Swamp rabbits as indicators of wildlife habitat quality in bottomland hardwood forest ecosystems

Reforestation of bottomland hardwood (BLH) forests has occurred within the Lower Mississippi Alluvial Valley (LMAV), USA, to support a wide range of ecosystem services, but especially wildlife habitat enhancement. As ecosystem restoration efforts proceed in BLH ecosystems, managers and policymakers are seeking criteria to evaluate wildlife habitat enhancement goals. Specialist wildlife that evolved within forest ecosystems can be sensitive to the composition, structure, and function of an ecosystem in relation to the system's natural or historical range of variation and thereby serve as indicators of habitat quality. The swamp rabbit (Sylvilagus aquaticus) is a specialist species of BLH forests throughout the LMAV and therefore may be an appropriate indicator species for this ecosystem. To address this, we reviewed peer-reviewed literature to evaluate the utility of swamp rabbits as an indicator species according to three commonly-used criteria: habitat factors defining swamp rabbit relationships to BLH forests, the importance of swamp rabbit habitat to other wildlife, and the efficiency of swamp rabbit monitoring. We conclude that the swamp rabbit is a suitable indicator of wildlife habitat quality in BLH ecosystems in the LMAV because they evolved and remain endemic to the ecosystem, use habitat that integrates desirable characteristics that positively influence wildlife biodiversity, and are easy to monitor routinely.     

Sex-specific differences and long-term trends in habitat selection of American woodcock

Effective wildlife management requires an understanding of how individuals select environmental factors, although few studies assess how habitat selection may differ over time or between sexes. During the post-breeding period (15 May to 1 Sep), we tracked 146 male American woodcock (Scolopax minor) in Rhode Island, USA, from 2010–2021 to assess how habitat selection varied over time, and 17 females and 51 males during the final 2 years of the study to document sex-specific differences in habitat selection. Males generally had smaller home ranges (35.0 ± 10.7 [margin of error] ha) and preferred habitat mosaics that consisted of forested wetlands, young forest patches, areas of deciduous forest, moist soils with gentle slopes, and riparian corridors. We detected subtle differences between sexes in selection for wetland young forest, upland young forest, percent slope, distance to upland young forest, distance to streams, and distance to moist soils. During 2020–2021, females tended to have larger home ranges (78.7 ± 46.4 ha) than males (35.0 ± 10.7 ha) and more strongly selected sites closer to riparian corridors, while males selected areas that were closer to upland young forest with flatter slopes than the available surrounding landscape. Such sex-specific differences in habitat selection may be related to males and females prospecting for potential breeding sites during this post-breeding period for the following spring. We used the top-ranked habitat selection models for males and females to produce a spatially explicit state-wide map that identifies low-to-high likelihood of use areas that can be used to guide forest management decisions in southern New England to maximize benefits for American woodcock.     

Habitat preferences of medium/large mammals in human disturbed forests in Central Japan

It is a great concern whether human disturbed forest, i.e., secondary forest or monoculture forest, can be a habitat for the wildlife. We examined habitat preference of medium/large terrestrial mammal species in a human-disturbed mountainous settlement area of Akiyama Region, Central Japan, by using camera-traps, which were placed at conifer plantation forest, high/low-disturbed deciduous broad-leaved forest, and broad-leaved/conifer mixed forest in 2008 and 2009. Camera-traps were operational for 4568.6 trap-nights producing 740 photo-captures of 13 medium/large terrestrial mammal species. Japanese serow and Japanese hare dominated 54 % of all photo-captures. Low-disturbed deciduous broad-leaved forest showed the richest mammal fauna (12 spp.). We suggested that fruit trees and understory vegetation provided suitable habitat for frugivorous as well as herbivorous mammals. The mixed forest showed the lowest mammal fauna (6 spp.), which located higher elevation. High-disturbed deciduous broad-leaved forest (9 spp.) was also supposed to be a better habitat for some frugivorous mammals and herbivorous mammals, but tended to be avoided by Japanese marten and Japanese macaque. Conifer plantation forest (7 spp.) with understory vegetation was supposed to be a better habitat for Japanese serow and Japanese hare, but not for the other species. Without fruit trees, conifer plantation forest was supposed to be non-attractive habitat for frugivorous mammals. We demonstrated that, if a forest had been disturbed by human, the forest can be a habitat for terrestrial herbivores, but this was not always true for frugivores.     

Resource selection by the eastern massasauga rattlesnake on managed land in southwestern Michigan

The eastern massasauga rattlesnake (Sistrurus catenatus catenatus) has experienced population declines throughout its range and is now a candidate for federal protection. However, little is known about massasauga habitat selection in Michigan, particularly in actively managed landscapes. Our objectives were to: 1) quantify whether massasaugas in southwestern Michigan select certain vegetation types disproportionately to their availability and 2) quantify whether the vegetation structure associated with snake locations differed between managed (e.g., burning, woody species removal) and unmanaged stands. We implanted radio transmitters in 51 snakes from 2004 to 2005 and 2008 to 2009. We quantified second-order resource selection using compositional analysis, and modeled the effect of habitat management efforts on vegetation using 4 structural variables. All snakes selected cover types disproportionately to their availability (P = 0.001); a ranking matrix ordered the vegetation types, from most to least used, as: early-mid successional deciduous wetland > early-mid successional deciduous upland > developed > late successional mixed lowland forest > late successional deciduous upland forest. We found that snakes in managed areas were associated with greater amounts of dead herbaceous cover (P = 0.005) and less woody stem density (P < 0.001) and tree dominance (P < 0.001) than were snakes in unmanaged areas; however, live herbaceous cover was comparable. Our results can be used by regional managers to provide early and mid successional habitat with structure similar to that selected by snakes in Michigan. © 2011 The Wildlife Society.     

Morphological Variation in Two Facultative Epiphytic Bromeliads Growing on the Floor of a Swamp Forest1

The epiphytic tank bromeliads Nidularium procerum (a CAM plant) and TV. innocentii (a C3 plant) can be found as terrestrial plants in the understory of a Brazilian swamp forest. They occur in segregated patches differing in light and flooding regimes; however, plants of each species are found in the other species preferred habitat in a narrow boundary zone where the two populations meet. Although ecophysiological factors were previously thought to dictate the distribution of these species at this site, we suggest that their current distribution is probably related to colonization history and subsequent competition for space.     

Predicting greater sage‐grouse habitat selection at the southern periphery of their range

Mapping suitable habitat is an important process in wildlife conservation planning. Species distribution reflects habitat selection processes occurring across multiple spatio‐temporal scales. Because habitat selection may be driven by different factors at different scales, conservation planners require information at the scale of the intervention to plan effective management actions. Previous research has described habitat selection processes shaping the distribution of greater sage‐grouse (Centrocercus urophasianus; sage‐grouse) at the range‐wide scale. Finer‐scale information for applications within jurisdictional units inside the species range is lacking, yet necessary, because state wildlife agencies are the management authority for sage‐grouse in the United States. We quantified seasonal second‐order habitat selection for sage‐grouse across the state of Utah to produce spatio‐temporal predictions of their distribution at the southern periphery of the species range. We used location data obtained from sage‐grouse marked with very‐high‐frequency radio‐transmitters and lek location data collected between 1998 and 2013 to quantify species habitat selection in relation to a suite of topographic, edaphic, climatic, and anthropogenic variables using random forest algorithms. Sage‐grouse selected for greater sagebrush (Artemisia spp.) cover, higher elevations, and gentler slopes and avoided lower precipitations and higher temperatures. The strength of responses to habitat variables varied across seasons. Anthropogenic variables previously reported as affecting their range‐wide distribution (i.e., roads, powerlines, communication towers, and agricultural development) were not ranked as top predictors at our focal scale. Other than strong selection for sagebrush cover, the responses we observed differed from what has been reported at the range‐wide scale. These differences likely reflect the unique climatic, geographic, and topographic context found in the southern peripheral area of the species distribution compared to range‐wide environmental gradients. Our results highlight the importance of considering appropriateness of scale when planning conservation actions for wide‐ranging species.     

Habitat structure is more important than vegetation composition for local‐level management of native terrestrial reptile and small mammal species living in urban remnants: A case study from Brisbane,Australia

Abstract As urban areas continue to expand and replace natural and agricultural landscapes, the ability to manage and conserve native wildlife within urban environments is becoming increasingly important. To do so we first need to understand species' responses to local‐level habitat attributes in order to inform the decision‐making process and on‐ground conservation actions. Patterns in the occurrence of native terrestrial reptile and small mammal species in 59 sites located in remnant urban habitat fragments of Brisbane City were assessed against local‐level environmental characteristics of each site. Cluster analysis, multidimensional scaling ordination, and principal axis correlation were used to investigate relationships between species' occurrences and environmental characteristics. Native reptiles were most strongly associated with the presence of termite mounds, a high amount of fallen woody material, and a moderate amount of weed cover. Native small mammals were most strongly associated with the presence of grass trees (Xanthorrhoea spp.), and both reptiles and small mammals were negatively influenced by increased soil compaction. Significant floristic characteristics were considered to be important as structural, rather than compositional, habitat elements. Therefore, habitat structure, rather than vegetation composition, appears to be most important for determining native, terrestrial reptile and small mammal species assemblages in urban forest fragments. We discuss the management implications in relation to human disturbances and local‐level management of urban remnants.     

Addressing regional relationships between white‐tailed deer densities and land classes

White‐tailed deer (Odocoileus virginianus) populations have recovered to about 30 million animals in the United States, but land cover has changed during the interval of recovery. To address the relationship between deer densities and current land cover at regional scales, I applied random forests and extreme gradient boosting classifiers to model low and high deer density classes, at two different thresholds (5.8 and 11.6 deer/km²), and land classes in three regions during approximately 2003. For low and high deer density classes divided at 5.8 deer/km², deciduous broadleaf forest overall was the most influential and positive variable in the central east and central regions and crop and pasture were the most influential and negative variables in the southeast region. Deer density increased with area of deciduous and mixed forests, woody wetlands, and shrub in all regions. Deer density decreased with area of crop, developed open space, and developed low and medium residential density in all regions. For density classes divided at 11.6 deer/km², deer density had the strongest relationship with woody wetlands in the central east region, mixed and deciduous forest in the southeast region, and woody wetlands and herbaceous vegetation in the central region. Deer density increased with deciduous and mixed forests, woody wetlands, and shrub in all regions. Conversely, deer density decreased with herbaceous vegetation, crop, and developed low residential densities in all regions. Therefore, at regional scales, deer overall occurred at greater densities in forests and woody wetlands and lower densities in agricultural and residential development, which did not appear to support more deer. Deer preference for forests does result in damage to forest products, but alternatively, some may consider that deer provide important socioeconomic and ecological services by reducing number of small trees, particularly in the absence of other disturbances that historically controlled tree biomass.     

Nesting Habitat of the Lilac-crowned Parrot in a Modified Landscape in Mexico

Parrot populations are being increasingly pressured to occupy modified or fragmented landscapes, yet little is known of the habitat requirements of most species, particularly with regard to the effects on breeding habitat. We evaluated nesting habitat of the lilac-crowned parrot Amazona finschi in the modified landscape of coastal Michoacan in Mexico. We located 90 parrot nests in 12 tree species in Michoacan, with lilac-crowned parrots presenting a narrow niche-breadth of tree species used for nesting. Considering an additional 82 nest trees recorded for lilac-crowned parrots in Jalisco, we determined a 51 percent similarity in cavity resource use by parrots in the two dry forest regions. Overall, the predominant nest tree species with 76 percent of nests were Astronium graveolens , Piranhea mexicana , Brosimum alicastrum , and Tabebuia spp., all characteristic of semi-deciduous forest. Only 8 percent of nests occurred in trees characteristic of deciduous forest. Parrots utilized large trees with canopy level cavities as nest sites, and preferred conserved semi-deciduous forest for nesting, with fewer nests than expected in deciduous forest and transformed agricultural land. Nest areas in semi-deciduous forest occurred on significantly steeper terrain, as remnant semi-deciduous forest is restricted to steep ridges and canyons. Those parrot nests in modified habitats and forest patches were located near to continuous forest, with nest trees in open agricultural land being significantly closer to continuous forest than nests in disturbed forest patches. These results demonstrate the importance of conserved semi-deciduous forest as breeding habitat for the threatened, endemic lilac-crowned parrot, making wild populations of the species vulnerable to the high rate of transformation and fragmentation of tropical dry forest.     

Calving rate,calf survival rate,and habitat selection of forest-dwelling caribou in a highly managed landscape

Logging negatively affects the threatened forest-dwelling caribou (Rangifer tarandus caribou) through its positive effects on large predator populations. As recruitment is a key component of caribou population growth rate, we assessed calving rates of females and calf survival rates during the most critical period for calf survival, the calving period. We also identified causes of calf mortality and investigated the influence of predation risk, food availability, and human disturbance on habitat selection of females during the calving period at both the home-range and forest stand scales. We hypothesized that caribou should display habitat selection patterns to reduce predation risk at both scales. Using telemetry, we followed 22 females and their calves from 2004 to 2007 in a highly managed study area in Québec, Canada. Most females (78.5 ± 0.05 [SE]) gave birth each year, but only 46.3 ± 8.0% of the calves survived during the first 50 days following birth, and 57.3 ± 14.9% of them died from black bear (Ursus americanus) predation. At the home-range scale, caribou selected calving areas located at upper slope positions and avoided high road density areas. Surprisingly, they also selected the forested habitat type having the lowest lateral cover (mixed and deciduous stands) while avoiding the highest cover (regenerating conifer stands). At the forest stand scale, caribou selected areas located at relatively high elevations and with a lower basal area of black spruce trees. The selection of upper slope positions likely favored spatial segregation between calving females and wolves (Canis lupus) but not black bear. Our results suggest that calving females used areas from which they could visually detect approaching predators. While wolf avoidance appeared to be effective in a highly managed landscape, caribou did not appear to have adjusted their predator avoidance strategy to the recent increase in black bear abundance, who have benefited from increased food abundance. This situation requires focused attention from wildlife managers as logging activities are progressing towards the north within the core of forest-dwelling caribou range. © 2011 The Wildlife Society.     

Habitat use under latent predation risk. A case study with wintering forest birds

We test whether the spatial distribution of birds within a habitat is determined by predation risk and also by interspecific competition. The work was carried out in a montane mixed forest of central Spain with four Parus species, the long-tailed tit ( Aegithalos caudatus ) and the nuthatch ( Sitta europaea ). Experimental feeders, that varied in their risk of predation, were used to control the effect of natural variations in food availability and quality on the habitat use patterns of different species. Tree gleaning passerines avoided feeding on dark inner forest places far from edges, distant from protective cover, outside the inner tree canopy and near the ground; they preferred deciduous, relatively clear forest plots. These effects remained invariable across years and weather conditions. There was a common pattern of selection of foraging locations by the four Parus species: proximity to cover and height above ground and over the lowest branches of the tree canopy positively influenced the use of feeding places. According to these patterns, the vigilance proportion of species was significantly higher when feeding far from cover than when birds were feeding near pine foliage. This pattern was also common for the four studied Parus species. Nevertheless, the interspecific dominance hierarchy of the species was positively correlated with the use of the safest feeders (feeders farther the ground and nearer from protective cover within tree canopy), being the converse with the most exposed ones. Therefore, the results of this paper demonstrate that the selection of feeding locations within habitat follows a pattern minimizing predation risk. Interspecific dominance hierarchies can lead to the exploitation of unfavourable risky patches by subordinate species.     

Multiscale Nest-Site Selection by Black-Capped Vireos

Abstract: We used an information-theoretic approach to investigate nest-site selection by black-capped vireos (Vireo atricapilla) at the landscape and habitat-patch scales on Fort Hood Military Reservation in central Texas, USA, during 2003 and 2004. We used a use-availability sampling design and logistic regression to compare woody cover characteristics at nests to random points in the landscape to determine habitat selection at the landscape scale. At the habitat-patch scale, we used matched case-control logistic regression to compare habitat measures at nests and random non-nest points to evaluate support for hypotheses concerning the influence of woody cover, nest-patch, and nest-site characteristics on black-capped vireo nest-site selection. At the landscape scale, we found strong support (Akaike wt [w_j] = 1.0) for a model with a cubic effect of percent woody cover and woody cover edge density. Sites with the greatest predicted probabilities of use had woody cover values between 30% and 60% and increasing amounts of edge. We found strong support (w_i = 0.93) for the global model at the habitat-patch scale that included characteristics of the nest site, nest patch, and woody cover within 25 m. Based on odds ratios and confidence limits, percent woody cover, cover below 2 m, cover type, and substrate height had the greatest effect on nest-site selection. The predicted probability a site was selected for a nest site increased with foliage cover below 2 m, taller substrates, deciduous cover, and decreased at high levels of percent woody cover (especially >80%). Texas red oak (Quercus buckleyi) was the most used nest substrate (100 of 358 nests), followed by shin oak (Q. sinuata var. breviloba; 86 of 358 nests) and Ashe juniper (Juniperus ashei; 44 of 358 nests). Black-capped vireos used Texas red oak and shin oak in greater proportion to their availability, whereas Ashe juniper was used less in proportion to its availability, suggesting vireos avoided this species. We suggest that managers promote dense deciduous cover for nesting habitat and maximize edge-to-area ratios to maintain spatial and structural heterogeneity.     

Contribution of woody debris to trout habitat modification in small streams in secondary deciduous forest, northern Japan

Field studies to examine the influence of woody debris on rainbow trout (Oncorhynchus mykiss) abundance through habitat modification were conducted in two small streams, the Horonai and Uenae streams, running through secondary deciduous forest in south-western Hokkaido, northern Japan. Reach-based woody debris volume (total woody debris volume per 100 m² of study reach) was significantly correlated with the total basal area of riparian stands along the margins of the Horonai stream, but no significant relationship was evident between them for the Uenae stream. This inconsistency between the streams was considered to be a result of the difference in stream size (width, depth and discharge). Woody debris was the principal agent for pool formation, although it had a far smaller volume than that found in streams draining old-growth coniferous forest in North America, where most of the previous studies have been carried out. Untransported debris pieces of larger volume more effectively contributed to pool formation than smaller transported pieces. The volume of individual debris scour pools was positively correlated with the volume of woody debris associated with each. Similarly, reach-based pool volume increased with total woody debris volume, but the relationship was less clear in the Uenae stream, having more abundant transported woody debris than the Horonai stream. The biomass of rainbow trout in individual pools, which were regarded as the most preferred habitat type for stream salmonids, was correlated with pool volume. A positive relationship also existed between reach-based standing crop and pool volume. These results revealed that secondary deciduous forest, like old-growth coniferous forest, plays an important role in enhancing the carrying capacity for rainbow trout by supplying woody debris which promoted preferred habitat formation.     

Extraction of non-timber forest products in the forests of Biligiri Rangan Hills, India. 4. impact on floristic diversity and population structure in a thorn scrub forest

Impact of extraction of non-timber forest products (NTFPs) was analyzed in a thorn scrub forest in Biligiri Rangaswamy Temple (BRT) wildlife sanctuary, India. Six species are most commonly extracted from BRT scrub for subsistence and income generation by an aboriginal tribe, the Soliga. Although the forest has been provided protection from indiscriminate felling since 1978 under a wildlife sanctuary cover, changes in vegetation structure are still occurring as a consequence of anthropogenic pressure in the form of extraction of fuelwood and other NTFPs. The results indicate that large woody species are being replaced by small woody species. The population structure also is becoming increasingly skewed to the smaller size classes due to extraction-bound mortality of the individuals, particularly those>7 cm dbh and above. The data suggest that the scrub community itself may be a manifestation of long persisting anthropogenic pressure in the form of extraction of a variety of forest products, and it currently represents a downward transition from a deciduous forest to a shrub thicket.     

Hierarchical Den Selection of Canada Lynx in Western Montana

Abstract We studied den selection of Canada lynx (Lynx canadensis; hereafter lynx) at multiple ecological scales based on 57 dens from 19 females located in western Montana, USA, between 1999 and 2006. We considered 3 spatial scales in this analysis, including den site (11-m-radius circle surrounding dens), den area (100-m-radius circle), and den environ (1-km radius surrounding dens). Lynx denned in preexisting sheltered spaces created by downed logs (62%), root-wads from wind-thrown trees (19%), boulder fields (10%), slash piles (6%), and live trees (4%). Lynx preferentially selected den sites with northeasterly aspects that averaged 248. Average distance between dens of 13 females monitored in consecutive years was 2,248 m, indicating low den site fidelity. Lynx exhibited habitat selection at all 3 spatial scales. Based on logistic regression, den sites differed from the surrounding den areas in having higher horizontal cover and log volume. Abundant woody debris from piled logs was the dominant habitat feature at den sites. Lynx generally denned in mature spruce-fir (Picea-Abies) forests with high horizontal cover and abundant coarse woody debris. Eighty percent of dens were in mature forest stands and 13% in mid-seral regenerating stands; young regenerating (5%) and thinned (either naturally sparse or mechanically thinned) stands with discontinuous canopies (2%) were seldom used. Female lynx selected den areas with greater spruce-fir tree basal area, higher horizontal cover, and larger-diameter trees compared to random locations within their home range. Lynx selected den environs in topographically concave or drainage-like areas, and farther from forest edges than random expectation. Maintaining mature and mid-seral regenerating spruce-fir forests with high horizontal cover and abundant woody debris would be most valuable for denning when located in drainages or in concave, drainage-like basins. Management actions that alter spruce-fir forests to a condition that is sparsely stocked (e.g., mechanically thinned) and with low canopy closure (<50%) would create forest conditions that are poorly suitable for lynx denning.     

Ranging of <Emphasis Type="Italic">Rhinopithecus bieti</Emphasis> in the Samage Forest,China. II. Use of Land Cover Types and Altitudes

We investigated composition and structure of a temperate montane forest called Samage at Baimaxueshan National Nature Reserve in Yunnan, one of the last refuges for the highly endangered black-and-white snub-nosed monkeys (Rhinopithecus bieti). There is a patchwork of vegetation types at Samage, and we distinguished 6 major land cover types within the home range of the focal group. We tracked the semihabituated Gehuaqing band for a full annual cycle to study their habitat utilization and altitudinal ranging. We analyzed the group’s selective use of particular habitat types via selection ratios. We calculated habitat availability from a GIS database. We found that they used mixed deciduous broadleaf/conifer forest disproportionately to its availability in all months. Subjects completely avoided meadows. Pine and evergreen broadleaf forests acted as corridors between patches of mixed forest and monkeys visited them occasionally, but at low frequencies and mostly in transit. The focal band stayed at elevations ranging from ca. 2600 m to 4000 m, and the mean elevation used is 3200 m. We found evidence for seasonal variation in use of elevational zones. The band stayed at significantly higher elevations in summer than in spring. The descent in spring was likely related to a flush of immature leaves at low-lying elevations. Availability of preferred fruits also had a highly positive influence on altitudinal ranging, i.e., during months with high fruit availability (late summer, early fall), the band stayed at medium elevations where preferred fruits were most abundant. Higher concentrations of lichens and the snub-nosed monkeys’ search for not yet depleted fruits probably caused them to remain at mid-elevations in winter. There is no significant correlation between climate parameters and elevation used. One of the main inferences of this investigation is that, contrary to previous accounts, Rhinopithecus bieti is not universally associated with high-elevation dark fir forest, but at Samage exhibits an overwhelming preference for mixed forest. Moreover, our analyses support the hypothesis that elevational migration, in this temperate-subtropical forest, is influenced by the temporal fruiting of major food trees and that climate has only a negligible effect on elevation use. Dayong Li and Cyril C. Grueter contributed equally to the paper.     

Gradient analysis and classification of the woody vegetation for four sites in southern Illinois and adjacent Missouri

The woody vegetation and associated soil-site variables from a range of upland to swamp sites were measured using 480 0.04 ha plots from Little Black Slough, Goose Pond and Horseshoe Lake in Illinois, and Mingo Wildlife Refuge, Missouri. Multiple regression, correlation, and factor analysis were used to relate soil-site data to vegetation structure and composition. Coenoclines of both the understory and overstory were constructed to represent the upland-swamp vegetation gradient of the region near the northern terminus of the southern floodplain forest. Percent sand, depth of flooding, and silt content were variables most strongly related to the understory coenocline. Depth of flooding, and clay content were most strongly related to the overstory coenocline. Beta diversities of the understory and overstory coenoclines were 5.8 and 6.9HC. Understory density and overstory basal area increased and species richness and heterogeneity decreased along the upland-swamp gradient.Classification techniques identified three or four major overstory vegetation types within each study area. The 15 overstory types were ordinated and environmental characteristics summarized for each. Mingo Wildlife Refuge had the least flooding and lowest soil clay content. Classification of all 480 plots from the four study areas identified three major understory groups (mesic, floodplain and swamp) and eight overstory groups. These eight include aQuercus velutina-Q. alba, Quercus rubra-Q. alba, Liquidambar styraciflua-Ulmus americana, Quercus phellos-Q. palustris, Quercus lyrata-Acer rubrum, Acer rubrum-Nyssa aquatica, Nyssa aquatica-Taxodium distichum and aTaxodium distichum-Nyssa aquatica type arranged from upland to swamp.Botanical nomenclature follows Mohlenbrock (1975).Horseshoe Lake and Little Black Slough studies were supported, in part, by McIntire-Stennis Grants to PAR through the Department of Forestry, Southern Illinois University. The Department of Botany, Southern Illinois University provided support for the studies in Goose Pond, Illinois and Mingo Wildlife Refuge, Missouri. We thank Chris Baker and especially Claudia Mitchell for aid in data acquisition and analysis.     

Selection of food patches by sympatric herbivores in response to concealment and distance from a refuge

Small herbivores face risks of predation while foraging and are often forced to trade off food quality for safety. Life history, behaviour, and habitat of predator and prey can influence these trade‐offs. We compared how two sympatric rabbits (pygmy rabbit, Brachylagus idahoensis; mountain cottontail, Sylvilagus nuttallii) that differ in size, use of burrows, and habitat specialization in the sagebrush‐steppe of western North America respond to amount and orientation of concealment cover and proximity to burrow refuges when selecting food patches. We predicted that both rabbit species would prefer food patches that offered greater concealment and food patches that were closer to burrow refuges. However, because pygmy rabbits are small, obligate burrowers that are restricted to sagebrush habitats, we predicted that they would show stronger preferences for greater cover, orientation of concealment, and patches closer to burrow refuges. We offered two food patches to individuals of each species during three experiments that either varied in the amount of concealment cover, orientation of concealment cover, or distance from a burrow refuge. Both species preferred food patches that offered greater concealment, but pygmy rabbits generally preferred terrestrial and mountain cottontails preferred aerial concealment. Only pygmy rabbits preferred food patches closer to their burrow refuge. Different responses to concealment and proximity to burrow refuges by the two species likely reflect differences in perceived predation risks. Because terrestrial predators are able to dig for prey in burrows, animals like pygmy rabbits that rely on burrow refuges might select food patches based more on terrestrial concealment. In contrast, larger habitat generalists that do not rely on burrow refuges, like mountain cottontails, might trade off terrestrial concealment for visibility to detect approaching terrestrial predators. This study suggests that body size and evolutionary adaptations for using habitat, even in closely related species, might influence anti‐predator behaviors in prey species.     

Tigers need cover: multi-scale occupancy study of the big cat in Sumatran forest and plantation landscapes

The critically endangered Sumatran tiger (Panthera tigris sumatrae Pocock, 1929) is generally known as a forest-dependent animal. With large-scale conversion of forests into plantations, however, it is crucial for restoration efforts to understand to what extent tigers use modified habitats. We investigated tiger-habitat relationships at 2 spatial scales: occupancy across the landscape and habitat use within the home range. Across major landcover types in central Sumatra, we conducted systematic detection, non-detection sign surveys in 47, 17×17 km grid cells. Within each cell, we surveyed 40, 1-km transects and recorded tiger detections and habitat variables in 100 m segments totaling 1,857 km surveyed. We found that tigers strongly preferred forest and used plantations of acacia and oilpalm, far less than their availability. Tiger probability of occupancy covaried positively and strongly with altitude, positively with forest area, and negatively with distance-to-forest centroids. At the fine scale, probability of habitat use by tigers across landcover types covaried positively and strongly with understory cover and altitude, and negatively and strongly with human settlement. Within forest areas, tigers strongly preferred sites that are farther from water bodies, higher in altitude, farther from edge, and closer to centroid of large forest block; and strongly preferred sites with thicker understory cover, lower level of disturbance, higher altitude, and steeper slope. These results indicate that to thrive, tigers depend on the existence of large contiguous forest blocks, and that with adjustments in plantation management, tigers could use mosaics of plantations (as additional roaming zones), riparian forests (as corridors) and smaller forest patches (as stepping stones), potentially maintaining a metapopulation structure in fragmented landscapes. This study highlights the importance of a multi-spatial scale analysis and provides crucial information relevant to restoring tigers and other wildlife in forest and plantation landscapes through improvement in habitat extent, quality, and connectivity.     

Factors Associated with Succession of Abandoned Agricultural Lands along the Lower Missouri River, U.S.A.

The 1993 flood of the Missouri River led to the abandonment of agriculture on considerable land in the floodplain. This abandonment led to a restoration opportunity for the U.S. Federal Government, purchasing those lands being sold by farmers. Restoration of this floodplain is complicated, however, by an imperfect understanding of its past environmental and vegetative conditions. We examined environmental conditions associated with the current placement of young forests and wet prairies as a guide to the potential successional trajectory for abandoned agricultural land subject to flooding. We used Bayesian mixed-effects logistic regression to examine the effects of flood frequency, soil drainage, distance from the main channel, and elevation on whether a site was in wet prairie or in forest. Study site was included as a random effect, controlling for site-specific differences not measured in our study. We found, after controlling for the effect of site, that early-successional forest sites were closer to the river and at a lower elevation but occurred on drier soils than wet prairie. In a regulated river such as the lower Missouri River, wet prairie sites are relatively isolated from the main channel compared to early-successional forest, despite occurring on relatively moister soils. The modeled results from this study may be used to predict the potential successional fate of the acquired agricultural lands, and along with information on wildlife assemblages associated with wet prairie and forest can be used to predict potential benefit of these acquisitions to wildlife conservation.