Spatial Ecology STUDIES IN FREE RANGING ANIMALS
Spatial Ecology STUDIES IN FREE RANGING ANIMALS
M Jeri Imansyah, Komodo Survival Program (firstname.lastname@example.org)
Habitat loss and fragmentation are currently the most serious threats to wildlife worldwide, so it is important to understand how patterns and processes of landscape change will cause individual populations and species to respond to these broad-scale modifications (Blumstein & Fernandez-Juricic 2004; Collinge 2001). Spatial heterogeneity processes directly affect ecological systems (Gardner et al. 1989). The spatial arrangement of individuals within a population will reflect aspects of its behavior and ecology, and is important in determining population persistence and gene flow within and between sub-populations (Brown & Downhower 1988; Johnson 2000). Thus, the dynamics of an animal population depends not only on birth and death rates, but also on an animal’s ability to move into or out of a population (Dasmann 1964). Determining the number of individuals persisting in an area is a basic question in ecology, but it is more important to understand how an animal responds to changing landscape conditions, regardless of whether it is at the individual, population or community level (Lawson et al. 2006).
Krebs (1999) pointed out that spatial ecology as a science aims to understand the ecological processes that determine the location of individuals, which are rarely spread evenly over the landscape. Collinge (2001) concluded that spatial ecology is an ecological study, which centers upon understanding how landscape configurations influence the community and population dynamics of organisms. Spatial ecology is at the very core of the science of ecology (Boyce & McDonald 1999). Whitaker and Shine (2003) stated that studying spatial ecology can contribute at least three potential benefits; first, a better understanding of movement and habitat selection by the animal, second, giving information regarding animal-human interactions, and third, as an aid in assessing the response and role of an animal in regards to their habitat. Collinge (2001) emphasized that empirical studies in spatial ecology beneficially links conservation biology research to practical mechanisms for species management and conservation planning. In studying spatial ecology, authors included studies of dispersal (e.g. Olsson & Shine 2003), movement and activity area, habitat use, activity patterns (Fitzgerald et al. 2002; Piepgras & Lang 2000), diets (Thompson & Thompson 2001; Whitaker & Shine 2003), and anthropic habitat changes (Pearson et al. 2005; Fitzgerald et al. 2002).
Dispersal is the movement of an individual from its natal area to an unoccupied and suitable area within which it is able to establish its own home range. Caughley and Sinclair (1994) emphasised that migration is not the equivalent of dispersal. Greenwood and Swingland (1984) described dispersal as being caused by the need for an individual to search for food sources. Lebreton et al. (2003) studied the importance of dispersal as a mechanism in reproduction.
It is essential in studying spatial ecology to investigate dispersal patterns. Dispersal is recognized as a key process in ecology, evolution, and conservation and it is important to understand the consequences to an animal’s behaviour as it responds to the habitat (van Dyck & Baguette 2005). Dispersal can affect the dynamics and persistence of populations, distribution and abundance, community structure, gene flow, local adaptation, speciation, and the evolution of life-history traits (Lebreton et al. 2003; Roper et al. 2003). Thus, dispersal is one of the most critical events in the life of most animals and one of the most important processes affecting the ecology and evolution of populations (Roper et al. 2003).
Blumstein, D.T. & Fernandez-Juricic, E. 2004. Editorial: The emergence of conservation behavior. Conservation Biology 18(5): 1175-1177.
Boyce, M.S. & McDonald, L. 1999. Relating population to habitat using resource selection function. Trends in Ecology and Evolution 14: 268-272.
Brown, L. & Downhower, J.F. 1988. Analyses in behavioral ecology: a manual for lab and field. Sunderland: Sinauer Associates, Inc.
Caughley, G. & Sinclair, A.R.E. 1994. Wildlife ecology and management. London: Blackwell Science.
Collinge, S.K. 2001. Introduction spatial ecology and biological conservation. Biological Conservation 100: 1-2.
Dasmann, R.F. 1964. Wildlife biology. New York: John Willey & Sons. Inc.
Fitzgerald, M., Shine, R. & Lemckert, F. 2002. Spatial ecology of arboreal snakes (Hopochepalus stephensii Elapidae) in an eastern Australian forest. Australian Journal of Ecology 27: 537-545.
Gardner, R.H., O’Neill, R.V., Turner, M.G. & Dale, V.H. 1989. Quantifying scale-dependent effects of animal movement with simple percolation model. Landscape Ecology 3(3/4): 217-227.
Greenwood, P.J. & Swingland, I.R. 1984. Animal movement: approaches, adaptations, and constraints. In Swingland, I.R. & Greenwood, P.J. (eds.). The ecology of animal movement, pp. 1-6. Oxford: Clarendon Press.
Johnson, G. 2000. Spatial ecology of the eastern Massasauga (Sistrurus c. catanatus) in a New York peatland. Journal of Herpetology 34: 186-192.
Krebs, C.J. 1999. Ecological methodology. Second edition. California: Addison-Wesley Educational Publisher.
Lawson, D., Jensen, H.J. 2006. The species-area relationship and evolution. http://uk.arxiv.org/abs/q-bio.PE/0412024 [July 20th, 2006].
Lebreton, J.D., Hines, J.E., Pradel, R., Nichols, J.D. & Spendelow, J.A. 2003. Estimation by capture-recapture of recruitment and dispersal over several sites. OIKOS 101: 253–264.
Olsson, M. & Shine, R. 2003. Female-biased natal and breeding dispersal in an alpine lizard, Niveoscincus microlepidotus. Journal of Linnean Society 79: 277-283.
Pearson, D., Shine, R. & Williams, A. 2005. Spatial ecology of a threatened phyton (Morelia spilota imbricata) and the effects of anthropogenic habitat change. Australian Journal of Ecology 30: 261-274.
Piepgras, S.A. & Lang, J.W. 2000. Spatial ecology of Blanding’s turtle in Central Minnesota. Chelonian Conservation and Biology 3: 589-601.
Roper, T.J., Ostler, J.R. & Conradt, L. 2003. The process of dispersal in badgers Meles meles. Mammal Review 33: 314–318.
Thompson, G.G. & Thompson, S.A. 2001. Behaviour and spatial ecology of Gilbert’s dragon Lophognanthus gilberti (Agamidae: Reptilia). Journal of the Royal Society of Western Australia 84: 153-158.
van Dyck, H. & Baguette, M. 2005. Dispersal behavior in fragmented habitat: routine or special movement. Basic and Applied Ecology 6: 534-545.
Whitaker, P.B. & Shine, R. 2004. A Radiotelemetric study of movements and shelter-site selesction by free-ranging Brownsnakes (Pseudonaja textile, Elapidae). Herpetological Monographs 17: 130-144.