Habitat Matrix Research Articles

Delineating fragmented grassland patches in the tropical region using multi-seasonal synthetic aperture radar (SAR) and optical satellite images

ABSTRACT Globally, grasslands are declining and are in highly degraded conditions. In South Asia, grasslands are neglected and treated as wastelands. They remain unprotected, highly fragmented, and poorly understood, which has led to a loss of unique biodiversity and livelihoods. Mapping grasslands accurately is a challenge and current maps based on optical remote sensing often over- or underestimate grasslands in South Asia due to the prevalent complex landscape matrix, small patch sizes, and obscuring monsoonal clouds. Synthetic Aperture Radar (SAR), fused with moderate spatial resolution optical data, has been used to delineate grasslands, but the high-resolution, freely available European Space Agency (ESA)’s Sentinel-1 (SAR) and Sentinel-2 (Optical) provide an opportunity to map small and fragmented patches. Further, high-resolution imageries require high computing power, which is often limited to stand-alone machines. Here, we demonstrate that using cloud computing and optimal use of multi-seasonal imagery, one can obtain a highly accurate land-cover land use (LCLU) classification for a complex habitat matrix. We performed LCLU classification using the Support Vector Machine (SVM) algorithm of Sentinel-1, Sentinel-2, and Sentinel-1 and Sentinel-2 (Combined) in Google Earth Engine (GEE). GEE is a freely accessible cloud computing platform. We compared the accuracy of grassland classes between a) Sentinel-1 seasonal (pre-, during, and post-monsoon), b) Sentinel-2 post-monsoon, and c) combined Sentinel-1 and Sentinel-2. We tested this method at two sites in a highly fragmented habitat matrix in arid and semi-arid areas of Western and Southern India. The classification results have shown that the overall accuracy for the combined image classification was higher than only Sentinel-2 or Sentinel-1 alone for both sites. Grassland class accuracy was also consistent with combined image classification across the sites. Our results identified newer grassland areas that coarse land use management maps used by the government did not. Since the computation was conducted in GEE, a regular laptop was sufficient for the user and processing was completed rapidly. We, therefore, suggest that this approach of using cloud computing and optimal use of resource-hungry (computation and storage) high-resolution Sentinel-1 and Sentinel-2 data can be used to identify major LCLU classes and patchy grasslands in the arid and semi-arid regions of India and has the potential to map at a continent level.

Ecology of an Isolated Muskrat Population during Regional Population Declines

Evidence indicating a decline in Ondatra zibethicus (Muskrat) populations in the United States during the past 40 years has led to speculation regarding factors influencing Muskrat survival. In order to understand population dynamics and survival, it is important to first define the ecology of local populations. We investigated the dwelling structure use, movements, home range, and survival of radio-tagged Muskrats (n = 14) in an urban wetland complex in central Pennsylvania. We used locations collected from intensive radio-telemetry monitoring to determine number of lodging structures used, hourly movement, and size and percent area overlap of home ranges. Muskrats shared an average of 9 lodging structures, and on average, 68% of a Muskrat's home range overlapped home ranges of other Muskrats. We used 4 home-range estimators (kernel density estimator [KDE]href, KDEad hoc, KDEplug-in, and local convex hull estimator) to assess the ability of each estimator to represent Muskrat home ranges. The KDEplug-in that constrained the estimate of home range to habitat boundaries provided the most appropriate home-range size for Muskrats in a linear–non-linear habitat matrix. We also calculated overwinter survival estimates using known-fate models. Our top model indicated a positive effect of the average weekly precipitation on survival, with an overwinter survival estimate of 0.59 (SE = 0.16). The main cause of Muskrat mortality was predation by Neovison vison (American Mink; n = 6). The small sample size and uncertainty surrounding our model selection led to weak estimates of survival; however, our model suggests that snowfall may be an important factor in Muskrat survival. Our study provides novel data on Muskrat ecology in Pennsylvania as well as preliminary evidence for future investigations of factors affecting Muskrat survival during the winter months.

Population genetic structure and microendemism in aquatic Empididae (Diptera) in transient tufa biotopes on tropical karst

ABSTRACTPopulation genetic structure of an aquatic insect obligately associated with fragmented and temporally unstable tufa formations on tropical karst was investigated using mtCOI sequence data. A median‐joining (MJ) haplotype network calculated from 263 COI sequences of Hemerodromia conspecta Plant (Diptera: Empididae: Hemerodromiinae) sampled from its 12 known sites in Thailand indicated a high level of genetic structure and identified five distinct lineages present in geographically close localities. Haplotype diversity (h), nucleotide diversity (π) and pairwise comparisons of FST suggested considerable differentiation among populations but evolutionary distance judged from the Kimura 2‐parameter was too low (0.98–4.58) to establish any lineage as a discrete species, however, it was considered as evidence of ongoing processes of allopatric speciation. Mismatch distribution analysis and low nucleotide diversity associated with high haplotype diversity in three lineages was consistent with the sudden expansion model but very low haplotype diversity of a fourth lineage provided strong indication that it had historically experienced a profound population bottleneck. Long path lengths in the MJ network suggested prolonged isolation of the four major lineages and mismatch distribution analysis indicated that their populations experienced a late Pleistocene expansion that was complete by the early Holocene, entirely consistent with evidence for a climatically driven period of late Cenozoic tufa deposition followed by late Quaternary decline. The allopatric distribution of geographically fragmented and genetically distinct lineages suggests that vicariant diversification is driving active processes of speciation and microendemism occurring within multiple microrefugia set within a wider matrix of unsuitable habitats.

Bioacoustics Reveal Species-Rich Avian Communities Exposed to Organophosphate Insecticides in Macadamia Orchards

Organophosphates are the most widely used insecticide class in agriculture. The effects of organophosphates on insectivorous birds can potentially reduce the capacity of these birds to regulate insect pest populations as well as jeopardizing the survival of vulnerable bird species in matrix habitats. In this study, we investigated the diversity of birds inhabiting commercial macadamia orchards in Australia and assessed community-wide exposure of birds to an organophosphate insecticide (trichlorfon). We also studied the impact of trichlorfon on arthropods, and how this affected bird activity. We used a novel approach, combining bird acoustic surveys, and three different arthropod trapping devices. Birds and arthropods were surveyed immediately before and after a trichlorfon application, in sprayed and unsprayed orchards, at six different sites. Surveys showed that trichlorfon applications produced no changes in bird activity, either at the species or community level. Only one species (Lichmera indistincta) showed a significant increase in acoustic activity after treatment. These results indicate that several (62) bird species, some of which have been noted as undergoing regional decline, are exposed to trichlorfon applications. Additionally, trichlorfon applications also produced rapid, negative impacts on certain arthropod groups, particularly spiders. Because almost (80%) of the bird species recorded in the study include arthropods in their diets, then arthropod contaminated by trichlorfon are likely consumed by these orchard-dwelling birds. We recommend that pest management should incorporate strategies to reduce wildlife exposure to toxic chemicals to meet the joint goals of crop production and wildlife conservation in structurally complex agricultural habitats.

Reintroducing species when threats still exist: assessing the suitability of contemporary landscapes for island endemics

AbstractReintroducing species into landscapes with persistent threats is a conservation challenge. Although historic threats may not be eliminated, they should be understood in the context of contemporary landscapes. Regenerating landscapes often contain newly emergent habitat, creating opportunities for reintroductions. The Endangered St Croix ground lizard Pholidoscelis polops was extirpated from the main island of St Croix, U.S. Virgin Islands, as a result of habitat conversion to agriculture and predation by the small Indian mongoose Herpestes auropunctatus. The species survived on two small cays and was later translocated to two islands. Since the 1950s, new land-cover types have emerged on St Croix, creating a matrix of suitable habitat throughout the island. Here we examined whether the new habitat is sufficient for a successful reintroduction of the St Croix ground lizard, utilizing three complementary approaches. Firstly, we compared a map from 1750 to the current landscape of St Croix and found statistical similarity of land-cover types. Secondly, we determined habitat suitability based on a binomial mixture population model developed as part of the programme monitoring the largest extant population of the St Croix ground lizard. We estimated the habitat to be sufficient for > 142,000 lizards to inhabit St Croix. Thirdly, we prioritized potential reintroduction sites and planned for reintroductions to take place during 2020–2023. Our case study demonstrates how changing landscapes alter the spatial configuration of threats to species, which can create opportunities for reintroduction. Presuming that areas of degraded habitat may never again be habitable could fail to consider how regenerating landscapes can support species recovery. When contemporary landscapes are taken into account, opportunities for reintroducing threatened species can emerge.

Diversity of Bird Communities in Tea (Camellia sinensis) Plantations in Fujian Province, South-Eastern China

Habitat conversion in mountain areas threatens their biodiversity. The effect on biodiversity of creating a mountain landscape with a network of forest fragments and a cultivated habitat matrix is poorly documented in China. Bird communities in forest fragments and tea plantations were censused by field observations in two years (2018–2019) in three tea-growing locations, Anxi, Beifeng, and Wuyishan in Fujian Province, south-eastern China. Out of a potential pool of 247 forest-associated bird species, we detected the presence of 82, mostly resident species, 32–47 of those regularly visiting tea plantations. Species-accumulation curves indicated the near-completeness of the census. The Rényi diversity profiles indicated a more diverse community in forest fragments than nearby tea plantations at Anxi and Beifeng, but the tea plantations at Wuyishan supported a more diverse bird community than the forest. Avian communities in tea plantations were a significantly nested subset of the forest communities. Tea plantations can provide resources for forest-associated birds, but the effectiveness of preserving avian diversity depends on natural forest fragments and can be enhanced by landscape-scale management, when the biocontrol potential of birds can also be enhanced.

Investigating the role of matrix habitat use in determining avian area-sensitivity.

The absence of some species from small habitat patches has long posed a challenge for conservationists, yet the underlying mechanisms that cause this “area‐sensitivity” remain poorly understood. Capacity of a species to extend their activities into the surrounding matrix habitat represents one potential determinant of area‐sensitivity. Species may be able to occupy smaller patches if they can utilize matrix habitat beyond patch boundaries, whereas area‐sensitive species may be restricted to larger patches due to their inability to utilize the surrounding matrix. We investigated the potential role of matrix utilization in determining area‐sensitivity by mapping the movements of two shrubland‐obligate passerines with contrasting patch area requirements in shrub‐dominated forest openings ranging in area by nearly an order of magnitude. Our findings were consistent with our predictions; the less area‐sensitive chestnut‐sided warbler (Setophaga pensylvanica) exhibited greater use of matrix habitat than the highly area‐sensitive prairie warbler (S. discolor). Furthermore, chestnut‐sided warblers that occupied smaller openings used mature forest more than conspecifics in larger patches, yet forest use by prairie warblers was unrelated to opening size. Chestnut‐sided warblers foraged as frequently in mature forest as within shrubland, whereas prairie warblers foraged significantly more in openings compared to forest. The findings of this study suggest that the ability or inclination of a species to utilize surrounding matrix habitat explains at least some of the observed variation in area‐sensitivity in songbirds and potentially other taxa.

Capturing and Marking Raccoons for Individual Recognition in Camera Studies using Tail‐fur Clipping and Dyes

ABSTRACTI developed a method of marking raccoons (Procyon lotor) for individual recognition under trail camera surveillance using restraint cones, tail‐fur clipping, and hair dyeing in an old field‐agricultural habitat matrix in southwest Wisconsin, USA, during 2012 and 2018–2019. I live‐trapped and marked 29 individual raccoons and monitored them using trail cameras during early May to mid‐August. Fur‐clipping and dye markings typically remained recognizable using camera imagery for approximately 2 months, depending on proximity to monitoring cameras, vegetation structure, and onset of the annual pelage molt; thus, these techniques have potential value in short‐term field studies where individual animal histories are desired. The described procedure can be safely and quickly performed by a single person with minimal stress to the animal and does not require the administration of sedating drugs. Although restraining cones and similar marking methods have been used for decades, refinements specific to their combined use in raccoon‐related camera studies are absent from published literature. © 2020 The Wildlife Society.

Home range of the mouse Phyllotis osilae in forest fragments of Polylepis subtusalbida with different habitat matrix

Home range is an aspect of ecology that allows us to understand the mechanisms and spatial relationships that underlie habitat choice and animal responses to environmental change. However, studies on this subject have been focused mainly on medium and large mammals, while those on small mammals are scarce. Small mammals play important roles in maintaining ecological processes, such as the survival of several plant species. Phyllotis osilae is a phyllotine rodent, which functions as a potential seed disperser for Polylepis subtusalbida , a tree that is endemic and categorized as Vulnerable (VU) for Bolivia. The forests of P. subtusalbida are highly fragmented, with reforestation with introduced species such as Pinus radiata and Eucalyptus globulus . The question we pose for this study is: how does the home range of P. osilae vary between fragments of P. subtusalbida with different types of matrix (natural grassland and exotic tree plantations)? The study was carried out on four fragments of P. subtusalbida in Tunari National Park in the city of Cochabamba, Bolivia: two fragments in the exotic tree plantation matrix (Pajcha locality) and two in the natural grassland matrix (San Miguel locality). For telemetry purposes, radio collars were installed on 16 individuals. The home ranges were calculated using the Minimun Convex Polygon (MCP) at 95 %, in the same way the Kernel density (KDE) was estimated at 95 %. The percentage of presence of P. subtusalbida and matrix trees within each home range was determined, with an area interval between 50.5 m 2 and 3,010 m 2 . No significant differences were found between both matrices regard to the area of activity; however, in the comparison of the percentages of presence of P. subtusalbida trees and matrix, significant differences were found. Our results for home ranges show that the matrix would not have an effect on the area, but on its mobility; this is evidenced by the absence of movements of P. osilae from the fragments to the exotic matrix. In this case, the exotic tree matrix is operating as a barrier and is reflected in the almost total absence of this vegetation matrix in the home range. P. osilae may be playing an important role in the recovery and conservation of these ecosystems, so knowing aspects of their natural history as well as their responses to fragmentation is of great importance in understanding the fate of the Polylepis forests.

Changing ecologies, shifting behaviours: Behavioural responses of a rainforest primate, the lion-tailed macaque Macaca silenus, to a matrix of anthropogenic habitats in southern India.

With the uncontrolled expansion of anthropogenic modifications of the environment, wildlife species are forced to interact with humans, often leading to conflict situations that have detrimental effects for both wildlife and humans. Such interactions are escalating globally, making it crucial for us to devise strategies for both, the management of conflict and the conservation of these often-threatened species. We studied a case of potentially detrimental human-wildlife interactions between an endemic, habitat-specialist primate, the lion-tailed macaque Macaca silenus and resident human communities that has developed in recent years in the Western Ghats mountains of southern India. Primates provide useful model systems to understand the extent and nature of behavioural changes exhibited by wildlife in response to anthropogenic habitats with varying degrees of human influence. We documented behaviours, including foraging and intra-species social interactions, to examine the decisions made by the macaques as they exploited four human-modified habitats, which, for the purpose of this study, have been qualitatively characterised to include structural features of the habitat, type of food resources available and the presence of humans. Access to human-origin food, either cooked or packaged, acquired directly from homes or garbage pits, in the human-dominated habitat appeared to significantly reduce active foraging and searching for food, allowing them to engage in other behavioural activities, such as resting. Furthermore, patterns of reciprocated affiliation dissipated in certain human-dominated habitats, with individuals seeming to have adopted novel behavioural strategies, leading to altered social dynamics in the troop, possibly in response to provisioning. This study thus highlights the importance of understanding behavioural changes displayed by animals in response to human interactions; such knowledge could be crucial for the planning and implementation of management and conservation strategies for endangered species such as the lion-tailed macaque and possibly other wildlife in the increasingly anthropogenic landscapes of the tropical world.

Small habitat matrix: How does it work?

We present herein our perspective of a novel Small Habitats Matrix (SHM) concept showing how small habitats on private lands are untapped but can be valuable for mitigating ecological degradation. Grounded by the realities in Sabah, Malaysian Borneo, we model a discontinuous "stepping stones" linkage that includes both terrestrial and aquatic habitats to illustrate exactly how the SHM can be deployed. Taken together, the SHM is expected to optimize the meta-population vitality in monoculture landscapes for aerial, arboreal, terrestrial and aquatic wildlife communities. We also provide the tangible cost estimates and discuss how such a concept is both economically affordable and plausible to complement global conservation initiatives. By proposing a practical approach to conservation in the rapidly developing tropics, we present a perspective from "ground zero" that reaches out to fellow scientists, funders, activists and pro-environmental land owners who often ask, "What more can we do?"

Individual-based modeling highlights the importance of mortality and landscape structure in measures of functional connectivity

Functional landscape connectivity is vital for the conservation of wildlife species. Landscape connectivity models often overlook factors such as mortality and asymmetry in landscape resistance that can have a significant impact on functional connectivity. Individual-based models (IBMs) can be used to explore such factors through the implementation of mechanistic dispersal behavior. Furthermore, population-level patterns of animal dispersal and landscape connectivity resulting from the simulation of alternative landscapes or scenarios of animal behavior can be compared. Use an IBM to evaluate the effects of disperser mortality, asymmetrical dispersal due to landscape structure, and land-use change on the functional landscape connectivity between two populations of reintroduced American martens Martes americana. We applied a previously calibrated IBM of marten dispersal to simulate movement between two reintroduced populations in Wisconsin and Michigan, USA. We used machine learning analyses to determine how each factor affected dispersal between populations (connectivity) across five consecutive generations. Functional landscape connectivity between populations was not always correlated with more traditional dispersal metrics, such as dispersal distance. Mortality had the greatest impact on functional connectivity. Land-use change and landscape configuration affected connectivity mostly when mortality was not incorporated into simulations. These experimental factors had a stronger effect on long-distance dispersal between populations than on more local dispersal. Conservation planning for landscape connectivity may benefit from accounting for mortality risks within matrix habitat. The development of individual-based models that incorporate landscape heterogeneity and complex animal behaviors when investigating long-distance dispersal can provide unique and specific insights into both landscape connectivity and wildlife conservation.

Rusty Blackbirds select areas of greater habitat complexity during stopover

Abstract The Rusty Blackbird (Euphagus carolinus) is a widespread, uncommon migrant that has experienced heavy population declines over the last century. This species can spend over a quarter of their annual cycle on migration, so it is important to determine their habitat requirements during stopover events to inform effective conservation planning. We assessed their habitat selection at an important stopover site in northern Ohio during both fall and spring migration. Since stopover habitat selection is scale-dependent, we investigated both patch-scale (between patches) and fine-scale (within a patch) selection using radio telemetry to locate foraging and roosting flocks, and compared habitat variables between used and available points across the study site. At the patch scale, we found that birds preferred dogwood–willow swamp, low-lying forest patches, and areas of greater habitat complexity for foraging in both seasons. At the fine scale, spring migrants foraged closer to habitat edges than random, and preferred areas with more wet leaf litter and shallow water, and less grass cover. Fall migrants also preferred shallow water and leaf litter cover, and avoided areas with dense grass, forbs, and herbaceous shrub cover. By contrast, birds consistently roosted in dense stands of emergent Phragmites or Typha marsh, suggesting that the best stopover or staging sites are those with a matrix of different wetland habitats. Although the migratory range of Rusty Blackbirds is currently dominated by agricultural development, our results suggest that fragmented landscapes can still provide adequate habitat for migrants if the available land is managed for a variety of wet habitat types.

Regional variation in habitat matrix determines movement metrics in Baudin’s cockatoos in southwest Western Australia

Abstract ContextThe Baudin’s cockatoo is one of three black cockatoo species endemic to Western Australia and is listed as Endangered by state and federal governments. Although there is a Recovery Plan in place for this species, conservation efforts are hindered by gaps in knowledge regarding the species movement ecology. AimsTo identify key foraging and roosting habitat for Baudin’s cockatoos and to determine differences in flock movements, including the spatial extent of movement, in Urban, Peri-urban and Forest regions using telemetry data. MethodsWild Baudin’s cockatoos that had been injured and undergone rehabilitation were equipped with satellite PTT (platform transmitter terminal) and GPS tags and released back into wild flocks. The study birds, and the flocks into which they integrated, were tracked in the field to collect telemetry and observational data. Satellite data were used to define the types of movement behaviour (resident, ranging, migratory), and GPS data were analysed to determine key foraging and roosting habitat, and to calculate home range area estimates. Key resultsThere was a significant difference in flock movement between the Urban/Peri-urban regions and the Forest region in terms of daily distances moved and distances between roosts, with these parameters being far greater for the Forest region. Additionally, flock sizes were larger in the Forest region compared with the Urban and Peri-urban regions. In Urban and Peri-urban regions, key habitat comprised remnant vegetation in urban green space (nature reserves, parks and private property), and roadside and riparian vegetation, which served as movement corridors in the landscape. ConclusionsThe research shows that it is important to maintain vegetation connectivity in the landscape. This enables Baudin’s cockatoos to utilise key patches of remnant vegetation in their non-breeding wintering grounds in Urban and Peri-urban regions of the Perth Peel Coastal Plain. Further research on the movement ecology of Baudin’s cockatoos should focus on habitat suitability modelling, which, in combination with the identified key habitat sites, will benefit the decision-making process in relation to conservation management of this endangered black cockatoo species. ImplicationsThis research has benefited the conservation management of Baudin’s cockatoos by providing information on key habitat through satellite tracking and outlining the importance of the connective features of remnant vegetation. We advocate for further telemetry studies combined with habitat suitability modelling to preserve the necessary habitat for the persistence of this species in the Western Australian landscape.

Influence of food availability, plant productivity, and indigenous forest use on ranging behavior of the endangered samango monkey (Cercopithecus albogularis schwarzi), in the Soutpansberg Mountains, South Africa.

Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated landscape. The aim of this study was to determine and compare the influence of ground-based food availability, remotely sensed plant productivity, and indigenous forest use on the ranging patterns of the endangered samango monkey (Cercopithecus albogularis schwarzi). We collected monthly ranging data on two habituated samango monkey groups, from February 2012 to December 2016, from our field site in the Soutpansberg Mountains, South Africa. We used linear mixed models to explore how food availability, plant productivity, and indigenous forest use influenced monthly ranging patterns, while controlling for group size, number of sample days and day length. We found that as more areas of high plant productivity (derived from remotely sensed EVI) were incorporated into the ranging area, both total and core monthly ranging areas decreased. In addition, both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging area. However, we found no effect of either ground-based food availability or remotely sensed plant productivity on ranging patterns. Our findings demonstrate the behavioral flexibility in samango monkey ranging, as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest patches. In addition, we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging, forest-dwelling guenon, over ground-based estimates of food availability.

Finding Clues in Cities: Nest Site Selection by House Sparrows Across a Varied Habitat Matrixin Delhi, India

With changing urbanization pattern and architectural style, the house sparrow is rapidly losing its nesting ground leading to a drastic decline in its population. We studied the sparrow nest site selection to make recommendations to the Forest Department and NGOs in the conservation of sparrows in Delhi, India. Active nests were located across the habitat matrix in East Delhi. The maximum number of nests was found in suburban and high-density urban areas. The most preferred place for nesting was rolling shutters and wall crevices. The presence of old buildings, vegeta-tion patch, water source, grocery shops, food provi-sioning, open drains and open dumps influence the sparrow nest selection site. By conserving natural habitat and installing nest boxes at suitable places, the sparrows can be conserved.

Agricultural land in the Amazon basin supports low bird diversity and is a poor replacement for primary forest

Abstract The Amazon has a long history of disturbance under subsistence agriculture, but slash-and-burn agriculture is small in scale and has relatively low impact on resident avifauna. More recently, the Amazon has suffered extensive deforestation in favor of cattle ranching and other modern systems of agriculture. Cattle pastures, mechanized agriculture, and even tree plantations have detrimental effects on bird communities, greatly lowering diversity, especially that of primary forest interior specialists. A rising threat to the Amazon is the spread of oil palm plantations that retain few bird species and are not viable alternatives to forest. Embedded within the expanding agropastoral mosaic are forest fragments that have experienced a well-documented loss of diversity. Yet, the matrix can mitigate the recovery of fragmented bird communities depending on the type of secondary regrowth. Connectivity via matrix habitats or forest corridors is critical for the maintenance of forest avifauna. With so many types of land use developing across the Amazon, the “tropical countryside” has potential value for bird diversity. However, evidence suggests that the agropastoral mosaic harbors a small, more homogenized avifauna with few forest species, especially when primary forest is absent from the landscape. For the Amazon Basin’s bird life to be conserved into the future, preservation of large tracts of well-connected primary forest is vital. Tropical countryside dominated by agriculture simply cannot sustain sufficient levels of biodiversity.

Marked decline in forest-dependent small mammals following habitat loss and fragmentation in an Amazonian deforestation frontier.

Agricultural frontier expansion into the Amazon over the last four decades has created million hectares of fragmented forests. While many species undergo local extinctions within remaining forest patches, this may be compensated by native species from neighbouring open-habitat areas potentially invading these patches, particularly as forest habitats become increasingly degraded. Here, we examine the effects of habitat loss, fragmentation and degradation on small mammal assemblages in a southern Amazonian deforestation frontier, while accounting for species-specific degree of forest-dependency. We surveyed small mammals at three continuous forest sites and 19 forest patches of different sizes and degrees of isolation. We further sampled matrix habitats adjacent to forest patches, which allowed us to classify each species according to forest-dependency and generate a community-averaged forest-dependency index for each site. Based on 21,568 trap-nights, we recorded 970 small mammals representing 20 species: 12 forest-dependents, 5 matrix-tolerants and 3 open-habitat specialists. Across the gradient of forest patch size, small mammal assemblages failed to show the typical species-area relationship, but this relationship held true when either species abundance or composition was considered. Species composition was further mediated by community-averaged forest-dependency, so that smaller forest patches were occupied by a lower proportion of forest-dependent rodents and marsupials. Both species richness and abundance increased in less isolated fragments surrounded by structurally simplified matrix habitats (e.g. active or abandoned cattle pastures). While shorter distances between forest patches may favour small mammal abundances, forest area and matrix complexity dictated which species could persist within forest fragments according to their degree of forest-dependency. Small mammal local extinctions in small forest patches within Amazonian deforestation frontiers are therefore likely offset by the incursion of open-habitat species. To preclude the dominance of those species, and consequent losses of native species and associated ecosystem functions, management actions should limit or reduce areas dedicated to pasture, additionally maintaining more structurally complex matrix habitats across fragmented landscapes.

Forest fragments become farmland: Dietary Response of wild chimpanzees (Pan troglodytes) to fast-changing anthropogenic landscapes.

Behavioral flexibility, including an ability to modify feeding behavior, is a key trait enabling primates to survive in forest fragments. In human-dominated landscapes, unprotected forest fragments can become progressively degraded, and maybe cleared entirely, challenging the capacity of primates to adjust to the changes. We examined responses of wild chimpanzees (Pan troglodytes schweinfurthii) to major habitat change: that is, clearance of forest fragments for agriculture. Over 7 years, fragments in Bulindi, Uganda, were reduced in size by 80%. We compared the chimpanzees' diet at the start and end of this period of rapid deforestation, using data derived mainly from fecal analysis. Similar to other long-term study populations, chimpanzees in Bulindi have a diverse diet comprising over 169 plant foods. However, extensive deforestation seemed to impact their feeding ecology. Dietary changes after fragment clearance included reduced overall frugivory, reduced intake of figs (Ficus spp.; formerly a dietary "staple" for these chimpanzees), and reduced variety of fruits in fecal samples. Nevertheless, the magnitude of most changes was remarkably minor given the extent of forest loss. Agricultural fruits increased in dietary importance, with crops accounting for a greater proportion of fruits in fecal samples after deforestation. In particular, cultivated jackfruit (Artocarpus heterophyllus) became a "staple" food for the chimpanzees but was scarcely eaten before fragment clearance. Crops offer some nutritional benefits for primates, being high in carbohydrate energy and low in hard-to-digest fiber. Thus, crop feeding may have offset foraging costs associated with loss of wild foods and reduced overall frugivory for the chimpanzees. The adaptability of many primates offers hope for their conservation in fragmented, rural landscapes. However, long-term data are needed to establish whether potential benefits (i.e. energetic, reproductive) of foraging in agricultural matrix habitats outweigh fitness costs from anthropogenic mortality risk for chimpanzees and other adaptable primates.

Multiple fragmented habitat-patch use in an urban breeding passerine, the Short-toed Treecreeper.

Individual responses of wild birds to fragmented habitat have rarely been studied, despite large-scale habitat fragmentation and biodiversity loss resulting from widespread urbanisation. We investigated the spatial ecology of the Short-toed Treecreeper Certhia brachydactyla, a tiny, resident, woodland passerine that has recently colonised city parks at the northern extent of its range. High resolution spatiotemporal movements of this obligate tree-living species were determined using radio telemetry within the urbanized matrix of city parks in Copenhagen, Denmark. We identified regular edge crossing behaviour, novel in woodland birds. While low numbers of individuals precluded a comprehensive characterisation of home range for this population, we were able to describe a consistent behaviour which has consequences for our understanding of animal movement in urban ecosystems. We report that treecreepers move freely, and apparently do so regularly, between isolated habitat patches. This behaviour is a possible driver of the range expansion in this species and may contribute to rapid dispersal capabilities in certain avian species, including Short-toed Treecreepers, into northern Europe. Alternatively, these behaviours might be common and/or provide an adaptive advantage for birds utilising matrix habitats, for example within urban ecosystems.