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Climate change is poised to exert a significant impact on species distribution in the future, and Taxus cuspidata as an endangered species is no exception. Predicting the potential distribution of T. cuspidata is essential for decision‐makers to develop conservation policies and explicitly implement conservation measures. In this study, a combined model was employed to predict potentially suitable habitats for T. cuspidata based on extant data of T. cuspidata distributions in northeastern China. Our findings suggest that mean diurnal range (bio2) and isothermality (bio3) were identified as dominant factors influencing T. cuspidata distribution. Under future climate scenarios, suitable habitat areas increased only in the SSP126 scenario in the 2070s, declining in all other scenarios. In all climate scenarios, the centroid of suitable habitats ultimately shows a trend in northward movement. Decreases in suitable habitat predominantly occurred in Yanbian Korean Autonomous Prefecture, Baishan city, and Tonghua city. Overall, this study highlights a projected habitat reduction due to climate change. Recommendations entail the strategic establishment of nature reserves and the implementation of initiatives aimed at population replenishment. [ABSTRACT FROM AUTHOR]

Our recent study compared monitoring data collected using surrogate metrics during 2014–2018 inclusive with baseline data from 2007 to evaluate the trajectory of the population status of the threatened heath skink Liopholis multiscutata in Victoria. The heath skink is a secretive burrowing species that is a habitat specialist and exists in north‐western Victoria as a few small and highly disjunct populations on large dunes in semi‐arid heathland or mallee. We re‐assessed the trajectories of the Victorian populations with additional monitoring data collected in 2021 and found continuing decline across all four Victorian heath skink populations. Urgent management intervention is required to arrest this decline, likely due to predation, reduced availability of habitat and life history and demographic traits that make this species susceptible to decline. [ABSTRACT FROM AUTHOR]

Sea otters (Enhydra lutris kenyoni) historically occurred in Washington State, USA, until their local extinction in the early 1900s as a result of the maritime fur trade. Following their extirpation, 59 sea otters were translocated from Amchitka Island, Alaska, USA, to the coast of Washington, with 29 released at Point Grenville in 1969 and 30 released at La Push in 1970. The Washington Department of Fish and Wildlife has outlined 2 main objectives for sea otter recovery: a target population level and a target geographic distribution. Recovery criteria are based on estimates of population abundance, equilibrium abundance (K), and geographic distribution; therefore, estimates of these parameters have important management implications. We compiled available survey data for sea otters in Washington State since their translocation (1977–2019) and fit a Bayesian state‐space model to estimate past and current abundance, and equilibrium abundance at multiple spatial scales. We then used forward projections of population dynamics to explore potential scenarios of range recolonization and as the basis of a sensitivity analysis to evaluate the relative influence of movement behavior, frontal wave speed, intrinsic growth, and equilibrium density on future population recovery potential. Our model improves upon previous analyses of sea otter population dynamics in Washington by partitioning and quantifying sources of estimation error to estimate population dynamics, by providing robust estimates of K, and by simulating long‐term population growth and range expansion under a range of realistic parameter values. Our model resulted in predictions of population abundance that closely matched observed counts. At the range‐wide scale, the population size in our model increased from an average of 21 independent sea otters (95% CI = 13–29) in 1977 to 2,336 independent sea otters (95% CI = 1,467–3,359) in 2019. The average estimated annual growth rate was 12.42% and varied at a sub‐regional scale from 6.42–14.92%. The overall estimated mean K density of sea otters in Washington was 1.71 ± 0.90 (SD) independent sea otters/km2 of habitat (1.96 ± 1.04 sea otters/km2, including pups), and estimated densities within the current range correspond on average to 87% of mean sub‐regional equilibrium values (range = 66–111%). The projected value of K for all of Washington was 5,287 independent sea otters (95% CI = 2,488–8,086) and 6,080 sea otters including pups (95% CI = 2,861–9,300), assuming a similar range of equilibrium densities in currently un‐occupied habitats. Sensitivity analysis of simulations of sea otter population growth and range expansion suggested that mean K density estimates in currently occupied sub‐regions had the largest impact on predicted future population growth (r2 = 0.52), followed by the rate of southward range expansion (r2 = 0.26) and the mean K density estimate of currently unoccupied sub‐regions to the south of the current range (r2 = 0.04). Our estimates of abundance and sensitivity analysis of simulations of future population abundance and geographic range help determine population status in relation to population recovery targets and identify the most influential parameters affecting future population growth and range expansion for sea otters in Washington State. [ABSTRACT FROM AUTHOR]

In the past, sturgeons played an important role in commercial and recreational fisheries in the Danube River and its tributaries. Human impacts in the Danube River Basin coupled with exploitation of sturgeon stocks led to all species being either locally extinct, critically endangered or of unknown status.Sterlet (Acipenser ruthenus, Linnaeus 1758) is the last known sturgeon species occurring in the upper and middle Danube; however, the population of this species is considered unbalanced and decreasing since the beginning of the twenty‐first century.The decline of sturgeon stocks has been noted before owing to their economic importance. With commercial fisheries being forbidden in the Slovak section of the Danube River, there is generally no information available about the status of what is considered a local population.Databases containing recreational catch of sterlet (2003–2018) and historical records of commercial harvest (1961–1990) were used to describe the trend in the weight and number of sterlet caught over the following years.Modelling indicated that the number of fish caught each year appears to be lower, while the average weight of each individual is increasing. This might suggest that the population is ageing.Although older individuals can contribute a great deal more to spawning because they produce a greater number of eggs, several problems are apparent. The number of spawners might be decreasing as a result of bycatch or fishing, their ability to spawn might be obstructed, or annual recruitment may fail owing to unpredictable events.Although restocking programmes are in place to help maintain the sterlet population in the Danube River, their efficiency seems to be drastically low. In fact, restocking could be of little value unless studies on the availability of key habitats are conducted and their protection and restoration are ensured. [ABSTRACT FROM AUTHOR]

Aim: The introduction of aquatic non‐indigenous species (ANS) has become a major driver for global changes in species biogeography. We examined spatial patterns and temporal trends of ANS detections since 1965 to inform conservation policy and management. Location: Global. Methods: We assembled an extensive dataset of first records of detection of ANS (1965–2015) across 49 aquatic ecosystems, including the (a) year of first collection, (b) population status and (c) potential pathway(s) of introduction. Data were analysed at global and regional levels to assess patterns of detection rate, richness and transport pathways. Results: An annual mean of 43 (±16 SD) primary detections of ANS occurred—one new detection every 8.4 days for 50 years. The global rate of detections was relatively stable during 1965–1995, but increased rapidly after this time, peaking at roughly 66 primary detections per year during 2005–2010 and then declining marginally. Detection rates were variable within and across regions through time. Arthropods, molluscs and fishes were the most frequently reported ANS. Most ANS were likely introduced as stowaways in ships' ballast water or biofouling, although direct evidence is typically absent. Main conclusions: This synthesis highlights the magnitude of recent ANS detections, yet almost certainly represents an underestimate as many ANS go unreported due to limited search effort and diminishing taxonomic expertise. Temporal rates of detection are also confounded by reporting lags, likely contributing to the lower detection rate observed in recent years. There is a critical need to implement standardized, repeated methods across regions and taxa to improve the quality of global‐scale comparisons and sustain core measures over longer time‐scales. It will be fundamental to fill in knowledge gaps given that invasion data representing broad regions of the world's oceans are not yet readily available and to maintain knowledge pipelines for adaptive management. [ABSTRACT FROM AUTHOR]

Trout and charr, members of the salmonid family, have high conservation value but are also susceptible to anthropogenic threats in part due to the specificity of their habitat requirements. Understanding historical and future threats facing these species is necessary to promote their recovery. Of freshwater trout and charr in the Canadian Rocky Mountain region, westslope cutthroat trout (Oncorhynchus clarkii lewisi), bull trout (Salvelinus confluentus; a charr species) and Athabasca rainbow trout (Oncorhynchus mykiss) are of conservation concern. And indeed, range contractions and declining populations are evident throughout much of their ranges. Range contraction was most evident in the southern Alberta designatable unit (DU) of westslope cutthroat trout. Diminished populations were also evident in the downstream watersheds of the Alberta bull trout range, and throughout the Athabasca rainbow trout range. We assessed historical and future threats to evaluate the relative importance of individual threats to each DU and compare their impact among species. Individual threats fall into the broad categories of angling, non‐native species and genes, habitat loss and alteration, and climate change. Severity of each threat varies by DU and reflects the interaction between species' biology and the location of the DU. Severity of threats facing each DU has changed over time, reflecting extirpation of native populations, changes in management and industry best practices, expansion of non‐native species and progressing climate change. The overall threat impact for each DU indicates a high probability of substantial and continuing declines and calls for immediate action. [ABSTRACT FROM AUTHOR]

Threatened species that exist in small isolated populations are vulnerable to extinction processes, so effectively monitoring the trajectory of such populations will help determine the most appropriate management actions to combat extinction threats. In this study, we aimed to track the population status of the fossorial heath skink Liopholis multiscutata that is listed as threatened in Victoria, south‐eastern Australia, and exists there as a few small and highly disjunct populations, by using an appropriate surrogate population monitoring metric. This secretive lizard is a habitat specialist, is highly localised in Victoria and lives in warrens in semi‐arid heathland or mallee on large dunes. Survey data, which included every warren and their constituent burrows, as well as an assessment of whether each burrow was 'active', were collected for the four known Victorian populations in 2007 and annually during 2014–2018 inclusive. We compared five population indices per monitoring site: number of active warrens (NAW), number of active burrows (NAB), population area for 80% of active warrens (PA80), percentage of warrens that were active (PAW) and average number of active burrows per active warren. The heath skink currently occurs in small populations (8–46 active warrens) and these populations have typically declined over recent years. NAW was the most robust metric; NAB and PA80 did not reveal strong temporal trends. PAW indicated that inactive warrens and burrows persist less than a year and hence may provide information about recent (within months) population changes. It is imperative to establish a material link between the effective monitoring of small, vulnerable populations and the implementation of management actions that benefit such populations. Here, NAW could be used as a long‐term monitoring tool to provide an estimate of the minimum population size of the heath skink at a site. Its use would also ensure continuity in monitoring approaches for the Victorian populations. [ABSTRACT FROM AUTHOR]

Whitespotted conger (Conger myriaster) is a marine migratory species with important economic and ecological values in Northwestern Pacific. The population status and distribution of whitespotted conger may have changed in the eastern coastal water of China owing to the intensive fishing pressure and human activities in the past few decades. There have been miscellaneous concerns about its population trend and potential environment‐driven variations in spatiotemporal distribution. Delta‐generalized linear models, generalized linear mixed models, and a set of correlation analyses were performed to answer the above concerns, and a stratified random sampling‐designed bottom trawl survey from 2011 to 2017 in Haizhou Bay of the central Yellow Sea was conducted to collect samples. Our study suggested that whitespotted conger remained a relatively stable population status with slight fluctuations likely caused by climate variability during 2011–2017. The hierarchical generalized linear mixed models with spatial random effect performed better than the generalized linear model and the common generalized linear mixed models. Spatiotemporal differences of whitespotted conger were significantly associated with bottom water salinity, depth, sampling time, and space, which were probably mainly influenced by a combination of the Cold Water Mass, the Yellow Sea Warm Current, and the Yellow Sea Coastal Current. The predicted spatiotemporal distribution of whitespotted conger has a monthly variation matching its seasonable migration and an overall higher abundance in the deeper water than that in the neritic areas in Haizhou Bay. [ABSTRACT FROM AUTHOR]

Habitat characteristics are primary determinants of nearshore marine communities. However, biological drivers like predation can also be important for community composition. Sea otters (Enhydra lutris ssp.) are a salient example of a keystone species exerting top‐down control on ecosystem community structure. The translocation and subsequent population growth and range expansion of the northern sea otter (Enhydra lutris kenyoni) in Washington State over the last five decades has created a spatio‐temporal gradient in sea otter occupation time and density, and acts as a natural experiment to quantify how sea otter population status and habitat type influence sea otter diet. We collected focal observations of sea otters foraging at sites across the gradient in varying habitat types between 2010 and 2017. We quantified sea otter diet composition and diversity, and long‐term rates of energy gain across the gradient. We found that sea otter diet diversity was positively correlated with cumulative sea otter density, while rate of energy gain was negatively correlated with cumulative density. Additionally, we found that habitat type explained 1.77 times more variance in sea otter diet composition than sea otter cumulative density. Long‐term diet studies can provide a broader picture of sea otter population status in Washington State. [ABSTRACT FROM AUTHOR]

ABSTRACT: The California sea lion (Zalophus californianus) population in the United States has increased steadily since the early 1970s. The Marine Mammal Protection Act of 1972 (MMPA) established criteria for management of marine mammals based on the concept of managing populations within the optimal sustainable population (OSP), defined as a range of abundance from the maximum net productivity level (MNPL) to carrying capacity (K). Recent declines in California sea lion pup production and survival suggest that the population may have stopped growing, but the status of the population relative to OSP and MNPL is unknown. We used a time series of pup counts from 1975 to 2014 and a time series of mark‐release‐resight‐recovery data from 1987 to 2015 for survival estimates to numerically reconstruct the population and evaluate the current population status relative to OSP using a generalized logistic model. We demonstrated that the population size in 2014 was above MNPL and within its OSP range. However, we also showed that population growth can be dramatically decreased by increasing sea surface temperature associated with El Niño events or similar regional ocean temperature anomalies. In this analysis we developed a critical tool for management of California sea lions that provides a better understanding of the population dynamics and a scientific foundation upon which to base management decisions related to complex resource issues involving this species. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

The present study reports the population of Macaca munzala in Tawang and West Kameng districts and its predictive distribution range in Arunachal Pradesh, estimated using ecological niche modeling. Environmental variables and occurrence data from a preliminary survey were used in the MaxEnt modeling, a statistical model to know the potential distribution area of the enigmatic species in Arunachal Pradesh. Later, a population survey was carried out in Tawang and West Kameng districts of the state following existing trails and paths. The distribution model revealed that only 2.4% of the total landmass of the state is potential distribution habitat range for M. munzala, whereas 10.19% of the total area of the two districts were shown to be potential habitat of the species. A total number of 971 individuals (including two solitary males) comprising 41 troops of M. munzala were recorded during the population survey. The mean troop size was 23.63 ± 1.21 individuals per troop ranging from 12 to 44 individuals. On average, M. munzala troops were comprised of juveniles (30.37%), adult females (23.83%), infants (18.22%), adult males (11.53%), sub-adult females (9.81%), and sub-adult males (6.23%). Our observed population size of M. munzala is higher in Tawang and West Kameng districts when compared with the earlier available records. This study showed the potential distribution of M. munzala based on environmental variables and the present population status in Tawang and West Kameng districts of Arunachal Pradesh, India. [ABSTRACT FROM AUTHOR]

In the Southern Ocean, wide-ranging predators offer the opportunity to quantify how animals respond to differences in the environment because their behavior and population trends are an integrated signal of prevailing conditions within multiple marine habitats. Southern elephant seals in particular, can provide useful insights due to their circumpolar distribution, their long and distant migrations and their performance of extended bouts of deep diving. Furthermore, across their range, elephant seal populations have very different population trends. In this study, we present a data set from the International Polar Year project; Marine Mammals Exploring the Oceans Pole to Pole for southern elephant seals, in which a large number of instruments ( N = 287) deployed on animals, encompassing a broad circum-Antarctic geographic extent, collected in situ ocean data and at-sea foraging metrics that explicitly link foraging behavior and habitat structure in time and space. Broadly speaking, the seals foraged in two habitats, the relatively shallow waters of the Antarctic continental shelf and the Kerguelen Plateau and deep open water regions. Animals of both sexes were more likely to exhibit area-restricted search ( ARS) behavior rather than transit in shelf habitats. While Antarctic shelf waters can be regarded as prime habitat for both sexes, female seals tend to move northwards with the advance of sea ice in the late autumn or early winter. The water masses used by the seals also influenced their behavioral mode, with female ARS behavior being most likely in modified Circumpolar Deepwater or northerly Modified Shelf Water, both of which tend to be associated with the outer reaches of the Antarctic Continental Shelf. The combined effects of (1) the differing habitat quality, (2) differing responses to encroaching ice as the winter progresses among colonies, (3) differing distances between breeding and haul-out sites and high quality habitats, and (4) differing long-term regional trends in sea ice extent can explain the differing population trends observed among elephant seal colonies. [ABSTRACT FROM AUTHOR]

This study is a quantitative evaluation of historic nesting levels of the Kemp's ridley sea turtle (Lepidochelys kempii) in 1947 based on (1) the Herrera film of a 1947 arribada, (2) Hildebrand's 1947 report regarding the 1947 arribada shown in the Herrera film, (3) historic documentation regarding the Herrera film, and (4) current nesting characteristics related to arribada size relative to total nests for a season. Using this information in a quantitative approach, we estimate a total of approximately 26 916 nests during the 1947 arribada recorded by Herrera. Based on current nesting trends, we also predict that this would equate to approximately 121 517 total nests for the 1947 season (range of 82 514–209 953), which would represent approximately 48 607 nesting females (range of 33 006–83 981). This suggests that during and prior to the 1947 nesting season a relatively robust population of Kemp's ridleys existed, which could support arribadas consisting of at least 26 916 females. The results of the current study indicate that from 1947 through 1985 (the lowest point in the decline of Kemp's ridley nesting) the Kemp's ridley population underwent a 99.4% decline (range of 99.2–99.7%) from an estimated 121 517 nests per season in 1947 to 702 nests per season in 1985. Although the Kemp's ridley population has been recovering since the 1985 season, it has deviated from its exponential recovery rate and has declined in recent years. The current levels of nesting (12 053 nests in 2014) are still relatively low at 9.9% (range of 5.7–14.6%) of the total estimated nests that occurred in 1947. It is currently not clear whether this population will recover to historic levels considering recent nesting trends and due to a variety of threats that may hinder its recovery. [ABSTRACT FROM AUTHOR]

Poyang Lake is the largest freshwater lake in China and flows into the Yangtze River. It is a traditional habitat for the endangered Yangtze finless porpoise, which has not been well investigated. To reveal the distribution of the porpoise in Poyang Lake, 12 passive acoustic surveys were conducted along 123 km of the main channel of the lake during different seasons (spring transition season, wet season, autumn transition season, and dry season) from 2008 to 2012. We counted the number of phonating porpoises encountered and calculated the detection rate (encountered individuals detected per kilometer). The median porpoise detection rates ranged from 0 to 0.65 individuals per kilometer during the different surveys. The highest median detection rate of 0.50 was detected in the autumn transition season. The seasonal shrinking of the lake during the dry season may cause a concentration of porpoises in the narrow channels and a high incidence of collisions with cargo ships and fishing boats. Conservation actions should be focused on the main channel of the lake during the dry and transition seasons. In addition, the expansion of the existing reserve to include areas with high porpoise detection rates is necessary. [ABSTRACT FROM AUTHOR]

ABSTRACT Activity time budgets in apex predators have been proposed as indicators of population status relative to resource limitation or carrying capacity. We used archival time-depth recorders implanted in 15 adult female and 4 male sea otters ( Enhydra lutris) from the northernmost population of the species, Prince William Sound, Alaska, USA, to examine temporal patterns in their foraging behavior. Sea otters that we sampled spent less time foraging during summer (females 8.8 hr/day, males 7.9 hr/day) than other seasons (females 10.1-10.5 hr/day, males 9.2-9.5 hr/day). Both sexes showed strong preferences for diurnal foraging and adjusted their foraging effort in response to the amount of available daylight. One exception to this diurnal foraging mode occurred after females gave birth. For approximately 3 weeks post-partum, females switched to nocturnal foraging, possibly in an effort to reduce the risk of predation by eagles on newborn pups. We used multilevel mixed regression models to assess the contribution of several biological and environmental covariates to variation in the daily foraging effort of parous females. In the random effects only model, 87% of the total variation in foraging effort was within-otter variation. The relatively small among-otter variance component (13%) indicates substantial consistency in the foraging effort of sea otters in this northern population. In the top 3 models, 17% of the within-otter variation was explained by reproductive stage, day length, wind speed, air temperature and a wind speed × air temperature interaction. This study demonstrates the potential importance of environmental and reproductive effects when using activity budgets to assess population status relative to carrying capacity. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

In the north-west Atlantic Ocean, stock assessments conducted for some commercially harvested coastal sharks indicate declines from 64 to 80% with respect to virgin population levels. While the status of commercially important species is available, abundance trend information for other coastal shark species in the north-west Atlantic Ocean are unavailable. Using a generalized linear modelling (GLM) approach, a relative abundance index was derived from 1994 to 2009 using observer data collected in a commercial bottom longline fishery. Trends in abundance and average size were estimated for bull shark Carcharhinus leucas, spinner shark Carcharhinus brevipinna, tiger shark Galeocerdo cuvier and lemon shark Negaprion brevirostris. Increases in relative abundance for all shark species ranged from 14% for C. brevipinna, 12% for C. leucas, 6% for N. brevirostris and 3% for G. cuvier. There was no significant change in the size at capture over the time period considered for all species. While the status of shark populations should not be based exclusively on abundance trend information, but ultimately on stock assessment models, results from this study provide some cause for optimism on the status of these coastal shark species. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the population status of leatherback nests in Florida. The study uses a multilevel Poisson regression to know the rate of growth for leatherback turtle nest numbers and to recognize the hierarchical structure of the data while integrating variables related to survey report. Results show that marine food web dynamics and climate variability which could improve productivity and decrease predators may served as the driving factors of the said trend.

General consensus among scientists, commercial interests, and the public regarding the status of shark populations is leading to an increasing need for the scientific community to provide information to help guide effective management and conservation actions. Experience from other marine vertebrate taxa suggests that public, political, and media pressures will play an increasingly important part in setting research, management, and conservation priorities. We examined the potential implications of nonscientific influences on shark research. In particular, we considered whether lethal research sampling of sharks is justified. Although lethal sampling comes at a cost to a population, especially for threatened species, the conservation benefits from well-designed studies provide essential data that cannot be collected currently in any other way. Methods that enable nonlethal collection of life-history data on sharks are being developed (e.g., use of blood samples to detect maturity), but in the near future they will not provide widespread or significant benefits. Development of these techniques needs to continue, as does the way in which scientists coordinate their use of material collected during lethal sampling. For almost half of the known shark species there are insufficient data to determine their population status; thus, there is an ongoing need for further collection of scientific data to ensure all shark populations have a future. Shark populations will benefit most when decisions about the use of lethal sampling are made on the basis of scientific evidence that is free from individual, political, public, and media pressures. [ABSTRACT FROM AUTHOR]

The Bohor reedbucks Redunca redunca (Pallas, 1767) were studied in the Bale Mountains National Park (BMNP), Ethiopia to assess their population ecology and activity patterns. The total count method was used to assess population size. Activity patterns of a herd were studied with five minutes recording intervals. There were 406 Bohor reedbucks in the study area of which 96.8% (n = 393) was confined to the Gaysay-Adelay area. The population was female-biased. Excluding juveniles, 57.1% (n = 232) was females and 33.5% (n = 136) was males. More adults (71.7%, n = 291) were observed than sub-adults (18.9%, n = 77) and juveniles (9.4%, n = 38). The herd size of Bohor reedbucks varied from 3 to 5. Herds were seen in aggregations of up to 59 individuals during the dry season in swamp grassland habitat. The maximum number observed in such aggregations during the wet season was 38. The diurnal activity pattern showed feeding peaks early in the morning and late in the afternoon, with resting during the mid-day. Two feeding peaks were observed in the nocturnal activity phase: one during dusk and the other around midnight. In contradiction to the general concept of occurrence of smaller herds during the dry season, the Bohor reedbucks aggregate in swamps during the dry season. They were also active during night and day time. [ABSTRACT FROM AUTHOR]

Lynx (Lynx canadensis) occur in the northern counties of Washington state, USA; however, current distribution and status of lynx in Washington is poorly understood. During winters 2002-2004 we snow-tracked lynx for 155 km within a 211-km² area in northern Washington, to develop a model of lynx-habitat relationships that we could use to assess their potential distribution and status in the state. We recorded movements and behaviors of lynx with a Global Positioning System and overlaid digitized lynx trails on various habitat layers using a Geographic Information System. Based on univariate analyses, lynx preferred Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) forests, with moderate canopy and understory cover, and elevations ranging from 1,525 m to 1,829 m but avoided Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) forests, openings, recent burns, open canopy and understory cover, and steep slopes. A map of suitable lynx habitat based on a logistic regression model built using these candidate variables revealed that habitats at elevations >1,400 m where lynx historically occurred in Washington are intersected and fragmented by landscape features and forest conditions that are generally avoided by lynx. Our habitat suitability map predicts 3,800 km² of lynx habitat in Washington that could support 87 lynx, far fewer than previous estimates. Since 1985, natural fires have burned >1,000 km² of forested habitat in Okanogan County, the only region in Washington where lynx occurrence has been documented during that period. Loss of suitable habitat from natural and human-caused disturbances, and the lack of verifiable evidence of lynx occurrence in historic lynx range, suggests that fragmented landscape conditions may have impeded recolonization of these areas by lynx. Consequently, translocations may be necessary to ensure lynx persistence in Washington. We suggest that managers assess the potential for translocation by first identifying the scale and distribution of potential foraging habitats for lynx based on our or similar habitat models, survey various habitat conditions to obtain reliable estimates of snowshoe hare densities, and identify a genetically compatible source population of lynx. If habitat and source populations are adequate, reintroducing lynx to areas of their historic range may be an appropriate conservation strategy. [ABSTRACT FROM AUTHOR]

We describe a method to convert continuously collected time-depth data from archival time-depth recorders (TDRs) into activity budgets for a benthic-foraging marine mammal. We used data from 14 TDRs to estimate activity-specific time budgets in sea otters (Enhydra lutris) residing near Cross Sound, southeast Alaska, USA. From the TDRs we constructed a continuous record of behavior for each individual over 39-46 days during summer of 1999. Behaviors were classified as foraging (diving to the bottom), other diving (traveling, grooming, interacting), and nondiving (assumed resting). The overall average activity budget (proportion of 24-hr/d) was 0.37 foraging (8.9 hr/d), 0.11 in other diving (2.6 hr/d), and 0.52 nondiving time (12.5 hr/d). We detected significant differences in activity budgets among individuals and between groups within our sample. Historically, the sea otter population in our study area had been expanding and sequentially reoccupying vacant habitat since their reintroduction to the area in the 1960s, and our study animals resided in 2 adjacent yet distinct locations. Males (n = 5) and individuals residing in recently occupied habitat (n = 4) spent 0.28-0.30 of their time foraging (6.7-7.2 hr/d), 0.17-0.18 of their time in other diving behaviors (4.1-4.3 hr/d), and 0.53-0.54 of their time resting (12.7-13.0 hr/d). In contrast, females (n = 9) and individuals residing in longer occupied habitat (n = 10) spent 0.40 of their time foraging (9.6 hr/d), 0.08-0.09 of their time in other diving behaviors (1.9-2.2 hr/d), and 0.51-0.52 of their time resting (12.2-12.5 hr/d). Consistent with these differences, sea otters residing in more recently occupied habitat captured more and larger clams (Saxidomus spp., Protothaca spp., Macoma spp., Mya spp., Clinocardium spp.) and other prey, and intertidal clams were more abundant and larger in this area. We found that TDRs provided data useful for measuring activity time budgets and behavior patterns in a diving mammal over long and continuous time periods. Fortuitous contrasts in time budgets between areas where our study animals resided suggest that activity time budgets estimated from TDRs may be a sensitive indicator of population status, particularly in relation to prey availability. [ABSTRACT FROM AUTHOR]

We estimated the number of live Australian fur seal pups using capture-mark-resights, direct ground counts, or aerial photography at all breeding sites following the pupping season of November-December 2002. Pups were recorded at 17 locations; nine previously known colony sites, one newly recognized colony and seven haul-out sites where pups are occasionally born. In order of size, the colonies were Lady Julia Percy Island (5,899 pups), Seal Rocks (4,882), The Skerries (2,486), Judgment Rocks (2,427), Kanowna Island (2,301), Moriarty Rocks (1,007), Reid Rocks (384), West Moncoeur Island (257), and Tenth Island (124). The newly recognized site was Rag Island, in the Cliffy Group, where we recorded 30 pups. We also recorded pups at the following haul-out sites: Cape Bridgewater (7 pups), Bull Rock (7), Wright Rock (5), Twin Islet (1), The Friars (1), Ile des Phoques (1), and Montague Island (1). In total, we estimate there were 19,819 (SE = 163) live pups at the time of the counts, We discuss trends in pup numbers and derive current population estimates for the Australian fur seal. [ABSTRACT FROM AUTHOR]

Complete population estimates for widely distributed species are rarely possible. However, for the third time in 10 years, an International Piping Plover (Charadrius melodus) Breeding and Winter Census was conducted throughout the species range in 2001. Nearly 1,400 participants from 32 U.S. states and Puerto Rico; 9 Canadian provinces; St. Pierre and Miquelon, France; Cuba; and the Bahamas visited 2,244 sites covering 11,836 km of shoreline habitat. During the winter census, 2,389 piping plovers were observed at 33.5% of potentially occupied sites (n = 352). Of these, 56.8% had ≤10 birds present. The breeding census recorded 5,945 adults at 777 of 1,892 sites surveyed. More than 80% of sites with piping plovers present had ≤10 birds. Results indicated an 8.4% increase from 1991 but only a 0.2% increase since 1996. Regional trends suggest that since 1991, number of breeding birds increased on the Atlantic Coast by 78% (2,920 birds; 12.4% increase since 1996) and by 80% in the Great Lakes (72 birds; 50% increase since 1996). However, plovers declined 15% (2,953 birds; 10% decline since 1996) in Prairie Canada/U.S. northern Great Plains. Subregional trends since 1991 reflect a 32.4% decline in Prairie Canada (972 birds; 42.4% decline since 1996), a 2.5% decline in the U.S. northern Great Plains (1,981 birds; 24% increase since 1996), 5.5% decline in eastern Canada (481 birds; 14% increase since 1996), although a 66.2% increase on the U.S. Atlantic Coast (2,430 birds; 12% since 1996). While numbers were down in much of the U.S. northern Great Plains since 1996, an increase (460%, 1,048 birds; 67.7% increase since 1991) was detected on the Missouri River. Results from 3 complete species census efforts provide essential data for conservation planning and assessment and illustrate the utility of global censuses for species of concern. [ABSTRACT FROM AUTHOR]

1. Information on the abundance of European pinnipeds is required to assess interactions with fisheries and to meet new conservation obligations under the European Community (EC) Habitats Directive. A detailed time-series of data has documented increases in grey seal populations, but there remains considerable uncertainty over the current status of UK harbour seal populations. 2. We present data on changes in the abundance of harbour seals in a study area within Orkney, Scotland, UK, previously considered a stronghold for this species. In 1998, intensive shore-based counts of both adults and pups were only 16-36% of similar counts made between 1984 and 1987. Furthermore, a significant reduction in the proportion of yearlings present in haul-out groups indicated a reduction in local recruitment. 3. Current monitoring of UK harbour seals, using wider-scale aerial survey techniques, has provided important estimates of site distribution and relative abundance at regional and national scales. However, these larger-scale surveys lack associated data on within-year variation in counts at particular sites. Consequently, they cannot currently be used to explore the spatial scale of the changes in seal numbers that we report here. Similarly, current data from wider-scale monitoring cannot be used to determine whether observed local changes in abundance result from redistribution or a change in survival or reproduction. 4. Management and monitoring plans are currently being developed for special areas of conservation (SAC) for harbour seals in response to the EC Habitats Directive. We suggest that more intensive research is required to assess whether or not similar changes in the abundance and age structure of seals have occurred in these areas. Without a better understanding of the current status of harbour seals both within and outside proposed SAC, future efforts to monitor the effectiveness of management initiatives will be constrained. [ABSTRACT FROM AUTHOR]