Small Mammals in Prairie Wetlands: Habitat Use and the Effects of Wetland Modifications

Although well documented for other habitat types, small mammal habitat use patterns in prairie wetlands are poorly understood. The distribution of the mammal fauna of South Dakota is also not well known. Because of the lack of information in these areas, evaluation of the impacts of wetland modifications on the resident mammal community is not possible. The objectives of this study were (1) to document the species composition and abundance of small mammal communities inhabiting prairie wetland basins, (2) to determine the effects of small scale habitat modification on small mammals, (3) and to explain local species distribution patterns using habitat measurements. This study was conducted during the summers of 1981 and 1982. Meadow voles (Microtus pennsylvanicus) were the most common small mammal in prairie wetlands, followed by deer mice (Peromyscus spp.), masked shrews (Sorex cinereous), meadow jumping mice (Zapus hudsonius) and northern short-tailed shrews (Blarina brevicauda). Deer mine were more common in modified habitats within wetland basins than in undisturbed habitat. Modification of wetlands tended to reduce the species diversity of small mammals I the modified areas. Local distributions of species seemed to be largely determined by soil moisture. Meadow voles used the wettest habitats and deer mice used the driest. Both species of shrew seemed to use habitats intermediate in terms of moisture between wetlands and uplands

Factors Affecting the Observed Densities of Ringed Seals, Phoca hispida, in the Alaskan Beaufort Sea, 1996-99

Aerial surveys were conducted during late May and early June 1996-99 in the central Beaufort Sea of Alaska, using strip-transect methods. The purpose of these surveys was to quantify and model the effects of environmental covariates on ringed seal counts and to provide density estimates that would be useful for evaluating trends in seal abundance. Total survey effort included 40-88 transect lines per year covering 1198-2701 km². Observed densities ranged from 0.81 seals/km² in 1996 to 1.17 seals/km² in 1999. We examined the effects of habitat, weather, and time of day on observed seal densities, using univariate chi-square goodness-of-fit tests. We also used a multivariate generalized linear model to estimate the relationship between seal counts and covariates. Three habitat-related variables - water depth, location relative to the fast ice edge, and ice deformation - had substantial and consistent effects. The highest densities occurred at depths between 5 and 35 m. Densities were also highest in relatively flat ice and near the fast ice edge, declining both shoreward and seaward of that edge. Univariate analysis suggested that observed densities were generally highest at about 1200 h Alaska daylight time, but time was not a significant variable in the generalized linear models. Analyses of the effects of weather factors on seal counts were inconclusive. This was likely at least partially because temperature and wind speed were measured at survey altitude, rather than on the ice surface, and surveys were conducted only in weather considered suitable for hauling out. The final multivariate model did not account for a substantial proportion of the variation in seal counts. We think this result was largely due to date-related variation in the proportion of seals hauling out, an issue our surveys were not suited to address.De 1996 à 1999, à la fin de mai et au début de juin, on a effectué des relevés aériens dans la partie centrale de la mer de Beaufort alaskienne, en utilisant des méthodes d'échantillonnage en bande. Ces relevés avaient pour but de quantifier et de modéliser les effets de covariables environnementales sur le comptage des phoques annelés, et de fournir des estimations de densité qui pourraient servir à évaluer les tendances dans l'abondance des phoques. Le travail de relevé a porté chaque année sur un total allant de 40 à 88 lignes-transects, couvrant une superficie de 1198 à 2701 km². Les densités observées allaient de 0,81 phoque par km² en 1996 à 1,17 phoque par km² en 1999. On a étudié les effets de l'habitat, du climat et du moment de la journée sur les densités de phoques observées, à l'aide de tests d'adéquation chi carré à une variable. On a également eu recours à un modèle linéaire généralisé à plusieurs variables pour évaluer le rapport entre les comptages de phoques et les covariables. Trois variables reliées à l'habitat - profondeur de l'eau, position par rapport à la lisière de la banquise côtière et déformation de la glace - avaient des effets importants et constants. Les plus fortes densités se produisaient à des profondeurs de 5 à 35 m. Elles se retrouvaient également sur la glace relativement plane et près de la lisière de la banquise côtière, diminuant à la fois en direction du rivage et en direction de la mer depuis la lisière. L'analyse à une variable suggère que les densités observées étaient généralement plus fortes à environ 12 h (heure avancée de l'Alaska), mais le moment de la journée ne constituait pas une variable d'importance dans les modèles linéaires généralisés. Les analyses de l'impact des facteurs météorologiques sur les comptages de phoques n'ont pas donné de résultats concluants. Ceci était probablement dû au moins en partie au fait que la température et la vitesse du vent étaient mesurées à l'altitude où se faisaient les relevés plutôt qu'à la surface de la glace, et les relevés n'étaient effectués que par temps jugé approprié pour que les phoques montent sur la glace. Le modèle final à plusieurs variables ne représentait pas une proportion substantielle de la variation dans les comptages de phoques. Ce résultat, selon nous, était dû en grande partie à une fluctuation reliée à la date dans la proportion de phoques qui montaient sur la glace, question que nos relevés n'étaient pas conçus pour aborder

‘Post-Olympic Blues’ –The Diminution of Celebrity in Olympic Athletes

Objectives: To explore the concept of the ‘post-Olympic blues’ through examining the antecedents of the negative affect experienced following Olympic participation and to articulate whether the post-Olympic blues is a ‘normal’ short-term phenomenon or whether it is more serious and enduring.Design and method: Four female British athletes who competed in the 2016 Rio Olympic Games were interviewed and asked to draw timelines about their Olympic experiences on one or two occasions. The interviews and timelines were analyzed using Interpretative Phenomenological Analysis.Results: The athletes’ experiences of the Olympic and post-Olympic period were characterized by highs around the Olympic Games and lows following their return to the United Kingdom. There were distinct temporal periods that were pertinent in the consideration of the ‘post-Olympic blues’; The Olympic Experience, The Homecoming, and Moving Forwards. A fourth theme Celebrity involved integral and dynamic development over time. Celebrity comprised the development and the subsequent destruction of the athletes as celebrities.Conclusion: This study has articulated what post-Olympic blues means to those who have experienced it, identified the negative impact that the athletes’ celebritization had on their mental wellbeing, and suggested that the negative emotions and subsequent behaviors were interpreted to be a normal response to returning home following Olympic participation. It is hoped that this research will engage coaching teams to formulate what support should be offered for athletes prior to and after the Olympic Games to limit the wellbeing impact that that the post-Olympic blues has on athletes

EFFECTS OF EXTENDED ON SANDHILL CRANE REPRODUCTION

Photoperiod studies were conducted with greater sandhill cranes (Grus canadensis tabida) from 1969 to 1972 and from 1982 to 1987 at the Patuxent Wildlife Research Center, Maryland. When housed indoors and exposed to long photoperiods, males produced semen during winter. When exposed to artificially extended photoperiods during spring in outdoor pens, females apparently laid earlier in the year and laid more eggs than they would have without the added light. Cranes did not exhibit any signs of photo refractory response to extended photo periods

Data from: Survival of adult Steller sea lions in Alaska: senescence, annual variation and covariation with male reproductive success

Population dynamics of long-lived vertebrates depend critically on adult survival, yet factors affecting survival and covariation between survival and other vital rates in adults remain poorly examined for many taxonomic groups of long-lived mammals (e.g. actuarial senescence has been examined for only 9 of 34 extant pinniped species using longitudinal data). We used mark-recapture models and data from 2,795 Steller sea lion (Eumetopias jubatus) pups individually-marked at 4 of 5 rookeries in southeastern Alaska (SEAK) and resighted for 22 years to examine senescence, annual variability, and covariation among life-history traits in this long-lived, sexually-dimorphic pinniped. Sexes differed in age of onset (~16–17 and ~8-9 years for females and males, respectively), but not rate (-0.047 and -0.046/year of age for females and males) of senescence. Survival of adult males from northern SEAK had greatest annual variability (~±0.30 among years), whereas survival of adult females ranged ~±0.10 annually. Positive covariation between male survival and reproductive success was observed. Survival of territorial males was 0.20 higher than that of non-territorial males, resulting in the majority of males alive at oldest ages being territorial

Factors Affecting Haul-Out Behavior of Harbor Seals (<i>Phoca vitulina</i>) in Tidewater Glacier Inlets in Alaska: Can Tourism Vessels and Seals Coexist?

<div><p>Large numbers of harbor seals (<i>Phoca vitulina</i>) use habitat in tidewater glaciers in Alaska for pupping, breeding, and molting. Glacial fjords are also popular tourist destinations; however, visitation by numerous vessels can result in disturbance of seals during critical life-history phases. We explored factors affecting haul-out behavior of harbor seals at a glacial site frequented by tourism vessels. In 2008-10, we deployed VHF transmitters on 107 seals in Endicott Arm, Alaska. We remotely monitored presence and haul-out behavior of tagged seals and documented vessel presence with time-lapse cameras. We evaluated the influence of environmental and physical factors on the probability of being hauled out, duration of haul-out bouts, and as factors associated with the start and end of a haulout. Location, season, hour, and interactions of location by year, season, hour, and sex significantly influenced haul-out probability, as did ice, weather, and vessels. Seals were more likely to be hauled out with greater ice availability during the middle of the day, and less likely to be hauled out if vessels were present. Cruise ships had the strongest negative effect; however, most vessel types negatively affected haul-out probability. Haul-out duration was longest in association with starting on incoming tides, clear skies, no precipitation, occurring in the middle of the day, and ending in the late afternoon or evening. End of haulouts was associated with increasing cloud cover, low ice availability, and vessel presence; large-sized tourism vessels or all-vessel-types combined were significant predictors of ending a haul-out bout. Probability of being hauled out was highest in June, during pupping season. Potential disturbances of harbor seals could be reduced, enabling longer resting times for seals and fewer interruptions for nursing pups, if vessels focused the majority of visits to glacial habitat to before or after the hours of 08:00-17:00 or, less optimally, 09:00-16:00.</p></div

Summary of Vessel Effects on Seal Behavior.

<p>Estimates of haul-out probability, haul-out start, and haul-out end are odds ratios, which estimate the effects of vessel presence for each size category, relative to when there were no vessels of that size present. Estimates for durations are the geometric mean duration (dur.) of haulouts when a vessel was present relative to when there were no vessels. The observed effect of longer duration of haulouts in the presence of vessels is likely spurious, as a result of the confounding effects of the presence of numerous vessels during midday, at a time when the majority of seals haul out (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125486#pone.0125486.g008" target="_blank">Fig 8</a>). Significant effects (i.e., factors where the CI does not cross 1 or no effect) have solid symbols.</p

Dates of operation for time-lapse cameras.

<p>Cameras were used to detect vessel presence and assess environmental variables such as weather conditions and ice coverage. Horizontal bars indicate the range of dates (color-coded by camera site) that each time-lapse camera was functional at each remote monitoring station throughout the years of the study.</p

Predictors related to the probability of an observation being an ‘end-of-haulout’ observation.

<p>Predictors of the probability of an observation being an ‘end-of-haulout’ observation were assessed compared to predictors consistent with ‘middle-of-haulout’ observations. Odds ratios are the relative odds of a seal being hauled out for one value of the covariate vs. another value [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125486#pone.0125486.ref047" target="_blank">47</a>]. Numbers in parentheses for vessel predictors are numbers of vessels.</p><p>¹Odds ratios for ‘Low’ and ‘High’ ice are relative to ‘Medium’ ice.</p><p>²Results for binary vessel predictors (i.e., absence/presence); results for the binary vessel variables are easier to interpret, but show similar patterns to the continuous vessel predictor models. Odds ratios for vessel predictors are the odds of an ‘end’ observation when a vessel is present, relative to when no vessel is present.</p><p>Predictors related to the probability of an observation being an ‘end-of-haulout’ observation.</p