Rest Sites Research Articles

Selection of rest structures and microsites by fishers in Oregon

ABSTRACTMost previous studies of resting habitat for fishers (Pekania pennanti) in the Pacific coastal region of the western United States and Canada were focused on habitat conditions within rest sites (typically ≤0.5 ha), which include the rest structure (e.g., live tree, snag, log) at its center. Studies of selection for rest structures were sparse and compared characteristics of rest structures to those occurring within rest sites; none investigated selection by sampling resource availability throughout the study area. In addition, limited data were available on the use of rest microsites (e.g., mistletoe brooms, platform branches, cavities) by fishers, and no studies have quantified their availability. To better inform forest management activities designed to improve resting habitat for fishers, we documented use of rest structures and microsites throughout the year by 12 female and 7 male fishers on the west slope of the Cascade Range in southern Oregon, USA from 1995 to 2001, systematically sampled the availability of rest structures and microsites, and used logistic regression modeling to investigate selection of rest structures. Fishers primarily used live trees (65%), snags (14%), and logs (16%) for resting; in all 3 resulting models, the characteristic that best distinguished used from available rest structures was the presence of a suitable rest microsite: mistletoe broom or cavity in live trees, cavity in snags, and hollow end in logs. Only the snag and log models included covariates associated with tree size, likely reflecting the need for enclosed rest microsites (cavities, hollow ends) to be large enough to contain an adult fisher. We then used our availability data to model the ecological characteristics associated with mistletoe brooms in live trees, cavities in snags, and hollow ends in logs. Whether a tree was a hemlock (Tsuga spp.) had the greatest effect on the presence of suitable mistletoe broom microsites, but the most important characteristics of snags with cavities and logs with hollow ends were being in moderate stages of decay and relatively large in diameter at breast height (snags) or diameter 3 m from the large end (logs). Forest structures containing suitable rest microsites for fishers were uncommon in our study and may represent a limited resource. Accordingly, we recommend that management of resting habitat for fishers be focused on retaining relatively large structures that already contain suitable rest microsites, rather than simply retaining the largest available structures. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Seasonal temperature acclimatization in a semi-fossorial mammal and the role of burrows as thermal refuges.

Small mammals in habitats with strong seasonal variation in the thermal environment often exhibit physiological and behavioral adaptations for coping with thermal extremes and reducing thermoregulatory costs. Burrows are especially important for providing thermal refuge when above-ground temperatures require high regulatory costs (e.g., water or energy) or exceed the physiological tolerances of an organism. Our objective was to explore the role of burrows as thermal refuges for a small endotherm, the pygmy rabbit (Brachylagus idahoensis), during the summer and winter by quantifying energetic costs associated with resting above and below ground. We used indirect calorimetry to determine the relationship between energy expenditure and ambient temperature over a range of temperatures that pygmy rabbits experience in their natural habitat. We also measured the temperature of above- and below-ground rest sites used by pygmy rabbits in eastern Idaho, USA, during summer and winter and estimated the seasonal thermoregulatory costs of resting in the two microsites. Although pygmy rabbits demonstrated seasonal physiological acclimatization, the burrow was an important thermal refuge, especially in winter. Thermoregulatory costs were lower inside the burrow than in above-ground rest sites for more than 50% of the winter season. In contrast, thermal heterogeneity provided by above-ground rest sites during summer reduced the role of burrows as a thermal refuge during all but the hottest periods of the afternoon. Our findings contribute to an understanding of the ecology of small mammals in seasonal environments and demonstrate the importance of burrows as thermal refuge for pygmy rabbits.

Characteristics of bat rest sites in buildings of Sincelejo, Sucre, Colombia

Characteristics of bat rest sites in buildings of Sincelejo, Sucre, Colombia

Drivers of diurnal rest site selection by spotted hyaenas

AbstractRest sites are key locations to many animals but their selection has been poorly studied in large carnivores. We investigated seasonal diurnal rest site selection by spotted hyaenas (Crocuta crocuta) in Hwange National Park, Zimbabwe. We assessed the effects on hyaena diurnal rest site selection of (1) distance to the nearest waterhole, as waterholes can be considered prey hotspots in the study ecosystem, (2) habitat type and vegetation characteristics, in particular visibility as it influences detection risk and shade for thermoregulation, (3) location within the core territory of their main competitor/predator, the African lion (Panthera leo), where encounter risk would be higher, (4) distance to the closest lion and (5) distance to the nearest road as they can facilitate travelling by carnivores. We defined rest sites as midday locations of hyaenas equipped with GPS collars. Hyaenas preferred to rest in woodland areas with low visibility, close to roads and far from a lion. Distance to the nearest waterhole and location within lion core territory did not affect hyaena rest site selection. Overall, our study points to the combined importance of the structure of the vegetation (providing safety and shade), the availability of roads (to move through and exploit this bushed environment) and the avoidance of proximity to lions.

Springtime migratory restlessness and departure orientation of Great Knots (Calidris tenuirostris) in the south compared to the north Yellow Sea

BackgroundThe motivation of birds to proceed with migration is associated with both endogenous and exogenous factors. According to their migratory situation and to the characteristics of stopover sites, birds might exhibit migratory motivation differently among sites. Although migratory motivation of migrating birds has been well studied in many species, the investigation of the same species in different migratory situations and at different stopover sites is still limited. We predicted that birds at different stopover sites could differ in migratory disposition, including expression of migratory restlessness and responses to environmental cues.MethodsHere we compared migration motivation and orientation of Great Knots (Calidris tenuirostris) at two stopover sites, Chongming Dongtan in the south Yellow Sea, which is a temporary rest site, and Yalujiang Estuary Wetland in the north Yellow Sea, which is a critical refuelling site, during northward migration. Modified Emlen funnels, with thermal paper inside to record scratches of the birds, were used to detect activity (intensity and direction) of birds. Environmental conditions, including wind direction and speed, cloud cover, tide condition, times of the day (before and after sunset) were recorded during experiments. Generalized linear models were used to detect the effects of endogenous and exogenous factors on the migratory motivation of the birds.ResultsIn the south Yellow Sea, the migratory activity intensity of Great Knots was positively related to wind assistance. In the north Yellow Sea, where birds exhibited higher intensity of migratory activity than in the south, the intensity increased and the motivation to initiate migration grew stronger as the season advanced. The Great Knots exhibited wind-related orientation behaviour in the funnels at both sites.ConclusionsThe results suggest that the intensity of migratory motivation differed between the two sites. Departure decisions of Great Knots appear to be affected mainly by external factors at the temporary rest site in the south Yellow Sea but possibly by endogenous factors at the final pre-breeding refuelling site in the north Yellow Sea.

Seasonal variation in behavioral thermoregulation and predator avoidance in a small mammal

Lay SummaryBehavior of pygmy rabbits varied seasonally to accommodate both thermal challenges and predation risk. We quantified selection of rest sites and activity during summer and winter to evaluate behavioral tradeoffs between thermal and security resources. Our work suggests that behavior might buffer individuals of this species against a changing climate, and it highlights the need for incorporating behavior into models of how individuals and populations of animals respond to climate change.

Huddling is more important than rest site selection for thermoregulation in southern bamboo lemurs

Resting site selection can have important effects on the behaviour and fitness of organisms. The maintenance of optimal body temperatures (Tb) when faced with environmental variables has often been attributed to either specific microhabitat rest site characteristics or to behavioural strategies. Among many small group-living endotherms, social thermoregulation (i.e. huddling) is utilized as an energy conservation mechanism at low ambient temperatures (Ta), thus decreasing the metabolic cost of maintaining Tb. Although unusual among primates, lemurs maintain a low metabolic rate and exhibit a diversity of thermoregulatory strategies; however, objective Tb measurements have thus far been limited to small-bodied lemurs (e.g. Cheirogaleids). As such, we sought to determine whether a medium-sized lemur model, the southern bamboo lemur, Hapalemur meridionalis, would maintain thermoregulation through microhabitat rest site selection, huddling behaviour, or potentially both strategies. Within a degraded littoral forest fragment in southeast Madagascar, we conducted full-day focal observations on three groups of H. meridionalis between January and December 2013. Adult individuals were collared with data-loggers that collected instantaneous skin temperature Tsk (°C). We calculated the mean Tsk of the focal individual during each resting bout, and the proportional rate of huddling between the focal individual and conspecifics. In addition, we recorded all resting sites utilized for at least 15 min and collected standard tree characteristics. We fitted linear mixed-effects models to determine the thermoregulatory combined effect of specific resting site characteristics, huddling behaviour and environmental variables on Tsk. Our results showed that lemurs selected tree sites with larger diameter at breast height; however, huddling was most predictive of increasing Tsk whereas resting site characteristics were not included in the best-fit model. It is possible that microhabitat rest site selection is not significant in a degraded forest as the potential environmental buffering is limited; thus, thermoregulatory mechanisms are probably best served by behavioural strategies, i.e. social huddling.

Space use, movements, and rest site use by short‐tailed weasels Mustela erminea in managed forests of western Oregon

Weasels Mustela spp. are specialized, small predators which demonstrate pronounced differences in size and social status according to sex and age, and these differences may manifest in spatial patterns including home range size and habitat selection. In forested North America, favored prey (voles; Microtus spp. and Myodes spp.) of short‐tailed weasels Mustela erminea often reach high abundances in early stage forest, but availability of that cover type is limited where intensive plantation forestry occurs. We estimated home range size, including home range core area and arrangement, habitat selection, wet season rest site reuse and movements for 25 (18 M: 7 F) short‐tailed weasels Mustela erminea that we radio‐collared in managed plantation forests in western Oregon, USA in 2012–2013. Average fixed kernel 90% home range size was 51.3 hectares for males (95% confidence interval = 30.8–71.7 ha) and 8.6 hectares for females (95% confidence interval = 6.41–10.79 ha). Juvenile males had larger core areas than adult males, and all females had similar core areas. Core areas for all individuals were negatively correlated with % early stage forest cover. Females strongly selected early stage forest cover at both study area and home range scales, and males were less selective of particular cover types. Home ranges of observed males did not overlap, but partly overlapped the home ranges of females. Short‐tailed weasels reused the same rest site in 43% ± 4 (mean ± SE) of cases observed during the wet season (n = 10 individuals, 292 rest sites). We conclude that space use by short‐tailed weasels in western Oregon is influenced by sex, age, and cover type, especially availability of early stage forest, in managed conifer forests.

Environmental Impacts of Sand and Gravel Mining on Water Quality and Biodiversity in Kalak Sub-District

Nine sites were chosen, five of them were old excavation pits and the other three new excavation pits with one (un excavation pit) in the Greater Zab river. Samples were collected at nine sites for six months, from July to December 2013. Some physical and chemical parameters were analyzed at studied sites including, water and air temperature, pH, EC, turbidity, DO, BOD 5 , COD, NH 4 + , NO 2 - , NO 3 - , TDN and TDP. Sites 6, 7 and 8 tended to have higher turbidity. The lower value of dissolved oxygen recorded at site 2. The highest COD, BOD 5 , NH 4 + and TDP levels were recorded at Site 2. Site 8 had the highest value of NO 3 - , NO 2 - and TDN. The average value of the Water Quality Index based on European standard -WQI was ranged from 47% to 67%. WQI for sites 1, 3, 4, 5 and 9 fall under medium category, meanwhile, for the rest sites (sites 2, 6, 7, 8) fall under bad category. Sixty nine species of zooplankton were identified, which belonged to rotifer with fourteen families and forty four species with percentage composition of 88.17%. Rotifera forms a prominent group among the zooplankton, followed by Copepoda with one family and eleven species with percentage composition of 6.02%, then by Cladocera with four families and fourteen species with percentage composition of 5.79%. The highest density of zooplankton was obtained at site 2. According to Shanon-Weiner index, site 4 had the highest diversity. Concerning to Sorensen similarity index, the highest percentage of similarity to zooplankton community occurred between site 2 and site 4 reached to 84%.Concerning to the benthic macro –invertebrates, only three species- Limnodrilus hoffmeistern; Limnodrilus spirals; Limnodrilus claparedeianus were found. The high density of benthic invertebrate was observed at sites 1 and 2, on the other hand, zooplanktons and benthic macro –invertebrates were clearly absent at sites 6, 7, 8 and 9.

Graph theory illustrates spatial and temporal features that structure elephant rest locations and reflect risk perception

Understanding the spatial structuring of animal behaviors and how they link landscapes can be critical for conservation management. This emerging field has been greatly facilitated by technologically advanced acquisition and analysis of data on animal movements. The framework of graph theory, which directly quantifies network connectivity properties, provides a useful addition to this tool set. Using a novel application of graph theory, we investigate the structure and patterning of African elephant Loxodonta africana rest sites, a potentially critical feature structuring spatial properties of animal populations. Elephants in the study rested intermittently and for short durations (1–3 rests d–1, lasting 3–5 h total). They switched circadian rest patterns according to landscape attributes, resting more during the day and further from permanent water in areas with high human density outside protected areas. Within protected areas and during the dry season, elephants showed clustering and sequential use of rest nodes (repeated motifs). Repeated use of specific rest nodes (self‐looping) was more frequent than expected if rest nodes were chosen at random, particularly when outside protected areas further from water, indicating the importance of preferred rest sites. Our results suggest that elephants adjust resting behavior when in human‐dominated areas, using preferred resting sites presumably in locations that reduce the risk of interactions. This study demonstrates how graph theory may be used practically to gain novel insight into behaviours, such as resting, that are discrete in time and space. Furthermore, analysis of the spatial and network properties of rest sites, given an individual's susceptibility when engaged in rest behavior, allowed characterization of spatio‐temporal risk perception, providing a powerful behavioral based means to quantify the landscape of fear.

Predicting survivors: animal temperament and translocation

Translocation is an important conservation management tool. However, not all individuals are equally suited to translocation, and temperament traits (e.g., boldness, reactivity, exploration, sociability, and aggression) are likely to influence survival in a new environment. A few empirical studies have examined the consequences of personality differences on captive-bred translocated animals, but this has not been done for wild-caught animals. We compared behavioral responses to trapping, processing, holding, and release for 56 wild common brushtail possums (Trichosurus vulpecula). Twenty individuals were captured twice, once to attach radio-tracking collars, the second time (2 weeks later) for the translocation. Consistency of behavioral responses was compared between capture events and radio-tracking allowed estimates of pretranslocation home range, rest site selection, and foraging behavior. Survivors (n = 10 survivors, 5 months later) were individuals showing the most fear or emotional reactivity during holding (less likely to have slept, eaten, defecated, or nested) and those that had the smallest home ranges and selected the safest den sites in their original habitat. Conversely, the greatest increase in body mass was recorded for individuals that had demonstrated unsafe behavior in their original habitat. To our knowledge, this is the first time this type of behavioral screening during handling and holding prior to release as part of a translocation has been undertaken. These methods have broad applicability for screening potential translocation candidates and are easily translated to a range of threatened and vulnerable animal species.

Ab initio study of atomic disorder on As-rich GaAs(111)A surface

Abstract Mechanisms for the appearance of disorder on the As-rich GaAs(111)A surface were investigated employing density functional theory (DFT). Focus was given to the As trimer interactions by considering different surface symmetries and rest site occupations. The (2 × 2) and the c(4 × 2) structure models with As trimer and an As rest site were found the most energetically stable under the As-rich experimental conditions at T = 0 K. Low interactions between neighboring As trimers causes disorder in thermodynamic equilibrium at finite temperatures. A careful analysis of the configurational entropy contributions including the different statistics was carried out. The experimentally observed As-rich (2 × 2) structure was confirmed to be kinetically stabilized. The stabilization mechanism is discussed with respect to the As trimer migration on the surface, which is limited by a large diffusion barrier through the As rest sites.

Potential role of prey in the recovery of American martens to Wisconsin

The American marten (Martes americana), the only state-listed endangered mammal in Wisconsin, has undergone serial reintroductions within the state. Recovery has been slower than anticipated and the limiting factors remain unidentified. The lack of basic knowledge on marten foraging in the Great Lakes Region led us to quantify the diet of martens inhabiting the Chequamegon-Nicolet National Forest (CNNF) in northern Wisconsin using a dual approach of scat and stable isotope analyses. We collected marten scat at winter rest sites within the CNNF from 2000–2011. We identified prey items based on morphological characteristics of indigestible prey remains and calculated percent occurrence for each prey item. We sampled marten hair from museum specimens, and opportunistically from carcasses within the CNNF for isotopic analysis. We collected hair and feather samples from potential prey species in the CNNF in 2010–2013. Our concurrent analyses revealed that shrews and deer were most important to the diet of martens in Wisconsin. These findings contrast with studies conducted elsewhere that report voles as the principle diet items, and shrews as one of the least used prey items. Consequently, such a strong reliance on secondary, less profitable or high-risk prey could be contributing to the delayed recovery of martens in Wisconsin. © 2014 The Wildlife Society.

Bias in the use of broadscale vegetation data in the analysis of habitat selection

Effective conservation efforts often depend on accurate identification of habitat requirements. Studies that identify habitat requirements for animals typically investigate use of structural habitat (vegetation) instead of functional habitat (conditions for biological fitness). The spatial scale of data could bias the match between functional and structural habitat because broadscale structural habitat maps exclude small habitat patches (inclusions) and broadscale location error can bias estimates of habitat use. To investigate how spatial scale affects the match between functional and structural habitat, we backtracked American marten (Martes americana) and fisher (Pekania [formerly Martes] pennanti) movement paths during winter and compared results from selection and tortuosity analyses conducted with broadscale (4 ha) and fine-scale (0.02 ha) structural habitat data. Functional habitat (rest sites and prey kill sites) occurred disproportionately in hemlock–cedar. Finescale structural habitat data detected greater selection and tortuosity within hemlock–cedar by traveling martens, but broadscale structural habitat data did not, which demonstrates that combining fine-scale location data with fine-scale structural habitat data improves the match between functional and structural habitat and understanding of habitat requirements. Selection and tortuosity indexes were poorly correlated, indicating that factors other than structural habitat influenced movement patterns. Within-stand structural habitat heterogeneity is important to martens and fishers, especially when heterogeneity includes mature conifer inclusions within primarily deciduous forests. Broadscale data may identify structural habitat associated with required types, rather than required habitat itself, when functional habitat corresponds with landscape features such as inclusions.

Selection and spatial arrangement of rest sites within northern tamandua home ranges

AbstractThe distribution of suitable rest sites is considered to be a key determinant of spatial patterns in animal activity. However, it is not immediately evident which landscape features satisfy rest site requirements or how these sites are configured within the home range. We used Global Positioning System (GPS)/accelerometer telemetry to investigate rest site selection at the home‐range scale for northern tamanduas Tamandua mexicana on Barro Colorado Island (BCI), Panama. We developed models specifying each tamandua as the individual experimental unit and averaged coefficients to produce population‐level estimates. Tamanduas had on average 17.8 (± 8.1) rest sites within their home range and used 1.36 (± 0.51) on any given day. These rest sites tended to be located in the core of tamandua home ranges, with active locations associated with the periphery of the home range. Rest sites were positively associated with (1) a high density of Attalea butyracea palm trees; (2) elevation; (3) tall vegetation. There was a slight negative relationship between the distribution of rest sites and slope, and no apparent relationship between rest site selection and relative distance to forest canopy gaps. From focal animal observations, we identified that tamandua rest sites were typically located in trees (90%), with 25% (12 of 49) occurring in palms. We contend that northern tamanduas on BCI selected vegetated arboreal rest sites because of reduced likelihood of detection from terrestrial predators in these sites. Our models identified considerable individual variation in rest site selection, which suggests that the practice of pooling individuals and fitting models at an aggregate level may be inappropriate for certain types of habitat selection research.

Optimal location of spelling yards for the northern Australian beef supply chain

The northern Australia cattle industry is currently facing important challenges, which include increasing demand, a strong reliance on live exports, and a changing climate. This paper presents a strategic optimisation model to help the stakeholders determine the optimal location of cattle rest sites (known as spelling yards) and the optimal flows from breeding farms to ports, abattoirs and saleyards, subject to budget, site capacities and service requirements. The model also considers the operational guidelines that regulate maximum driving hours and water deprivation times. Our contribution is twofold: the model not only recommends spelling yard sites and shows that an additional abattoir can increase the value of the supply chain by over $715M, but also represents an important step towards rationalising this supply chain’s future operations by compiling a body of data that was previously unavailable for research and analysis.

Spatial analysis of limiting resources on an island: diet and shelter use reveal sites of conservation importance for the Rottnest Island quokka

Context For conservation of any species, we need baseline data that will guide conservation planning strategies. Identifying plant resources used by animal species for food and shelter is the first important step towards fauna conservation. The second step is to determine the extent and distribution of these resources and thus identify prime habitat or habitat that could be improved through suitable management actions. This information provides the necessary spatial targeting required to make the most of few resources and a shortage of time. Aims Applying this model approach, we identified plant species used as food or shelter resources by the conservationally significant quokka (Setonix brachyurus) across Rottnest Island, Western Australia in the aftermath of the hottest and driest summer on record. Methods Dietary analysis was carried out using microhistological examination of plant cuticle remains from faecal samples for 67 locations across the island. Plants acting as diurnal rest shelters (n = 73 sites) were identified through observation of individuals flushed during surveys. Identifying key resources requires both a comprehensive analysis of the current use, as well as knowledge of availability of resources to determine selectivity. We therefore compared food plants or rest sites with a comprehensive survey of floristic diversity and abundance for 210 stratified-randomly located sites across the island. Key results We identified eight plant species that quokkas fed on preferentially and identified four plant species that were the principal shelter sites. We then used hyperspectral remote sensing data to map the distribution of these plant species to quantify their distribution and identify key habitat areas. Conclusions Understanding resource limitation over the most physiologically challenging time of the year provides important information for quokka conservation. Quokkas prefer Malvaceae species as food plants, and use dense, abundant shrubs for shelter. Implications Quokkas appear to have shifted their use of food plants since a previous study (50 years ago), likely reflecting modification of island vegetation due to anthropogenic influences, fire and herbivory over time. In the face of changing climate, this information will serve as an important guide towards conservation management actions on the island (e.g. future planning of revegetation and habitat protection/enhancement).

인천연안 갯벌의 다환방향족탄화수소의 농도분포와 발생원 평가

인천연안 8개 지역 갯벌의 72개 지점의 표층퇴적물과 24개 지점의 주상퇴적물 시료를 2011년 봄 가을 2회에 걸쳐 채취하여, 다환방향족탄화수소(PAHs), 석유계총탄화수소(TPHs) 및 벤젠-톨루엔-에틸벤젠-자일렌(BTEX)의 시 공간적 농도분포 특성을 조사하였다. 또한 PAHs 화합물 구성비에 의한 오염발생기원을 평가하였다. 갯벌 전체의 PAHs 평균농도는 <TEX>$95.62{\mu}g/kg$</TEX>으로 조사되었고, 계절별 PAHs 농도분포는 가을철이 봄철보다 낮은 특징을 보였다. 주상퇴적물의 PAHs 농도가 표층퇴적물보다 높았으며, 주상퇴적물의 상부가 하부보다 높은 농도분포를 보였다. 전체 갯벌의 TPHs 평균농도는 46 mg/kg으로 조사되었고, TPHs 평균농도 분포 양상은 봄철보다 가을철이 현저하게 높고, 표층퇴적물이 주상퇴적물보다 높게 나타났다. 갯벌 퇴적물내 PAHs의 오염발생 기원을 평가한 결과, 장화리 갯벌의 표층퇴적물과 소래 및 옥련 갯벌의 주상퇴적물의 PAHs 배출원은 연소와 석유류기원으로 조사되었고, 나머지 모든 갯벌은 연소기원으로 나타났다. Samples for estimating concentrations of polycyclic aromatic hydrocargons(PAHs), total petroleum hydrocarbons(TPHs), and benzene-toluene-ethylbenzene-xylene(BTEX) were collected at the tidal flat sediments of 8 coastal sites in Incheon, at seventy-two sampling stations for the surface sediment and twenty-four stations for the sediment core, twice in the spring and fall in 2011. This study was performed to evaluate the distributions of seasonal and spatial concentrations of PAHs, TPHs, and BTEX in the tidal flat sediments. The source origin of PAHs were carried out. The total average concentration of PAHs in the tidal flat sediment was <TEX>$95.62{\mu}</TEX><TEX>g/kg$</TEX>. The characteristic of PAHs concentration distributions was observed that the average concentration in the autumn was lower than that in the spring, and higher concentration in the sediment core than the surface sediment, and greater vertical concentration at the top rather than the bottom in the sediment core. The total average concentration of TPHs at all sampling sites was in the value of 46 mg/kg. The characteristic of the TPHs concentration distribution was observed that the average concentration in the fall was much higher than that in the spring, and higher concentration in the surface sediment than the sediment core. The possible source of PAHs inputs were mainly derived from both pyrogenic and petrogenic origin at the surface sediment at Janghwari site and the sediment cores of both Sorae and Okyeon sites, while the rest sites of study areas originated with pyrogenic combustion.

Resting site selection by large herbivores – The case of European bison (Bison bonasus) in Białowieża Primeval Forest

Resting site selection by European bison (Bison bonasus, L., 1758), the largest terrestrial mammal of Europe, was studied in the free-ranging population in Białowieża Primeval Forest (Poland) in 2009–2010. In total, 104 sites of 21 bison (both collared and uncollared) were analysed to determine the most important microhabitat characteristics selected by resting bison during summer and winter and to study the influence of supplementary feeding on resting behaviour of this herbivore. Resting sites were identified on the basis of GPS locations and activity records collected by GPS collars, as well as direct observations of bison, and were compared with control sites. Microhabitat selection by bison did not differ significantly between the sexes. During summer and winter, bison resting sites displayed a high tree density, low visibility and high complexity (structures providing cover). Summer resting sites were also characterised by a significantly lower abundance of blood-sucking insects and denser canopy than control sites. Winter resting sites showed a lower complexity and higher visibility than summer sites, and were less often located in mixed forest habitats. During winter, bison rested more frequently in forest below 50 years of age than in older forest. Resting sites of non-fed bison were more often located in young coniferous forests, were lower in visibility and situated closer to open areas than sites of bison using supplementary winter feeding, suggesting a trade-off between food and cover. The results indicate that European bison select their resting sites in areas of mosaic habitat structure providing cover from disturbances with access to profitable natural forage grounds.

Hábitos alimenticios y dieta invernal de &lt;i&gt;Charadrius melodus&lt;/i&gt; (Charadriiformes: Charadriidae) en Boca Ciega, Tamaulipas, México

Charadrius melodus es una especie migratoria en peligro de extinción. Cada año, la Laguna Madre recibe aves migratorias invernales, incluyendo a la especie antes mencionada, sin embargo su estabilidad se encuentra amenazada por el cambio de hábitat ocasionado por el dragado que se está realizando en la zona. La falta de estudios sobre C. melodus durante el invierno en la Laguna Madre, motivó la realización del trabajo (diciembre 2009-marzo 2010). Los objetivos fueron: 1) determinar la importancia del área invernal, 2) describir la etología y preferencias de sustrato en la alimentación, 3) analizar ítems alimenticios potenciales y describir la diversidad simpátrica asociadas a C. melodus. Se observaron 99 individuos durante el muestreo. Las pruebas de Cochran y Kendall presentaron una alta significancia de la especie con un tipo de sustrato y las pruebas de signos utilizando una distribución binomial indicaron que existe una alta preferencia hacia un tipo de sustrato. La mayor actividad registrada durante el periodo de muestreo fue la de alimentación. Los recursos alimenticios encontrados en las muestras de sedimentos fueron larvas de Dípteros. Las especies simpátricas a C. melodus pertenecen al orden Charadriiformes con dos familias: Charadriidae nueve especies y Scolopacidae dos especies. Por la importancia de la zona, se recomienda proteger Boca Ciega, pues representa sitios de alimentación, protección y descanso para el Chorlo melódico.