Nelson's Sharp-tailed Sparrows (Ammodramus nelsoni) that breed along the Atlantic coast of North America (Acadian subspecies subvirgatus) are considered saltmarsh specialists. However, these sparrows occasionally use upland habitats, such as hayfields. To evaluate the importance of hayfields as breeding habitat, we studied populations of A. n. subvirgatus in saltmarsh and hayfields in Nova Scotia, Canada, in 2004 and. We monitored relative abundance and breeding phenology at 64 point-count stations (48 in hayfields and 16 in saltmarsh) and used an ordinal (0-5) observational index to quantify reproductive activity. A. n. subvirgatus showed more evidence of reproductive activity in saltmarsh (44% of point-count stations) than hayfields (28%; P = 0.07). However, there was no difference in either mean reproductive activity (saltmarsh = 0.83, hayfields = 0.53; P = 0.69) or mean relative abundance (saltmarsh = 0.27, hayfields = 0.26; P = 0.93). Although A. n. subvirgatus apparently breeds primarily in saltmarsh, hayfields appear to be an alternative breeding habitat. Use of hayfield habitat by A. n. subvirgtus, however, seems to vary between southern Maine and eastern Canada, suggesting that management plans will require approaches uniquely tailored to specific regions. SINOPSIS. Uso diferencial de habitat por individuos de Ammodramus nelsoni subvirgatus:implicaciones para su conservación a nivel regional La subespecie Acadian del Gorrión de Nelson (Ammodramus nelsoni subvirgatus), que se reproduce a lo largo de la costa del Atlántico en Norte América, es considerada un especialista de marjales. Sin embargo, estos gorriones han sido observados (ocasionalmente) usar habitats de tierras altas como sembrados de heno. Para evaluar la importancia de las siembras de heno como habitat reproductivo del ave, estudiamos poblaciones de la subespecie subvirgatus del Gorrion de Nelson que se reprodujeron en marjales y en campos de heno, en Nova Scotia, Canada durante el 2004 y el 2005. Monitoreamos la abundancia relativa y la fenología reproductiva en 64 estaciones de punto (48 en campos de heno y 16 en marjales) y utilizamos uníndice de observación (0-5) para cuantificar la actividad reproductiva. Se encontró evidencia de mayor actividad reproductiva en los marjales (44% de las estaciones) que en los campos de heno (28%; P = 0.07). Sin embargo, no se encontró diferencia en la actividad promedio reproductiva (marjales = 0.83, campos de heno = 0.53; P = 0.93). Aunque el ave anida principalmente en marjales, los campos de heno parecen ser un buen habitat alterno para la reproducción. El uso de campos de heno, parece variar entre localidades como el sur de Maine y el este de Canada, lo que sugiere que los planes de manejo tienen que amoldarse con especificidad a cada región.
Generalized recommendations for the conservation of birds in agro-ecosystems have been elusive because studies are often of a local nature, and do not compare source data against those from other regions. In this study, we developed geographically broad habitat relationship models to provide conservation prescriptions for three species that breed in farmed grasslands: Bobolink (Dolichonyx oryzivorus), Savannah Sparrow (Passerculus sandwichensis), and Nelson's Sharp-tailed Sparrow (Ammodramus nelsoni subvirgatus). We develop models from our study in Nova Scotia, Canada and confront them with independent data from Wisconsin, USA pastures and Iowa, USA restored prairies. Vegetation that was higher and denser in the prebreeding season was linked to increased occupancy rates and abundance of Bobolinks in each study region. Providing tall spring grass is easily accomplished by not cutting late in the previous year. Savannah Sparrows were instead associated with shorter and sparser spring grass, which highlights the need to simultaneously provide heterogeneous habitat for otherwise ecologically similar species. Nelson's Sharp-tailed Sparrows were more likely to occur, and be numerous, in areas with greater availability of drainage ditches. They and several other species would benefit from provision of ditches with adequate vegetation to promote occupancy. By combining these with other well-established recommendations, such as a delayed first harvest, a greater net conservation benefit can be realized from these working landscapes. RÉSUMÉ. Les recommandations d'ordre général pour la conservation des oiseaux des écosystèmes agricoles sont difficiles à définir parce que les études n'ont souvent qu'une portée locale et ne comparent pas les données d'origine à celles d'autres régions. Dans cette étude, nous avons développé des modèles de relations avec l'habitat à grande échelle dans le but de fournir des recommandations pour la conservation de trois espèces qui nichent dans les prairies cultivées : le Goglu des prés (Dolichonyx oryzivorus), le Bruant des prés (Passerculus sandwichensis) et le Bruant de Nelson (Ammodramus nelsoni subvirgatus). Nous avons élaboré des modèles à partir de notre étude en Nouvelle-Écosse, au Canada, et nous les avons comparés à des données indépendantes récoltées aux États-Unis, dans des pâturages au Wisconsin et des prairies restaurées en Iowa. La végétation plus haute et plus dense avant la saison de nidification était associée à des taux d'occupation plus élevés et à un plus grand nombre de goglus dans chaque aire d'étude. Il est facile d'obtenir de l'herbe haute au printemps en évitant de couper tardivement l'automne précédent. À l'opposé, les Bruants des prés étaient associés à la présence d'herbes courtes et éparses au printemps, ce qui met en évidence la nécessité de fournir des habitats hétérogènes pour des espèces néanmoins écologiquement similaires. Les Bruants de Nelson fréquentaient davantage et étaient plus nombreux dans les aires où il y avait plus de fossés de drainage. Cette espèc...
The wise use of wetlands is expected to contribute to ecological integrity, as well as to secure livelihoods, especially of communities dependent on their ecosystem services for sustenance. This paper provides a conceptual framework capable of examining the goals of wetland management, poverty reduction and sustainable livelihoods. The framework highlights ecological character as a social construct and, with the notion of wetlands as settings for human well-being, builds a concept for assessing the inter-linkages between ecosystem services and livelihoods. The value and broader applicability of our framework is then tested by applying it to a case study from India (Lake Chilika) to evaluate the degree to which the mutual goals of improving both human well-being and the ecological character of wetlands have been achieved. The case study maps changes in human well-being induced in the basin communities due to external vulnerability contexts, institutions and freedoms. It further assesses the response strategies in terms of their impacts on ecological character and poverty status.Key words livelihoods; biodiversity; development; Ramsar Convention; wetlands; ecosystem services; poverty; Chilika Lake Evaluation des liens entre services écosystémiques des zones humides et pauvreté: cadre général et étude de cas Résumé L'utilisation rationnelle des zones humides est censée contribuer à l'intégrité écologique, ainsi qu'à assurer les moyens de subsistance, en particulier des collectivités tributaires de leurs services écosystémiques pour la nourriture et les ressources de base. Cet article fournit un cadre conceptuel capable d'examiner les objectifs de gestion des zones humides, la réduction de la pauvreté et les moyens de subsistance durables. Le cadre souligne le caractère écologique comme une construction sociale et, avec la notion de zones humides comme cadre pour le bien-être humain, construit un concept pour l'évaluation des liens entre les services écosystémiques et les moyens de subsistance. La valeur et l'applicabilité plus large de notre cadre sont ensuite testées en l'appliquant à une étude de cas en Inde (Lac Chilika) pour évaluer à quel niveau les objectifs communs d'amélioration à la fois du bien-être humain et du caractère écologique des zones humides ont été atteints. L'étude de cas dresse la carte des changements dans le bien-être humain, induits, dans les communautés du bassin, par des contextes de vulnérabilité externe, les institutions et les libertés. Il évalue ensuite les stratégies de réponse en termes de leurs impacts sur le caractère écologique et le niveau de pauvreté.
Common eiders (Somateria mollissima) are large sea ducks with a circumpolar distribution and have high cultural significance to sport hunters and indigenous peoples in many countries. Their gregarious habits, including colonial breeding and forming large flocks during migration and winter, make eiders susceptible to environmental stressors during breeding and non-breeding seasons. Our objective was to assess whether low adult survivorship could be contributing to suspected local population declines in Nova Scotia, Canada. We banded molting male and breeding female common eiders along the marine coastline of Nova Scotia and recaptured them in later years. We found that from 1997 to 2011, when males and females were banded, male survival (S) was high (S ¼ 0.92; 95% CI ¼ 0.87-0.95), whereas female survival was approximately 10% lower (S ¼ 0.83; 95% CI ¼ 0.78-0.87) and at a level comparable to what has been reported in other regions of the world where eider populations are thought to be in decline. Recovery rates (f) of harvested male and female eiders were indistinguishable (f ¼ 0.013; 95% CI ¼ 0.010-0.016), suggesting that lower female survival is attributable to factors other than hunting. Supplementary analyses using a longer-term data set for females only and including live recapture data indicated that female survival rates have not changed markedly during the past 40 years and that the emigration rate from colonies is low ($6%). We conclude that to successfully conserve this population, sources of non-harvest female mortality should be investigated and used to develop targeted management solutions. We speculate that one of those sources of mortality is predation on females at breeding colonies, notably from eagles and mustelids.
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