Habitat ecology

Study of habitat characteristics and distribution pattern of Tokay Gecko (Gekko gecko) was carried out in Barak valley of southern Assam by transect method. 112 individuals were recorded during the study period. Out of which, highest individuals were found in Irongamara of Cachar district. In the study area, the average encounter rate was 6.92/km. Gekko gecko is distributed thoughout the Barak valley. In addition, it was found in houses like mud house, pucca house and RCC buildings, irrespective of trees which is its natural habitat. Mud house as their most preferred habitat as they were mostly found perching on the mud walls, individuals were found perching at medium level height i.e., 2m above the ground. Trees with good canopy cover are their other suitable habitat. Among plants, the species was more abundant in Ficus sp. due to moderately high temperature and moderate moisture inhabiting in the hole. Most of the calls were given during evening hours, which is the peak hour for feeding by clinching on the outside wall of the house at night. The species mainly feed on the insects. Cockroach, moth and spider are recorded as their favourite prey. The local village men have a social taboo for the species and it is believed that it occurrence in houses bring 'good fortune' for the family. Of late, severe illegal trading of the animal has brought about drastic decline of the species from the study area.

"The Segura River Basin is one of the most arid and regulated zones in the Mediterranean as well as Europe that includes four hydrologic river types, according to their natural flow regime: main stem rivers, stable streams, seasonal streams and temporary streams. The relationships between flow regime and fluvial and
riparian habitats were studied at reference and hydrologically altered sites for each of the four types. Flow regime alteration was assessed using two procedures: (1) an indirect index, derived from variables associated with the main hydrologic pressures in the basin, and (2) reference and altered flow series analyses
using the Indicators of Hydrologic Alteration (IHA) and the Indicators of Hydrologic Alteration in Rivers (IAHRIS). Habitats were characterized using the River Habitat Survey (RHS) and its derived Habitat Quality Assessment (HQA) score, whereas riparian condition was assessed using the Riparian Quality Index
(RQI) and an inventory of riparian native/exotic species. Flow stability and magnitude were identified as the main hydrologic drivers of the stream habitats in the Segura Basin. Hydrologic alterations were similar to those described in other Mediterranean arid and semiarid areas where dams have reduced flow magnitude and variability and produced the inversion of seasonal patterns. Additionally, the Segura Basin presented two general trends: an increase in flow torrentiality in main stems and an increase in
temporality in seasonal and temporary streams. With the indirect alteration index, main stems presented the highest degree of hydrologic alteration, which resulted in larger channel dimensions and less macrophytes and mesohabitats. However, according to the hydrologic analyses, the seasonal streams presented the greatest alteration, which was supported by the numerous changes in habitat features. These changes were associated with a larger proportion of uniform banktop vegetation as well as reduced riparian native plant richness and mesohabitat density. Both stream types presented consequent reductions in habitat
and riparian quality as the degree of alteration increased. However, stable streams, those least impacted in the basin, and temporary streams, which are subject to great hydrologic stress in reference conditions, showed fewer changes in physical habitat due to hydrologic alteration. This study clarifies the relationships between hydrologic regime and physical habitat in Mediterranean basins. The hydrologic and habitat indicators that respond to human pressures and the thresholds that imply relevant changes in habitat and riparian quality presented here will play a fundamental role in the use of holistic frameworks when developing environmental flows on a regional scale."

Processes of habitat selection occur at multiple spatiotemporal scales, where large-scale selection is often determined by predation risk and landscape features, and finer scale selection by resource abundance and quality. To determine whether this hierarchy exists in relatively homogenous systems, we investigated patterns of habitat (landscape topography) and resource (feeding patch and plant group) selection by a medium-sized ungulate, the Tibetan argali (Ovis ammon hodgsoni Blyth, 1840), in the high-altitude rangelands of the Indian Trans-Himalaya. We ran ecological niche factor analyses to explore habitat selection, bias-reduced logistic regression to analyze the selection of feeding patches, fuzzy correspondence analysis for vegetation categories, and microhistological analyses for the selection of plant groups. For springs and summers of 2005–2007, argali preferred an intermediate range of altitude, slope, and forage abundance. Selection of feeding patch was mainly determined by forage quality, not biomass, selecting graminoids and forbs, in particular. The avoidance of habitat with high forage abundance could indicate a trade-off between forage quality and quantity; a pattern consistent at the feeding-patch scale. Our results provide evidence that the hierarchical pattern of habitat selection probably also occurs in relatively homogeneous systems.