Modeling Trends from North American Breeding Bird Survey Data: A Spatially Explicit Approach

Population trends, defined as interval-specific proportional changes in population size, are often used to help identify species of conservation interest. Efficient modeling of such trends depends on the consideration of the correlation of population changes with key spatial and environmental covariates. This can provide insights into causal mechanisms and allow spatially explicit summaries at scales that are of interest to management agencies. We expand the hierarchical modeling framework used in the North American Breeding Bird Survey (BBS) by developing a spatially explicit model of temporal trend using a conditional autoregressive (CAR) model. By adopting a formal spatial model for abundance, we produce spatially explicit abundance and trend estimates. Analyses based on large-scale geographic strata such as Bird Conservation Regions (BCR) can suffer from basic imbalances in spatial sampling. Our approach addresses this issue by providing an explicit weighting based on the fundamental sample allocation unit of the BBS. We applied the spatial model to three species from the BBS. Species have been chosen based upon their well-known population change patterns, which allows us to evaluate the quality of our model and the biological meaning of our estimates. We also compare our results with the ones obtained for BCRs using a nonspatial hierarchical model (Sauer and Link 2011). Globally, estimates for mean trends are consistent between the two approaches but spatial estimates provide much more precise trend estimates in regions on the edges of species ranges that were poorly estimated in non-spatial analyses. Incorporating a spatial component in the analysis not only allows us to obtain relevant and biologically meaningful estimates for population trends, but also enables us to provide a flexible framework in order to obtain trend estimates for any area.     

Evaluation of Habitat Suitability Models for Forest Passerines Using Demographic Data

ABSTRACT Habitat suitability is often used as a surrogate for demographic responses (i.e., abundance, survival, fecundity, or population viability) in the application of habitat suitability index (HSI) models. Whether habitat suitability actually relates to demographics, however, has rarely been evaluated. We validated HSI models of breeding habitat suitability for wood thrush (Hylocichla mustelina) and yellow-breasted chat (Icteria virens) in Missouri, USA. First, we evaluated HSI models as a predictor of 3 demographic responses: within-site territory density, site-level territory density, and nest success. We demonstrated a link between HSI values and all 3 types of demographic responses for the yellow-breasted chat and site-level territory density for the wood thrush. Second, we evaluated support for models containing HSI values, models containing measured habitat features (e.g., tree age, tree species, ecological land type), and models containing management treatments (e.g., even-aged and uneven-aged forest regeneration treatments) for each demographic response using model selection. Models containing HSI values received more support, in general, than models containing only habitat features or management treatments for all 3 types of wildlife response. The assumption that changes in habitat suitability represent wildlife demographic response to vegetation change is supported by our models. However, differences in species ecology may contribute to the degree to which HSI values are related to specific demographic responses. We recommend validation of HSI models with the particular demographic data of interest (i.e., density, productivity) to increase confidence in the model used for conservation planning.     

Using abundance and habitat variables to identify high conservation value areas for threatened mammals

The present study used abundance and habitat variables to design High Conservation Value Forests for wildlife protection. We considered great apes (Gorilla gorilla gorilla and Pan troglodytes troglodytes) as model species, and we used nest surveys, dietary analysis and botanical inventories to evaluate whether the traditional methods that use abundance data alone were consistent with the survival of the species. We assumed that setting a local priority area for animal conservation can be made possible if at least one variable (abundance or habitat variables) is spatially clustered and that the final decision for a species may depend on the pattern of spatial association between abundance, nesting habitat and feeding habitat. We used Kernel Density Estimation to evaluate the spatial pattern of each biological variable. The results indicate that all three variables were spatially clustered for both gorillas and chimpanzees. The abundance variables of both animal species were spatially correlated to their preferred nesting habitat variables. But while the chimpanzee feeding habitat variable was spatially correlated to the abundance and nesting habitat variables, the same pattern was not observed for gorillas. We then proposed different methods to be considered to design local priority areas for the conservation of each great ape species. Alone, the abundance variable does not successfully represent the spatial distribution of major biological requirements for the survival of wildlife species; we, therefore, recommend the integration of the spatial distribution of their food resources to overcome the mismatch caused by the existence of a biological interaction between congeneric species.     

Forest edges have high conservation value for bird communities in mosaic landscapes

A major conservation challenge in mosaic landscapes is to understand how trait‐specific responses to habitat edges affect bird communities, including potential cascading effects on bird functions providing ecosystem services to forests, such as pest control. Here, we examined how bird species richness, abundance and community composition varied from interior forest habitats and their edges into adjacent open habitats, within a multi‐regional sampling scheme. We further analyzed variations in Conservation Value Index (CVI), Community Specialization Index (CSI) and functional traits across the forest‐edge‐open habitat gradient. Bird species richness, total abundance and CVI were significantly higher at forest edges while CSI peaked at interior open habitats, i.e., furthest from forest edge. In addition, there were important variations in trait‐ and species‐specific responses to forest edges among bird communities. Positive responses to forest edges were found for several forest bird species with unfavorable conservation status. These species were in general insectivores, understorey gleaners, cavity nesters and long‐distance migrants, all traits that displayed higher abundance at forest edges than in forest interiors or adjacent open habitats. Furthermore, consistently with predictions, negative edge effects were recorded in some forest specialist birds and in most open‐habitat birds, showing increasing densities from edges to interior habitats. We thus suggest that increasing landscape‐scale habitat complexity would be beneficial to declining species living in mosaic landscapes combining small woodlands and open habitats. Edge effects between forests and adjacent open habitats may also favor bird functional guilds providing valuable ecosystem services to forests in longstanding fragmented landscapes.     

Estimating relative population size included within protected areas

We propose and test a method to determine the proportion of specific animal national populations included in a network of protected areas. The proposed method further allows identifying the best potential new sites to be included in the network, to reach target population sizes and so to test whether a network extension is realistic or not. We used data from the French Breeding Bird Survey (BBS) and spatial interpolation models known as kriging to predict the relative abundance of species at a national scale. We applied the proposed methodology to Special Protection Areas (SPAs) and a sample of 20 bird species concerned by the Directive of the Council of the European Community on the Conservation of Wild Birds. We estimated which relative part of the national population is included within the boundaries of all national SPAs. Our results suggest that the current SPA network is probably not efficient to ensure favorable national conservation status for the most widespread species, but allows reaching a 5% target value for more localized ones. Consequently, we discuss the limit of such a protected area network to ensure the global conservation of widespread species, and therefore the need for other large-scale conservation measures.     

Pasture area and landscape heterogeneity are key determinants of bird diversity in intensively managed farmland

Agriculture intensification has drastically altered farmland mosaics, while semi-natural grasslands have been considerably reduced and fragmented. Bird declines in northern temperate latitudes are attributed to habitat loss and degradation in farmed landscapes. Conversely, landscape-modification effects on grassland/farmland bird communities are less studied in the South American temperate grasslands. We investigated how bird communities were influenced by landscape characteristics in the Rolling Pampa (Argentina). We sampled bird communities in 356 landscapes of 1-km radius that varied in cover and configuration of pastureland, flooding grassland and cropland. Using generalized linear models, we explored the relationship between both bird species richness and abundance, and landscape structure. Analyses were carried out for all species, and open-habitat, grassland and aquatic species. Pasture area was far the most important factor, followed by landscape composition, in predicting species richness and abundance, irrespective of specific habitat preferences, followed by partially-flooded grassland cover and its mean shape index. Grassland fragmentation did not affect species richness or abundance. When comparing the effects of landscape variables on bird richness and abundance (using mean model coefficients), pasture and grassland area effects were on average more than four times greater than those of compositional heterogeneity, and about ten times greater than shape effects. To conserve species-rich bird communities persisting in Rolling Pampa farmland, we recommend the preservation of pasture and grassland habitats, irrespective of their fragmentation level, in intensively managed farmland mosaics.     

Distribution and habitat suitability index model for the Andean catfish Astroblepus ubidiai (Pisces: Siluriformes) in Ecuador

In conservation biology there is a basic need to determine habitat suitability and availability. Astroblepus ubidiai (Siluriforms), the only native fish in the highlands of Imbabura province in the Ecuadorian Andes, was abundant in the past in the Imbakucha watershed and adjacent drainages, but currently it is restricted to a few isolated refuges. Conservation actions are needed if this unique fish is to persist. A Habitat Suitability Index (HSI) for the species has been developed in order to aid management decisions. In this HSI model biomass density (B) was selected as a better indicator of habitat quality than either abundance or density. A population well-being index (PI) was constructed with the combination of B and an indicator of fish health (proportion of fish in the population with parasites and deformities). Based in other models of benthic fish the habitat variables current velocity, flow, depth, width, cover, invertebrate composition, vegetation type, terrestrial vegetation, land use, substrate, temperature, pH, TDS, oxygen, altitude, and slope were included in the analysis. An anthropogenic perturbation index (H) and a fragment isolation index (FII) were developed and included as habitat variables as well. The HSI model was applied to refuges and a sample of 15 aquatic bodies without fish populations within the study region. From the sampled sites without A. ubidiai 26.6% presented low quality, and the remaining 73.3% had medium quality according to the HSI estimated. Good quality habitat for dispersal, escape or translocations is rare in the region. The low HSIs estimated in some of the refuges suggests that current populations are not settled in the most favorable habitat but in the habitat least favorable to the agents of decline.     

Reclamation and habitat‐disturbance effects on landbird abundance and productivity indices in the oil sands region of northeastern Alberta,Canada

The pace and scale of reclamation in Alberta's oil sands region are increasing, and techniques to measure and validate the ecological function of developing habitats are needed. In Alberta, achievement of equivalent land capability to that present before disturbance is a regulatory requirement of reclamation certification. We compared landbird abundance and productivity indices from mist‐netting data collected in 2011–2013 using the Monitoring Avian Productivity and Survivorship (MAPS) protocol with local habitat covariates at 35 monitoring stations in natural, reclaimed, and disturbed habitats. Principal component analysis of habitat covariates explained 83% of the variation in 20 habitat‐structure variables. We found significant relationships between habitat covariates and captures of adult birds, young birds, and/or the probability of capturing a young bird (productivity) for 12 landbird species; in some cases, capture responses contrasted with productivity responses to habitat variables. Responses to reclamation age were as expected, given habitat preferences of our target species. Positive responses to reclamation age from obligate forest‐dwelling species take more years to become evident than those for species preferring successional‐stage habitats, while one species that prefers open, grassland habitats appeared to decline with reclamation age, presumably due to habitat succession. Application of the MAPS protocol as a tool to evaluate and track the performance of reclaimed and disturbed habitats is demonstrated, with landbird abundance and productivity indices in natural habitats being useful indicators of equivalent land capability.     

Isolation determines patterns of species presence in highly fragmented landscapes

In fragmented landscapes, changes in habitat availability, patch size, shape and isolation may affect survival of local populations. Proposing efficient conservation strategies for such species relies initially on distinguishing the particular effects of those factors. To address these issues, we investigated the occurrence of 3 bird species in fragmented Brazilian Atlantic Forest landscapes. Playback techniques were used to collect presence/absence data of these species inside 80 forest patches, and incidence models were used to infer their occupancy pattern from landscape spatial structure. The relative importance of patch size, shape and surrounding forest cover and isolation was assessed using a model selection approach based on maximum likelihood estimation. The presence of all species was in general positively affected by the amount of surrounding habitat and negatively affected by inter‐patch distances. The joint effects of patch size and the surrounding landscape characteristics were important determinants of occupancy for two species. The third species was affected only by forest cover and mean patch isolation. Our results suggest that local species presence is in general more influenced by the isolation from surrounding forests than by patch size alone. We found evidence that, in highly fragmented landscapes, birds that can not find patches large enough to settle may be able to overcome short distances through the matrix and include several nearby patches within their home‐ranges to complement their resource needs. In these cases, patches must be defined as functionally connected habitat networks rather than mere continuous forest segments. Bird conservation strategies in the Atlantic forest should focus on increasing patch density and connectivity, in order to implement forest networks that reduce the functional isolation between large remnants with remaining core habitat.     

GRASSLAND BIRDS NESTING IN HAYLANDS OF SOUTHERN SASKATCHEWAN: LANDSCAPE INFLUENCES AND CONSERVATION PRIORITIES

Abstract: To determine the benefits to grassland birds of converting cropland to hayland in southern Saskatchewan, Canada, we quantified the relative nest abundance and success of grassland nesting birds in haylands and the influence landscape variables have on these parameters. We found nests of 26 species of grassland nesting birds, primarily waterfowl and vesper sparrow (Pooecetes gramineus). With the exception of the northern pintail (Anas acuta), few nesting attempts were recorded for species of high priority in the Prairie Pothole Bird Conservation Region. Mayfield nest success for all waterfowl (20 and 13% in 1999 and 2000, respectively) was high relative to previously reported nest success estimates in other habitat types—especially spring-seeded cropland—and was near levels thought to be required to sustain populations (15–20%). Vesper sparrow nest success (39 and 33% in 1999 and 2000, respectively) also was high relative to that reported in other studies. Haying destroyed few nests as wet weather delayed operations in 1999 and 2000. More nests may be destroyed by haying in other years as approximately 25% of nests in this study were still active on the long-term average haying date for southern Saskatchewan. Among models we developed to explain waterfowl relative nest abundance, amount of cropland in the surrounding landscape and field area were the most informative. Evidence that a specific set of landscape variables was important to models of waterfowl nest success was equivocal. Landscape variables did not explain variation in vesper sparrow relative nest abundance or nest success. Within our study area, conversion of cropland to hayland appears to provide significant benefits to a variety of grassland species, including some species of high conservation priority (e.g., northern pintail). Grassland species of conservation concern nested less frequently in hayland than in native grassland.     

Discrepancies in occupancy and abundance approaches to identifying and protecting habitat for an at‐risk species

Predicting how environmental factors affect the distribution of species is a fundamental goal of conservation biology. Conservation biologists rely on species distribution and abundance models to identify key habitat characteristics for species. Occupancy modeling is frequently promoted as a practical alternative to use of abundance in identifying habitat quality. While occupancy and abundance are potentially governed by different limiting factors operating at different scales, few studies have directly compared predictive models for these approaches in the same system. We evaluated how much occupancy and abundance are driven by the same environmental factors for a species of conservation concern, the greater short‐horned lizard (Phrynosoma hernandesi). Occupancy was most strongly dictated by precipitation, temperature, and density of ant mounds. While these factors were also in the best‐supported predictive models for lizard abundance, the magnitude of the effects varied, with the sign of the effect changing for temperature and precipitation. These discrepancies show that while occupancy modeling can be an efficient approach for conservation planning, predictors of occupancy probability should not automatically be equated with predictors of population abundance. Understanding the differences in factors that control occupancy versus abundance can help us to identify habitat requirements and mitigate the loss of threatened species.     

To a charismatic rescue: Designing a blueprint to steer Fishing Cat conservation for safeguarding Indian wetlands

Wetland conservation in the Indo-tropics can benefit from the protection of the charismatic Fishing Cat. India, supporting ∼ 40% of its known range, is a stronghold for the species. Here, using multiple information sources we outline a framework to safeguard fishing cats in India. Specifically, we a) estimated district-level Conservation priority scores (using presence records, and habitat suitability and habitat connectivity) to identify ecologically important habitats, b) estimated state-level Conservation likelihood scores assessing the success potential of any conservation intervention, c) collated district-level Conservation initiative information identifying ongoing efforts for species and/or habitat conservation. We consecutively assessed the spatial congruence between (a), (b) and (c) to delineate species’ conservation areas and corresponding action goals (blueprint). Using information on habitat suitability, we also delineated survey landscapes. Although Fishing Cat records were found in 12 Indian states, only a small proportion of the state area was identified harbouring optimal habitat for the species. Three broad habitat clusters - Terai arc, Eastern coast, and Brahmaputra floodplains - were identified, with overall high habitat connectivity. Most districts ranking high in Conservation priority scored low in Conservation likelihood. Districts with Fishing Cat presence (n = 60) were delineated into four tiers of action landscapes and the majority of districts classified as survey landscapes (n = 156) were found in the Terai arc. We use our results to recommend and discuss conservation actions for districts identified in our blueprint. Flagship species conservation approach has substantial potential to enrich wetland conservation, for which our blueprint can act as a baseline.     

Planning for the restoration of native biodiversity within the Goulburn Broken Catchment, Victoria, using spatial modelling

Summary   Conservation planning aims to ensure the protection and continuation of biodiversity. In rural landscapes in Victoria, this will require the restoration of habitat and biophysical processes to levels that can sustain the majority of species. Planning is required at scales large enough to have ecological relevance. In this study, a land-use change scenario that plans for the conservation of native biodiversity within the Goulburn Broken Catchment was developed using simple ecological principles. A set of indicative rules for restoring remnant native vegetation was modelled within a geographical information system. The modelling of the rules resulted in a change in rural landscapes from highly fragmented (with few large remnants) to highly connected. Future applications of this approach include incorporating the biodiversity rules into a biophysical model to assess the effect of planning landscapes for the conservation of biodiversity on hydrological and economic outcomes for the region. In addition, the rules are to be refined so that the priority landscapes for biodiversity planning can be identified.     

Spatial Models of Northern Bobwhite Populations for Conservation Planning

Abstract: Since 1980, northern bobwhite (Colinus virginianus) range-wide populations declined 3.9% annually. Within the West Gulf Coastal Plain Bird Conservation Region in the south-central United States, populations of this quail species have declined 6.8% annually. These declines sparked calls for land use change and prompted implementation of various conservation practices. However, to effectively reverse these declines and restore northern bobwhite to their former population levels, habitat conservation and management efforts must target establishment and maintenance of sustainable populations. To provide guidance for conservation and restoration of habitat capable of supporting sustainable northern bobwhite populations in the West Gulf Coastal Plain, we modeled their spatial distribution using landscape characteristics derived from 1992 National Land Cover Data and bird detections, from 1990 to 1994, along 10-stop Breeding Bird Survey route segments. Four landscape metrics influenced detections of northern bobwhite: detections were greater in areas with more grassland and increased aggregation of agricultural lands, but detections were reduced in areas with increased density of land cover edge and grassland edge. Using these landscape metrics, we projected the abundance and spatial distribution of northern bobwhite populations across the entire West Gulf Coastal Plain. Predicted populations closely approximated abundance estimates from a different cadre of concurrently collected data but model predictions did not accurately reflect bobwhite detections along species-specific call-count routes in Arkansas and Louisiana. Using similar methods, we also projected northern bobwhite population distribution circa 1980 based on Land Use Land Cover data and bird survey data from 1976 to 1984. We compared our 1980 spatial projections with our spatial estimate of 1992 populations to identify areas of population change. Additionally, we used our projection of the spatial distribution and abundance of bobwhite to predict areas of population sustainability. Our projections of population change and sustainability provide guidance for targeting habitat conservation and rehabilitation efforts for restoration of northern bobwhite populations in the West Gulf Coastal Plain.     

Modeling ecological minimum requirements for distribution of greater sage‐grouse leks: implications for population connectivity across their western range,U.S.A

Greater sage‐grouse Centrocercus urophasianus (Bonaparte) currently occupy approximately half of their historical distribution across western North America. Sage‐grouse are a candidate for endangered species listing due to habitat and population fragmentation coupled with inadequate regulation to control development in critical areas. Conservation planning would benefit from accurate maps delineating required habitats and movement corridors. However, developing a species distribution model that incorporates the diversity of habitats used by sage‐grouse across their widespread distribution has statistical and logistical challenges. We first identified the ecological minimums limiting sage‐grouse, mapped similarity to the multivariate set of minimums, and delineated connectivity across a 920,000 km² region. We partitioned a Mahalanobis D² model of habitat use into k separate additive components each representing independent combinations of species–habitat relationships to identify the ecological minimums required by sage‐grouse. We constructed the model from abiotic, land cover, and anthropogenic variables measured at leks (breeding) and surrounding areas within 5 km. We evaluated model partitions using a random subset of leks and historic locations and selected D² (k = 10) for mapping a habitat similarity index (HSI). Finally, we delineated connectivity by converting the mapped HSI to a resistance surface. Sage‐grouse required sagebrush‐dominated landscapes containing minimal levels of human land use. Sage‐grouse used relatively arid regions characterized by shallow slopes, even terrain, and low amounts of forest, grassland, and agriculture in the surrounding landscape. Most populations were interconnected although several outlying populations were isolated because of distance or lack of habitat corridors for exchange. Land management agencies currently are revising land‐use plans and designating critical habitat to conserve sage‐grouse and avoid endangered species listing. Our results identifying attributes important for delineating habitats or modeling connectivity will facilitate conservation and management of landscapes important for supporting current and future sage‐grouse populations.     

A Hierarchical Model for Estimating Change in American Woodcock Populations

Abstract The Singing-Ground Survey (SGS) is a primary source of information on population change for American woodcock (Scolopax minor). We analyzed the SGS using a hierarchical log-linear model and compared the estimates of change and annual indices of abundance to a route regression analysis of SGS data. We also grouped SGS routes into Bird Conservation Regions (BCRs) and estimated population change and annual indices using BCRs within states and provinces as strata. Based on the hierarchical model–based estimates, we concluded that woodcock populations were declining in North America between 1968 and 2006 (trend = −0.9%/yr, 95% credible interval: −1.2, −0.5). Singing-Ground Survey results are generally similar between analytical approaches, but the hierarchical model has several important advantages over the route regression. Hierarchical models better accommodate changes in survey efficiency over time and space by treating strata, years, and observers as random effects in the context of a log-linear model, providing trend estimates that are derived directly from the annual indices. We also conducted a hierarchical model analysis of woodcock data from the Christmas Bird Count and the North American Breeding Bird Survey. All surveys showed general consistency in patterns of population change, but the SGS had the shortest credible intervals. We suggest that population management and conservation planning for woodcock involving interpretation of the SGS use estimates provided by the hierarchical model.     

Habitat Availability Is a More Plausible Explanation than Insecticide Acute Toxicity for U.S. Grassland Bird Species Declines

Grassland bird species have experienced substantial declines in North America. These declines have been largely attributed to habitat loss and degradation, especially from agricultural practices and intensification (the habitat-availability hypothesis). A recent analysis of North American Breeding Bird Survey (BBS) “grassland breeding” bird trends reported the surprising conclusion that insecticide acute toxicity was a better correlate of grassland bird declines in North America from 1980–2003 (the insecticide-acute-toxicity hypothesis) than was habitat loss through agricultural intensification. In this paper we reached the opposite conclusion. We used an alternative statistical approach with additional habitat covariates to analyze the same grassland bird trends over the same time frame. Grassland bird trends were positively associated with increases in area of Conservation Reserve Program (CRP) lands and cropland used as pasture, whereas the effect of insecticide acute toxicity on bird trends was uncertain. Our models suggested that acute insecticide risk potentially has a detrimental effect on grassland bird trends, but models representing the habitat-availability hypothesis were 1.3–21.0 times better supported than models representing the insecticide-acute-toxicity hypothesis. Based on point estimates of effect sizes, CRP area and agricultural intensification had approximately 3.6 and 1.6 times more effect on grassland bird trends than lethal insecticide risk, respectively. Our findings suggest that preserving remaining grasslands is crucial to conserving grassland bird populations. The amount of grassland that has been lost in North America since 1980 is well documented, continuing, and staggering whereas insecticide use greatly declined prior to the 1990s. Grassland birds will likely benefit from the de-intensification of agricultural practices and the interspersion of pastures, Conservation Reserve Program lands, rangelands and other grassland habitats into existing agricultural landscapes.     

A dynamic multi‐scale occupancy model to estimate temporal dynamics and hierarchical habitat use for nomadic species

Distribution models are increasingly being used to understand how landscape and climatic changes are affecting the processes driving spatial and temporal distributions of plants and animals. However, many modeling efforts ignore the dynamic processes that drive distributional patterns at different scales, which may result in misleading inference about the factors influencing species distributions. Current occupancy models allow estimation of occupancy at different scales and, separately, estimation of immigration and emigration. However, joint estimation of local extinction, colonization, and occupancy within a multi‐scale model is currently unpublished. We extended multi‐scale models to account for the dynamic processes governing species distributions, while concurrently modeling local‐scale availability. We fit the model to data for lark buntings and chestnut‐collared longspurs in the Great Plains, USA, collected under the Integrated Monitoring in Bird Conservation Regions program. We investigate how the amount of grassland and shrubland and annual vegetation conditions affect bird occupancy dynamics and local vegetation structure affects fine‐scale occupancy. Buntings were prevalent and longspurs rare in our study area, but both species were locally prevalent when present. Buntings colonized sites with preferred habitat configurations, longspurs colonized a wider range of landscape conditions, and site persistence of both was higher at sites with greener vegetation. Turnover rates were high for both species, quantifying the nomadic behavior of the species. Our model allows researchers to jointly investigate temporal dynamics of species distributions and hierarchical habitat use. Our results indicate that grassland birds respond to different covariates at landscape and local scales suggesting different conservation goals at each scale. High turnover rates of these species highlight the need to account for the dynamics of nomadic species, and our model can help inform how to coordinate management efforts to provide appropriate habitat configurations at the landscape scale and provide habitat targets for local managers.     

Prioritizing Remnant Forests for the Conservation of Mysore Slender Lorises (<Emphasis Type="Italic">Loris lyddekerianus lyddekerianus</Emphasis>) in Karnataka,India Through Estimation of Population Density

Information on a species’ distribution, abundance, and habitat requirements is important for formalizing a comprehensive management and conservation strategy. This becomes an even higher priority when the distribution of a species lies largely outside demarcated protected areas for wildlife. We used line transect distance sampling to estimate the density of an arboreal, nocturnal, and threatened primate, the slender loris (Loris lyddekerianus lyddekerianus) across diverse habitat types including both reserve forests and production landscapes in the southern part of the state of Karnataka, India. Abundance estimates varied from 0.16 individuals/ha in Devrayandurga State Forest to 2.57 individulas/ha in Ippadi State Forest, with the mean density estimate being highest in the Forest Division of Tumkur, at 165 individuals/km². Based on density estimates for the survey regions, their current habitat status, and perceived threats, we identify Ippadi, Ujjani, Devrayandurga, and Savanadurga state forests as priority areas for conservation of the slender loris. We propose that these areas be declared protected. The required management intervention is preventing further degradation of the habitat and enhancing canopy contiguity to facilitate loris movement.     

Fauna habitat modelling and mapping: A review and case study in the Lower Hunter Central Coast region of NSW

Abstract Habitat models are now broadly used in conservation planning on public lands. If implemented correctly, habitat modelling is a transparent and repeatable technique for describing and mapping biodiversity values, and its application in peri‐urban and agricultural landscape planning is likely to expand rapidly. Conservation planning in such landscapes must be robust to the scrutiny that arises when biodiversity constraints are placed on developers and private landholders. A standardized modelling and model evaluation method based on widely accepted techniques will improve the robustness of conservation plans. We review current habitat modelling and model evaluation methods and provide a habitat modelling case study in the New South Wales central coast region that we hope will serve as a methodological template for conservation planners. We make recommendations on modelling methods that are appropriate when presence‐absence and presence‐only survey data are available and provide methodological details and a website with data and training material for modellers. Our aim is to provide practical guidelines that preserve methodological rigour and result in defendable habitat models and maps. The case study was undertaken in a rapidly developing area with substantial biodiversity values under urbanization pressure. Habitat maps for seven priority fauna species were developed using logistic regression models of species‐habitat relationships and a bootstrapping methodology was used to evaluate model predictions. The modelled species were the koala, tiger quoll, squirrel glider, yellow‐bellied glider, masked owl, powerful owl and sooty owl. Models ranked sites adequately in terms of habitat suitability and provided predictions of sufficient reliability for the purpose of identifying preliminary conservation priority areas. However, they are subject to multiple uncertainties and should not be viewed as a completely accurate representation of the distribution of species habitat. We recommend the use of model prediction in an adaptive framework whereby models are iteratively updated and refined as new data become available.