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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Génétique de la conservation et du paysage : étude des populations de lagopède alpin et de perdrix grise en France.

Bech, Nicolas 26 November 2010 (has links) (PDF)
Le lagopède alpin (Lagopus muta) et la perdrix grise (Perdix perdix) atteignent dans les Pyrénées les limites méridionales de leurs aires de répartition mondiale. Les populations pyrénéennes de ces deux sous-espèces (Lagopus muta pyrenaica et Perdix perdix hispaniensis) sont donc en situation d'isolat biogéographique. Les deux espèces sont d'excellents bio-indicateurs de l'évolution des milieux ouverts d'altitude. Sous la pression conjuguée des contraintes environnementales et anthropiques, ces milieux connaissent actuellement une évolution sensible caractérisée par un relèvement altitudinal des étages de végétation et donc un rétrécissement de l'habitat disponible pour les espèces d'altitude. La régression des activités agro-pastorales accentue ce phénomène généralisé de reforestation des milieux. Une conséquence attendue de ces bouleversements est l'augmentation du degré de fragmentation des habitats notamment pour les populations d'altitude. Au-delà de l'influence du paysage sur la structuration des populations, un autre facteur pourrait structurer les populations de perdrix grise : les lâchers d'individus d'élevage dans des populations sauvages. Dans cette thèse, nous nous intéressons à la structuration génétique du lagopède alpin des Pyrénées et de la perdrix grise en France afin d'aider à la décision des plans de conservation.
12

Play Behavior and its Importance for Welfare in Chickens and Other Farm Animals.

Lundén, Gabrielle January 2020 (has links)
Play is a self-motivated seemingly non-functional behavior mainly observed in young animals. Moreover, play behaviors can be divided into three categories; social play, object play and locomotor play. The type of activity the category contains varies, as play behaviors vary between species. Play behavior is seen as an indicator of positive emotions in animals, therefore play could be an indicator of welfare. However, the relationship between play and welfare requires further studies. In this study, information was compiled from various articles about play and its relation to welfare. Above all, the study focuses on welfare and play in chickens, as studies on chickens are most lacking. Play provides several benefits regarding motor training, social cohesion and cognitive training. Livestock such as calves, piglets and lambs have all been observed playing. No play has been confirmed in chickens which is mainly due to lack of research. However, play has been observed in other bird species, including birds within the order Galliformes. Amount and type of play varies depending on the environment, which suggests that animal welfare has a great significance for play. If no play occurs, one could conclude that welfare needs to be improved. Lack of play observed in chickens could be due to poor welfare or lack of research. After all, presence of play in other bird species increases the probability that chickens also play. Results indicate that play could be used as an indicator for welfare.
13

Characterizing bone growth and pneumaticity development in birds: Insights from the turkey (Meleagris sp.)

Sze, Nicholas Dawson 13 May 2023 (has links)
No description available.

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