We investigated the horizontal habitat use of three sympatric Paradoxurinae species, the common palm civet
Paradoxurus hermaphroditus
, the small-toothed palm civet
Arctogalidia trivirgata
and the ...binturong
Arctictis binturong
, occurring within a small area in a lowland dipterocarp rainforest in Sabah, Malaysian Borneo. We evaluated their preference for forests near open-canopy areas (forest edge habitat) or more mature interior forests (interior-forest habitat) by tracking radio-collared civets in their activity and inactivity periods. We demonstrated that all three Paradoxurinae species occurred in the same area, and extensive range overlap indicated lack of interspecific territoriality. The binturong preferred neither forest edge nor interior-forest habitats. Meanwhile, both the common palm civet and the small-toothed palm civet showed a similar preference for forest edge habitats. Food distribution may affect their habitat use. We could not find clear habitat segregation among the three sympatric Paradoxurinae species, but vertical habitat use may also affect their coexistence. Further effort is needed to elucidate both the horizontal and vertical habitat segregation of sympatric Paradoxurinae species.
Understanding the process animals follow to select habitat, rather than just documenting the habitat they use, will improve our ability to predict how the animals use habitat in other locations and ...how they will respond to changes in habitat. Animals are usually assumed to select habitats hierarchically, preferentially using specific macrohabitats at a landscape scale and specific microhabitats within the preferred macrohabitats. We used four years of telemetry data from 34 individuals to test this hierarchical model of habitat selection with eastern massasauga rattlesnakes (
Sistrurus c. catenatus) in Ontario. Snakes were selective at the microhabitat scale, preferentially using locations with closer retreat sites and shrubs than random. Gravid females were most selective, using sites with more rock cover and less canopy closure than sites used by males and nongravid females. Snakes preferred forested habitats for hibernation and steadily increased their use of open, wetland, and edge habitats to a peak in mid-summer. Landscape-scale habitat preferences were generally mild and could be explained by the relative availability of suitable microhabitat within habitats, suggesting habitat selection was primarily driven by microhabitat preferences. The lack of selectivity at the landscape scale may be a consequence of fine-grained differences between habitats that allow massasauga rattlesnakes to find suitable microhabitats in all available macrohabitats. For species that select habitat primarily at the microhabitat scale (e.g., the rattlesnakes we studied), landscape-scale modeling of habitat use will only be effective to the extent habitats reflect the availability of suitable microhabitat within.
The author discusses the concept of denizenship and the different articulations of embodied transnational belonging, exploring projects by Joanna Rajkowska and Nada Prlja. Through metaphors of an ...ecotone and edge habitat, facilitating exchange within and between communities, she examines spaces across and in-between in which national identifications of individuals in Europe are deconstructed. The article discusses transition (through Rajkowska's artistic practice) and tension (through Prlja's artistic practice) zones, drawing upon Jacques Derrida's discourse on hospitality, in order to seek for alternative modes of thinking about citizenship. These are based on generosity, friendship, hospitality and acknowledge locatedness of individuals and the space in-between - being here and there, at home and not at home. Rajkowska and Prlja's projects offer fresh and innovative articulations of cosmopolitan and hospitable spaces, which enable communities based on identification with others.
Background How do Orange River Francolins (Scleroptila levaillantoides) adapt to an intensive farming landscape with grass (grazing) camps and crop cultivation? To answer this question, a study was ...carried out in south-east of Johannesburg in South Africa to clarify the interaction of francolins with a landscape consisting of land use mosaics. Methods A transect-road of 45 km was traversed weekly during November 2015-October 2016 through flat maize (Zea mays) and cattle (Bos primigenius) grazing fields. Francolins were counted in three land use mosaic types along the transect-road (including the road): grass camps on both sides of the road (grass/grass edges); arable fields on both sides (arable/arable edges) and arable land on one side with grass camps on the opposite side of the road (arable/grass edges). Results Francolins used all three mosaic types, but the arable/arable edges were least frequented. Nonetheless, the arable/arable edges played an important part: francolins, including females with chicks, moved along the arable/arable edges, which enabled contact between sub-populations, and the arable/arable edges provided temporary cover (e.g. stubble and maize plants) and ploughed firebreaks to forage (e.g. for bulbs). Conclusion Cultivation of crop within grasslands does not constrain breeding, movement and habitat use by the Orange River Francolin. For conservation purposes it is critical that the fine-scale mosaic of grazing and cultivation areas remain intact.
Roads may have detrimental effects on many bird species, but areas adjacent to roads also provide habitat and food for some species. To address the influence of roadside habitat on the federally ...threatened Florida Scrub-Jay (Aphelocoma coerulescens), we compared foraging effort, the amount of food collected, and estimated energy intake in three habitat types: (1) edges along a paved road (roadside), (2) edges created by human-maintained habitat without a road (pasture), and (3) natural scrub-dominated areas with minimal human-maintained edges (interior). We used focal watches of male breeders during three stages of the breeding season (incubation, nestling, and fledged young) in two consecutive years to assess variation in food availability and energetic intake among the three habitat types. Florida Scrub-Jays in roadside habitats handled (consumed, cached, or fed to their mate or offspring) significantly more food items and spent less time foraging during the nestling stage than interior and pasture jays, but no differences in handled food were found among the three habitat types during the incubation and fledgling stages. Although they spent less time foraging, roadside jays had higher rates of energy intake than interior and pasture jays during the incubation stage. There were no differences in these measures of foraging during the incubation, nestling, and fledgling stages between interior and pasture jays. Our results suggest that roads or roadside habitat, not simply edge habitats, have a positive effect on food availability and energy intake in Florida Scrub-Jays, although the patterns differ across breeding stages.
Widespread colonization by invasive species often obscures their underlying niche requirements. A robust inference into habitat requirements demands direct measures of invasive species performance ...linked with associated environmental conditions. In the context of general ecological theory, we investigated the niche requirements of
Microstegium vimineum
, an invasive grass in the U.S. that overruns native vegetation in forest understories. We examined
M. vimineum
's performance and reproduction as a function of environmental drivers across forested and unforested habitats along a 100-km regional and climatic gradient in the southeastern U.S. from the southern Appalachian Mountains to the Georgia piedmont. We then measured
M. vimineum
performance and reproduction in response to direct environmental drivers (diffuse light, litter cover, soil moisture, herbaceous cover, soil pH, clay content and temperature) in paired invaded and uninvaded plots. Lastly, we experimentally investigated recruitment in the context of experimental and natural disturbances. We find that all habitats are not equally suitable for
M. vimineum
-even those within which it occurs-and that the environmental conditions associated with roadsides and waterways are most suitable for
M. vimineum
persistence and spread.
Microstegium vimineum
's soil moisture, light and leaf litter requirements may delineate the boundaries of suitable habitat for the exotic invader. Significant decreases in
M. vimineum
recruitment, performance and reproduction along these environmental gradients suggest its potential niche limitations. Nevertheless, we also find significant dispersal limits on
M. vimineum
populations not subject to conspicuous overland water flow. We discuss our findings in the context of spread, impact and management of invasive species.
Knowledge of the spatial distribution of the wintering habitats of migratory raptors is a prerequisite to understanding their wintering ecology and managing their habitats. Oriental honey buzzards ...(OHBs, Pernis ptilorhynchus) are migratory raptors with wintering grounds in Indonesia. OHBs’ wintering habitats can be divided into core and edge habitats with unique landscape characteristics, which influence wintering-site selection. Twenty-three satellite-tracked OHBs (2006–2010) used Borneo as their wintering grounds. The primary aim of this study was to analyze OHBs’ wintering habitat distributions (core and edge habitats) in Borneo and their landscape characteristics in the province of South Kalimantan. Fixed-kernel density estimation was used to estimate the edge and core habitats of 23 OHBs in Borneo. We used a 95 % fixed kernel (FK_95 %) and a 50 % fixed kernel (FK_50 %) to estimate the spatial distribution of edge and core habitats, respectively. Factor analysis was used to analyze landscape characteristics of core and edge habitats. Results showed that edge and core habitats covered about 153,463.4 km²(20.7 %) and 27,528.3 km²(3.7 %) of the Borneo area, respectively. Habitat selection by OHBs at wintering sites in both core and edge habitats was highly influenced by the availability of thermal winds and food. However, the more frequent presence of OHBs in core habitats indicates that habitat selection is basically influenced by increased thermal winds associated with particular landform characteristics. Identification of these landscape characteristics provides useful baseline information for ecological-based development, particularly for landscape management and biodiversity conservation.
In central Chile, the bur beak chervil (Anthriscus caucalis M. Bieb.; Apiaceae) is an annual naturalized herb introduced from Europe at least 120 years ago. Anthriscus is distributed in vegetation ...formations such as sclerophyllous shrublands (locally known as “matorral”) and spiny savannas of Acacia caven (locally known as “espinal”). In matorral formations, Anthriscus grows at the edge of native woody fragments. Because these fragments are refuges where native herbs recruit, we studied the impact of Anthriscus on the diversity and survival of native forbs established in these sheltering microsites. First, we characterized the spatial distribution of Anthriscus in the matorral, sampling in different micro-habitat types. We differentiated three microhabitat types: under the canopy of a fragment, at the edge of the canopy of a fragment, and in open sites outside the fragments. A total of 40 1 × 1 m quadrates were randomly distributed in each habitat type. Inside each of them, we recorded the number of seedlings and established plants, including Anthriscus. Then we evaluated experimentally the effect of Anthriscus on diversity and evenness of the local herb assemblages. For this purpose we conducted a field trial using 34 metallic enclosures (0.5 × 0.5 m) arranged in pairs. In each pair, Anthriscus individuals were removed from one plot, the other paired plot acting as control. We periodically recorded the presence and abundance of the remanent species of herbs inside the plots, and then we characterized the species diversity and evenness over time (Shannon's index, H′ and Pielou's index, J′). Finally, in a second experiment we measured experimentally the presence or absence of Anthriscus against the survival of four native herb species (Bowlesia incana, Bromus berteroanus, Pectocarya linearis, and Moscharia pinnatifida). Here we used 20 0.5 × 0.5 m plots where we randomly transplanted seedlings of native herbs and Arnthiscus. Then, for each species and plot we determined their survival (%) according to the number of seedlings initially transplanted. The samplings show strong association between the presence of Anthriscus on edge habitat in the matorral. The maximum densities were noted in these microhabitat types whereas in open areas and under-fragment sites Anthriscus shows very low or null densities. At the end of the first trials, the plots with Anthriscus showed a Shannon diversity index H′ = 0.41 (±0.11 SE), while in plots without Anthriscus this value was 1.19 (±0.1 SE), both as averages. Pielou's evenness index (J′) yielded values of 0.23 (±0.06 SE) and 0.59 (±0.04 SE) for treatments with and without Anthriscus, respectively. Similarly, the second trials shows that the survival of the four native herbs was drastically decreased in the presence of Anthriscus: by 64% for Bowlesia incana, 43% for Bromus berteroanus, 46% for Moscharia pinnatifida, and 76% for Pectocaria linearis. Our study shows that the effects of Anthriscus include an inhibition of the establishment of native plants and a decrease in their survival in edge habitats, therefore affecting the composition and diversity of the local herb layer. Thus, Anthriscus is invading a refuge habitat for native herbs in the Chilean matorral, decreasing the native herb diversity and survival.
While the ecological importance of vegetated marsh edge habitats for many estuarine-dependent nekton is well documented, less is known about nekton use of the non-vegetated, water edge adjacent to ...marsh habitats and how physical variation of these habitats affects habitat use. The effects of morphological variation of these edge habitats on nekton communities were studied in Barataria Bay, Louisiana, USA. Monthly seining in fall 2003 (September, October, November) and spring 2004 (March, April, May) was conducted at 75 marsh edge study sites <10 m from the water–vegetation interface. Morphological variation in edge habitats (i.e. elevation, slope, irregularity) was quantified concurrent with nekton sampling at each sample site. Nekton assemblages were analyzed seasonally as different community assemblages were present in fall and spring, although consistent patterns emerged. Temperature and salinity were the dominant factors influencing nekton assemblages. Edge habitats with shallower slopes and greater marsh inundation supported more organisms and more resident species; in contrast, edges with steeper slopes supported more diverse and species-rich assemblages, possibly providing greater niche availability due to larger water depth gradients and increased edge irregularity, particularly when the adjacent marsh is not flooded. Use of the gently sloped sites by organisms probably reflects increased access to the marsh when flooded, and may provide shallow water refuge for many smaller species. Non-vegetated marsh edge provides valuable habitat for species, and the physical variation that exists within this habitat helps support a high species diversity.
While many species show positive relationships between population density and habitat patch area, some species consistently show higher densities in smaller patches. Few studies have examined ...mechanisms that may cause species to have negative density-area relationships. We tested the hypothesis that greater reproduction in edge versus interior habitats and small versus large fragments contributes to higher densities of white-footed mice (Peromyscus leucopus) in small versus large forest fragments. We also examined vegetation structure and foraging tray utilization to evaluate if greater reproduction was a result of higher food availability. There were greater number of litters and proportion of females producing litters in the edge versus interior of forest fragments, which may have contributed to greater population growth rates and higher densities in edge versus interior and small versus large fragments. Data on vegetation structure and giving-up densities of seeds in artificial patches suggest that food availability may be higher in edge versus interior habitats and small versus large fragments. These results, in an area with few or no long-tailed weasels, provide a distinct contrast to the findings of Morris and Davidson (Ecology 81:2061, 2000) who observed lower reproduction in forest edge habitat as a result of high weasel predation, suggesting that specialist predators may be important in affecting the quality of edge habitat. While we cannot exclude the potential contributions of immigration, emigration, and mortality, our data suggest that greater reproduction in edge versus interior habitat is an important factor contributing to higher densities of P. leucopus in small fragments.
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