Habitat selection and conservation of Sharpe's longclaw (Macronyx sharpei), a threatened Kenyan grassland endemic

Montane grassland is a severely threatened habitat in Kenya. Despite a high level of faunal endemism, it has received very little conservation attention. We investigated habitat selection in a threatened grassland endemic bird species, Sharpe's longclaw (Macronyx sharpei) (family Motacillidae), in order to understand its likely response to land-use changes. Between November 1995 and May 1996, we studied 41 territories of this species on the Kinangop Plateau in central Kenya. With an overall density of 0.4 birds ha⁻¹, longclaws lived in permanent groups of two to seven individuals. They were sedentary and territorial, with a mean home range size of 0.5 ha. The species avoided non-grassland areas entirely, and within grassland showed a strong preference for short grass with tussocks. Territory sizes and foraging ranges were smaller, and rates of pecking for food higher, in this grassland type than in open short grass or long grass. Land use changes, in particular conversion to cultivation or woodlots and ploughing up of grassland to remove tussocks, pose a serious and immediate threat to this species. Dairy farming is potentially compatible with grassland conservation, and conservation-friendly livestock rearing needs to be promoted through economic incentives, awareness-raising and technical advice.     

Habitat requirements of the endangered pygmy bluetongue lizard, Tiliqua adelaidensis

The pygmy bluetongue lizard, Tiliqua adelaidensis, occupies spider burrows as home sites. It is an endangered species, known from only 19 small natural grassland sites in the mid-north of South Australia, all on privately owned land. Habitat requirements of the pygmy bluetongue lizard were investigated at four sites. Both within and between sites, lizards were more likely to be found in areas with a greater number of deep spider burrows. Areas where lizards were not found tended to lack these burrows. Strong site similarities were found for a range of habitat parameters examined. Within these grasslands there was no specific vegetation community associated with areas occupied by pygmy bluetongue lizards. However there was a distinct vegetation community associated with an absence of lizards. Generally there was no difference in the abundance and diversity of ground dwelling invertebrates between areas with and without lizards. As the only protected area of natural grassland within the known distribution, Mokota Conservation Park was assessed as a potential reintroduction site. It was found to be unsuitable due to a low number of deep spider burrows and a vegetation community similar to that found in uninhabited areas of known lizard inhabited sites. Unless other conservation areas can be established, preservation of this lizard will rely on habitat management by private land holders. Community goodwill and informed advice to the land holders will be essential in this process.     

Adaptive selection of foraging and nesting habitat by black kites (Milvus migrans) and its implications for conservation: a multi-scale approach

Black kites (Milvus migrans) are vulnerable and in decline within Europe. Here, we investigate selection of foraging and breeding habitat in a high-priority population in the Italian pre-Alps. Compared to a random distribution, kites foraged preferentially near water, over extensively managed grassland and within 1 km of nest-sites. Urban areas were positively selected near lakes but otherwise avoided. Foraging performance was higher over water than over terrestrial habitats. Kites nested on cliffs and trees and preferentially near water, far from paths and villages and in rugged and steep micro-sites. Tree-nests were located in the most mature tree in the stand. Productivity was positively related to the availability of water bodies. Therefore, food availability and human disturbance/persecution limited foraging and breeding performance. Guidelines to maintain or enhance current population levels include: (1) setting up reserves covering 10% of the areas within 1 km of large lakes; (2) converting current derelict coppice-woodland to high forest; and (3) enhancing subsidies for extensively managed grassland. Our results highlight the importance of cross-scale models integrating selection of foraging and breeding habitat and reinforce the importance of the spatial configuration of key resources for more realistic conservation management in mosaic landscapes.     

Habitat selection of endangered and endemic large flying-foxes in Subic Bay, Philippines

Large flying-foxes in insular Southeast Asia are the most threatened of the Old World fruit bats due to high levels of deforestation and hunting and effectively little local conservation commitment. The forest at Subic Bay, Philippines, supports a rare, large colony of vulnerable Philippine giant fruit bats (Pteropus vampyrus lanensis) and endangered and endemic golden-crowned flying-foxes (Acerodon jubatus). These large flying-foxes are optimal for conservation focus, because in addition to being keystone, flagship, and umbrella species, the bats are important to Subic Bay’s economy and its indigenous cultures. Habitat selection information streamlines management’s efforts to protect and conserve these popular but threatened animals. We used radio telemetry to describe the bats’ nighttime use of habitat on two ecological scales: vegetation and microhabitat. The fruit bats used the entire 14,000 ha study area, including all of Subic Bay Watershed Reserve, as well as neighboring forests just outside the protected area boundaries. Their recorded foraging locations ranged between 0.4 and 12 km from the roost. We compared the bats’ use to the availability of vegetative habitat types, riparian areas, and bat trees. The fruit bats’ locations showed a preference for undisturbed forest types and selection against disturbed and agricultural areas. Bat locations also showed selection for particular fruiting/flowering bat trees. The bats showed strong preference for riparian areas; locations were in riparian areas over four times more than expected. From these results we recommend that management focus flying-fox conservation efforts on undisturbed forest and riparian areas.     

Habitat selection by the pale-headed brush-finch (Atlapetes pallidiceps) in southern Ecuador: implications for conservation

The pale-headed brush-finch (Atlapetes pallidiceps) is threatened with extinction due to habitat loss, but very little is known about its ecological requirements. We used multiple logistic regression to study habitat selection of this species at landscape, territory, and nest site scales in order to make recommendations about effective management. Habitat selection by the sympatric stripe-headed brush-finch (Buarremon torquatus) was examined with the same methods in order to analyse interspecific resource partitioning and potential competition. The pale-headed brush-finch selected semi-open habitat types with intermediate scrub heights, and avoided forests. Nest sites depended on the presence of vines or bamboo. By contrast, the stripe-headed brush-finch chose dense habitat with low ground cover under tall vegetation and avoided semi-open habitat. The two species had overlapping territories but differed significantly in microhabitat use and the use of vegetation strata. We found no convincing evidence that the stripe-headed brush-finch displaces the pale-headed brush-finch from optimal habitat. The preservation of semi-open scrubland maintained by low-intensity grazing is suggested for future conservation of the pale-headed brush-finch.     

Habitat and survival of capercaillie Tetrao urogallus nests and broods in the Bavarian alps

The capercaillie Tetrao urogallus has become endangered in central Europe, most probably as a result of habitat changes. Breeding ecology was studied by following radio-tagged hens through egg-laying, incubation, and chick-rearing between 1988 and 1992. Loss of chicks rather than nests was the main determinant of reproductive success. All adult hens incubated, two-thirds of the nests hatched, and one-fifth of the chicks survived until autumn. Both nests and broods were mostly found in habitats with rich ground vegetation. Nest cover was probably a major factor for hatching success. Brood home ranges averaged 148 ha during the period from hatching to late summer. Broods preferred old forest stands with rich ground vegetation and high invertebrate abundance, which occur under moderate canopy cover. Bilberry Vaccinium myrtillus was an essential feature for brood habitat at forest stand, home range, and landscape scale, and should therefore be a major goal for capercaillie habitat management in central Europe.     

A test of the hierarchical model of habitat selection using eastern massasauga rattlesnakes (Sistrurus c. catenatus)

Understanding the process animals follow to select habitat, rather than just documenting the habitat they use, will improve our ability to predict how the animals use habitat in other locations and how they will respond to changes in habitat. Animals are usually assumed to select habitats hierarchically, preferentially using specific macrohabitats at a landscape scale and specific microhabitats within the preferred macrohabitats. We used four years of telemetry data from 34 individuals to test this hierarchical model of habitat selection with eastern massasauga rattlesnakes (Sistrurus c. catenatus) in Ontario. Snakes were selective at the microhabitat scale, preferentially using locations with closer retreat sites and shrubs than random. Gravid females were most selective, using sites with more rock cover and less canopy closure than sites used by males and nongravid females. Snakes preferred forested habitats for hibernation and steadily increased their use of open, wetland, and edge habitats to a peak in mid-summer. Landscape-scale habitat preferences were generally mild and could be explained by the relative availability of suitable microhabitat within habitats, suggesting habitat selection was primarily driven by microhabitat preferences. The lack of selectivity at the landscape scale may be a consequence of fine-grained differences between habitats that allow massasauga rattlesnakes to find suitable microhabitats in all available macrohabitats. For species that select habitat primarily at the microhabitat scale (e.g., the rattlesnakes we studied), landscape-scale modeling of habitat use will only be effective to the extent habitats reflect the availability of suitable microhabitat within.     

Food selection and internal processing in Archegozetes longisetosus (Acari: Oribatida)

The nutritional biology of the oribatid mite Archegozetes longisetosus Aoki was examined using a control (starvation) and four types of food: Protococcus sp. algae from tree bark, two fungi—Stachybothrys sp. and Alternaria sp.—and filter paper. Direct observations, histology, enzymology and plating techniques were employed to record contact with food, contents and structure of the alimentary tract, presence and viability of bacterial microorganisms inside the mite body, and chitinase and cellulase activity of mite homogenates. Algae were highly palatable, resulting in high apocrine secretion and guts that were continuously full. Initially there was no evidence of chitinase or cellulase production. Chitinase activity started after 10 days, probably due to consumption of fungi that invaded the algal cover, and correlated with the presence of chitinolytic bacteria (Serratia rubidea) in the mite homogenate. Alternaria was grazed intensively, but cell walls of spores and hyphae remained intact and no chitinase was detected suggesting that only cell contents were enzymatically digested. Stachybothrys sp. was rejected as food. The bacterium Alcaligenes faecalis was dominant in homogenates in each of the treatments, but under starvation Achromobacter xylosoxidans became co-dominant. Cellulase activity was not detected in any treatment, but strong chitinase activity was induced with a filter paper (colonized by invasive fungi) diet. Furthermore, bacteria were common in mesenchyme between the internal organs in the filter paper and starvation treatments.     

Habitat modelling for the conservation of the rare ground beetle species Carabus variolosus (Coleoptera, Carabidae) in the riparian zones of headwaters

Carabus variolosus is a highly endangered insect which is listed in the EC Habitats and Species Directive. Detailed knowledge of the habitat requirements of this semi-aquatic woodland carabid beetle is needed if effective conservation and management strategies are to be developed. Previous habitat models have proved to be a successful analytical and predictive tool for the conservation of species. We conducted an intensive study over a two year period on two extant C. variolosus populations in Westphalia (Germany) using live capture pitfall traps. We analysed the distribution of the beetles over their main activity period in relation to a large number of edaphic and vegetation variables in order to estimate habitat suitability models and describe optimum ranges. C. variolosus is restricted to the fringes of water bodies and to areas of high soil moisture that display patches of bare soil, shows a slight preference for sparse tree vegetation, and avoids acidic soil. Temporal and spatial transferability of the statistically significant habitat models indicates their robustness and validity. Based on the results of our study, we suggest management measures for the conservation of C. variolosus, which promote the rehabilitation of natural flood plains of headwater areas.     

Habitat selection by East Caucasian tur (Capra cylindricornis)

Habitat selection by East Caucasian tur (Capra cylindricornis), a species of global conservation concern, was examined in relation to terrain, climate and degree of human disturbance using a Geographical Information System and logistic regression. The study area was in the part of the Greater Caucasus of Georgia, where the species protection was not enforced. Two models of tur habitat requirements were obtained: one model at a scale of 20 × 20 m plots, and the other one at a scale of different habitat fragments made up of 20 × 20 m plots identified by the first model at its optimal cut-off value. The second model refined the first one.The first model suggested that the probability of a 20 × 20 m plot being part of tur habitat was positively correlated with slope, distances to roads and livestock summer camps, and negatively correlated with human population density and annual rainfall. The probability had a bell-shaped correlation with elevation, reaching its maximum at 3008.4 m. The second model suggested that a fragment of a land made up of 20 × 20 m plots with optimal characteristics for tur occurrence was more likely to contain tur if the area of the fragment was larger and its distance to the nearest area where tur occurred was shorter.The results show that the occurrence of East Caucasian tur is affected by climate, terrain, human disturbance and habitat fragmentation, and can be predicted regardless of seasonality in the species movements. These models can be applied to the management of the species and its habitat in the areas of the Caucasus that lie at >1000 m asl and have an annual rainfall >600 mm, and where the species protection is not enforced.     

Patch connectivity and genetic diversity conservation in the federally endangered and narrowly endemic plant species Astragalus albens (Fabaceae)

To evaluate the sufficiency of US federal critical habitat designations and a proposed conservation plan in promoting the long-term persistence of the endangered plant Astragalus albens, patterns of genetic diversity and landscape connectivity were examined. A. albens harbors substantial genetic variation and shows no evidence of historic bottlenecks, suggesting little risk of extinction due to genetic homogeneity (A = 2.40; P = 0.50) or inbreeding (f = −0.08) within occurrences. Low genetic differentiation among occurrences (θ_p = 0.01) indicates relatively high gene flow or little genetic drift. The 91 patches of A. albens were connected into a single network at a distance of 2100 m; 94% of patches were <1000 m from at least one other patch. Managing ecological conditions that maintain large population sizes and connectivity among populations throughout the species’ ecological and geographic ranges will most likely conserve existing diversity. Both reserve networks partially accomplish these goals by including most extant occurrences and >89% of the aerial extent of the species, including the largest populations, and capturing all detected alleles. However, both conservation networks fail to conserve occurrences from one portion of the species’ range, possibly speeding loss of unique local adaptations. In addition, connectivity of the whole network is reduced with the 65 patches designated as critical habitat being connected at a distance of 6200 m and the proposed reserve sites being connected at a distance of 9500 m. Although total network connectivity would be reduced, connectivity at scales most relevant to gene flow (e.g., <1000 m) remains sufficiently in tact to provide a relatively promising outlook for species persistence.     

土壤施肥对烟粉虱生长发育、寄主选择及繁殖的影响

为探讨土壤施肥对烟粉虱种群的影响,在室内采用盆栽方法测定了11种氮、磷、钾施肥组合处理和对照处理的黄瓜苗上烟粉虱的发育历期、存活率、若虫大小、寄主选择、繁殖力及寿命等生命参数。结果表明,烟粉虱的发育历期受施肥影响显著;施肥对卵和低龄若虫存活率无显著影响,但对高龄若虫存活率及各龄若虫大小影响显著;成虫较喜欢在氮肥施用量适中且不施用钾肥和磷肥的黄瓜植株上取食和产卵,而不喜好氮肥施用量大且施用钾肥和磷肥的植株;烟粉虱的寿命及繁殖力在单独施用磷肥的黄瓜植株上低于对照处理的植株,在其他施肥处理上均高于对照。在氮肥施用量大且施用钾肥和磷肥的植株上,一个世代后烟粉虱种群增殖最大,达74．4倍;在单独施用磷肥时增殖最小,仅17．2倍。     

First-best, second-best, and heuristic solutions in conservation reserve site selection

Previous studies which dealt with the conservation reserve site selection problem used either optimization methods, specifically linear integer programming (IP), or heuristic algorithms. The trade-off between computational efficiency versus optimality has been discussed in some articles and conflicting messages were signaled. Although the problem of suboptimality was acknowledged, some authors argued that heuristics may be preferable to exact optimization because IP models are computationally complex and may not be solvable when too many reserve sites are involved. On the other hand, some studies reported that fairly large problems could be solved easily. This paper shows that although the computational complexity argument can be valid for large reserve selection problems, by properly guiding the solver and exploiting the problem structure, formal optimization can deliver second-best (near-optimal) solutions that dominate the greedy heuristic solutions.     

Habitat and food choice of the critically endangered cao vit gibbon (Nomascus nasutus) in China: Implications for conservation

Knowledge of habitat and feeding ecology is essential for developing an effective conservation management plan for threatened primates. Despite having been rediscovered nearly a decade ago, very little is known of the critically endangered cao vit gibbon (Nomascus nasutus) or its habitat. We analysed forest cover, made direct observations and conducted interviews of local elders to better understand forest changes and to determine the forest characters and species important to the survival of the gibbon. Interviews indicated human-induced forest resource exploitation focused on species-specific and larger trees most easily accessed. Gibbon forest habitat comprised four primary forest types. The mean canopy height over the whole site was 10.52 m. Gibbons consumed 81, or nearly half of the tree and liana species recorded in the site; however, only 19 species provide 77.8% of the diet. Six of the 19 food species were logged for different reasons throughout the history of the site. We conclude that effective conservation management of primates with highly limited distributions, focused dietary needs, and in degraded ecosystems will require active forest restoration, such as planting important food species in degraded sites.     

Habitat correlates of distribution and local population decline of the endemic Sardinian newt Euproctus platycephalus

Habitat-based statistical models relating patterns of presence and absence of species to habitat variables could be useful to resolve conservation-related problems and highlight the causes of population declines. In this paper, we apply such a modelling approach to an endemic amphibian, the Sardinian mountain newt Euproctus platycephalus, considered by IUCN a critically endangered species. Sardinian newts inhabit freshwater habitat in streams, small lakes and pools on the island of Sardinia (Italy). Reported declines of newt populations are not yet supported by quantitative data, however, they are perceived or suspected across the species' historical range. This study represents a first attempt trying to statistically relate habitat characteristics to Sardinian newt occurrence and persistence. Linear regression analysis revealed that newts are more likely to be found in sites with colder water temperature, less riparian vegetation and, marginally, absence of fish. The implications of the results for the conservation of the species are discussed, and suggestions for the short-term management of newt inhabited sites suggested.     

Habitat selection by the Mediterranean horseshoe bat, Rhinolophus euryale (Chiroptera: Rhinolophidae) in a rural area of southern Italy and implications for conservation

We studied habitat selection by Rhinolophus euryale in a rural area of southern Italy in 1998-2000 by radio-tracking. Two comparisons were carried out, one between habitat occurrence within individual home ranges and within the study area, the other between time spent in each foraging habitat and habitat occurrence within the home range. The first analysis showed that olive groves and conifer plantations were, respectively, the most and the least important habitats. The second analysis highlighted the importance of woodland for R. euryale, while urban sites, open areas and conifer plantations were avoided. We recommend that clearing of continuous, large areas of woodland for tree harvesting should be avoided. Conifers should not be used for reforestation. Urbanisation should be limited in the areas of greatest importance for the species, and linear landscape elements such as tree lines and hedgerows should be maintained.     

Adding burrows to enhance a population of the endangered pygmy blue tongue lizard, Tiliqua adelaidensis

The endangered pygmy blue tongue lizard, Tiliqua adelaidensis, occupies spider burrows in a population near Burra, South Australia. In each of twelve 20 × 20 m plots at that population, we added 36 artificial burrows, providing about a ten fold increase in suitable burrows for lizards. Over three surveys during the spring and summer of 2001/2002 there were significant increases in lizard numbers in the experimental plots relative to the controls, both for adult lizards and for new recruits after clutches were produced. This local increase in population density may be due to lizards locating suitable burrows more easily where burrow numbers were supplemented. The increased availability of high quality burrows may also reduce mortality among lizards searching for suitable burrows. Additional burrows also led to an increase in local density of a burrow-dwelling centipede that is a potential predator of lizards, but there was no evidence of predation, and any negative predation impact was outweighed by the beneficial effect of providing more burrows. Overall the results suggest that adding artificial burrows could enhance local population density and recruitment success, and that this could be a valuable tool in the conservation management of this endangered species.     

Habitat use, predicted distribution and conservation of green peafowl (Pavo muticus) in Dak Lak Province, Vietnam

In the last few decades, green peafowl numbers have declined drastically across their south-east Asian range, primarily, it is believed, due to human persecution and loss of habitat. They were formerly common across Vietnam, but are now restricted to a few central provinces. In this study green peafowl were surveyed in Dak Lak province, Vietnam, using a point-count methodology to assess their status and distribution, and to investigate their habitat use. Results showed that the most used habitat was dry deciduous forest with access to permanent water and free from human disturbance. Green peafowl density was lower in mixed and evergreen forest and lower when water was distant and/or human settlement was nearby. A map of predicted distribution was created which predicted that eastern and north-eastern Dak Lak are important areas containing much of the remaining habitat and populations of green peafowl. Several key river systems within this area were predicted to be of particular value. Deciduous forest < 2 km from water and > 2 km from human settlement was estimated to occupy only 3% of the province but to hold 37% of green peafowl. Conservation of green peafowl in Dak Lak, and elsewhere, should concentrate on maintaining undisturbed access to permanent water within large tracts of dry deciduous forest. The spread of human settlement presents the greatest threat; both directly due to hunting pressure and habitat loss and indirectly by preventing access to water in otherwise suitable areas.     

Effects of Land Use and Wildfires on the Habitat Selection of Great Bustard (Otis tarda l.)—Implications for Species Conservation

Increasing agricultural activities have been shown to affect soil and vegetation changes leading to serious biodiversity declines throughout the world. These effects are amplified in dry grassland areas, where resulting changes in habitat structure affect threatened animals on long temporal scales. Great bustards (Otis tarda) inhabit open landscapes where fire and grazing have been a part of the natural disturbance regime since historical times. Even fire and grazing are hypothesized to be important factors in the lifecycle of the species, studies are still missing on disturbance‐related lekking distribution patterns of great bustards. We analyzed the importance of fires and grazing on the spatial distribution of lekking bustards controlling for habitat types, habitat diversity, distance from roads and social effects. Our standardized dataset spanned 31 years, being one of the largest datasets on bustard lekking. During the 31 years we observed 10 118 individuals at 639 observation points in Hortobágy National Park, East‐Hungary. One of the most important predictors for total number of birds and number of males was the area burnt in previous years. We found that increased habitat diversity had a positive effect on female numbers. Models fit on second‐ and third‐year burn data detected no substantial role of burning on lekking distribution. Our results suggest that introduction of a patch‐burning management system in lekking areas could increase the availability of optimal lek sites for bustards. As an effective management tool, we suggest applying patch‐burning annually in a spatially mosaic structure inside the area occupied by each sub‐population unit. Copyright © 2016 John Wiley & Sons, Ltd.     

Roost selection by barbastelle bats (Barbastella barbastellus, Chiroptera: Vespertilionidae) in beech woodlands of central Italy: consequences for conservation

We investigated roost selection by Barbastella barbastellus in a mountainous area of central Italy. Twenty-five bats, mostly lactating females, were radio-tracked to 33 roost trees. Trees in unmanaged woodland were favoured as roost trees; woodland subject to limited logging was used in proportion to availability, and areas where open woodland and pasture occurred were avoided. Selection depended on tree condition (dead beech trees were preferred) and height (roost trees were taller than random ones). Cavity selection was based on cavity type, height and entrance direction: roost cavities were mainly beneath loose bark, at a greater height above ground and facing south more frequently than random cavities. Untouched areas of mature woodland should be preserved to provide roosting conditions for B. barbastellus. In logged areas, harvesting protocols should save dead and mature trees; frequent roost switching and small colony size imply that large numbers of roost trees are needed.