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Microhabitat Characteristics (microhabitat + characteristic)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Pond characteristics as determinants of species diversity and community composition in desert bats

ANIMAL CONSERVATION, Issue 5 2010
O. Razgour
Abstract Although water availability is known to affect landscape-scale patterns of wildlife diversity and distribution in arid environments, little is known about the microhabitat characteristics that shape the local-scale distribution of desert bats. We examined the relative importance of pond microhabitat characteristics for the conservation of bats, and hypothesized that in arid environments, patterns of bat diversity and community composition relate to the size of the pond and its hydroperiod (the number of months a pond holds water), a term we use to distinguish between permanent, semi-permanent and temporary ponds. We combined acoustic monitoring with video recording and an experimental approach to study bat activity over natural ponds in the Negev Desert, Israel. We found that both within and between ponds bat species richness and activity significantly increased with pond size. An experimental reduction of pond size led to a significant reduction in bat species richness and activity and affected the bat community composition. In contrast to pond size, pond hydroperiod did not affect bat diversity, as temporary ponds had equivalent levels of bat species richness and activity to permanent ponds. However, hydroperiod did couple with pond size to affect the bat community composition, whereby non-desert bat species that have a higher frequency of drinking were associated with larger and more permanent ponds. Our results highlight the importance of larger temporary ponds (ponds over 15 m in length and 0.5 m in depth) for the conservation of biodiversity in arid environments. [source]

Experimental manipulation reveals the importance of refuge habitat temperature selected by lizards

AUSTRAL ECOLOGY, Issue 3 2010
MICHA ANDERSSON
Abstract Refuges provide shelter from predators, and protection from exposure to the elements, as well as other fitness benefits to animals that use them. In ectotherms, thermal benefits may be a critical aspect of refuges. We investigated microhabitat characteristics of refuges selected by a heliothermic scincid lizard, Carlia rubrigularis, which uses rainforest edges as habitat. We approached lizards in the field, simulating a predator attack, and quantified the refuge type used, and effect of environmental temperatures (air temperature, substrate temperature and refuge substrate temperature) on the amount of time skinks remained in refuges after hiding (emergence time). In respone to our approach, lizards were most likely to flee into leaf litter, rather than into rocks or woody debris, and emergence time was dependent on refuge substrate temperature, and on refuge substrate temperature relative to substrate temperature outside the refuge. Lizards remained for longer periods in warmer refuges, and in refuges that were similar in temperature to outside. We examined lizard refuge choice in response to temperature and substrate type in large, semi-natural outdoor enclosures. We experimentally manipulated refuge habitat temperature available to lizards, and offered them equal areas of leaf litter, woody debris and rocks. When refuge habitat temperature was unmanipulated, lizards (85%) preferred leaf litter, as they did in the field. However, when we experimentally manipulated the temperature of the leaf litter by shading, most skinks (75%) changed their preferred refuge habitat from leaf litter to woody debris or rocks. These results suggest that temperature is a critical determinant of refuge habitat choice for these diurnal ectotherms, both when fleeing from predators and when selecting daytime retreats. [source]

Ecological parameters of the leaf-litter frog community of an Atlantic Rainforest area at Ilha Grande, Rio de Janeiro state, Brazil

AUSTRAL ECOLOGY, Issue 3 2007
M. Van SLUYS
Abstract The Atlantic Rainforest originally covered much of the Brazilian coast and is now reduced to approximately only 7% of its original area. Data on abundance distribution and microhabitat characteristics of anuran amphibians living on the forest floor leaf litter in the Atlantic Rainforest are scarce. In this study, we analysed the effect of litter depth and structure on the abundance and species richness of leaf-litter frogs in an area of Atlantic Rainforest at Ilha Grande, Rio de Janeiro State, south-eastern Brazil. We performed monthly samples (nocturnal and diurnal) from August 1996 to October 1997 using small (2 m × 1 m) plots. We sampled 234 plots, totalling 468 m2 of forest leaf litter. We estimated leaf-litter depth and the proportion of leaves in the plot and tested their effect on the total abundance of frogs and species richness using multiple regression analysis. We found 185 frogs from eight species: Brachycephalus (=Psyllophryne) didactylus (Izecksohn, 1971) (Brachycephalidae), Dendrophryniscus brevipollicatus Jiménez de la Espada 1871 (Bufonidae), Adenomera marmorata Steindachner 1867, Eleutherodactylus parvus (Girard 1853), Eleutherodactylus guentheri (Steindachner 1864), Eleutherodactylus binotatus (Spix 1824) and Zachaenus parvulus (Girard 1853) (Leptodactylidae), and Chiasmocleis sp. (Microhylidae). Brachycephalus didactylus was the most abundant species, with 91 individuals, whereas Dendrophryniscus brevipollicatus was the rarest, with two individuals. Mean litter depth and the proportion of leaves in the leaf litter were significantly related to frog abundance (R2 = 0.17; F2,107 = 10.779; P = 0.0001) and species richness (R2 = 0.11; F2,107 = 6.375; P = 0.002) indicating that microhabitat characteristics may affect local distribution and abundance of frogs in the forest floor. [source]