Thesica.org, the #1 open access web portal for PhD theses...

Why PhD theses...

PhD thesis is the result of years of hard work.

keyword researchMeasured by download count PhD theses are one of the most popular items world wide on open access repositories. But unless a thesis is published, it is very difficult for other researchers to find out about it and get access to it. Theses are often under-used by other researchers. Thesica.org attempts to address this issue by making it easy to identify and locate copies of many theses in various disciplines.

Jaguars as landscape detectives for the conservation of Atlantic forests in Brazil

Jaguars as landscape detectives for the conservation of Atlantic forests in Brazil
Laury Cullen Jr.

2006

Durrell Institute of Conservation and Ecology, University of Kent, Canterbury CT2 7NZ, UNITED KINGDOM.

ABSTRACT

In this thesis, I show how the jaguar Panthera onca can be used as a landscape detective. A landscape detective is defined as a species that helps determine how to manage landscapes and to design and manage protected area networks. Life history and behavioural features of jaguar make them potentially suitable as landscape species. The main aim of this study is to use the jaguar as a landscape detective to develop a network of core protected areas for the Upper Paraná Region, which lies in the highly threatened Atlantic Forest of Brazil. Information was collected on jaguar density and home range, which was combined with habitat requirements of the species and GIS-generated maps of land cover to develop a map of habitat suitability. This map was used to understand the spatial structure of the jaguar metapopulation, identifying habitat patches of high suitability where jaguar populations exist and are likely to survive over the long-term. Camera trapping and capture-recapture models were used to derive jaguar population size in Morro do Diabo State Park (MDSP). Camera trapping was carried out simultaneously with VHF and GPS telemetry to verify density estimates. Jaguar densities were estimated to vary between 2.47/100 km2 and 2.20/100 km2. Jaguar home ranges and movements were also studied for 10 individuals in MDSP and Ivinhema State Park (ISP). In MDSP the yearly 85% fixed-kernel home range averaged 162 km2 for male jaguars and 60 km2 for females. In ISP the only male monitored had a yearly 85% home range of 147 km2, while two females monitored averaged 130 km2. Dry season 85% home ranges were similar to wet season home ranges. Female home ranges overlapped between 15 to 25%, while males overlapped on average 32%. Mean annual and multiyear 85% home ranges were larger than those reported by previous studies. The mean yearly distances between consecutive locations for all 10 individuals studied averaged 2.76 km. On average, jaguars moved similar distances in the wet to the dry season (2.85 to 2.40 km/day). The average maximum distance moved by any jaguar between consecutive locations was 13.18 km/day. Occasionally 30 km movements were recorded when male jaguars traversed open pastures and gallery forests over very short periods. Using compositional analysis, I assessed habitat selection by jaguars at second- and third-orders of selection. At second-order selection, jaguars consistently preferred primary forests and dense marshes, and avoided human-dominated areas such as intensively managed open pastures. Although the avoidance of disturbed and developed habitat types by jaguars is not surprising, this is the first study to document such evidence. At third-order selection, jaguars concentrate their core areas in areas of high prey density, whether wild herbivores or livestock. With this information, I developed the landscape detective model to help identify strategic transit refuges or stepping stones for dispersing jaguars that could improve the dispersal potential of corridors between suitable habitat patches. The model produced a habitat suitability map and patch structure with 3 suitable patches having a total area of over 4,000 km2 and a carrying capacity of 126 jaguars in the Upper Paraná Atlantic Forest. The habitat-based landscape detective model was linked to a population viability analysis. Under the "current" scenario, the metapopulation tended to decrease. The median time to decline to half of the initial abundance, from 126 to 63 jaguars, was about 18 years, while the risk of extinction within the next 50 years was predicted at around 25%. However, the results under a predicted "protection" scenario were quite different showing a stable metapopulation with a low risk of extinction, a high predicted abundance and a high occupancy. The results of the model can help develop agroforestry programmes to improve habitat quality of potential wildlife corridors and buffer zones. The findings of this thesis show how a landscape detective species can be used to improve landscape management and protected area networks. If the jaguar is to have a chance of surviving in future human dominated landscapes, protected area management will need to integrate applied research with good policies for the involvement of NGO and Universities, co-management of protected areas, participation of local communities through community-based landscape restoration programmes, and environmental education.