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Madagascar is renowned for its biodiversity, but also for forest loss, fragmentation, and degradation, making it a global conservation priority. With few studies dedicated to Madagascar's carnivores, little is known about their ecology. My objectives were to 1) compare density estimation techniques applicable to enumerating rare and/or elusive carnivores, 2) investigate Malagasy carnivore distributions, abundance and density, and occupancy/use across four sites that vary in forest disturbance, and 3) explore temporal activity patterns of rainforest carnivores. I found the spatially-explicit-capture-recapture models were empirically superior, as they are flexible and account for spatial variation in detection probability and area estimation. I found both endemic and exotic carnivore composition varied among four rainforest sites: Primary, Selectively-logged, Fragments <2.5 km and Fragments >15 km from contiguous-primary rainforest. All endemic carnivores were present in the Primary and Selectively-logged rainforest, while endemic carnivore species richness decreased and exotic carnivore species richness increased in the fragmented forests. Malagasy civet (Fossa fossana) density ± SE was significantly less in the Selectively-logged compared to the Primary rainforest (1.38 ± 0.22, 3.19 ± 0.55 civets/km2, respectively); they were absent from both fragmented forests. Fossa (Cryptoprocta ferox) density ± SE was not different between the Primary and Selectively-logged rainforests (0.12 ± 0.05, 0.09 ± 0.04 adults/km2, respectively); a single animal was detected in the Fragments <2.5 km, while none were detected in the Fragments >15 km. Malagasy carnivores had varied temporal activity overlap (5.8-88.8%). C. ferox preferred crepuscular activity, but overall exhibited a cathemeral activity pattern. / Master of Science

Tableau d'honneur de la Faculté des études supérieures et postdoctorales, 2022 / La perte et la fragmentation d'habitats naturels au profit de l'intensification agricole et de l'expansion urbaine sont à la source du déclin des communautés d'insectes pollinisateurs. Ce projet a pour but 1) d'évaluer l'impact du type de paysage (agricole, résidentiel et industriel) sur les communautés d'abeilles, de guêpes et de syrphes et 2) de déterminer la valeur écologique des surfaces gazonnées pour soutenir ces pollinisateurs comparativement aux prairies semi-naturelles. Pour ce faire, 18 gazons et 18 prairies semi-naturelles répartis uniformément entre les paysages agricoles, résidentiels et industriels de l'Agglomération de Québec ont été échantillonnés pour évaluer l'abondance, la richesse et la composition en abeilles, en guêpes et en syrphes. L'environnement agricole était nocif pour les abeilles et les guêpes pour lesquelles une réduction de leur abondance et de leur richesse a été observée comparativement au milieu résidentiel, alors que les aires industrielles limitaient l'abondance et la richesse des guêpes seulement. Pour l'ensemble des paysages, les prairies semi- naturelles étaient indispensables pour l'établissement de communautés d'abeilles et de syrphes abondantes en individus et riches en espèces, alors que les aires gazonnées présentaient une forte dominance du genre d'abeille *Lasioglossum* et de l'espèce de syrphe *Toxomorus marginatus*. Pour les guêpes, les ressources des gazons étaient peu attirantes et visitées sporadiquement. Les résultats suggèrent que les actions de conservation visant les abeilles et les guêpes devraient assurer la présence de davantage d'espaces naturels dans les paysages agricoles et industriels. D'autre part, malgré le rôle esthétique et récréatif des gazons, ceux-ci attirent peu les communautés d'insectes pollinisateurs ce qui souligne l'importance de conserver des prairies semi-naturelles. / The decline of pollinating insects is partly caused by the loss and fragmentation of natural habitats, for which land conversion to the benefit of agricultural intensification and urban expansion plays a key role. This project aims to 1) assess the impact of landscape matrices (agricultural, residential, and industrial) on bee, wasp, and flower fly communities and 2) determine the ecological value of lawns to support those communities compared to semi-natural meadows. We sampled 18 lawns and 18 meadows distributed evenly between agricultural, residential, and industrial areas in the Quebec City Agglomeration to assess the abundance, richness, and composition of bees, wasps, and flower flies. The agricultural environment was harmful for bees and wasps for which a reduction in their abundance and richness was observed compared to residential areas, while the industrial areas limited the abundance and richness of wasps only. Thus, residential neighborhoods offered the greatest potential for maintaining social wasp's diversity and favored the abundance most bee species from the entire agricultural-urban system. Semi-natural meadows were beneficial for the colonization of bees and flower flies having various ecological requirements, while lawns revealed a strong dominance for the bee genus *Lasioglossum* and the flower flies species *Toxomorus marginatus* respectively. Lawn resources were unattractive and sporadically visited by wasps. Our results showed that conservation actions should prioritize landscape management to conserve central-place foragers, such as bees and wasps by increasing natural areas within agricultural and industrial landscapes. Moreover, despite their aesthetic and recreational role, lawns are detrimental to wasp communities and selectively sustain a limited number of bee and flower fly species. Our results highlight the importance of conserving meadows within managed ecosystems.

La population de l'Est de la grue du Canada (Antigone canadensis) est en pleine expansion démographique dans l'Est nord-américain et son aire de répartition géographique s'est récemment élargie au Québec. Cette espèce omnivore et opportuniste niche en milieu humide ouvert et elle peut se nourrir en milieu agricole ce qui crée des conflits avec les agriculteurs dans certaines régions, principalement en Abitibi-Témiscamingue. Dans cette étude, je modélise la dynamique spatiale et temporelle de la grue du Canada du Québec méridional entre 2004 et 2019 et j'identifie les variables d'habitat ayant un effet sur l'occupation par la grue pendant la période de reproduction. Pour ce faire, j'ai construit un modèle prédictif de la colonisation et de l'extinction de la grue afin de déterminer son expansion spatiale ainsi que déterminer s'il y a une préférence pour certains habitats. Pour élaborer les modèles de variabilité spatio-temporelle d'occupation de l'habitat et de colonisation-extinction, j'ai utilisé des bases de données existantes : 1) les données d'inventaire annuel de sauvagine par hélicoptère du Québec méridional d'Environnement et Changement climatique Canada, 2) la base de données du "Deuxième atlas des oiseaux nicheurs du Québec méridional" et 3) les données du projet de science citoyenne eBird. Les résultats obtenus dans cette étude aident à mieux comprendre les facteurs qui ont une influence sur l'occupation, la colonisation et l'extinction de la grue dans le territoire québécois. Dans l'ensemble, cette étude met en lumière des nouvelles informations de l'utilisation de l'habitat de la grue du Canada au Québec et permet de mieux comprendre la dynamique de l'espèce sur le territoire. / The Eastern Population of sandhill cranes(Antigone canadensis) has increased in eastern North America and expanded its range in breeding areas in Quebec, becoming one of the largest species nesting in Quebec. This omnivorous and opportunistic species nests in open wetlands and can feed on agricultural lands, which generates conflicts with farmers in certain regions, mainly in Abitibi-Témiscamingue. In this study, I model the spatial and temporal dynamics of sandhill cranes in Southern Quebec between 2004 and 2019 and I identify the habitat variables at the landscap escale that have an impact on sandhill crane occupancy during the breeding period. To do so, I built a prediction model of the colonization and extinction of cranes to determine its spatial expansion and to identify any preference for certain habitats. To elaborate the patterns of spatio temporal variability of habitat occupancy and of colonization-extinction, I used preexisting datasets, including 1) the data from the Eastern Waterfowl Survey Canadian Wildlife Service, 2) the dataset from the Second Atlas of Breeding Birds of Southern Quebec and 3) data from the citizen science project eBird. Results obtained in this study help to better understand the variables influencing occupancy, colonization and extinction of cranes in southern Quebec. Overall, this study sheds light on the first data about this species in Quebec and allows to better understand the species dynamic on the territory.

Orientadores: Paulo Inácio de Knegt López de Prado, Emerson Monteiro Vieira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-16T00:11:22Z (GMT). No. of bitstreams: 1 Paise_Gabriela_D.pdf: 1506226 bytes, checksum: 2321b37857a637b42de135349a06edea (MD5) Previous issue date: 2010 / Resumo : Os efeitos negativos da fragmentação de habitats sobre pequenos mamíferos são amplamente reconhecidos. Entretanto, a intensidade desses efeitos depende de diversos fatores como o padrão de fragmentação, a escala avaliada, a permeabilidade de diferentes tipos de matrizes e a plasticidade comportamental de diferentes grupos de espécies. Neste estudo avaliamos os efeitos da fragmentação, em uma paisagem extremamente fragmentada de Mata Atlântica, na comunidade de pequenos mamíferos (i) através do uso diferencial de habitats pela comunidade e por guildas de espécies que usam habitats florestais, áreas abertas ou ambos (generalistas); (ii) através dos padrões de utilização de micro-habitats; (iii) através da similaridade na utilização da paisagem, entre sexos e espécies generalistas de habitat, em diferentes escalas espaciais. Nós utilizamos armadilhas de intercepção e queda em seis sítios de amostragem, nos quais avaliamos cinco habitats: floresta com rio, floresta sem rio, borda de floresta, matriz de pasto com rio e matriz de pasto sem rio. Nós detectamos que o habitat mais antrópico e inóspito, a matriz sem rio, suportou menor abundância de espécies. As guildas de espécies responderam diferentemente aos habitats da paisagem. Houve menor tolerância das espécies florestais ao habitat matriz sem rio. Até mesmo as espécies generalistas sofrem os efeitos negativos da matriz sem rio, diminuindo em abundância. Um pequeno aumento na estrutura da vegetação, como observado nas matrizes ripárias, mitigam o efeito negativo da matriz, tornando a abundância, riqueza e diversidade da matriz com rio comparável aos habitats florestais. A riqueza e abundância das guildas de espécies associadas à macro-habitats foram em geral influenciadas pela estrutura da vegetação em escala de micro-habitats e revelam um alto grau de especificidade de micro e macro-habitat. Esta especificidade mostra que, mesmo em paisagens altamente fragmentadas e alteradas, não ocorre a invasão das áreas florestais pela guilda de espécies de áreas abertas e que guildas de espécies florestais são incapazes de utilizar micro-habitats extremamente modificados. Nossos resultados indicam que a similaridade na utilização da paisagem varia entre espécies e sexos, entre diferentes escalas espaciais e pode ser fortemente dependente do padrão de fragmentação. O manejo das paisagens fragmentadas requer a existência de matrizes permeáveis, como a matriz de pasto com rio, as quais poderão funcionar como habitats potenciais, diminuindo a divisão da paisagem e facilitando a manutenção da comunidade original na paisagem fragmentada. / Abstract: The negative effects of habitat fragmentation on small-mammals are widely recognized. Nevertheless, the intensity of these effects depend on multiple factors such as the pattern of fragmentation, the evaluated scale, the permeability of different types of matrices, and the behavioral plasticity of different groups of species. In this study, we evaluated the effects of fragmentation on the community of small-mammals in a severely fragmented landscape of Brazilian Atlantic forest (i) through the differential use of habitats by the small-mammal community and by small-mammal guilds that use forest habitats, open areas or both (generalists); (ii) through the patterns of utilization of micro-habitats by small-mammal guilds; (iii) through the similarity in the use of the landscape, between sexes and generalist species in different space scales. We used pitfall traps installed in six sites. In each site, we sampled five habitats: forest fragments with streams, forest fragments without streams, forest edge, pasture matrix with streams, and pasture matrix without streams. We have detected that the pasture matrix without streams harbored lower species abundance than all other landscape units. The guilds responded differently to the different landscape units. The pasture matrix without streams is inhospitable for forest species which, even for generalists, suffer their effect, decreasing in abundance. A slight increase in the complexity of the vegetation, as observed in riparian matrices, mitigates its negative effect, making the abundance, richness and diversity of matrices with streams comparable to forest habitats. The richness and the abundance of macro-habitat-related guilds were, in general, influenced by the complexity of vegetation into the micro-habitat's scale and revealed a high degree of specificities of the macro- and micro-habitats. This specificity shows that, even in highly fragmented and altered landscapes, the invasion of forest habitats by open-area dwellers does not occur and that the forest dwellers are incapable to use the severely altered micro-habitats. Our results also indicate that in highly fragmented landscapes, the similarity in the use of the landscape varies between species and sexes, among different space scales, and can be strongly dependent on the pattern of fragmentation. The management of fragmented landscapes requires the existence of permeable matrices, as the pasture matrix with stream, which may function as potential habitat, decreasing the division of the landscape and facilitating the maintenance of the original community in the fragmented landscape. / Doutorado / Ecologia / Doutor em Ecologia

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Varying numbers of adult desert pupfish (Cyprinodon macularius) and mosquitofish (Gambusia affinis) were introduced separately into experimental habitats open to egress to determine resource requirements for each species and the relation between numbers and resources. Laboratory environments in which "voluntary" colonization was achieved, were created for both species. Results indicated that both species have the innate ability to regulate numbers in their respective populations to available resources via emigration. The number of resident fish varied directly with experimental reductions of cover. When adult mosquitofish were introduced into open tanks with established populations of adult desert pupfish in habitats containing constant resources, there was no significant change in population size for either species as compared to single species populations over a 5-day period. Adult desert pupfish and mosquitofish are able to coexist successfully in habitats open to egress for 5 days because they utilize available resources in very different ways and the number of fish that become residents do not go beyond resource limits. These data suggest that replacement of desert pupfish by mosquitofish in the American Southwest is a phenomenon that is the result of more long-term interactions between all life stages of the species and may be more likely to occur in environments of low complexity and closed to egress.