The European roe deer (Capreolus capreolus) population is in Portugal and Norway at the southwestern and northern edge of its distribution, respectively. Understanding the factors that act on these populations enlightens both local aspects concerning their conservation and wider scale aspects of the species bioclimatic envelope, which is crucial for being better able to predict the impacts of environmental change. The main aim of this thesis was to evaluate roe deer distribution in Portugal and Norway, two countries with contrasting landscapes, seasonality and with different anthropogenic pressure. The interspecific relationship with sympatric ungulates was also analysed. By using pellet group counts, we investigated habitat use of roe deer, identifying the major environmental descriptors, to understand the importance of forest structure, vegetation characteristics, landscape structure and human disturbance on their distribution. The analyses were based on presence – absence data and were carried out at two spatial scales. The results showed that habitat use of roe deer was different across countries. In Portugal, at the local scale, roe deer distribution was positively associated with high density of shrubs, especially heather and brambles, while the presence of red deer had a negative effect on their distribution. At a broad scale, roe deer was negatively associated with spatial heterogeneity, namely mean shape index and made less use of areas close to agricultural fields. In Norway, at the local scale, roe deer made more use of areas with high cover of deciduous trees and patches containing juniper and Vaccinium sp.. At a broad scale, roe deer use patches near edges between fields and forest. In both countries, roe deer make use of areas further away from roads. While in Norway roe deer in both summer and winter are always close to houses, in Portugal they are either far (summer) or indifferent (winter). Anthropogenic disturbance is better tolerated in Norway, where the importance of the critical season seems to be higher. Human disturbance may contribute to roe deer habitat loss in Portugal, while roe deer are able to persist close to humans in managed landscapes in Norway. In fact, some of the differences observed could be more due to the indirect impacts of human exploitation (e.g. presence of free-ranging dogs and hunting regulation) rather than the actual human presence or land-use per se. I conclude that the methodology and tools developed here are readily expandable to address similar questions in different contexts. Wildlife management would benefit greatly from a more holistic/integrative approach and that should include human aspects, as human disturbance is expected to continue increasing.

Using non-invasive techniques to examine black bear (Ursus americanus) abundance in the North Cascades Ecosystem, Washington State

Thesis (Master's)--University of Washington, 2013

Bald eagle (Haliaeetus leucocephalus) population increases in Placentia Bay, Newfoundland: evidence for habitat saturation?

Across North America, Bald Eagle (Haliaeetus leucocephalus) populations appear to be recovering following bans of DDT. A limited number of studies from across North America have recorded a surplus of nonbreeding adult Bald Eagles in dense populations when optimal habitat and food become limited. Placentia Bay, Newfoundland is one of these. The area has one of the highest densities of Bald Eagles in eastern North America, and has recently experienced an increase in the proportion of nonbreeding adults within the population. We tested whether the observed Bald Eagle population trends in Placentia Bay, Newfoundland during the breeding seasons 1990-2009 are due to habitat saturation. We found no significant differences in habitat or food resource characteristics between occupied territories and pseudo-absence data or between nest sites with high vs. low nest activity/occupancy rates. Therefore there is no evidence for habitat saturation for Bald Eagles in Placentia Bay and alternative hypotheses for the high proportion of nonbreeding adults should be considered. The Newfoundland population provides an interesting case for examination because it did not historically appear to be affected by pollution. An understanding of Bald Eagle population dynamics in a relatively pristine area with a high density can be informative for restoration and conservation of Bald Eagle populations elsewhere.

Protecting developing countries' forests: enforcement in theory and practice

This paper relates the key findings of the optimal economic enforcement literature to practical issues of enforcing forest and wildlife management access restrictions in developing countries. Our experiences, particularly from Tanzania and eastern India, provide detail of the key pragmatic issues facing those responsible for protecting natural resources. We identify large gaps in the theoretical literature that limit its ability to inform practical management, including issues of limited funding and cost recovery, multiple tiers of enforcement and the incentives facing enforcement officers, and conflict between protected area managers and rural people's needs.

Influence of Radiotransmitters on Fecal Glucocorticoid Levels of Free-Ranging Male American Kestrels

Although radiotelemetry is considered a valuable technique for ornithological field studies, several assumptions have been made about the impact that transmitters may have on the estimation of behavioral, ecological, and reproductive parameters. To assess the potential effects of backpack radiotransmitters, we captured and assigned 8 male American kestrels (Falco sparverius) into 2 groups: radiotagged (n = 6) and control individuals (leg-banded, n = 2). Thereafter, we collected feces approximately 2 hours after capture (day -1), and subsequently during days 0 (releasing day), 4, 7, 15, 30, 40, and 55. Prior to fecal analysis, we validated the corticosterone enzyme immunoassay using standard procedures (e. g., parallelism, dose-response curve), and we confirmed physiological significance of fecal glucocorticoid metabolites through adrenocorticotropin challenge, which induced an increase of 4-fold (446.10 +/- 60.73 ng/g) above baseline (114.27 +/- 15.23 ng/g) within 4 hours (P < 0.001). Both groups exhibited a significant increase in fecal glucocorticoids during day 0 (P < 0.001), but concentrations returned to preattachment values within 4 days. Fecal glucocorticoid concentrations did not differ between samples of radiotagged and leg-banded kestrels (P > 0.05). In spite of the small number of monitored subjects, these findings suggested that radiotransmitters did not affect adrenocortical activity in these male American kestrels. (JOURNAL OF WILDLIFE MANAGEMENT 73(5): 772-778; 2009)

Landscape influences on avian density in urban remnant vegetation

The management of urban environments is an increasingly important issue on an international scale as humans emigrate from rural areas to cities. Designing cities that can sustain mass human expansion while maintaining biodiversity is becoming an increasingly complex challenge for land managers. This is largely due to the lack of knowledge on how urbanization impacts upon biodiversity. Our previous research has highlighted the importance of urban remnant vegetation for avian diversity, but also suggested that landscape scale influences may have considerable impacts on the ability for a remnant to sustain species. We have since conducted a study examining avian diversity in 38 urban remnants ranging in size from 5ha to 107ha. These sites vary in relation to the quality of vegetation in the patch and their level of isolation from other remnant patches. This talk discusses the relative influences of remnant patch size, vegetation quality and isolation on avian diversity in urban remnant vegetation. We discuss how the findings of this research could be applied to managing avian diversity in the urban landscape.

Non-invasive sampling techniques : applications for mapping the generic variation of powerful owls

The Powerful Owl (Ninox strenua) is endemic to Australia, being resident in the three eastern mainland states and the Australian Capital Territory. It is classified nationally as of conservation significance and vulnerable in the state of Victoria. The elusive nature of this owl, along with its dispersed distribution, low population density and difficulty in identifying individual birds, limit the collection of ecological data. Molecular methods can be used to obtain crucial ecological information, essential for Powerful Owl conservation.

Non-invasive sampling is a relatively new method used for obtaining genetic material from free-ranging animals. This type of sampling however, is generally overlooked as a potential DNA source. Shed hair and feathers, faeces, urine, skins and eggshells are all potential sources of DNA. Non-invasive sampling regimes may be the only alternative for the genetic analysis of endangered and/or elusive species that are difficult to sample otherwise.

Powerful Owls moult annually. Shed feathers therefore, can be collected from under roost trees and used for genetic analysis. Feathers collected provide DNA that is unique to the individual and can provide additional ecological knowledge of the species.

In this study we collected shed Powerful Owl feathers during 2003 and 2004. In order to obtain samples from across the owl's large distribution, public awareness about the project via the way of flyers, mail-outs, media sources (radio, newspapers and magazines), email lists and public seminars was initiated. Overall, the collection strategy was very successful with over 500 Powerful Owl feather samples being collected.

Genetic information obtained from the analysis of DNA from feathers can enable a more rigorous assessment of population viability of the Powerful Owl. Specifically designed molecular markers will facilitate unequivocal identification of individual birds ("DNA fingerprinting"). Through the application of molecular techniques we can collect ecological information about the Powerful Owl such as, genetic divergence, population structure, dispersal patterns, migration and inbreeding. These questions can not be addressed via traditional data collection and will contribute significantly to the successful conservation of the Powerful Owl and potentially other raptor species.

Banding and radio-tracking juvenile powerful owls in Melbourne, Victoria : trials and tribulations

The Powerful Owl (Ninox strenua) is Australia's largest owl. Considering their large size they are a very cryptic species, with limited sexual dimorphism, silent fight and a highly camouflaged presence amongst secluded canopy vegetation. These features enable Powerful Owl presence to often go unnoticed and even for the trained eye, extremely difficult to study. Our research has focused on monitoring the behaviour of individual Powerful Owls in urban Melbourne, Australia.
The leg banding of Powerful Owls is a somewhat contentious issue in Australia and here we report on the suitability of different types of legs bands placed on the tarsus of juvenile Powerful Owls. There has been some debate over the band size that should be used and the consequent effects bands may pose for the owls as they mature. We also investigate the usefulness of bands as a technique to identify Powerful Owls once they have dispersed from the natal territory.
Radio-tracking juvenile Powerful Owls was also undertaken during this study, primarily to determine individual behaviour from post fledging until dispersal. This is the first study in Australia to attempt radio-tracking juvenile Powerful Owls and the results from this research highlight behavioural characteristics, mortality rates post fledging and dispersal movements for the twelve months post fledging.
Overall we found that aluminium legs bands are a useful tool for individual identification of juvenile Powerful Owls post fledgling, however, their presence is somewhat difficult to determine on mature adults as the tarsus feathers tend to cover the band and make vision from the ground difficult. Aluminium leg bands are also useful as an identification tool for deceased birds. Leather leg bands are more suitable than aluminium bands when attaching radio-transmitters as these provide more flexibility and can be removed by the owl if they become irritating.
Radio-tracking juvenile Powerful Owls provided invaluable information relating to juvenile behaviour and movements, showing that juveniles actually remain in territories adjacent to their natal territory for the twelve months post fledging. This information is vital for the successful conservation of this species, particularly in relation to habitat conservation and home-range modelling.