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Scutellastra mexicana is the largest species of giant limpet in the world. This species is distributed along the tropical Mexican Pacific and is now considered extinct in some areas of the region. In prehispanic Mexico, this limpet was used for food, ornamentation, and in mortuary offerings. More recently, its meat has been highly valued for human consumption. During the 1970s and 1980s, overexploitation of this resource caused the population to decrease drastically. This study is a report on the population status of the giant Mexican limpet S. mexicana on the Mexican Pacific coast. Free divers explored the rocky southern coast of Jalisco, Mexico, for the presence of specimens. A total of 404 limpets were identified at 18 sampling sites. Their density was estimated to be 0.0012 limpets/m² with a catch per unit effort of 7.6 limpets/dive hour. Limpet sizes ranged from 5.0 to 23.3 cm in length and from 3.8 to 20.7 cm in width, with a mean shell length of 13.4 cm. Currently, S. mexicana is under special protection by Mexican laws. However, this species is not listed as endangered by any international wildlife protection and conservation group. This may be due to the lack of information on this species' population dynamics over time in the Mexican Pacific and the lack of interest in this mollusc since it is a non‐charismatic species.

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 trans-port 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 rel-atively 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 detec-tion 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 fundamen-tal 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. Fil: Bailey, Sarah A.. Great Lakes Laboratory For Fisheries And Aquatic Scienc; Canadá Fil: Brown, Lyndsay. Marine Scotland Science; Reino Unido Fil: Campbell, Marnie L.. Deakin University; Australia Fil: Canning-Clode, João. Marine And Environmental Sciences Centre; Portugal Fil: Carlton, James T.. Williams College. Maritime Studies Program; Estados Unidos Fil: Castro, Nuno. Marine And Environmental Sciences Centre; Portugal Fil: Chainho, Paula. Marine And Environmental Sciences Centre; Portugal Fil: Chan, Farrah T.. Great Lakes Institute For Enviromental Research; Canadá Fil: Creed, Joel C.. Universidade do Estado de Rio do Janeiro; Brasil Fil: Curd, Amelia. Ifremer Institut Francais de Recherche Pour L'exploitation de la Mer; Francia Fil: Darling, John. United States Environmental Protection Agency; Estados Unidos Fil: Fofonoff, Paul. Smithsonian Environmental Research Ctr; Estados Unidos Fil: Galil, Bella S.. The Steinhardt Museum Of Natural History; Israel Fil: Hewitt, Chad L.. Murdoch University; Australia Fil: Inglis, Graeme J.. National Institute Of Water & Atmospheric Research Lt; Nueva Zelanda Fil: Keith, Inti. Charles Darwin Foundation; Ecuador Fil: Mandrak, Nicholas E.. University Of Toronto Scarborough; Canadá Fil: Marchini, Agnese. University of Pavia; Italia Fil: McKenzie, Cynthia H.. Fisheries And Ocean Canada. Northwest Atlantic Fisheries Centre; Canadá Fil: Occhipinti‐Ambrogi, Anna. University of Pavia; Italia Fil: Ojaveer, Henn. University of Tartu; Estonia Fil: Pires‐Teixeira, Larissa M.. Universidad de Lisboa; Portugal. Universidade do Estado do Rio de Janeiro; Brasil Fil: Robinson, Tamara B.. Stellenbosch University; Sudáfrica Fil: Ruiz, Gregory M.. United States Environmental Protection Agency; Estados Unidos Fil: Seaward, Kimberley. National Institute of Water & Atmospheric Research Ltd.; Nueva Zelanda Fil: Schwindt, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Son, Mikhail O.. Institute of Marine Biology; Ucrania Fil: Therriault, Thomas W.. Pacific Biological Station; Canadá Fil: Zhan, Aibin. Chinese Academy of Sciences; República de China

The fate of bycatch species released back into the water is crucial to estimate population status and consequent decisions to implement adequate management measurements for elasmobranchs. The shortnose guitarfish, Zapteryx brevirostris, is an endemic species of the Southwest Atlantic. It is currently listed as ‘Vulnerable’ both in the International Union for Conservation of Nature and Brazilian red lists. Although this species displays high tolerance to capture and transportation by fishers from the capture site to the fish market, a significant reduction in survival rates is observed during the reproductive period. Thus, the aim of the present study was to examine post-capture and post-commercial transportation consequences in pregnant females obtained as bycatch from artisanal fisheries in Southern Brazil. Results showed high abortion rates and reduced maternal survival after abortion, with all abortions occurring within 28 h of monitoring in laboratory. Stress plasma markers were also evaluated, to determine the physiological consequences of capture-induced parturition to pregnant females. Results showed alteration in all markers measured (plasma urea, pH, lactate, phosphorus, and potassium) with values for dead pregnant females being different from non-pregnant females and those which survived capture and subsequent abortions. The mortality caused by fisheries bycatch may prove difficult to manage, with immediate release and specific handling protocols for pregnant females implemented through environmental education environmental education and fishermen training programs, potential options to maintain adequate maternal survival and recruitment for this species. Fil: Wosnick, N.. Universidade Federal do Paraná; Brasil Fil: Awruch, Cynthia Andrea. University of Tasmania; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Adams, K. R.. University Of Wollongong; Australia Fil: Gutierre, S. M. M.. Universidade Federal do Paraná; Brasil Fil: Bornatowski, H.. Universidade Federal do Paraná; Brasil Fil: Prado, A. C.. Universidade Federal do Paraná; Brasil Fil: Freire, C. A.. Universidade Federal do Paraná; Brasil

Understanding and conserving migratory species requires a method for characterizing the seasonal flow of animals among habitats. Source-sink theory describes the metapopulation dynamics of species by classifying habitats as population sources (i.e. net contributors) or sinks (i.e. net substractors). Migratory species may have non-breeding habitats important to the species (e.g. overwintering or stopover habitats) that traditional source-sink theory would classify as sinks because these habitats produce no individuals. Conversely, existing migratory network models can evaluate the relative contribution of non-breeding nodes, but these models make an equilibrium assumption that is difficult to meet when examining real migratory populations. We extend a pathway-based metric allowing breeding habitats, non-breeding habitats and migratory pathways connecting these habitats to be classified as sources or sinks. Rather than being based on whether place- or season-specific births exceed deaths, our approach quantifies the total demographic contribution from a node or migratory pathway over a flexibly defined yet limited time period across an organism's life cycle. As such, it provides a snapshot of a migratory system and therefore does not require assumptions associated with equilibrium dynamics. We first develop a generalizable mathematical notation and then demonstrate how the metric may be used with two case studies: the common loon (Gavia immer) and Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri). These examples highlight how stressors can impact stopover and wintering habitats (loons) and habitat management targeting migratory pathways can improve population status (trout). Synthesis and applications. Each of the two case studies presented describes how effects at one location are felt by populations in another through the seasonal flow of individuals. The contribution metric we present should be helpful in allocating regulatory and management attention to times and locations most critical to migratory species persistence.

One in 6 species (13,465 species) on the International Union for Conservation of Nature (IUCN) Red List is classified as data deficient due to lack of information on their taxonomy, population status, or impact of threats. Despite the chance that many are at high risk of extinction, data-deficient species are typically excluded from global and local conservation priorities, as well as funding schemes. The number of data-deficient species will greatly increase as the IUCN Red List becomes more inclusive of poorly known and speciose groups. A strategic approach is urgently needed to enhance the conservation value of data-deficient assessments. To develop this, we reviewed 2879 data-deficient assessments in 6 animal groups and identified 8 main justifications for assigning data-deficient status (type series, few records, old records, uncertain provenance, uncertain population status or distribution, uncertain threats, taxonomic uncertainty, and new species). Assigning a consistent set of justification tags (i.e., consistent assignment to assessment justifications) to species classified as data deficient is a simple way to achieve more strategic assessments. Such tags would clarify the causes of data deficiency; facilitate the prediction of extinction risk; facilitate comparisons of data deficiency among taxonomic groups; and help prioritize species for reassessment. With renewed efforts, it could be straightforward to prevent thousands of data-deficient species slipping unnoticed toward extinction.

It is unlikely all male sage-grouse are detected during lek counts, which could complicate the use of lek counts as an index to population abundance. Understanding factors that influence detection probabilities will allow managers to more accurately estimate the number of males present on leks. We fitted 410 males with global positioning system and very high frequency transmitters, and uniquely identifiable leg-bands over 4 years in Carbon County, Wyoming. We counted male sage-grouse using commonly used lek-count protocols and evaluated variables associated with our ability to detect marked males using sightability surveys on 22 leks. We evaluated detection probabilities of male sage-grouse based on factors related to bird characteristics such as age or posture, lek and group size, lek characteristics such as vegetation cover or aspect, light conditions, weather, and observer. We then applied the detection probabilities to more accurately estimate male counts on leks. Detection probabilities were generally high ( = 0.87) but varied among leks from 0.77 to 0.93. Male sage-grouse detection declined with increasing sagebrush height and bare ground and increased with more snow cover. Detection probabilities were also lower when observers counted from a higher elevation than the lek. Our sightability models predicted detection well and can be used to accurately estimate male abundance on leks from lek counts, which is especially useful where accurate abundance estimates are required or inference about population status is based on only 1 count. Further, it is important to consider lek attendance as a component of counts on leks because it affects availability of male sage-grouse for detection during lek counts. Detection can be maximized by conducting lek counts from 30 minutes before sunrise to 30 minutes after sunrise, although current protocols recommend lek counts can be performed up to 1 hour after sunrise. Detection can also be maximized by conducting lek counts ≥2 days after snowfall, which maximizes attendance and detection. © 2015 The Wildlife Society.

Surveys based on nonrandom site selection, or convenience samples, are often a necessary part of large-scale monitoring programs to help minimize costs. The reliability of convenience samples to inform managers about distributions or population status of imperiled species is questionable, however, because the samples may not be representative of the whole population. We compared fish community data from 20 nonrandom, long-term monitoring sites for Rio Grande Silvery Minnow Hybognathus amarus with those from 20 randomly chosen samples collected during two surveys (one in summer, one in autumn) in the Rio Grande, New Mexico. We compared the species richness, community composition, and the catch per unit effort (CPUE). Fish species compositions, which were similar between both sets of summer and autumn surveys, were nearly identical in the autumn surveys. Similarly, we found consistent Rio Grande Silvery Minnow CPUE between surveys; summer random surveys estimated 0.32 fish/100 m2 sampled, whereas su...

Mean and maximum sizes in the catch are readily understood by both fishermen and scientists as important indicators of population health, but the maximum is more complicated to interpret because it increases with the number of observations. Size distributions of catches were computed for stable age distributions of hypothetical Atlantic populations of Blue Marlin Makaira nigricans. Fishing mortality rates were selected that reduced the population per age-1 recruit by 25, 50, 67, 75, and 90% by number from the unfished state. A new metric, NZ50, was applied to evaluate the performance of maximum size as an indicator of population status. Sample sizes required to include large marlin in a set of observations increased to disproportionately large numbers with increased fishing. With the best estimates of growth and a natural mortality of 0.1, the number of random observations required for a 50% probability of including a 350-cm individual increased by about 43% when the population was depressed by 25...

The Brook Trout Salvelinus fontinalis is an important species of conservation concern in the eastern USA. We developed a model to predict Brook Trout population status within individual stream reaches throughout the species’ native range in the eastern USA. We utilized hierarchical logistic regression with Bayesian estimation to predict Brook Trout occurrence probability, and we allowed slopes and intercepts to vary among ecological drainage units (EDUs). Model performance was similar for 7,327 training samples and 1,832 validation samples based on the area under the receiver operating curve (∼0.78) and Cohen's kappa statistic (0.44). Predicted water temperature had a strong negative effect on Brook Trout occurrence probability at the stream reach scale and was also negatively associated with the EDU average probability of Brook Trout occurrence (i.e., EDU-specific intercepts). The effect of soil permeability was positive but decreased as EDU mean soil permeability increased. Brook Trout were less...

This study considered whether different population viability analyses give similar estimates of extinction risk across management contexts. We compared the performance of population viability analyses developed by numerous scientific teams to estimate extinction risk of anadromous Pacific salmonids listed under the U.S. Endangered Species Act and challenged each analysis with data from 34 populations. We found variation in estimated extinction risk among analytical techniques, which was driven by varying model assumptions and the inherent uncertainty of risk forecasts. This result indicates that the scientific teams developed techniques that perform differently. We recommend that managers minimize uncertainty in risk estimates by using multiple models tailored to the local ecology. Assessment of relative extinction risk was less sensitive to model assumptions than was assessment of absolute extinction risk. Thus, the former method is better for comparing population status and raises caution about...

In Alberta, Canada, number of cougar (Puma concolor) mortalities caused by humans has increased rapidly over the past 2 decades. Management agencies sometimes use human-caused mortalities as an index of cougar population trend, which would indicate an increasing cougar population in Alberta, but mortalities may be decoupled from cougar numbers. Some authors suggest that higher human-caused cougar mortalities (primarily due to sport hunting) are causing cougar populations in North America to decline. We used the distribution of human-caused cougar mortalities in Alberta to evaluate change in cougar populations during 1991–2010, a period over which human-caused cougar mortality increased rapidly. We provide evidence that cougars have expanded their range in northern and eastern Alberta in tandem with increasing sport hunting and other sources of human-caused mortality. © 2013 The Wildlife Society.

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.

Mountain lions (Puma concolor) are often difficult to monitor because of their low capture probabilities, extensive movements, and large territories. Methods for estimating the abundance of this species are needed to assess population status, determine harvest levels, evaluate the impacts of management actions on populations, and derive conservation and management strategies. Traditional mark-recapture methods do not explicitly account for differences in individual capture probabilities due to the spatial distribution of individuals in relation to survey effort (or trap locations). However, recent advances in the analysis of capture-recapture data have produced methods estimating abundance and density of animals from spatially explicit capture-recapture data that account for heterogeneity in capture probabilities due to the spatial organization of individuals and traps. We adapt recently developed spatial capture-recapture models to estimate density and abundance of mountain lions in western Montana. Volunteers and state agency personnel collected mountain lion DNA samples in portions of the Blackfoot drainage (7,908 km2) in westcentral Montana using 2 methods: snow back-tracking mountain lion tracks to collect hair samples and biopsy darting treed mountain lions to obtain tissue samples. Overall, we recorded 72 individual capture events, including captures both with and without tissue sample collection and hair samples resulting in the identification of 50 individual mountain lions (30 females, 19 males, and 1 unknown sex individual).

Populations of landbirds (bird species that occupy terrestrial habitats for most of their life cycle) are declining throughout North America (north of Mexico) and Europe, yet little is known about how demography is driving this trend. A recent model of 5 geographically separated populations of Cerulean Warblers (Dendroica cerulea) that was based on within-season sampling of nest survival and fledgling success shows that all populations are sinks (annual reproduction is consistently less than annual adult mortality). I tested this indirect model by directly measuring fecundity (number of female fledglings/female) during the breeding season for 2 years in a Cerulean Warbler population occupying a mature forest in southwestern Michigan (U.S.A.) I determined territories of male birds on the basis of male plumage characters and phases of the nesting cycle (2007) and on uniquely color-banded males (2008). I transferred locations of identified males to topographic maps. I counted all fledglings in territories from May to July each year. The model I tested may apply only to single-brooded species; therefore, I searched the literature to estimate the percentage of single-brooded species in North America. The breeding season of Cerulean Warblers was short— nearly all nests were initiated from mid-May to late June. Nest predation and brood parasitism were primary and rare causes of nest failure, respectively. Significantly fewer Cerulean Warblers fledged from parasitized than from nonparasitized nests. Fledgling survival required to maintain the population size was well above previously published values for Neotropical migrants. Single-brooded species comprise 62% of North American breeding bird species for which the number of broods per year is known; I believe my results may apply to these species. The consistency between identification of populations as sources or sinks on the basis of either model estimates or direct measurements suggests that a demographic model relying on within-season sampling of fecundity is adequate to determine population status of single-brooded avian populations. In addition, on the basis of results of previous studies, annual adult survival rate of the Cerulean Warbler is typical of parulid warblers that are not declining. Thus, low fecundity, here determined with different quantitative methods, can drive status of landbird species with high-observed survival. Resumen: Las poblaciones de aves terrestres (especies de aves que ocupan habitats terrestres durante la mayor parte de su ciclo de vida) estan declinando en Norte America (al norte de Mexico) y Europa, pero se conoce poco la manera en que la demografia esta dirigiendo esta tendencia. Un modelo reciente de 5 poblaciones de Dendorica caerulea separadas geograficamente basado en muestreos de supervivencia de nidos y exito de volantones muestra que todas las poblaciones son sumideros (la reproduccion anual es consistentemente menor a la mortalidad anual de adultos). Probeeste modelo indirecto mediante la medicion directa de la fecundidad (numero de volantones hembra/hembra) durante la epoca de reproduccion durante 2 anos en una poblacion de D. caerulea en un bosque maduro en el suroeste de Michigan (E.U.A.). Determine los territorios de machos con base en caracteristicas del plumaje de machos y etapas del ciclo de nidificacion en (2007) y en machos con anillos de colores (2008). Transferi las localidades de machos identificados a mapas topograficos. Conte todos los volantones en territorios en mayo-julio cada ano. El modelo que probe puede aplicar solo a especies con una nidada; por lo tanto, revise la literatura para estimar el porcentaje de especies con una nidada en Norte America. La epoca de reproductiva de D. caerulea fue corta: casi todos los nidos fueron iniciados a mediados de mayo a fines de junio. La depredacion y parasitismo de nidos fueron las causas primarias y raras del fracaso de la nidada, respectivamente. Significativamente menos D. caerulea volaron de nidos parasitados que de nidos no parasitados. La supervivencia de volantones requerida para mantener el tamano poblacional estuvo muy por arriba de los valores publicados previamente para migrantes Neotropicales. Las especies con una nidada comprenden 62% de las especies norteamericanas cuyo numero de nidadas por ano es conocido; considero que mis resultados pueden ser aplicados a estas especies. La consistencia entre la identificacion de poblaciones como fuente o vertedero con base en estimaciones de modelos o medidas directas sugiere que un modelo demografico basado en muestreos de la fecundidad es adecuado para determinar el estatus demografico de poblaciones aviares con una sola nidada. Adicionalmente, con base en los resultados de estudios previos, la tasa anual de supervivencia de adultos de D. caerulea es tipica de parulidos que no estan declinando. Por lo tanto, la fecundidad baja, determinada aqui con metodos cuantitativos diferentes, puede influir en el estatus de especies de aves terrestres con alta supervivencia observada.

Impoundments, diversion dams, and stream dewatering have created a mosaic of large river fragments throughout the Great Plains of central North America. Coincident with these habitat changes are massive declines in the distribution and abundance of Great Plains fishes belonging to the “pelagic-spawning” reproductive guild. We analyzed longitudinal fragment lengths (measured in river kilometers, rkm) and literature accounts of population status for eight species from this guild across 60 fragments to derive thresholds in stream length associated with extirpations. Fragment length predicted population status (F2,21 = 30.14, P < 0.01), with lengths averaging 136 ± 21 rkm for extirpated, 226 ± 69 rkm for declining, and 458 ± 137 for stable populations. Fragment length explained 71% of reported extirpations and estimated thresholds in fragment length explained 67% of variation in population persistence. Our findings provide insight into appropriate spatial scales for conducting riverscape conservatio...

Considerable uncertainty often exists in estimates of demographic parameters based on data collected from harvested furbearer species. We used molecular genetic techniques to estimate rates of error in 2 methods of sex determination of harvested bobcats (Lynx rufus): manual examination of the carcass (field sex) and laboratory-based maximum canine root area (MRA sex). Error rates were high for both sexing techniques, and were associated with age and an age—sex interaction for the field and MRA sexing methods, respectively. These findings do not support the use of the field methods for identifying sex of harvested bobcats. The MRA method may be effective for determining sex of older bobcats but is limited by considerable overlap between sexes in juveniles and yearlings. If critical demographic parameters are estimated from harvest data, efforts should be made to identify and reduce rates of error before data are used to assess population status.

The study on the population status and human impacts on the endemic and endangered Swayne’s hartebeest (Alcelaphus buselaphus swaynei) was carried out in Nechisar Plains, Nechisar National Park, between 2009 and 2010. Direct and total count methods were applied in the population census. Data collected since 1967 were also examined to indicate trends of Swayne’s hartebeest populations and their translocation status. In eight illegal Guji Oromo settlements, a total of 134 household samples were identified for group discussion and interview. A trend on livestock population was carried out. The total count of Swayne’s hartebeest was 12, 11 and 12 during the 1st, 2nd and 3rd counts, respectively. The population has been decreasing and nowadays only 12 individuals remain. Most respondents had a negative attitude towards conservation areas. The increase in livestock population from 1985 to 1996 was 47.8%. It also increased by 49.9% and 56.5% during 2006 and 2010, respectively. There were 12,531 heads of livestock that depended on the grass plains illegally. Overstocking rate of livestock, illegal resource exploitation and loss of wildlife habitat were the major problems encountered. Active measures have to be implemented to control the human impact and safeguard the future of Swayne’s hartebeest. Resume L’etude du statut de la population et des impacts humains fut realisee sur l’espece endemique et en danger qu’est le bubale de Swayne Alcelaphus buselaphus swaynei dans les plaines de Nechisar, dans le Parc National de Nechisar, en Ethiopie, entre 2009 et 2010. On a applique des methodes de comptage total et direct dans les recensements de la population. On a aussi consulte les donnees recueillies depuis 1967 pour avoir une indication des tendances des populations de bubales et de leur statut de translocation. Dans huit etablissements Guji Oromo illegaux, on a identifie 134 foyers echantillons pour des discussions et des interviews en groupes. On a realise une etude de la tendance de la population de betail. Le nombre total des bubales fut respectivement 12, 11 et 12 lors des 1er, 2eme et 3eme comptages. La population diminue et aujourd’hui, il ne reste que 12 individus. La plupart des personnes interrogees avaient un sentiment negatif envers les aires de conservation. L’augmentation de la population de betail fut de 47,8 % entre 1985 et 1996. Elle a encore augmente de 49.9% en 2006 et de 56.5% en 2010. Il y avait 12.531 tetes de betail qui dependaient des plaines herbeuses illegalement. Le taux de surpâturage du betail, une exploitation illegale des ressources et une perte de l’habitat de la faune sauvage sont les principaux problemes rencontres. Il faut mettre en place des mesures dynamiques pour controler les impacts humains et preserver l’avenir du bubale de Swayne.

Canada is developing an indicator approach for assessing the biological status of conservation units of Pacific salmon Oncorhynchus spp. under its Wild Salmon Policy that is based, in part, on the abundance of adult fish. Two benchmarks will be used to place populations in one of three abundance categories. The lower benchmark is proposed to be at a level that allows for a substantial buffer between it and the abundance that would result in a population's being assessed as at risk of extirpation based on quantitative criteria used by the Committee on the Status of Endangered Wildlife in Canada. Using Monte Carlo simulation, we evaluated eight candidate lower benchmarks calculated from parameters of the stock–recruit relationship against two criteria, the probability of extirpation over 100 years and the probability of recovery to spawner abundances that result in the maximum sustainable yield in one or three generations. For modeled populations of moderate size (unfished equilibrium abundances >2...

Adaptive management of wild populations requires good knowledge of the population status. The main way to evaluate management performance is through recurring surveys, which often also serve as a decision basis for harvest quotas. We evaluated the effect of different survey reliabilities and frequencies during 1-4 years on management performance using a stochastic age and stage-specific population model for an Eurasian lynx Lynx lynx population. As a proxy for management performance, we looked at the proportion of time that the population remained within a preferred interval, the proportion of time with no harvest, the average harvest number and the total number of surveys during the 50-year period in the simulation. In general, management performance increased with increased monitoring accuracy. More interestingly, a more reliable survey performed less frequently performed better than a less reliable survey performed every year. The management performance was not perfect even with complete knowl...

We assessed population status and estimated selected demographic parameters for lake sturgeon Acipenser fulvescens in the Kettle River, Minnesota, using capture–recapture tagging data collected from 1992 to 2007. The lake sturgeon is an imperiled species of special concern in Minnesota, with population declines attributed to overfishing, pollution, and establishment of dams. In 1995, the recreational fishery was closed and the only dam on the Kettle River (Sandstone Dam) was removed, in part to promote lake sturgeon recovery. Recent incidental capture of lake sturgeon by anglers is prompting interest in re-opening the recreational fishery. We gathered information to determine (1) status and demography of the Kettle River population, (2) the effect of dam removal, and (3) the feasibility of re-opening the recreational fishery. Open-population capture–recapture models were used to examine population status and estimate survival, seniority, and the relative importance of survival and recruitment for...

The Guadalupe fur seal population at San Benito Islands is experiencing an exponential increase (r = 18.9%, r2 = 0.96) in this first phase of population growth. A similar pattern (r = 13.3%) was observed for Guadalupe fur seals from Gudalupe Island. The relatively rapid growth of the fur seal population on the San Benito Islands is due mainly to an increase in the number of females during the first 2 yrs and of juveniles during the last 2 yrs. The number of males and pups has been fairly constant over time. Apparently this first phase of population growth has been largely the result of the emigration of animals from GI; the only other breeding colony of the species.

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.

Redd counts are commonly used to monitor the current population status, trends in abundance, and distribution of bull trout Salvelinus confluentus. In many cases redd counts are conducted at subjectively selected sites, and there has been limited evaluation of statistical sampling designs. We evaluated the utility of the generalized random tessellation stratified (GRTS) sampling design to determine bull trout population status through redd counts. We tested a sampling effort that would be economically practical to implement on a continuous basis in multiple drainages within the southeastern Washington and Oregon portions of the Columbia River plateau. We evaluated the logistics of a pilot application of the GRTS design, compared GRTS-based estimates of redd abundance with those from census surveys, determined the precision of the GRTS estimates and the associated power for abundance comparisons, and compared the performance of the GRTS design with that of other probability sampling designs throug...

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. Resume On a etudie les reduncas Redunca redunca (Pallas, 1767) dans le Parc National des Bale Mountains (BMNP), en Ethiopie, pour connaitre l’ecologie et le schema des activites de leur population. On a utilise la methode des comptages totaux pour evaluer la taille de la population. On a etudie le schema des activites d’une harde en rapportant les observations a intervalles de cinq minutes. Il y avait 406 reduncas dans l’aire etudiee; 96,8% (n = 393) d’entre eux etaient confines dans la region Gaysay-Adalay. La population etait biaisee en faveur des femelles. Si l’on exclut les juveniles, 57,1% (n = 232) etaient des femelles et de 33,5% (n = 136) etaient des mâles. On a observe plus d’adultes (71,7%, n = 291) que de subadultes (18,9%, n = 77) et de juveniles (9,4%, n = 38). La taille d’une harde de reduncas variait de 3 a 5 individus. On a observe des agregats de hardes allant jusqu’a 59 individus en saison seche, dans la prairie marecageuse. Le plus grand agregat de ce genre observe en saison des pluies comptait 38 individus. Le schema d’activite diurne presentait des pics de nourrissage tot le matin et en fin d’apres-midi, et du repos pendant la mi-journee. On a observe deux pics de nourrissage pendant la phase d’activite nocturne : une au crepuscule et l’autre autour de minuit. Contrairement a l’idee generale selon laquelle les plus petites hardes s’observent pendant la saison seche, les reduncas se rassemblent dans les marais pendant cette saison. Ils sont aussi actifs le jour et la nuit.

The number of redds in a watershed is routinely used to monitor the population status of Pacific salmon Oncorhynchus spp. One limitation of this approach is that spawning escapement estimates derived from redd counts often assume one redd per female. We tested this assumption on spring-run Chinook salmon O. tshawytscha in the Wenatchee River watershed, Washington. Female spring Chinook salmon (N = 3,590) were injected with passive integrated transponder (PIT) tags at Tumwater Dam and were monitored annually on the spawning grounds over a 3-year period. Female Chinook salmon were observed on 75% of the 1,784 redds that were counted, and PIT-tagged females were detected on 42% of the redds. Of the female Chinook salmon detected on the spawning grounds, only 10 were detected on more than one redd. The number of redds constructed per PIT-tagged female (1.01 redds/female) was identical during each year of the study despite differences in the abundance of spawners. These results support the common assu...

Current fisheries management policies generally require an assessment of stock status, which is a difficult task when population and fisheries data are limited. Three simple metrics based on catch length compositions (i.e., that reflect exclusive take of mature individuals, P mat; that consist primarily of fish of optimal size, the size at which the highest yield from a cohort occurs, P opt; and that demonstrate the conservation of large, mature individuals, P mega) can be used to monitor population status relative to exploitation. The metrics (collectively referred to as Px ) were intended to avoid growth and recruitment overfishing, but there was no quantitative linkage to stock status and calculation of future sustainable catches. We attempt to make this connection by exploring the relationship of Px measures to fishing mortality and spawning biomass (SB). The relationships are compared specifically to the current target reference point (0.4 times the virgin, or unfished, SB [SB0]) and limit r...

It is theoretically and empirically well established that body mass variation in small birds reflects a trade-off between starvation risk and predation risk. This occurs because carrying increased fat reserves reduces starvation risk but also results in a higher predation risk due to reduced escape flight performance and/or the increased foraging exposure needed to maintain a higher body mass. In principle, therefore, the theory of mass-dependent predation risk could be used to understand how a bird perceives and responds to the risks in its environment, because its mass will reflect the predictability of foraging opportunities and predation risk. Mass in birds may then provide a relatively straightforward way of assessing the foraging environment of birds and so the potential conservation problems a species faces. This study tests, for the first time for any species, how body mass changes in response to changing starvation risk, changing predation risk and changing population status. Common Starling Sturnus vulgaris mass varies as predicted by starvation–predation risk trade-off theory: mass is lower when foraging conditions are more favourable and when predation risk is increased. The populations that are declining the most strongly have higher mass, which is most likely indicative of a poor foraging environment, leading to lower relative survival. The results suggest that increased mass in Starlings, and possibly in other species, may provide an indication of the poor quality of the foraging environment and/or rapidly declining populations.

Colony-wide boat-based censuses suggest that numbers of Common Guillemots at Bluff, Alaska declined markedly in the late 1970s and remained low until 1983. Annual land-based counts of study plots since 1979 generally showed no trend. However, numbers declined substantially in one study area between 1978 and 1983. Reproductive success varied considerably among years and was highest in moderately warm summers. Simulation analyses suggest that the changes in numbers cannot be attributed to changes in reproductive success several years previously. Thus, factors affecting survival, presumably in winter, are apparently implicated in the declines.

Asiatic black bears (Ursus thibetanus) and sun bears (Helarctos malayanus) are sympatric in mainland Southeast Asia and face similar threats of habitat loss and commercial poaching. They are rarely seen but leave distinct signs, especially claw marks on climbed trees. These markings, which are potentially valuable indicators of presence, population status, and behavior of black bears and sun bears, have limited usefulness if the 2 species cannot be differentiated. We measured 121 claw mark imprints on climbed trees from 43 known (mainly captive) individual black bears and sun bears of both sexes in Thailand and Cambodia. The span across the markings made by 3, 4, or 5 claws from the hind foot was significantly greater for black bears than sun bears. We developed discriminant function models with these variables and arranged them in a 3-step process that distinguished claw marks as either sun bear, black bear, or indeterminate. This procedure correctly classified 95% of claw marks from the experim...

The subpopulation of white sturgeon Acipenser transmontanus in the Canadian portion of the Columbia River between Hugh L. Keenleyside Dam and the U.S.-Canada border has been identified as endangered, with nearly 30 consecutive years of consistent recruitment failure. The objectives of this study were to determine the status and population attributes of this subpopulation. We estimated survival rates and abundance using catch-curve analysis and mark-recapture models. An annual survival rate of 89% (95% confidence interval [CI], 88-90%) was estimated for the subpopulation using catch-curve analysis for the time period 1993-2004. The survival rates estimated from the mark-recapture data were obtained using model-averaged parameter estimates from a multistrata Cormack-Jolly-Seber model. The annual survival rate from the mark-recapture model was estimated at 97% (95% CI, 92-99%) from 1993 to 2004. The mark-recapture methods estimated abundance for 2004 to be 1,157 individuals (95% CI, 414-1,900). The ...

The study aimed at determining the population status of the different Acacia tree species producing gum arabic in the undisturbed, grazed and cultivated habitats in the Karamoja region, Uganda. A total of 135 sample plots each measuring 20 × 20 m2 (0.04 ha) with each habitat having 45 plots were selected and established in the seven counties using a simple random sampling technique. The tree species present, their abundances and sizes were recorded. Twelve Acacia species were identified and a total of 5535 recorded in the sampled area. Out of these, five were gum-producing acacias. Acacia senegal dominated the acacias in all the seven counties and in all habitats of Karamoja with Acacia nilotica (72.3%), Acacia seyal (13.4%), Acacia sieberiana (4%) and Acacia gerrardii (2.6%). Non-gum-producing acacias constituted 7.19% of the total abundance. The tree densities increased with increase in tree size in the undisturbed and grazed habitats but decreased in the cultivated habitat. Most Acacia trees were of large size, an indication of old age and poor regeneration that could affect their future population status. It is recommended that further investigations be carried out into the causes of poor regeneration of Acacia species.

Band-recovery and wing-collection survey data have the potential to provide information on American woodcock (Scolopax minor) fall migration ecology in the Central Region of the United States, yet researchers have not recently analyzed these extensive data sets. We analyzed all direct recoveries of woodcock banded in Michigan, Minnesota, and Wisconsin, USA, as well as wing-collection survey data, to determine the progression of fall migration, the migration direction, and the final destination of woodcock migrating from these states. We did not observe migration initiation based on band recoveries until late October and early November, with most migration occurring during November. Wing-receipt data showed a similar trend, with most change in mean receipt latitude occurring from 1 November to 5 December. During November, wing receipts were spread through the entire Central Region. By 15–31 December, 92% (n = 26) of band recoveries were on the wintering grounds (south of latitude 33°N). Most banded woodcock from Michigan, Minnesota, and Wisconsin wintered in Louisiana, USA. Woodcock banded in these states will be exposed to harvest for most of the hunting season because they remain in these states through November. If the population status of local birds is a concern, managers should consider this migration pattern when setting season dates.

The sample sizes required to estimate fish length were determined by bootstrapping from reference length distributions. Depending on population characteristics and species-specific maximum lengths, 1-cm length-frequency histograms required 375–1,200 fish to estimate within 10% with 80% confidence, 2.5-cm histograms required 150–425 fish, proportional stock density required 75–140 fish, and mean length required 75–160 fish. In general, smaller species, smaller populations, populations with higher mortality, and simpler length statistics required fewer samples. Indices that require low sample sizes may be suitable for monitoring population status, and when large changes in length are evident, additional sampling effort may be allocated to more precisely define length status with more informative estimators.

How much sodium (Na) and potassium (K) should be in the human diet so that it would not be accompained with cardiovascular events is a perenial epidemiology challenge. Urinary Na and K are the standard short term biological indicators of Na and K dietary exposure. In this study we have assessed Na and K population status from frequency distribution properties of their concentration in the hair as a long term biological indicator. The study was conducted according to the Basic Principles of the Declaration of Helsinki. Na and K were analyzed in 1072 hair samples of healthy adult subjects (733 [female]and 339 [male]) with ICP MS and ICP EMS, respectively. The median values (μg•g­1) were Na ([female]254 and [male]371) and K ([female]74.3 and [male]143), respectively ; the log transformed data were analyzed with the method of median derivatives (Thyroid 2014 ; 24:1018­1026). The observed sigmoid curves had a linear range: Na ([female] 55, 6 ­ 1307, [male] 84.0 – 1450), K ([female] 18.9 – 467, [male] 25.8 – 1079). This linear and adequate segment of hair saturation with Na and K is itself an exponential 3­compartment Michaelis­Menton kinetic model, where the respective sparse, true, and ample adequate Na and K hair deposition may be identified. We propose that the human true adequate Na and/or K hair concentrations should be: Na ([female] 420 – 563, [male] 790 ­ 975), K ([female] 142 – 283, [male] 286 ­ 588).This is the first personalized human Na and K assessment based on the results of their intermediary metabolic response.

The conservation of golden eagles (Aquila chrysaetos) requires a thorough understanding of their demographic parameters. Productivity, commonly measured as the number of nestlings or fledglings per pair, is the parameter reported by most studies of nesting golden eagles and is often used as a measure of their population status. Survival may be an equally or more important parameter to measure; however, survival rates of golden eagles are not well documented. We used satellite telemetry to estimate the probability of first-year survival for migratory golden eagles raised in Denali National Park and Preserve, Alaska, USA. We calculated the probability of first-year survival using program MARK. Based on the best approximating model, monthly survival probability was 0.88 ± 0.04 (mean ± SE) during the autumn migration and early winter period for golden eagles marked in 1997 and 0.78 ± 0.05 during the same period for golden eagles marked in 1999. Monthly survival during the remaining 3 periods (i.e., l...

Current monitoring efforts for greater prairie-chicken (Tympanuchus cupido pinnatus) populations indicate that populations are declining across their range. Monitoring the population status of greater prairie-chickens is based on traditional lek surveys (TLS) that provide an index without considering detectability. Estimators, such as immigration–emigration joint maximum-likelihood estimator from a hypergeometric distribution (IEJHE), can account for detectability and provide reliable population estimates based on resightings. We evaluated the use of mark–resight methods using radiotelemetry to estimate population size and density of greater prairie-chickens on 2 sites at a tallgrass prairie in the Flint Hills of Kansas, USA. We used average distances traveled from lek of capture to estimate density. Population estimates and confidence intervals at the 2 sites were 54 (CI 50–59) on 52.9 km2 and 87 (CI 82–94) on 73.6 km2. The TLS performed at the same sites resulted in population ranges of 7–34 an...