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We monitored 75 natural nests of Graptemys geographica (Lesueur, 1817) in central Pennsylvania to determine the tactics and patterns of hatchling emergence. Following incubation, all hatchlings in 95% of nests delayed emergence from their natal nest cavities throughout autumn and winter until the following spring. Nests were constructed in a variety of substrates ranging from loose sand or coal to hard-packed clay mixed with gravel. Time from egg deposition to natural hatchling emergence averaged 333 days. During winter, hatchlings tolerated subzero temperatures as low as -8°C, which are lethal to hatchlings of some sympatric species. Emergence occurred from 10 April to 25 May, and most hatchlings were found during morning following rain. There was an interactive effect of minimum daily air temperature and rainfall level 1 day prior to emergence on the number of hatchlings emerging each day. One half of all hatchlings found dead were contained in nests in which autumn emergence had apparently occurred. We speculate that autumn emergence by hatchlings of some turtle species may be an adaptive response to nest conditions likely to provide poor environments for successful overwintering.Résumé : Nous avons suivi 75 nids naturels de Graptemys geographica (Lesueur, 1817) dans le centre de la Pennsylvanie afin de déterminer les stratégies et les patterns d'émergence des nouveau-nés. Après l'incubation, dans 95 % des nids, tous les nouveau-nés retardent leur émergence de la cavité du nid natal pendant l'automne et l'hiver jusqu'au printemps suivant. Les nids sont construits dans une variété de substrats, allant de sable ou de charbon non consolidé à de la glaise compacte mêlée de gravier. Le temps entre la ponte des oeufs et l'émergence naturelle des petits est en moyenne de 333 jours. En hiver, les petits supportent le gel jusqu'à -8°C, des températures létales pour les nouveaunés de quelques autres espèces sympatriques. L'émergence a eu lieu du 10 avril au 25 mai et la plupart des petits ont été retrouvés le matin après une pluie. Il y a un effet interactif entre la température minimale journalière de l'air et la quantité de précipitations la veille de l'émergence, d'une part, et le nombre de petits qui émergent chaque jour, d'autre part. La moitié de tous les nouveau-nés trouvés morts proviennent de nids où il s'est apparemment produit une émer-gence d'automne. Nous posons l'hypothèse que l'émergence à l'automne des nouveau-nés chez certaines espèces de tortues peut être une réaction adaptative à des conditions dans le nid qui vont vraisemblablement fournir un mauvais environnement pour survivre à l'hiver.[Traduit par la Rédaction] Nagle et al. 1218

Ultimate causes of animal dispersal have been hypothesized to benefit the dispersing individual because dispersal reduces competition for local resources, potential for inbreeding, and competition for breeding partners. However, proximate cues influence important features of dispersal behavior, including when dispersal occurs, how long it lasts, and direction, straightness, and distance of the dispersal path. Therefore, proximate cues that affect dispersal influence ecological processes (e.g., population dynamics, disease transmission, gene flow). We captured and radio‐marked 277 juvenile female white‐tailed deer (Odocoileus virginianus), of which 27 dispersed, to evaluate dispersal behavior and to determine proximate cues that may influence dispersal behavior. Female dispersal largely occurred at 1 year of age and coincided with the fawning season. Dispersal paths varied but generally were non‐linear and prolonged. Physical landscape features (i.e., roadways, rivers, residential areas) influenced dispersal path direction and where dispersal terminated. Additionally, forays outside of the natal range that did not result in dispersal occurred among 52% of global positioning system (GPS)‐collared deer (n = 25) during the dispersal period. Our results suggest intra‐specific social interactions and physical landscape features influence dispersal behavior in female deer. Female dispersal behavior, particularly the lack of directionality, the semi‐permeable nature of physical barriers, and the frequency of forays outside of the natal range, should be considered in regard to population management and controlling the spread of disease. © 2016 The Wildlife Society.

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