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This paper reports the very first data on the denning habits of the little-studied Molina's hog-nosed skunk ( Conepatus chinga). We identified and characterized 240 (males: n = 92, females: n = 148) den sites used by nine radio-tracked skunks from November 2002 to October 2003 and from December 2005 to October 2007. Most dens were found in underground burrows and we found no variation in dimensions of den entrances across seasons. On average, 24.1% of the den sites were reused by C. chinga. Den sites were not homogeneously distributed within an animal's home range, being the density in core areas greater than in proximity to the borders of home ranges. C. chinga selected specific habitat characteristics for their den sites, such as high shrub and grass cover. Accordingly, the habitats preferred by skunks were native grasslands and pastures. Also, C. chinga preferred den sites located close to fences, roads, and grass patches. We argue that these preferences for den sites may provide two, not mutually exclusive, advantages: access to consistent and predictable sources of food, and protection from predators. Our results suggest that availability of semi-natural grassland and pasture areas may favor the conservation of C. chinga in the human-modified landscapes of the Pampas. [ABSTRACT FROM AUTHOR]

Because leaf hairs serve as resistance against herbivores, among-population variation in hair production may arise from adaptation to local herbivore communities. It is possible that Japanese nettle ( Urtica thunbergiana) shows among-population variation in stinging hair abundance that is associated with the frequency of habitat use by sika deer ( Cervus nippon). We examined 31-32 individuals of each of 19 populations for leaf area, stinging hair number (/leaf) and stinging hair density (per square centimeter) in and away from Nara Park (6.6 km), where many deer have been protected for 1,200 years. At each site we also measured deer habitat use frequency, light intensity and soil fertility as environmental factors potentially affecting leaf traits. We analyzed our hierarchical data at the levels of individuals and populations using multilevel structural equation modeling. Leaf area had a positive direct effect on stinging hair number at the individual level but no significant effect at the population level. At the population level, deer habitat use frequency had a negative direct effect on leaf area and positive direct effects on stinging hair number and density, generating a negative indirect correlation between leaf area and stinging hair number. Light intensity had a negative direct effect on leaf area, while soil fertility had no significant effect on any trait. These results suggest that the relationships between leaf area and stinging hair number at the two levels do not align. We discussed what processes were involved in the effects of environmental factors on leaf traits. [ABSTRACT FROM AUTHOR]

The alarm pheromones often released by animals under stressful situations seem to elicit behavioral changes in conspecifics, which in the appropriate context can be viewed as anti-predatory responses. However, the releasing of alarm pheromones associated with predatory events has not been demonstrated in mammals. In the current study with wild-caught Cabrera voles, we carried out experiments in the laboratory and in the field to assess the release of alarm pheromones in scent-marks during simulated predatory events and disclose their effects on conspecifics. We first conducted an assay wherein voles where let to scent-mark a clean substrate in the absence of disturbance (control) and under the simulation of predatory events. Contrarily to the control, no fecal boli were released and the area marked with urine was significantly larger during the predatory simulation. In a subsequent assay, we assessed the voles' preference between urine-marks released under predatory simulation and in control conditions. Voles showed a significant preference by control substrates. Finally, a third assay was carried out in the vole's habitat wherein the individual activity was monitored by radio-tracking before and after placement of urine-marks obtained during the conditions described above. The vole's activity was only reduced near the urine-marks released during the simulated predatory events. The results suggest that: (1) during predatory attempts, Cabrera voles release an alarm pheromone in their urine-marks; (2) the putative alarm pheromone reduces the voles' activity in the surroundings of the marked area; (3) the putative alarm pheromone persists in the field affecting conspecifics' activity for several days. [ABSTRACT FROM AUTHOR]

We review studies that consider how food affects primate population abundance. In order to explain spatial variation in primate abundance, various correlates that parameterize quality and quantity of food in the habitat have been examined. We propose two hypotheses concerning how resource availability and its seasonality determine animal abundance. When the quality of fallback foods (foods eaten during the scarcity of preferred foods) is too low to satisfy nutritional requirement, total annual food quantity should determine population size, but this relationship can be modified by the quality or the quantity of fallback foods. This mechanism has been established for Japanese macaques and sportive lemurs that survive lean seasons by fat storage or extremely low metabolism. Second, when fallback food quality is high enough to satisfy nutritional requirement but quantity is limited, quantity of fallback food should be a limiting factor of animal abundance. This is supported by the correlation between fig density, which is a high-quality fallback food, and gibbon and orangutan abundance. For a direct test of these hypotheses, we need more research that determines both the quality of food that animals require to satisfy their nutritional requirement and the quantity of food production. Leaves are often regarded as superabundant, but this assumption needs careful examination. [ABSTRACT FROM AUTHOR]

llee effects, the reduction of vital rates at low population densities, can occur through several mechanisms, all of which potentially apply to reintroduced populations. Reintroduced populations are initially at low densities, hence Allee effects can potentially lead to reintroduction failure despite habitat quality being sufficient to allow long-term persistence if the population survived the establishment phase. The probability of such failures can potentially be reduced by releasing large numbers of organisms, by reducing post-release dispersal or mortality through management, or by directly managing the Allee effects, e.g., by implementing predator control or food supplementation until population size increases. However, such measures incur costs, as large releases have a greater impact on source populations, and management actions require financial and other resources. It is therefore essential to compare the costs and benefits of attempting to reduce Allee effects in reintroduction programs. Here we advocate the use of structured decision-making frameworks whereby alternative strategies are nominated, probability distributions of outcomes obtained under different strategies, and utilities assigned to different outcomes. We illustrate the potential application of such decision frameworks using projections from a stochastic population model including Allee effects. As there will seldom be estimates of Allee effects available from the species or system involved, it will be necessary to predict these effects based on the biology of the species and data from other systems. In doing so, it is important to identify mechanisms for proposed Allee effects, and to avoid misleading inferences from correlations subject to confounds. In particular, naive interpretations of correlations between numbers released and reintroduction success may exaggerate the benefits of releasing large numbers. [ABSTRACT FROM AUTHOR]

We used multiple lines of evidence to assess habitat selection, dietary choice, and nutritional outcomes for a population of North American elk ( Cervus elaphus), confined to a relatively small and isolated landscape of public and private land in south-central Great Plains, USA. The area of suitable elk habitat was a topographically diverse matrix of mature oak savannah, C4-dominated grasslands, and C3-dominated agricultural fields surrounded by unsuitable lowlands fragmented by anthropogenic activities. We hypothesized that such disparity in habitat availability and quality resulted in subpopulation differences in the overall elk population. We used 3 methods to evaluate this premise: radiotelemetry to determine home range and habitat use, microhistology of plant fragments in feces to determine dietary selection, and fecal nitrogen (N) and stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) to assess nutritional outcomes of habitat use and dietary choice. By comparing these 3 approaches, we wanted to determine if fecal indices alone could efficiently and accurately identify subpopulation structuring. Compositional analyses from radiotelemetry observations of 21 female elk identified 2 subpopulations that occupied relatively disjunct areas and showed differential preferences for forested and cultivated fields in summer but comparable preferences for cultivated fields in winter. A third unmarked subpopulation of elk was known to be largely confined to an adjacent wildlife refuge. Microhistological analyses of feces collected in all 3 areas highlighted distinct diets, outcomes of habitat occupation by the 3 subpopulations. Increased use of cultivated forages in winter was evident for 2 of the subpopulations, but the extent of use by elk was dependent on availability of cultivated forages in areas they occupied. The refuge subpopulation had no access to cultivated forage. Fecal N, fecal δ13C, and fecal δ15N supported the premise that the subpopulation with the greatest access to cultivated forages was on a higher nutritional plane than the other 2 subpopulations. Changes in fecal N, fecal δ13C, and fecal δ15N paralleled percentages of cultivated forages in the diets highlighting the utility of such fecal indices as supplemental to or surrogates for traditional methods of habitat use and dietary selection in free-ranging ungulates. [ABSTRACT FROM AUTHOR]

The array of definitions regarding ‘peri-urban’ areas do not allow the precise measurement of its boundaries in a city. In this study, I developed an easy-to-use method to calculate the area where urban and adjacent non-urban systems intermingle. To validate that such areas were ecologically meaningful, I compared bird community species-richness, abundance, and composition from ‘intra-’ and ‘peri-urban’ areas in a medium-sized neotropical city. Results show that ‘peri-urban’ areas represent an important ecological interaction area for birds, and differ greatly from ‘intra-urban’ areas. The proposed method is robust and useful for a great variety of amoeboid-growing cities. [ABSTRACT FROM AUTHOR]

Using data from a global positioning system (GPS), seven adult red deer ( Cervus elaphus L.) were tracked in the Parc National des Cévennes, southern France, between November 1998 and December 2000 to assess the factors affecting large-range movement patterns and habitat use. The home range varied from a single compact area for females to three distinct seasonal ranges for males, which used alternative migratory strategies (i.e. non-, downward- and upward-migrants). The migrants used mainly southerly and easterly aspects, and wintered in areas having steeper slopes than were used during summer or the rut season. For males, the time of rut migration was mid-September and they finally entered wintering ranges from mid-December to the beginning of January. Exploratory behaviour (i.e. individuals found outside the limits of their familiar area but returning to it a few days later) occurred in both sexes and for all individuals monitored during at least a 6-month period. Velocity and efficiency of exploratory movements were higher than usual movements. During these exploratory movements, hinds may have used different landscape attributes (elevation, slope, canopy cover) while stags did not. These results provide new empirical information that could be used for building and applying broad-scale spatial and landscape use models in ecological research. [ABSTRACT FROM AUTHOR]

Many conclusions about mammalian ranging behaviour have been drawn based on minimum convex polygon (MCP) estimates of home range size, although several studies have revealed its unpredictable nature compared to that of the kernel density estimator. We investigated to what extent the choice of home range estimator affected the biological interpretation in comparative studies. We found no discrepancy when the question asked covered a wide range of taxa, as real and very large differences in range size were likely to have masked smaller differences due to the choice of home range estimator. However, when the question asked concerned within-species characteristics, the choice of home range estimator explained as much of the variation in range size as did the ecological variable in question. The implications for macro-ecological and intraspecific studies are discussed. [ABSTRACT FROM AUTHOR]

Lowland rainforests on Borneo are being degraded and lost at an alarming rate. Studies on mammals report species responding in various ways to habitat changes that occur in commercial forestry concessions. Here we draw together information on the relationship between the ecological, evolutionary, and biogeographic characteristics of selected Bornean non-volant mammals, and their response to timber harvesting and related impacts. Only a minority of species show markedly reduced densities after timber harvesting. Nonetheless there are many grounds for concern as various processes can, and often do, reduce the viability of wildlife populations. Our review of what we know, and of current understanding, helps predict mammalian dynamics and subsequent mammal-induced ecosystem changes in logged forests. We identify groups of mammal species that, although largely unstudied, are unlikely to tolerate the impacts associated with timber harvesting. On a positive note we find and suggest many relatively simple and low-cost ways in which concession management practices might be modified so as to improve the value of managed forests for wildlife conservation. Improving forest management can play a vital role in maintaining the rich biodiversity of Borneo’s tropical rain forests. [ABSTRACT FROM AUTHOR]

Two to four species of tiger beetles co-occur in coastal habitats of Japan. We have already demonstrated that co-occurring species exhibit interspecific size differences in adult mandible length, suggesting food resource partitioning with respect to prey size. In the present study, we investigated the larval microhabitats of six coastal species to examine whether spatial segregation occurs during the larval stage. The larvae of each species were found in specific microhabitats:Cicindelalewisiioccurred at tidal flats,Abroscelis anchoralisat beaches,Chaetodera laetescriptaat coastal dunes, andLophyridia angulataat riverbanks in estuaries. Larvae of two congeners occurred in very different microhabitats:Callytron inspecularisat reed beds formed in tidal flats in estuaries andC. yuasaieither in rock crevices, where the soil had built up, or at clay cliffs. These larval microhabitats differed among species in terms of vegetation cover, salinity, and soil texture. The larvae of four species (C. lewisii,A. anchoralis,C. inspecularis, andC. yuasai) were found at sites exposed to seawater, suggesting a tolerance to salinity. Additionally, we found differences in adult limb proportion among species. These differences seemed to be adapted to soil types in the larval microhabitats. Finally, we discuss the patterns of species assemblage of coastal tiger beetles in terms of habitat selection associated with microhabitat specificity during the larval stage and interspecific interaction associated with adult mandible size. [ABSTRACT FROM AUTHOR]

Microhabitat factors associated with forage and bed sites of Indian muntjac (Muntiacus muntjak) were examined and compared in Hainan Island from 2001 to 2002. Habitat characteristics at forage and bed sites were measured by tracking five radio-collared adult muntjacs (three females, two males) and locating from fresh sign or muntjac flushed during transect surveys. Among six available habitat types, Indian muntjac preferred shrub grassland and thorny shrubland, and used dry savanna in proportion to its availability. Muntjac avoided woods, cultivated grassplot and deciduous monsoon forests. Comparing forage sites with bed sites, food availability was greater at forage sites. For bed sites, taller trees with larger canopies, taller shrubs, denser shrub canopy covers and concealment covers were essential factors. No seasonal difference (wet season vs. dry season) was found in food abundance at either forage sites or at bed sites. During the wet season, canopy closure for both types of sites was higher and at bed sites concealment cover was higher than during the dry season. Principal component analysis indicated that tree height, d.b.h. and maximum canopy diameters were important factors in habitat selection. The different microhabitat characteristics at forage and bed sites can be a clue to understanding the survival strategy of Indian muntjac, a small-bodied ungulate, in savanna woodlands. [ABSTRACT FROM AUTHOR]

To investigate how progressive urbanization influences the distribution of ant species in cities, I compared the ant species richness in urban parks of different areas and ages of Tokyo, the most intensively developed urban region in Japan, and its developing neighbor, Chiba City. A total of 43 ant species were found from 98 parks. Multiple regression analysis revealed that park area and age had a positive effect on the number of ant species in the parks and that the parks in Tokyo contained fewer species than did comparable parks in Chiba. Thus, the progression of urbanization reduces ant species richness in urban parks, most likely because it isolates the parks from the surrounding area. Next, in order to examine the relationships between the types of landform modification and the ant distribution in urban areas, I compared the ant species richness in urban parks of Chiba City among different landform types (upland + terraces, lowlands, cut and fill, banking, and reclamation). This study showed that the parks in the reclaimed lands and lowlands contained fewer ant species than did parks in other areas. The reason for this decline of ant fauna is discussed. [ABSTRACT FROM AUTHOR]

Stable (δ13 C and δ15 N) and radio- (14 C, 137 Cs and 210 Pb) isotopes were determined for termites that have been sampled from a dry evergreen forest in Thailand. A wood-feeding termite, Microcerotermes crassus , was separated from soil-feeders: Termes propinquus , Termes comis and Dicuspiditermes makhamensis by δ13 C and δ15 N values. The Termes group in Thailand had less diverse values in δ13 C and δ15 N than those in Australia, where the feeding habits of the ‘Termes ’ group are more diverse. Other soil-feeding termites produced similar δ13 C values, but a larger range in δ15 N values. 14 C-percent modern carbon (pMC) values suggest that the soil-feeding termites used younger carbon than the wood-feeding termites, and this was consistent with the termites from Cameroon, central Africa. Values of δ13 C and 14 C-pMC indicate that surface soil was used by a soil-feeding termite, D. makhamensis , in making the nest mounds, and deeper soil (10–30 cm) by a fungus-growing termite, Macrotermes carbonarius . 210 Pb and 137 Cs were scarcely incorporated into the termites, although 214 Pb was recovered from the workers. The results suggest that stable- and radioisotopes are useful in the study of detritivorous animals, organic matter decomposition and ecosystem engineering. [ABSTRACT FROM AUTHOR]