Habitat Usage Research Articles

Habitat Selection By Bristle-Thighed Curlews (Numenius tahitiensis) Breeding Within The Southern Nulato Hills, Alaska

ABSTRACT Bristle-thighed Curlews (Numenius tahitiensis, hereafter ‘curlews') breed only on low Arctic tundra in the southern Nulato Hills of the Yukon Delta National Wildlife Refuge (NWR) and on the Seward Peninsula, Alaska. Curlews use several distinct habitat types on the breeding grounds; however, quantified data of habitat use by curlews exist only for the Seward Peninsula. We investigated which available habitats on the breeding grounds were used most often by curlews in the Nulato Hills and compared availability with use to determine habitat selection using a land cover layer created in ArcGIS based on aerial photography and ground referenced locations. We also compared curlew habitat usage at our study site to habitats used on the Seward Peninsula. We used vegetation quadrats to determine plant composition within each habitat. We also determined percentage of habitat and plant composition within curlew territories. Curlews preferred shrub meadow tundra which consisted primarily of lichens (>50%), m...

Spatial and temporal patterns in the calling behavior of beluga whales, Delphinapterus leucas, in Cook Inlet, Alaska

AbstractCook Inlet beluga whales (CIBs) are an endangered population residing in Cook Inlet, Alaska. We characterized the calling behavior of CIBs to improve our understanding of sounds produced by this population. Bottom‐moored hydrophones were deployed at Eagle Bay in summer 2009 and at Trading Bay in summer and winter 2009. CIB sounds were qualitatively analyzed and categorized as a whistle, pulsed call, or click train. A total of 4,097 calls were analyzed, and 66 unique whistle contours were identified. Whistles were quantitatively analyzed using a custom Matlab program. A chi‐square test showed the call category usage at Eagle Bay during summer 2009 and those at Trading Bay during summer 2009 and winter 2009–2010 differed significantly (P < 0.001). Pulsed calls were more common during summer months, and click trains within the frequency band (12.5 kHz) were more common in Eagle Bay. The variation in calling behavior suggests differences in habitat usage or in the surrounding environment, including background noise. With the proposed development projects in Cook Inlet and the potential increase in ambient noise level due to ocean acidification, it is important to understand how this endangered population uses sound, and what anthropogenic factors may influence that use.

Yaban domuzu (Sus scrofa L.) üzerine ekolojik gözlemler ve tür habitat ilişkilerinin tespiti: Isparta-Gölcük Tabiat Parkı örneği

This study, which aims to determine the population, ecology of wild boar and habitat relations spreading in the Isparta Golcuk Nature Park, conducted between the years of 2011-2012. The study is carried out in three stages such as preliminary study, population inventory and habitat preferences. In order to determine the usage of habitat and habitat preference, Presence or Absence Method was applied. According to the statistical analysis based on the results of counting’s in totally 106 lines and in 2655 plots, and the relative frequency, showed that the wild boar uses 17 different habitat types, such as 10% the most of black pine forest, 10% cedar forest, and with decreasing rates the other forests. The positive substantive results of Multivariation and Chi-Square Test Analysis increased the importance of cedar wood. When the seasonal preference of the wild boar was analyzed, it was observed that it prefers black locust forests and agricultural fields during summer, and in the aspect preference, shadowy fields which change according to the day hours rather than South aspects. Keywords: Golcuk Nature Park, Wild boar, Habitat preference

Seasonal and environmental influences on recruitment patterns and habitat usage among resident and transient fishes in a World Heritage Site subtropical estuary.

This study investigated whether the fish communities inhabiting shallow non-vegetated habitats in two divergent bays in a subtropical World Heritage Site estuarine system differed according to wet (spring-summer) and dry (autumn-winter) seasons or polyhaline and mesohaline zones, within the broader objective of facilitating spatio-temporal management. Species richness (total of 74 taxa; total length, LT = 11-552 mm) and abundance (51 109 individuals) were mostly greater in the wet than dry season and in polyhaline than mesohaline areas. There was a major effect of rainfall on recruitment, particularly among transient fishes, which could be the result of enhanced survival of young via greater productivity (food resources) and protection from predators (via turbidity reducing visual cues). Salinity had strong interactive effects with rainfall and temperature in one bay, with greater species richness and overall abundances as well as large abundances of four key species [Anchoa januaria and Atherinella brasiliensis (pelagic residents), Cetengraulis edentulus (pelagic transient) and Diapterus rhombeus (demersal transient)] during the wet season in polyhaline areas; possibly reflecting a biodiversity hotspot that might be affected by distance to the estuary mouth and convergence hydrology. Regionally, the results support enforcing spatio-temporal restrictions to minimize anthropogenic activities within statutory (but not always enforced) protected areas. Globally, the data reiterate the need to identify and understand biotic and abiotic effects on estuarine ichthyofaunal distributions and abundances as a precursor to their management.

Can intensified forestry be responsible for changes in habitat usage by the forest-dwelling Black Stork?

Populations of the internationally protected Black Stork Ciconia nigra in the northern parts of the distribution range, located to the east of the Baltic Sea, have suffered decline over recent decades. Since early 1990s, however, logging intensity has increased. In this paper, considering a ten-year period from the mid-1990s, we ask: (a) Did changes occur in the habitat preferred by Black Stork in the decade? (b) did the decade of intensified forestry significantly change forest characteristics? and (c) could the intensified forestry explain any observed changes in the utilization of habitat by storks? We compared forest characteristics at the beginning and end of this period at 75 random points and compared the habitat at 75 nest sites occupied by the Black Stork in the mid-1990s and 75 occupied nest sites at the end of the 2000s. In the 0.7-km zones around the random points, the abundance of mature stands decreased between the mid-1990s and the end of the 2000s, as did the abundance of broadleaved trees, but black alders increased. Nevertheless, the age and composition of tree species within the stands around the random points remained similar. Some changes were noted though in the habitat around nests used by Black Storks during two periods, with the data indicating that the Black Storks tended to occupy sites of better habitat quality (e.g. with a higher density of hydrological network and old oak trees, older nest stands) at the end of the 2000s than in the mid-1990s. Our results, however, do not support the idea that intensified forestry over the short term induced changes in the habitat used by the Black Storks. It is possible that nesting Black Storks became concentrated into the prime habitat when population retracted and/or abandoned habitat where recently recovered by the White-tailed Eagle.

An experimental demonstration of the impact of predation on sexual segregation and primary sex ratios among ungulates

AbstractUnderlying mechanisms of sexual segregation among ungulates, and Trivers and Willard's hypothesis that mothers can influence primary sex ratios, continue to be topical theoretical issues. Over 2 years, using monthly repeated road transects, we determined the habitat and social segregation of male vs. female impala (Aepyceros melampus) and kudu (Tragelaphus strepsiceros) in a predator‐free, vs. a predator‐laden, South African reserve. We also determined, by the same technique but over 4 years, the primary sex ratio of the impala population free from predation. Significant overlap in habitat usage (Schoener's Index 0.63–0.8) was found between the two sexes when free from predation, but not (Schoener's Index 0.46–0.47) when under predation. While occupying the same habitats impala, kudu and wildebeest (Connochaetes taurinus) male and female groups maintained rigid social segregation throughout the year, even when at close quarters. Impala primary sex ratios were significantly biased towards females (male/female = 0.72; χ² = 4.3175, d.f. = 1, P‐value = 0.038) in the absence of predation. Our findings suggest that while risk of predation is a proximal cause of sexual segregation, thus lending support to the predator‐risk hypothesis, the underlying, functional mechanism of sexual segregation is the difference in the activity budgets of males vs. females (the activity‐budget hypothesis). Our findings also suggest that mothers may indeed be able to adjust primary sex ratios, with the postulated driver in this case being an abnormally high density of adult males.

Basin‐scale methods for predicting salmonid spawning habitat via grain size and riffle spacing, tested in a California coastal drainage

AbstractBasin‐scale predictive geomorphic models for river characteristics, particularly grain size, can aid in salmonid habitat identification. However, these basin‐scale methods are largely untested with actual habitat usage data. Here, we develop and test an approach for predicting grain size distributions from high resolution LiDAR (Light Detection and Ranging)‐derived topographic data for a 77 km2 watershed along the central California Coast. This approach improves on previous efforts in that it predicts the full grain size distribution and incorporates an empirically calibrated shear stress partitioning factor. The predicted grain size distributions are used to calculate the fraction of the bed area movable by spawning fish. We then compare the ‘movable fraction’ with 7 years of observed spawning data. We find that predicted movable fraction explains the paucity of spawning in the upper reaches of the study drainage, but does not explain variation along the mainstem. In search of another morphologic characteristic that may help explain the variation within the mainstem, we measure riffle density, a proxy for physical habitat complexity. We find that field surveys of riffle density explain 64% of the variation in spawning in these mainstem reaches, suggesting that within reaches of appropriate sized gravel, spawning density is related to riffle density. Because riffle density varies systematically with channel width, predicting riffle spacing is straightforward with LiDAR data. Taken together, these findings demonstrate the efficacy of basin‐scale spawning habitat predictions made using high‐resolution digital elevation models. Copyright © 2016 John Wiley & Sons, Ltd.

Feels like home: homing of mature large-bodied fish following translocation from a power-station canal

Fish translocation is a common method of conservation and fisheries enhancement. Monitoring post-translocation movements and migration provides useful information to inform translocation strategies. Three species of large-bodied fish (Yellowfin Bream Acanthopagrus australis, Luderick Girella tricuspidata, and Tarwhine Rhabdosargus sarba) impounded in a cooling water canal at a power station were translocated into the adjacent estuary (Lake Macquarie, New South Wales). Translocated fish were tagged with acoustic tags (n = 34) equipped with accelerometer sensors (providing a relative measure of fish activity) and released on either an artificial reef or a natural reef. In addition, 8 free-ranging Yellowfin Bream were captured and tagged on the artificial reef. Fish were tracked throughout Lake Macquarie on a dispersed array of 18 VemcoVR2W receivers, and on the artificial reef using a VR4-UWM Vemco Positioning System, for up to 11 months. Yellowfin Bream and Luderick rapidly migrated back to the power station, whereas Tarwhine remained near the release location. Translocated Yellowfin Bream showed divergent behavioural patterns to free-ranging Yellowfin Bream on the artificial reef, with much higher activity levels, elevated nocturnal activity, and different patterns of habitat usage, possibly reflecting divergent foraging behaviour. This study presents a rare example of non-natal homing to an artificial habitat in several large-bodied marine fish species. The role of low frequency sound in the homing of translocated fish, and factors contributing to the observed behavioural patterns are discussed. The presence of a homing signal which can facilitate return migration may decrease the efficacy of translocation efforts for adult marine fishes; however, these responses are species-specific and will require evaluation on a case-by-case basis.

Anemonefish musical chairs and the plight of the two-band anemonefish, Amphiprion bicinctus

Anemonefishes’ obligatory mutualism with sea anemones dictates their occurrence in marine habitats. We examined whether the spatial distribution, number, and size of the host anemones Heteractis crispa and Entacmaea quadricolor affected the settlement, habitat usage, and survival of the two-band anemonefish, Amphiprion bicinctus. In a 200 × 50 m study site off the coast of Israel in the Gulf of Eilat, we followed the fish and anemone populations initially in 13 censuses from October 1996 to August 1997 and follow-up censuses from 1998 to 2015. Based on size, anemonefish were categorized as adults, juveniles, or settlers. Settlers tended to cluster together but displayed significantly dispersed distributions in relation to adult individual fish and breeding pairs. Adult and juvenile anemonefish associated more with, and exhibited higher survival in, E. quadricolor. Settlers primarily inhabited H. crispa, with similar survival rates in the two anemone species. H. crispa was less occupied compared to E. quadricolor, but 95 % of the 233 anemones hosted fish during at least one census. From 1997 to 2015, anemone and anemonefish numbers plummeted by 86 % and 74 %, respectively. In 2015, all 27 remaining anemones were occupied, with most E. quadricolor inhabited by adults. The anemones left at the study site, on average, hosted more fish per anemone than those in the original population. This saturated habitat could hinder new anemonefish individuals from settling. These results indicate that if the anemone population does not recover, the anemonefish could face local extinction.

Inferring Evolution of Habitat Usage and Body Size in Endangered, Seasonal Cynopoeciline Killifishes from the South American Atlantic Forest through an Integrative Approach (Cyprinodontiformes: Rivulidae).

Cynopoecilines comprise a diversified clade of small killifishes occurring in the Atlantic Forest, one of the most endangered biodiversity hotspots in the world. They are found in temporary pools of savannah-like and dense forest habitats, and most of them are highly threatened with extinction if not already extinct. The greatest gap in our knowledge of cynopoecilines stems from the absence of an integrative approach incorporating molecular phylogenetic data of species still found in their habitats with phylogenetic data taken from the rare and possibly extinct species without accessible molecular information. An integrative analysis combining 115 morphological characters with a multigene dataset of 2,108 bp comprising three nuclear loci (GLYT1, ENC1, Rho), provided a robust phylogeny of cynopoeciline killifishes, which was herein used to attain an accurate phylogenetic placement of nearly extinct species. The analysis indicates that the most recent common ancestor of the Cynopoecilini lived in open vegetation habitats of the Atlantic Forest of eastern Brazil and was a miniature species, reaching between 25 and 28 mm of standard length. The rare cases of cynopoecilines specialized in inhabiting pools within dense forests are interpreted as derived from four independent evolutionary events. Shifts in habitat usage and biogeographic patterns are tentatively associated to Cenozoic paleogeographic events, but the evolutionary history of cynopoecilines may be partially lost by a combination of poor past sampling and recent habitat decline. A sharp evolutionary shift directed to increased body size in a clade encompassing the genera Campellolebias and Cynopoecilus may be related to a parallel acquisition of an internally-fertilizing reproductive strategy, unique among aplocheiloid killifishes. This study reinforces the importance of adding morphological information to molecular databases as a tool to understand the biological complexity of organisms under intense pressure from loss of habitat.

Consistency of trematode infection prevalence in host populations across large spatial and temporal scales.

Parasites can impart heavy fitness costs on their hosts. Thus, understanding the spatial and temporal consistency in parasite pressure can elucidate the likeliness of parasites' role as agents of directional selection, as well as revealing variable environmental factors associated with infection risk. We examined spatiotemporal variation in digenetic trematode infection in 18 populations of an intertidal host snail (Littorina littorea) over a 300km range at an 11-yr interval, more than double the generation time of the snail. Despite a complete turnover in the snail host population, the average change in infection prevalence among populations was <1% over the 11-yr span, and all but three populations remained within 5 percentage points. This consistency of prevalence in each population over time suggests remarkable spatiotemporal constancy in parasite delivery vectors in this system, notably gulls that serve as definitive hosts for the parasites. Thus, despite gulls' high mobility, their habitat usage patterns are ostensibly relatively fixed in space. Importantly, this spatiotemporal consistency also implies that sites where parasites are recruitment limited remain so over time, and likewise, that parasite hotspots stay hot.

Habitat Use and its Implications for the Conservation of the Overwintering Populations of Bean GooseAnser fabalisand Greater White-Fronted GooseA. albifronsin South Korea

Abstract The Korean peninsula is geographically important for the migration of geese. Several thousand geese visit South Korea every winter, but currently it is unclear which habitats are preferred by the geese. Understanding patterns of habitat usage is important for establishing conservation strategies, as some habitats may be disappearing more rapidly than others making it critical to know whether or not a disappearing habitat is crucial to certain birds. In this study, we investigated the habitat use of the wintering populations of Bean Goose Anser fabalis and Greater White-fronted Goose A. albifrons. We found that the wintering populations of these two geese species in South Korea have stabilized after sudden increases during the mid and late 2000s. Both species formed larger wintering populations at coastal lakes, on reclaimed lands, and at estuaries than on freshwater habitats, which may be related to the availability and/or diversity of food items. Considering that environmental changes resulting ...

The Cryptic Bombus lucorum Complex (Hymenoptera: Apidae) in Austria: Phylogeny, Distribution, Habitat Usage and a Climatic Characterization Based on COI Sequence Data.

Silas Bossert, Barbara-Amina Gereben-Krenn, Johann Neumayer, Bernhard Schneller, and Harald W. Krenn (2016) The Bombus lucorum complex represents a group of three distinct but cryptic bumblebee species in Europe. With the advent of DNA-based identification methods, their species status was confirmed and the use of COI barcoding proved to be an especially useful tool for species identification within the group. Meanwhile, the identification based on morphology remains difficult and recent studies challenged the general distinguishability by revealing an important character to be unreliable. This has consequences for our understanding of the distribution and ecology of the species in Europe and aggravates our patchy knowledge of the situation in Austria and the whole area of the European Alps. In this study, we investigate the exact species composition and distribution of the Bombus lucorum complex in Austria based on the reliable species identification with COI sequence data. The habitat usage is studied and the first extensive investigation of altitudinal and climatic differentiation is provided. The results support three distinct genotypic groups in the Bombus lucorum complex. B. lucorum and B. cryptarum co-occur in several areas across the country, with B. lucorum being the most common and most widespread species. The study provides no evidence for the presence of B. magnus in Austria. The less common species, B. cryptarum, mainly occurs in the high mountains and is the predominant species of the complex above altitudes of 2100 m a.s.l. Further, B. cryptarum is almost absent from woodlands and is relatively more abundant in habitats with colder climate than B. lucorum in Austria. Additionally, the results indicate a very low intraspecific genetic variation within B. lucorum and B. cryptarum. This study confirms previous findings of three distinct species within the species complex. Based on reliable COI identification, the first coherent overview of the species complex in Austria can be achieved. The climatic data allows us to explain the differences in the distribution patterns. Moreover, the low intraspecific variation may indicate past bottleneck conditions for B. lucorum and B. cryptarum.

Nine decades of fish movement research in southern Africa: a synthesis of research and findings from 1928 to 2014

Unprecedented concern over the biological effects of over-exploitation, together with rapid technological advances in biotelemetry, have provided the impetus for much research, on a global scale, into the movement of marine animals. We reviewed 101 marine and estuarine fish movement studies from southern Africa, published from 1928 to 2014, with the aim of synthesising research trends and findings. Trends showed an increasing emphasis on fish movement research in publications in the sub-tropical and warm-temperate biogeographic regions along the south and east coasts of southern Africa. Although 63 % of publications featured only marine studies, research into fine-scale habitat use in estuaries has been on the increase, concomitant with increasing accessibility of biotelemetry. Overall, 26 families were identified in the surveyed literature with regionally endemic sparids featuring in 32 % of the publications. Ten movement themes were identified in the surveyed literature, including broad-scale movement patterns, which featured in 68 % of studies, followed by fine-scale habitat usage (33 %) and protected areas (26 %). The most prominent phenomenon, emerging from this research, is that of partial migration, which describes the occurrence of resident and migratory behaviour within a coexisting animal population. Substantial progress has also been made in unravelling the complexities of fine-scale habitat usage in marine reserves and in estuaries. While this knowledge has enabled more effective management of South Africa’s multi-user, multi-species fisheries, focus should now be directed at improving our understanding of the commonalities in movement behaviour, the associated driving forces behind this behaviour and the nature of movement across reserve boundaries.

Using individual tracking data to validate the predictions of species distribution models

AbstractAimEstimating environmental suitability from species distribution data is crucial in defining spatial conservation measures. To this end, species distribution models (SDMs) are commonly applied, but seldom validated by completely independent data. Here, we use data on individual tracks derived from electronic tags as an alternative means of validating SDM outputs.LocationWest coast of Scotland, NE Atlantic.MethodsWe used a binomial generalized additive model (GAM) to predict the environmental suitability for flapper skate (Dipturus cf. intermedia) in Scottish waters. The GAM modelled relative habitat usage as a function of environmental variables using presence–absence data obtained from scientific trawl surveys. Additional data obtained from electronic tags attached to six individual flapper skates were used to estimate individual tracks using a tidal‐based geolocation model. Concordance between individual tracks and GAM‐predicted maps of relative habitat usage (RHU) was tested by comparing predicted RHU between estimated tracks and randomly generated tracks.ResultsEnvironmental suitability for the flapper skate was driven by depth and distance from the coast in the SDM. We found high spatial concordance between the estimated tracks of the six tagged individuals and regions of high RHU predicted by the SDM.Main conclusionsIntegrating outputs from an independent data source allowed us to validate predictions from a species distribution model (SDM). The integration of individual‐ and population‐level data sources increases confidence in the outputs being used to define spatial conservation measures. The information on flapper skate distribution provided by this study provides a useful framework for considering spatial conservation measures for this species.

Global spatial ecology of three closely-related gadfly petrels.

The conservation status and taxonomy of the three gadfly petrels that breed in Macaronesia is still discussed partly due to the scarce information on their spatial ecology. Using geolocator and capture-mark-recapture data, we examined phenology, natal philopatry and breeding-site fidelity, year-round distribution, habitat usage and at-sea activity of the three closely-related gadfly petrels that breed in Macaronesia: Zino’s petrel Pterodroma madeira, Desertas petrel P. deserta and Cape Verde petrel P. feae. All P. feae remained around the breeding area during their non-breeding season, whereas P. madeira and P. deserta dispersed far from their colony, migrating either to the Cape Verde region, further south to equatorial waters in the central Atlantic, or to the Brazil Current. The three taxa displayed a clear allochrony in timing of breeding. Habitat modelling and at-sea activity patterns highlighted similar environmental preferences and foraging behaviours of the three taxa. Finally, no chick or adult was recaptured away from its natal site and survival estimates were relatively high at all study sites, indicating strong philopatry and breeding-site fidelity for the three taxa. The combination of high philopatry, marked breeding asynchrony and substantial spatio-temporal segregation of their year-round distribution suggest very limited gene flow among the three taxa.

Juvenile winter flounder (Pseudopleuronectes americanus) and summer flounder (Paralichthys dentatus) utilization of Southern New England nurseries: Comparisons among estuarine, tidal river, and coastal lagoon shallow-water habitats.

This study evaluated the relative importance of the N arragansett Bay estuary (RI and MA, USA), and associated tidal rivers and coastal lagoons, as nurseries for juvenile winter flounder, Pseudopleuronectes americanus, and summer flounder, Paralichthys dentatus. Winter flounder (WF) and summer flounder (SF) abundance and growth were measured from May to October (2009-2013) and served as indicators for the use and quality of shallow-water habitats (water depth < 1.5-3.0 m). These bioindicators were then analyzed with respect to physiochemical conditions to determine the mechanisms underlying intra-specific habitat selection. WF and SF abundances were greatest in late May and June (maximum monthly mean = 4.9 and 0.55 flounder/m2 for WF and SF, respectively), and were significantly higher in the tidal rivers relative to the bay and lagoons. Habitat-related patterns in WF and SF abundance were primarily governed by their preferences for oligohaline (0.1-5 ppt) and mesohaline (6-18 ppt) waters, but also their respective avoidance of hypoxic conditions (< 4 mg DO/L) and warm water temperatures (> 25 °C). Flounder habitat usage was also positively related to sediment organic content, which may be due to these substrates having sufficiently high prey densities. WF growth rates (mean = 0.25 ± 0.14 mm/d) were negatively correlated with the abundance of conspecifics, whereas SF growth (mean = 1.39 ± 0.46 mm/d) was positively related to temperature and salinity. Also, contrary to expectations, flounder occupied habitats that offered no ostensible advantage in intra-specific growth rates. WF and SF exposed to low salinities in certain rivers likely experienced increased osmoregulatory costs, thereby reducing energy for somatic growth. Low-salinity habitats, however, may benefit flounder by providing refugia from predation or reduced competition with other estuarine fishes and macro-invertebrates. Examining WF and SF abundance and growth across each species' broader geographic distribution revealed that southern New England habitats may constitute functionally significant nurseries. These results also indicated that juvenile SF have a geographic range extending further north than previously recognized.

Mangrove fish of São Tomé Island (Gulf of Guinea): new occurrences and habitat usage

Mangroves are recognised as important nursery and feeding areas for resident and inshore fish species. However, the importance of West African mangroves to the life cycle of fish communities remains poorly studied. The present study is the first record of fish species in tropical insular mangroves for this region and its aim was to assess habitat usage by fish species. Two mangroves of São Tomé Island (Praia das Conchas and Malanza) were sampled with a multihabitat approach and using different fishing gear to maximise the diversity of fish species collected. Several environmental parameters were also measured. Both mangroves are nursery and opportunistic feeding grounds for fish species, as well as settlement areas for resident species. The highest number of both juveniles and adults (inshore and residents) was observed at the Malanza mangrove, which is also the largest and has the highest habitat heterogeneity. Four new occurrences were reported for the São Tomé and Principe area, namely Pomadasys jubelini, Bostrychus africanus, Dalophis cephalopeltis and the introduced species Oreochromis mossambicus.

Ecological influences on the local movement dynamics of the blackspotted topminnow, Fundulus olivaceus

Movement of individuals throughout a landscape is fundamental to a wide array of ecological processes; however, the interacting spatiotemporal effects of environmental influences on movement remain poorly understood. Using a series of mesocosm trials, we examined relationships between local abiotic and biotic variables and movement patterns of the blackspotted topminnow, Fundulus olivaceus, using passive integrated transponder (PIT) tags. In one series of trials, we assessed the influence of local population factors (density, sex ratio) and phenotypic variables (growth, condition) on movement rates across seasons (spawning, nonspawning). Movement was strongly influenced by different factors seasonally, and movement rates were approximately 7.5 times higher in the spawning season compared to nonspawning periods. Males moved more than females and movement was greater in low-density treatments; however, these patterns persisted only during the spawning period. In a second series of trials, we examined abiotic (habitat complexity) and biotic (predator; Micropterus punctulatus) influences on the movement dynamics and habitat usage of F. olivaceus. Predators were found to suppress movement; however, this response was ameliorated by the presence of habitat structure. Movement rates of F. olivaceus were negatively related to predator movement and individuals showed a higher propensity to group in the presence of the predator. The predator induced shifts in habitat usage, as individuals utilized the shallower habitat at a greater frequency and for longer durations compared to trials without a predator. Taken together, our results suggest local environmental variables may strongly influence spatiotemporal movement behaviors of F. olivaceus.

Assessing range-wide habitat suitability for the Lesser Prairie-Chicken

Population declines of many wildlife species have been linked to habitat loss incurred through land-use change. Incorporation of conservation planning into development planning may mitigate these impacts. The threatened Lesser Prairie- Chicken (Tympanuchus pallidicinctus) is experiencing loss of native habitat and high levels of energy development across its multijurisdictional range. Our goal was to explore relationships of the species occurrence with landscape characteristics and anthropogenic effects influencing its distribution through evaluation of habitat suitability associated with one particular habitat usage, lekking. Lekking has been relatively well-surveyed, though not consistently, in all jurisdictions. All five states in which Lesser Prairie-Chickens occur cooperated in development of a Maxent habitat suitability model. We created two models, one with state as a factor and one without state. When state was included it was the most important predictor, followed by percent of land cover consisting of known or suspected used vegetation classes within a 5000 m area around a lek. Without state, land cover was the most important predictor of relative habitat suitability for leks. Among the anthropogenic predictors, landscape condition, a measure of human impact integrated across several factors, was most important, ranking third in importance without state. These results quantify the relative suitability of the landscape within the current occupied range of Lesser Prairie-Chickens. These models, combined with other landscape information, form the basis of a habitat assessment tool that can be used to guide siting of development projects and targeting of areas for conservation.