Diet, dietary selectivity and density of South American grey fox, Lycalopex griseus, in Central Chile.
The South American grey fox Lycalopex griseus is a canid widely distributed in southern South America; however, some aspects of its biology are still poorly known. We studied the diet and density of L. griseus in the Lago Peñuelas Biosphere Reserve, in Central Chile. The trophic niche breadth was B = 6.16 (Bsta = 0.47) and prey diversity was H' = 2.46 (Hmax ' = 3.17, J' = 0.78). The highest proportions of prey consumed in the diet were Oryctolagus cuniculus (52.21%) and other mammals (32.78%). We compared these results with a latitudinal gradient of diet results for this species in Chile. L. griseus eats mostly mammals (>90% of total prey), consuming the rodent Phyllotis darwini and reptiles in the northern zone; Oryctolagus cuniculus, Octodon degus and Abrocoma bennetti in the central zone; Abrothrix spp. and lagomorphs in the southern zone; and Lepus capensis and Ovis aries in the austral zone. The estimated density of L. griseus in Lago Peñuelas NR was 1.3 foxes/km2 .
Contrasting variations in the diet of the Andean fox Lycalopex culpaeus Molina, 1782 on geographical and environmental scales in the Atacama Desert
Abstract We determined the seasonal diet of the Andean fox Lycalopex culpaeus in three habitats in the Atacama Desert, northern Chile, by analyzing their scat contents. We estimated the biomass and the number of individuals of each prey species consumed and compared our results with those of other studies on Lycalopex foxes in Chile and South America. In general, the L. culpaeus diet was characterized by a generalist behavior and higher dietary breadth than those in other ecosystems. In contrast with the other biomes of southern Chile and South America, insects represented the most frequent prey species in the present study and the main food item, comprising more than 50% of all prey at the three study sites; however, in terms of biomass, rodent and reptile prey showed the highest percentage from summer to winter. Significant differences were found between the biomass consumed among sites. Likewise, we found a relationship between the niche breadth of the diet and the primary productivity of the sites. Statistically significant differences in prey items consumed were noted across seasons and sites located at different altitudes, which reflected an opportunistic response to the availability of prey. Our report contributes to current data about the natural history of L. culpaeus in hyper-arid habitats.
Geographic And Environmental Influence On Maya Settlement Patterns Of The Northwest Yucatan: An Explanation For The Sparsely Settled Western Cenote Zone
Most settlement pattern research and GIS analysis of the ancient Maya of the Northern Yucatan have focused on water availability in a dry landscape where cenotes are often the only water source. While water is of paramount importance, permanent settlement secondarily requires farmable soil, a resource often as precious as water in many parts of the Yucatan. The dynamics between these resources reveal areas of ideal settlement and more challenging landscapes for which the Maya developed strategies to overcome environmental conditions. A region of the southwest "Cenote Zone", however, appears to have presented the ancient Maya with insurmountably poor environmental conditions despite abundant water resources. The lack of dense population and stone architecture in this area emphasizes the lack of a simple correlation between cenotes and settlement. This thesis uses GIS analysis to identify and explore such problematic settlement areas to better understand the factors and complexities involved in the more successful settlements of neighboring regions. iv This work is dedicated to my late father, who first introduced me to the Mundo Maya through a visit to the ruins of Tikal at the age of nine, and who instilled in me strength, curiosity, and a love for exploring the world. v ACKLOWLEDGEMENTS I'd like to acknowledge Dr. Arlen Chase and Dr. Diane Chase for providing such outstanding opportunities and instruction, and for leading by example both in the field and in the classroom. Dr. John Walker for his eye-opening perspectives, GIS instruction, inspiring hard-working attitude, and patience in the field. Dr. Clifford Brown and Dr. Walter Witschey for their invaluable correspondence and for their contributions to mapping and GIS data of Maya sites.