Niche Factor Analysis Research Articles

Spatial differences across the French Pyrenees in the use of local habitat by the endangered semi‐aquatic Pyrenean desman (Galemys pyrenaicus)

Abstract The implementation of effective and appropriate protection actions is frequently hindered by lack of thorough knowledge on species ecology especially in the case of endemic, vulnerable and elusive species. Using a recently updated and unpublished dataset describing the spatial distribution of the Pyrenean desman (Galemys pyrenaicus) in its northern range (French Pyrenees), an Ecological Niche Factor Analysis (ENFA) was conducted to provide a quantitative estimate of local habitat use by this endangered semi‐aquatic mammal. A comparative approach was used to investigate potential differences in habitat use among the three main hydrological regions of the French Pyrenees. The Pyrenean desman was identified as a marginal and specialist species concerning the selection of its local habitat in the French Pyrenees. Key habitat variables corresponded mainly to river‐bed characteristics (i.e. high heterogeneity of shelters and river substrates, fast flowing water facies, low amounts of fine sediment) and river‐bank characteristics (i.e. high proportion of rocks, low proportion of earth). A difference in habitat selection between the three hydrological regions of the French Pyrenees was also highlighted. A decrease in marginality and specialization from west to east as well as differences in habitat variables driving the ecological niche of the Pyrenean desman and its range suggested a spatial structure in desman populations regarding local ecological factors. These results stress the importance of effective and sustainable river management for the habitat quality of this endangered species and also demonstrate the importance of taking into account the variability in habitat preferences that can exist between geographically distinct populations. This finding has important implications for conservation planning that should thus be conducted at the population level instead of the traditional species level in order to target the specific needs of each hydrological region. Copyright © 2016 John Wiley & Sons, Ltd.

普洱市亚洲象栖息地适宜度评价

PDF HTML阅读 XML下载 导出引用 引用提醒 普洱市亚洲象栖息地适宜度评价 DOI: 10.5846/stxb201411142260 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金会资助项目（31172108）；美国内政部鱼和野生动物管理局亚洲象保护基金资助项目（98210-8-G565） Habitat suitability assessment for Asian elephant in Pu'er prefecture in the Yunnan province of China Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:亚洲象（Elephas maximus）属于我国Ⅰ级保护动物，在中国仅分布于云南省西双版纳国家级自然保护区、普洱市的思茅区、澜沧县和江城县，以及临沧南滚河国家级自然保护区。将普洱全境作为研究区域，利用野外调查数据，结合遥感与地理信息系统技术，运用生态位因子分析（ENFA）模型对普洱市亚洲象的栖息地适宜度进行了评价，并预测了适宜栖息地的分布。发现：普洱市亚洲象栖息地的边际值为0.991，表明亚洲象在普洱市境内对环境变量的选择不是随机的；耐受值为0.315，表明亚洲象在普洱市境内生态位较窄，受环境条件的制约。根据模型计算得到的栖息地适宜度指数，将普洱市的亚洲象栖息地分为最适栖息地，较适栖息地，边际栖息地和非栖息地4个等级，面积分别为409.32、574.32、2909.48、38722.32 km2。最适栖息地仅占全市面积的0.96%，而非栖息地占90.86%。利用GIS和Biomapper 4.0生成亚洲象栖息地分布图，发现普洱境内最适栖息地和较适栖息地面积狭小。对最适栖息地、较适栖息地和边际栖息地进行景观格局分析的结果表明，3种类型的栖息地破碎化均十分严重，连通度较低，栖息地内受到较大程度的人类活动的干扰。因此建议在普洱和西双版纳间尽快建立野生动物生态廊道，以加强亚洲象各种群间的交流。 Abstract:The Asian elephant (Elephas maximus) is listed as a first-class protected species in China, and is only distributed in Xishuangbanna, Pu'er, and Lincang prefectures of Yunnan Province. The main threats to the survival of elephants in China were habitat loss and fragmentation. Only 5 elephants were reported in Pu'er in 1996, and currently, there are over 80 elephants belonging to 8 groups living in the region. In this study, we collated 152 elephant occurrence points within the entire Pu'er range in 2010, and assessed habitat suitability for Asian elephant in Pu'er, based on Ecological Niche Factor Analysis (ENFA) of the field survey data. We also predicted the distribution of suitable habitats for elephants in Pu'er. The marginality value obtained from ENFA was 0.992. This result indicated that the deviation of the preferable niche of elephants was different from the average value of the environment, and that elephants chose their habitat non-randomly. The tolerance value was 0.315, which indicated that the niche of Asian elephant was narrow, and that environment indicators restricted the survival of elephants. Results showed that the elephants in Pu'er preferred natural forest with low elevation (<1419 m) and moderate slopes (<14°), as well as areas far from streams and human disturbance (villages and roads). We divided elephant habitat in Pu'er into 4 categories: optimal habitat (409.32 km2), suitable habitat (574.32 km2), marginal habitat (2909.48 km2), and unsuitable habitat (38722.32 km2). The unsuitable habitat accounted for 90.86% of the total area, whereas the optimal habitat occupied only 0.96%. Natural forest is the major vegetation type in optimal (55.6%), suitable (54.55%), and marginal (48.21%) habitats, but it constituted only 33.05% of the unsuitable habitat, indicating that natural forest is the preferred habitat for Asian elephants. According to landscape structure analysis using FRAGSTATS, the mean patch fractal dimension indices (FRAC_MN) for marginal, suitable, and optimal habitats were found to be close to 1, and the meancontiguity indices (CONTIG_MN) were found to be 0.12-0.15. Landscape analysis showed that the optimal, suitable, and marginal habitats all suffered severe fragmentation, low connectivity, and high levels of human disturbance. In comparison with real distribution, the predicted map incorporated some farmlands where Asian elephants forage. The proportion of optimal and suitable habitat in Pu'er is very low, owing to the loss of natural forest and the cultivation of economic plants. It is critical to establish protected areas in the habitat of Asian elephants, in combination with effective conservation measures. In addition, the three main areas of elephant distribution in Pu'er are isolated. It is understood that low connectivity among populations impedes important communication among different population groups. Therefore, it is also necessary to establish and restore ecological corridors to link the current elephant habitats in Pu'er, and to increase their connection with other elephant populations in Xishuangbanna. 参考文献 相似文献 引证文献

Land use and biodiversity patterns of the herpetofauna: The role of olive groves

The intensification of agriculture has significant environmental consequences. This intensification entails the simplification and homogenisation of the landscape, which leads to strong negative impacts at ecosystem level, including declines in animal biodiversity. The purpose of this study was to assess the effect of different land uses on reptilian and amphibian biodiversity patterns at a regional scale by analysing a large database on the presence of amphibians and reptiles in Andalusia (southern Spain). GIS techniques and the Ecological-Niche Factor Analysis (ENFA) were applied in order to assess whether the habitat was suitable for each reptilian and amphibian species, when the land use variables were excluded. The incongruence between the potential and the observed species richness was then correlated with the main types of land use in Andalusia. Our results showed that irrigated and unirrigated olive groves were associated with a biodiversity deficit of amphibians and reptiles respectively, whereas natural forests and pastures, along with more heterogeneous crops areas, were more suitable. A clustering analysis showed that generalist species were related to olive groves whereas rare and specialist species were related to land uses related to natural vegetation. In summary, our results indicate that large areas covered by olives groves harbour less amphibian and reptilian diversity, thus suggesting that agro-environmental schemes should be carried to promote the species richness in these crops.

Modeling the potential distribution and conservation status of three species of oak gall wasps (Hymenoptera: Cynipidae) in the Iberian range

Cynipids (Hymenoptera: Cynipidae) induce a wide variety of complex galls on plants of different botanical families, particularly on Quercus species. Cynipid galls are well known to host large communities of insects, providing fundamental ecological niches for different animal taxa, which are organized in structured and relatively isolated communities at the microhabitat level. Gall communities of Quercus woodlands could be a conservation concern considering some risks, which affect several species of the Parasitica group of Hymenoptera, within which gall wasps and their parasitoids and inquilines are included. These risks concerning Parasitica species are mainly due to three causes: their high trophic level, high host specialization and the lack of knowledge of their biology. In this paper, a preliminary approach to this issue is presented for the Iberian–Balearic range. We model and study the ecological niche of three cynipid gall species that induce galls on Quercus species (Andricus quercustozae, Biorhiza pallida and Plagiotrochus quercusilicis). The cynipid gall species were selected for their different sets of host species and life cycle. The Ecological Niche Factor Analysis and two niche models built for each species (MAXENT and Mahalanobis Distances) support the interpretation that the bioclimatic variables considered have effects on cynipids through their respective sets of host plants. In addition, the results regarding A. quercustozae are consistent with the hypothetical existence of cryptic sexual generation (exposed in other works) parasitizing cork oak (Quercus suber), which could have another key role in its conservation.

Habitat Modelling for Conservation Analysis using GIS and Remote Sensing in Lantau Island, Hong Kong

Knowledge of spatial distribution of faunal species is crucial to prioritize conservation resources. While vulnerable or endangered species are usually well-protected, common species were always overlooked. Traditional survey represented species distribution by discrete points, which is precise but often limited in applicability for conservation analysis. This study combined remote sensing; geographical information analytical tools and well-established multivariate statistical modelling to predict habitats of fifty common and representative animal species. Reliable ground data records from terrestrial biodiversity survey were collected and ecological niche factor analysis was used to identify pseudo-absence sites essential for habitat statistical models. Binary logistic regression models and generalized additive models were used to predict the faunal habitats. Species-richness map was then produced to identify biodiversity hotspots and possible conservation gaps of the current conservation system. Results from gap analysis showed that only 1% of faunal species richness hotspots coincided with existing protected sites of special scientific interest (SSSI). 45% of species-rich sites were under-protected. The results not only identified deficiency of existing protection system, where extra conservation planning efforts should be considered, but also highlighted the direction for future development to minimize the land use conflicts. Integration of geoinformatics and statistical analysis with ecological knowledge assist timely conservation policy making.

Using habitat models to evaluate protected area designing for giant pandas

Giant pandas (Ailuropoda melanoleuca) are now confined to fragmented habitats in western China, with more than 60 % of individuals inhabiting 63 protected areas. Knowledge of the environmental features required by giant pandas is critically important for protected area spatial arrangement and subsequent assessments. Here we developed a distribution model for giant pandas in the Tangjiahe Nature Reserve using Ecological Niche Factor Analysis (ENFA) model. We found that less than 40 % of this key reserve is of high suitability for giant pandas, highly suitable habitat being primarily characterized as coniferous forests away from roads within the reserve. Although there was a clear core zone occupied by giant pandas, which included the vast majority of known giant panda locations, only about 45 % of this zone was classified as highly suitable habitat (suitable and optimal). Therefore, the spatial arrangement within the reserve may need to be modified to effectively manage the remaining population of giant pandas. Of particular concern are several tourism proposals being considered by local government, which, if implemented, will increase the isolation of the local population from those in the surrounding area. Our analysis identifies Caijiaba and Baixiongping as areas that should become conservation priorities. Our approach provides valuable data to advise conservation policy and could be easily replicated across other protected areas.

Ecological niche of the Asiatic Cheetah (Acinonyx jubatus venaticus) in the arid environment of Iran (Mammalia: Felidae)

The Asiatic Cheetah, Acinonyx jubatus venaticus, is a species of global conservation concern and a small population occurs in Iran in fragmented habitats located in the central parts of the country with a continental, arid climate. Naybandan Wildlife Refuge (NWR) holds the largest population in Iran. To understand better the factors which determine the occurrence of cheetahs in these areas, we applied an Ecological Niche Factor Analysis (ENFA) to assess the relationship between occurrences of cheetahs across the NWR and topographic, biological, and anthropogenic factors. ENFA analysis results suggested that cheetahs have a tendency to inhabit areas different from the mean conditions of the study area and live in a narrow set of conditions. They prefer mountainous habitats far from flat areas, habitats near to water resources, and habitats with high prey densities. 13% of the NWR can be classified as suitable habitat for the cheetah, indicating a high conservation value of this reserve for the species.

ENiRG: R‐GRASS interface for efficiently characterizing the ecological niche of species and predicting habitat suitability

At the base of species distribution modelling is the ecological niche concept, which describes species' response to distribution of resources. The ecological niche factor analysis, which is implemented in ENiRG, allows to reconstruct species' niche from a set of environmental variables, describing the suitability of the habitat where species occurs. ENiRG overcomes the inefficient management of large volumes of spatial information from wide study areas, high resolution or high number of environmental descriptors. This package also offers the possibility of habitat suitability classification, projection of distributions under different past or future climate scenarios and a GUI to access the functionalities.

Habitat suitability for chiru (Pantholops hodgsonii): Implications for conservation management across the Tibetan region of Chang Tang

Understanding how population density relates to habitat underlies basic ecological theory and is pertinent to conservation issues. Chiru (Pantholops hodgsonii) are an endangered steppe-dwelling ungulate endemic to the Tibetan plateau. To prepare effective conservation and management strategies for this species, we require detailed knowledge of the relationship between group size and habitat conditions. We surveyed the Chang Tang region of Tibet and used data collected along vehicular line transects to record the presence and group size of chiru. Using ecological niche factor analysis, we inferred the ecological requirements of chiru in relation to a large number of topographic, vegetation, and anthropogenic variables. We used these analyses to estimate habitat suitability models and describe their optimum range. Areas favored by chiru had moderate grazing by domestic animals, gentle slopes, and villages present only at lower altitudes. Chiru showed a high level of specialization regarding the presence of villages and gentle slopes, and were negatively associated with areas of those easily accessed by people. We suggest new management measures for the long-term conservation of chiru. Specifically, we focus on the rehabilitation of natural plains for grazing by chiru, recognizing that conservation of large groups may require special efforts. For smaller groups and solitary chiru, the large tracts of unsuitable or marginal areas may expose them to different threats that could pose greater challenges for conservation management. © 2015 The Wildlife Society.

Habitat requirements of Eurasian pine marten Martes martes in a Mediterranean environment

Evaluating presence and habitat requirements of small carnivores is essential for their conservation. The Eurasian pine marten Martes martes, often described as a habitat specialist associated primarily with forest habitats, has been recently found to live even in patchily wooded country and in shrublands. We evaluated the environmental factors that determine the distribution of the pine marten in a Mediterranean landscape on the island of Sardinia (central Italy). Camera trapping sessions and scat surveys were carried out to assess the presence of the species, then a potential distribution model was developed using ecological niche factor analysis (ENFA), which requires only presence data. The pine marten selected highest altitudes, shrublands, rocky areas, and woodlands, and avoided urban areas and arable lands. Our results indicate that pine marten distribution in our study area is constrained by these variables. The ENFA analysis provided important clues about the distribution range of M. martes and its preferential environmental conditions, updating knowledge of its ecological requirements in Italy.

Towards a more holistic research approach to plant conservation: the case of rare plants on oceanic islands.

Research dedicated to rare endemic plants is usually focused on one given aspect. However, holistic studies, addressing several key issues, might be more useful, supporting management programmes while unravelling basic knowledge about ecological and population-level processes. A more comprehensive approach to research is proposed, encompassing: phylogenetics/systematics, pollination biology and seed dispersal, propagation, population genetics, species distribution models (SDMs), threats and monitoring. We present a holistic study dedicated to Veronica dabneyi Hochst. ex Seub., an endangered chamaephyte endemic to the Azores. Veronica dabneyi was mainly found associated with other endemic taxa; however, invasive plants were also present and together with introduced cattle, goats and rabbits are a major threat. Most populations grow at somewhat rocky and steep locations that appeared to work as refuges. Seed set in the wild was generally high and recruitment of young plants from seed seemed to be frequent. In the laboratory, it was possible to germinate and fully develop V. dabneyi seedlings, which were planted at their site of origin. No dormancy was detected and time for 50 % germination was affected by incubation temperature. Eight new microsatellite markers were applied to 72 individuals from 7 sites. A considerable degree of admixture was found between samples from the two islands Flores and Corvo, with 98 % of the genetic variability allocated within populations. Levels of heterozygosity were high and no evidence of inbreeding was found. Species distribution models based on climatic and topographic variables allowed the estimation of the potential distribution of V. dabneyi on Flores and Corvo using ecological niche factor analysis and Maxent. The inclusion of land-use variables only slightly increased the information explained by the models. Projection of the expected habitat in Faial largely coincided with the only historic record of V. dabneyi on that island. This research could be the basis for the design of a recovery plan, showing the pertinence of more holistic research approaches to plant conservation.

Projecting distribution of the overwintering population of Sogatella furcifera (Hemiptera: Delphacidae), in Yunnan, China with analysis on key influencing climatic factors.

Sogatella furcifera (Horváth) is the most threatening migratory rice pest in Yunnan, China. S. furcifera overwinters in low- altitude basins and valleys in southern Yunnan and migrates northward in spring and summer of the following year, causing serious damage during migration. The overwintering distribution, areas, and spatial pattern of S. furcifera are relevant to the migration and outbreak of this pest. Based on a 4-yr field survey (2010–2013), this study projected areas suitable for S. furcifera to overwinter using a species distribution model, and analyzed the key influencing climatic factors using principal component analysis (PCA) and ecological niche factor analysis (ENFA). Our field survey showed that the northern latitudinal- and upper elevation limits of overwintering S. furcifera was 25.4° N and 1,608 m in western Yunnan and 24.2° N and 1,563 m in eastern Yunnan. The species distribution model produced a fragmented distribution pattern, with most of which in western Yunnan and only a few in eastern Yunnan. The PCA and ENFA analyses showed that the mean temperature of the driest quarter and the precipitation of the coldest quarter significantly influenced the distribution of S. furcifera in winter. The results suggested that the complex topography, spatial differences in winter temperatures, and host availability altogether determined the distribution of overwintering S. furcifera . Compared with previous surveys, the northern latitudinal- and upper elevation limits of overwintering S. furcifera were higher, while the population became rarer in some suitable areas due to change of farmland utilization in winter and possibly climate change.

Predicting coexistence and predominance patterns between the introduced Manila clam (Ruditapes philippinarum) and the European native clam (Ruditapes decussatus)

In several European estuaries, the introduced Manila clam (Ruditapes philippinarum) has become a widespread and predominating species supplanting the native carpet shell clam (Ruditapes decussatus) whereas in other estuaries such as the Bay of Santander (Gulf of Biscay) this pattern has not been detected. Using this estuary as a case study, the potential coexistence/predominance patterns between these two species were explored with the objective of providing insight into the capacity of expansion of R. philippinarum. Firstly, the Ecological Niche Factor Analysis (ENFA) was applied to determine the niches of both species, using seven contemporary environmental variables, i.e. salinity, water depth, current velocity, and sediment sand, gravel, silt and organic matter content. Secondly, ENFA-derived habitat-suitability (HS) maps were simultaneously treated, using geospatial techniques and following HS index-based criteria, to determine the potential distribution patterns. Both species models performed well according to the cross-validation evaluation method. The environmental variables that most determined the presence of both clams were depth, current velocity and salinity. ENFA factors showed that R. philippinarum habitat differs more from the mean environmental conditions over the estuary (i.e. higher marginality) and has less narrow requirements (i.e. lower specialization). R. philippinarum dominated areas, determined by relatively lower current velocities and percentages of sand, higher organic matter contents and slightly shallower depths, were very reduced (i.e. 2.0% of the bay surface) compared to coexistence (47%) and R. decussatus predominance areas (7.4%). These results suggest that HS may regulate the expansion of R. philippinarum. ENFA, together with geospatial analysis of HS index, seems to be a valuable approach to explore the expansion potential of estuarine invasive or introduced species and thus support conservation decisions regarding native species.

Comparing species distribution models: a case study of four deep sea urchin species

There is an increasing demand for biodiversity mapping to address new challenges in the management of marine ecosystems. Species distribution models are a key tool in supplying part of this information. However, the use of these models in the marine environment is still developing and the reasons for the underlying use of different methodological approaches are not always clear. In this work, we compared four different statistical techniques: the ecological niche factor analysis (ENFA), the MAXimun ENTropy algorithm (MAXENT), general additive Models (GAMs), and Random Forest. ENFA and MAXENT were applied using presence-only data whereas GAM and Random Forest used presence–absence data. As a case study, we used four deep sea urchin species: Centrostephanus longispinus, Coelopleurus floridanus, Stylocidaris affinis, and Cidaris cidaris. The distribution of the studied sea urchins showed strong bathymetric segregation. Depth was the most important variable, followed by reflectivity and slope. The correlations between the predictive outputs of the models were similar between GAM, Random Forest and MAXENT, and lower for ENFA. Models using presence/absence data showed the highest scores in the four species, significantly outperforming ENFA in most of the cases, although differences with MAXENT were significant in only one species.

Recorded and potential distributions on the iberian peninsula of speciesof Lepidoptera listed in the Habitats Directive

Abstract. Using data on the known Iberian distributions of 10 species of Lepidoptera listed in the Habitats Directive referenced to the 10 × 10 km UTM grid, we determined their potential distributions and their relationships with selected bioclimatic factors associated with mean temperature and precipitation using Ecological Niche Factor Analysis (ENFA). Scores for Specialization and Marginality were determined in order to evaluate the relationships between the predictions of the model and climatic factors. The number of squares on the Iberian Peninsula in which the species are recorded and those squares predicted to be favourable for these species were determined if they matched the network of Protected Natural Areas. This suggested that a further eight 10 × 10 km squares should be included in Protected Natural Areas. The results also indicate that climate determines the distributions of most of the species. Although overall there is a close association between the observed and predicted distributions, the less thoroughly documented geographic ranges (i.e. those of the moth species) depart from this pattern.

Estimation of habitat suitability for the southern form of the short‐finned pilot whale (Globicephala macrorhynchus) in theNorthPacific

AbstractHabitat models were developed from dedicated sighting survey data collected during summers between 1983 and 2006 in theNorthPacificOcean. Our aim was to examine the distribution pattern of the southern form of the short‐finned pilot whale (Globicephala macrorhynchus) in relation to the physical environment. We tested two different types of analytical procedures for habitat estimation: generalized linear models (GLMs) and ecological niche factor analysis (ENFA). The area under the receiver operating characteristic curve and theBoyce index suggested thatGLMdefined the core habitat well, whereasENFAestimated the suitable habitat more correctly. These models indicated the core habitat within the subtropical gyre. Among the environmental variables used to construct the habitat models, the temperature at a depth of 200 m contributed most to bothGLMandENFA. This corresponds to the fact that the species mainly feeds on mesopelagic prey and that the axis of theKuroshioCurrent, in the northwestern part of the subtropical gyre, is characterized by its temperature at 200 m. Habitat suitability in the coastal waters off southernJapan also correlated with theKuroshio meander patterns. Thus, the southern form of the short‐finned pilot whale appears to be particularly well adapted to the ecosystem of theNorthPacific subtropical gyre.

Preferencia de hábitat del murciélago hortelano meridional Eptesicus isabellinus (Temminck, 1840) en ambientes mediterráneos semiáridos

Several molecular studies have recently reported the presence of a second species of the genus Eptesicus in the Iberian peninsula, the meridional serotine bat, E. isabellinus. This species is present in the south of Iberia and it seems to have an allopatric distribution with its twin species, E. serotinus. Ecological studies are now needed to understand the biology of E. isabellinus in southeast Spain. In this study, we used presence–only data for E. isabellinus to perform an ecological niche factor analysis (ENFA) and to create a habitat suitability map (HSM). Our results show that the species has a low marginality index, suggesting it is well adapted to the semiarid conditions of the study area. The main habitats used by E. isabellinus are water courses, scrublands, and zones with high primary productivity. The species avoids non–irrigated cropland and shows no preference for human settlements or irrigated cropland. This study provides information about the ecology of E. isabellinus in southeast Spain and allows us to discuss relevant aspects for its conservation.

Predicting suitable habitat for the gold coral Savalia savaglia (Bertoloni, 1819) (Cnidaria, Zoantharia) in the South Tyrrhenian Sea

The gold coral Savalia savaglia (Cnidaria, Zoantharia) is a rare component of the mesophotic zone of the Mediterranean Sea and northeastern Atlantic Ocean.During two field campaigns along the Italian coast in the South Tyrrhenian Sea, two populations of this species were discovered. The specimens were filmed and photographed by means of a Remotely Operated Vehicle (ROV).To identify the role of local bathymetry and other derived variables on presence and distribution of S. savaglia we used a Habitat Suitability (HS) modeling technique based on Ecological Niche Factor Analysis (ENFA), utilizing high-resolution multibeam bathymetry and ROV data.Among the set of environmental variables derived from multibeam data, slope, rugosity, eastness and distance to rocks, appear to be the main variables involved in S. savaglia distribution, pointing out that the habitat differs considerably from the mean environmental conditions over the study area, and that S. savaglia ecological niche is significantly narrower than the available habitat.The HS map was developed to differentiate the sea floor into suitability classes. The comparison between suitability classes and presence data showed that the HS map is coherent with the observed spatial distribution of the species. The most suitable habitat for S. savaglia is characterized by a rough sea floor with rocks that is steeply sloped, oriented northeast, and within a water depth range of 34–77m.Our study suggests that predictive modeling is an approach that can be applied to other deep coral species to locate areas with a suitable habitat. Considering the difficulties to reach the habitats in which these species live, this approach could be essential to planning further studies that help define areas where the species may be present.

Finescale ecological niche modeling provides evidence that lactating gray seals (Halichoerus grypus) prefer access to fresh water in order to drink

AbstractMany phocids are capital breeders, relying on stored reserves to sustain energetic requirements while on land. Their large body size, high energy expenditure during lactation, and the insulative effects of the blubber layer can lead to thermal stress from overheating, especially in warm and temperate climates. Thermal stress can influence fine‐scale site choice on breeding colonies, and behavioral thermoregulation has been proposed as an explanation for the clear preferences shown by breeding female gray seals for proximity to pools of water. However, anecdotal observations suggest that pools of water may also be preferred for drinking, though water intake is difficult to verify without real‐time physiological monitoring. Here, an alternative approach demonstrates that gray seals also require access to water for drinking. Using Ecological Niche Factor Analysis to examine fine‐scale physical determinants of pupping site choice at North Rona, Scotland, we found that lactating mothers showed preference for lower salinity pools. This is most pronounced early in the season, when ambient temperatures and presumably thermal stress are greatest. Given that the cooling effect of fresh and salt water should be equivalent, the most parsimonious explanation for this preference for fresh water pools is that lactating females use these pools for drinking.

Modeling the potential distribution of sun bear in Krau wildlife reserve, Malaysia

Information and data on the distribution of wildlife species become important when strategizing the management and conservation of the species. Species distribution models have increasingly been used as a predictive tool in wildlife conservation planning and management. This research assessed the distribution of the sun bear and identified the relevant distribution descriptive variables in the Krau Wildlife Reserve, Pahang, Malaysia using Ecological Niche Factor Analysis (ENFA). Marginality and specialization factors showed that the sun bear habitat is very specific compared to the entire study area and its niche breadth was slightly narrow. Among all the habitat suitability algorithms available in Biomapper software package, median with the extreme optimum algorithm was found to have the best predictive capabilities by means of a continuous Boyce index. Results showed that sun bear can rarely be found in high altitudes, prefers lowland Dipterocarp, and avoids Mountain Ericaceous and Mixed Hill Dipterocarp forests. It also prefers to live nearby rivers, tends to avoid villages and prefers regions with fine silty-clay and loamy textures soils.