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Dietary Flexibility (dietary + flexibility)
Selected AbstractsSeasonal differences in population-, ensemble- and community-level responses of bats to landscape structure in AmazoniaOIKOS, Issue 10 2010Brian T. Klingbeil The amount (composition) and spatial arrangement (configuration) of forest patches in fragmented landscapes influence the accessibility, as well as the abundance and diversity of resources available to bats. Moreover, tropical fruit and insect abundance differ seasonally in response to changes in precipitation, and many bats in the family Phyllostomidae employ seasonal reproductive strategies. Because reproductive activities involve constraints on time and energy as well as increased nutritional demands, foraging behavior and home range size may differ between wet and dry seasons. Nonetheless, seasonal variation in response to landscape structure by bats has not been examined previously. Consequently, population-, ensemble- and assemblage-level responses of phyllostomids to landscape composition and configuration were quantified separately during the wet and dry season at three circular focal scales (1, 3 and 5 km radii) for 14 sites in fragmented lowland Amazon forest. Responses to landscape characteristics were scale-dependent, species-specific, and seasonal. Abundances of frugivores responded to landscape composition in the dry season and to landscape configuration in the wet season. Conversely, abundances of animalivores responded to landscape configuration in the dry season and to landscape composition in the wet season. Divergent responses to landscape structure between seasons suggest that variation in resource abundance and diversity play a significant role in structuring population-, ensemble- and assemblage-level patterns. As such, considerations of the effects of dietary flexibility and reproductive constraints on foraging strategies and habitat use may be important when designing management plans that successfully promote long-term persistence of biodiversity in fragmented landscapes. [source] The effects of extreme seasonality of climate and day length on the activity budget and diet of semi-commensal chacma baboons (Papio ursinus) in the Cape Peninsula of South AfricaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2010A.C. van Doorn Abstract We examined the effects of extreme seasonality on the activity budget and diet of wild chacma baboons with access to a high-quality, human-derived food source. The Cape Peninsula of South Africa is unusual among nonhuman primate habitats due to its seasonal extremes in day length and climate. Winter days are markedly shorter and colder than summer days but have higher rainfall and higher primary production of annually flowering plants. This combination of fewer daylight hours but higher rainfall is substantially different from the ecological constraints faced by both equatorial baboon populations and those living in temperate climates with summer rainfall. We sought to understand how these seasonal differences affect time budgets of food-enhanced troops in comparison to both other food-enhanced troops and wild foraging troops at similar latitudes. Our results revealed significant seasonal differences in activity budget and diet, a finding that contrasts with other baboon populations with access to high-return anthropogenic foods. Similar to nonprovisioned troops at similar latitudes, troop members spent more time feeding, socializing, and traveling during the long summer days compared to the short winter days, and proportionately more time feeding and less time resting in summer compared to winter. Summer diets consisted mainly of fynbos and nonindigenous foods, whereas winter diets were dominated by annually flowering plants (mainly grasses) and ostrich pellets raided from a nearby ostrich farm. In this case, food enhancement may have effectively exaggerated seasonal differences in activity budgets by providing access to a high-return food (ostrich pellets) that was spatially and temporally coincident with abundant winter fallback foods (grasses). The frequent use of both alien vegetation and high-return, human-derived foods highlights the dietary flexibility of baboons as a key element of their overall success in rapidly transforming environments such as the South African Cape Peninsula. Am. J. Primatol. 72:104,112, 2010. © 2009 Wiley-Liss, Inc. [source] Responses of squirrel monkeys to seasonal changes in food availability in an eastern Amazonian forestAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2007Anita I. Stone Abstract Tropical forests are characterized by marked temporal and spatial variation in productivity, and many primates face foraging problems associated with seasonal shifts in fruit availability. In this study, I examined seasonal changes in diet and foraging behaviors of two groups of squirrel monkeys (Saimiri sciureus), studied for 12 months in Eastern Brazilian Amazonia, an area characterized by seasonal rainfall. Squirrel monkeys were primarily insectivorous (79% of feeding and foraging time), with fruit consumption highest during the rainy season. Although monkeys fed from 68 plant species, fruit of Attalea maripa palms accounted for 28% of annual fruit-feeding records. Dietary shifts in the dry season were correlated with a decline in ripe A. maripa fruits. Despite pronounced seasonal variation in rainfall and fruit abundance, foraging efficiency, travel time, and distance traveled remained stable between seasons. Instead, squirrel monkeys at this Eastern Amazonian site primarily dealt with the seasonal decline in fruit by showing dietary flexibility. Consumption of insects, flowers, and exudates increased during the dry season. In particular, their foraging behavior at this time strongly resembled that of tamarins (Saguinus sp.) and consisted of heavy use of seed-pod exudates and specialized foraging on large-bodied orthopterans near the forest floor. Comparisons with squirrel monkeys at other locations indicate that, across their geographic range, Saimiri use a variety of behavioral tactics during reduced periods of fruit availability. Am. J. Primatol. 69:1,16, 2007. © 2006 Wiley-Liss, Inc. [source] Intestinal morphology and histology of the striped catfish Pseudoplatystoma fasciatum (Linnaeus, 1766) fed dry dietsAQUACULTURE NUTRITION, Issue 6 2009A.P.O. RODRIGUES Abstract This study unveils histological features of the intestinal tract of juvenile striped catfish Pseudoplatystoma fasciatum (Linnaeus, 1776) in three size classes (weight, standard length): I , 36.84 ± 10.19 g, 14.52 ± 1.54 cm; II , 59.03 ± 11.47 g, 17.17 ± 1.06 cm; III , 89.72 ± 18.70 g, 20.79 ± 1.55 cm, respectively. Histological organization of the juvenile speckled catfish intestine bears features common to the carnivorous fish, but the organ presents some convolutions that indicate a certain degree of dietary flexibility, a surprising trend, common only to omnivorous Siluriforms. The architecture of the mucosa of the speckled catfish intestine indicates that the species concentrates digestion and absorption of nutrients in the medium intestine, a common feature among carnivorous Teleosts. [source] | ||||||||||