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Título: Spatial ecology and conservation of the North American wood turtle (Glyptemys insculpta) in a fragmented agri-forest landscape
Autores: Saumure, Raymond A.
Fecha: 2004
Publicador: McGill University - MCGILL
Fuente:
Tipo: Electronic Thesis or Dissertation
Tema: Wood turtle -- Ecology -- Québec (Province).
Wood turtle -- Dispersal -- Québec (Province).
Wood turtle -- Conservation -- Québec (Province).
Descripción: The impact of agricultural practices on wood turtle (Glyptemys insculpta) movements and survivorship was investigated in a fragmented agri-forest landscape over two years. Agricultural activities and machinery contributed to the death of 20% of radio-tracked turtles. Annual survivorship of adults was 0.904 and 0.868 and for juveniles it was 0.815 and 0.831 for 1998 and 1999, respectively. Mutilation rates in adults were 90% +/- 3% in both years; in contrast, the maximum rate in juveniles was 57%. Setting the cutting height of disc mowers to 100 mm would increase harvest yields, reduce wear on machinery, decrease soil erosion, and reduce turtle mortality and mutilation rates. The concepts of integral, statistical, and linear range are introduced as distinct estimators of turtle movements. Since integral ranges include all habitats critical to survival, they provide an important contribution to our knowledge of imperiled species. Statistical ranges are stable and easily promote within and between study comparisons. Linear ranges quantify migratory and ranging movements. Thread-trailing techniques were used to record the fine-scale movements of six adult male G. insculpta translocated to an experimental hayfield patch-matrix. Although patch size had no effect on move length or path sinuosity, habitat structure did. Paths were generally straighter and move length longer in the harvested portion of a hayfield. Apparent habitat boundaries were shown to be permeable. Subjects exhibit three movement phases: agitation dispersal, local search, and ranging. Thus, G. insculpta exhibit predetermined movement patterns and move to maximize the likelihood of locating resources, while minimizing the probability of revisiting previously searched areas. Recent changes in agricultural practices and machinery are having a decidedly negative impact on G. insculpta. This study provides new insights into the movements of G. insculpta. Such knowledge will be an es
Idioma: en