Submitted by Mariana Dornelles Vargas (marianadv) on 2015-05-04T14:37:06Z No. of bitstreams: 1 ecologia_reprodutiva.pdf: 5894767 bytes, checksum: fbc8661025167b9eb4559c7b3bbbb661 (MD5) / Made available in DSpace on 2015-05-04T14:37:06Z (GMT). No. of bitstreams: 1 ecologia_reprodutiva.pdf: 5894767 bytes, checksum: fbc8661025167b9eb4559c7b3bbbb661 (MD5) Previous issue date: 2011 / Nenhuma / A variação nos padrões de larga escala, como o clima e a disponibilidade de recursos, podem influenciar a fenologia e o sucesso reprodutivo dos indivíduos. Em menor escala, características como qualidade do adulto, composição e localização dos ninhos são cruciais para o sucesso reprodutivo. O objetivo do estudo é descrever a fenologia e avaliar o sucesso reprodutivo de Skua Marrom na Ilha Elefante, Arquipélago das Shetlands do Sul, além de avaliar algumas características dos ninhos que podem influenciar a variação destes fatores. Os dados foram coletados em 2009/10 e 2010/11, em Stinker Point, Ilha Elefante, sendo monitorados periodicamente 37 e 40 pares reprodutivos, respectivamente. A cada visita foram registradas as datas de postura, de nascimento, o número de ovos e filhotes nos ninhos. A posição geográfica dos ninhos e das colônias de aves reprodutivas (recursos) foi registrada com receptor de GPS. As distâncias dos ninhos para os recursos e para o vizinho mais próximo (DVProx) foram calculadas no software Arcgis. A proporção dos componentes dos ninhos (musgos, líquens e rochas) foi obtida através do processamento das fotografias dos ninhos no software Envi. Nenhum padrão, que relacione estes componentes às datas de postura e ao sucesso reprodutivo, foi constatado. A postura dos ovos ocorreu, em média, na primeira quinzena de dezembro. O sucesso reprodutivo variou significativamente entre estações (χ2=20,25 P<0,001) e a probabilidade de sobrevivência dos filhotes em relação a data de postura dos ovos (Nagelkerke R²=0.137 P=0,01), sendo maior nos meses de dezembro, independente do período (Nagelkerke R²= 0.137 P= 0,01). Observou-se uma relação significativa entre o sucesso reprodutivo e a distância da colônia de Pygoscelis antarctica em 2009/10 (Nagelkerke R2=0,20 P=0,03) e em 2010/11 (Nagelkerke R²=0.177 P=0,02). A DVProx influenciou negativamente na sobrevivência dos filhotes (Nagelkerke R2=0,30 P=0,02). As distâncias dos recursos e DVProx não variaram em relação às datas de postura. A menor probabilidade de sobrevivência dos filhotes mais próximos aos recursos não corrobora com o descrito na literatura, porém, dois fatores observados podem justificar tal padrão: ninhos próximos aos recursos estão mais agregados, aumentando a competição e predação intraespecífica; e o acesso à informação social, observado através da diferença nas datas de postura, resulta na maior concentração de indivíduos nestes locais, e consequentemente em diferentes probabilidades de sobrevivência dos filhotes. / Large scale patterns, as climate and resources show time fluctuations, what can influence individuals phenology and reproductive success. On a smaller scale, factors like adult quality, nest composition and location are also important to reproductive success. We aim to describe and evaluate Brown Skua phenology and reproductive success at Elephant Island, South Shetlands, and to evaluate how some nests characteristics can influence those factors fluctuations. Data were collected at 2009/10 and 2010/11 reproductive seasons at Stinker Point, Elephant Island, where 37 and 40 reproductive pairs were monitored each season. Laying and hatching date, number of chicks and eggs were recorded each nest visit. Nests and other seabird colonies (resources) location were recorded using a handheld GPS receiver. Distances of the nests to resources and to the nearest neighbor (NND) were calculated by means of Arcgis software. Nest components proportion (mosses, lichens and rocks) were obtained through photo classification at Envi software. There is no pattern on egg laying date and reproductive success in relation to nest components. Mean egg laying date were at early December. Reproductive success differed between seasons (χ2=20,25 P<0,001) and chick survival probability varied according to laying order (Nagelkerke R²=0.137 P=0,01), being higher at December both seasons (Nagelkerke R²= 0.137 P= 0,01). Reproductive success was related to the distance from nests to Pygoscelis antarctica breeding colonies at 2009/10 (Nagelkerke R2=0,20 P=0,03) and 2010/11 (Nagelkerke R²=0.177 P=0,02). NND were negatively correlated to chick survival (Nagelkerke R2=0,30 P=0,02). Egg laying date did not differ according to NND neither according to nest distance from other seabirds breeding colonies. We found a lower chick survival probability at nests closer to recourses, what differ from what is described at literature, nevertheless, two factors observed could explain this pattern, which are: nests located near to resources are found to be densely distributed, what increases competition and conspecific predation; social information access, based on egg laying date, results on a higher nests concentration and consequently on different chick survival probabilities.

This project describes various aspects of the breeding ecology and behaviour of the brown falcon Falco berigora, a common but poorly study Australian raptor. In particular it examines (a) the main influences on reproductive success; (b) tests predictions of theories proposed to explain the evolution and maintenance of sexual size dimorphism (RSD; females the larger sex) in raptors; and (c) investigates sex allocation patterns in the light of current sex ratio and parental investment theory. The study was conducted between July 1999 and June 2002 approximately 35 km southwest of Melbourne, at the Western Treatment Plant (WTP), Werribee (38°0’S 144°34’E) and surrounds, a total area of approximately 150 km2.¶ · In all plumage and bare part colouration of 160 free-flying falcons was described. The majority of variation in these characters could be attributed to distinct age and/or sex differences as opposed to previously described colour ‘morphs’.¶ · Nestling chronology and development is described and formulae based on wing length derived for determining nestling age. An accurate field-based test for determining nestling sex at banding age is also presented.¶ · Strong sex role differentiation was apparent during breeding; typical of falcons females performed most parental duties whilst males predominantly hunted for their brood and partner. Based on observations of marked individuals, both sexes of brown falcons aggressively defended mutual territories throughout the year, with just 10% of each sex changing territories during the entire study period. Males performed territorial displays more frequently than females, the latter rarely displaying alone.¶ · The diet of the population as a whole was very broad, but within pairs both sexes predominantly specialised on either lagomorphs, small ground prey (e.g. house mice Mus musculus), small birds, large birds or reptiles, according to availability.¶ · Reproductive parameters such as clutch size and the duration of parental care were constant across all years, however marked annual differences in brood size and the proportion of pairs breeding were evident.¶ · Age was an important influence upon reproductive success and survival, with immature birds inferior to adults in both areas. However, interannual differences were by far the most influential factor on breeding success and female survival. Heavy rain downpours were implicated as the main determinant of reproductive success and adult female mortality in a population largely devoid of predation or human interference.¶ · Female-female competition for territorial vacancies was intense; larger adult females were more likely to be recruited and once breeding fledged more offspring. In contrast, male recruitment and breeding success was unrelated to either body size or condition indices, although smaller immature males were more likely to survive to the next breeding season. This directional selection is consistent only with the predictions of the intrasexual competition hypothesis.¶ · Despite marked RSD (males c. 75% of female body mass), throughout the nestling phase female nestlings did not require greater quantities of food than their male siblings. However, female parents fed their last-hatched sons but not daughters, resulting in the complete mortality of all last-hatched female offspring in focal nests. Given last-hatched nestlings suffered markedly reduced growth rates and female, but not male, body size is important in determining recruitment patterns, the biased allocation amongst last-hatched offspring is likely to reflect differing benefits associated with investing in small members of each sex, consistent with broad-scale Trivers-Willard effects. Recruitment patterns support this, with surviving last-hatched females, in contrast to males, unable to gain recruitment into the breeding population upon their return to the study site.¶ Thus selection appears to act at the nestling, immature and adult stages to maintain RSD in the focal population. Larger females were favoured in the nestling phase, at recruitment and once breeding had greater reproductive success. In contrast, selection favoured a reduction or maintenance of immature male size as smaller birds had a greater chance of survival in the year following recruitment than their larger counterparts; thereafter male size was unimportant. Together, this directional selection favouring increased female competitive ability is consistent only with the predictions of the intrasexual competition hypothesis, which appears the most probable in explaining the maintenance and perhaps evolution of RSD in raptors.

<p>Pollination is one of the most important factors determining the reproductive success of plants. This thesis examines processes associated to varying pollination, with focus on plant responses. The first aim was to examine the possibility and constraints for short-term evolution of flower size in <i>Raphanus raphanistrum</i>. The results showed that there exists a possibility for pollinator-mediated short-term evolution of flower size in the study species. Flower size was strongly correlated to plant size. Since flower size cannot evolve separately from plant size, this correlation may constitute a constraint to the evolution of flower size. The second aim was to determine how varying pollen load affects later flowering, reproduction and growth of maternal plants. High pollen load treatment resulted in larger or more flowers on late flowers, which may enhance pollen dispersal and reproductive success, while the total seed mass was the same between treatments. The results indicate that the study species <i>R. raphanistrum</i>, <i>Sinapis arvensis</i> and <i>Brassica napus</i> have plastic responses in floral traits according to the present pollination level. The third aim was to determine how varying pollen load affects seed quality and offspring vigor. The results suggest that high pollen load had no positive effects on seed quality or offspring vigor due to pollen competition. Instead, seed mass determined seed quality and offspring vigor in the three study species and low pollen load treatment resulted in highquality offspring due to heavier seeds. The fourth aim was to examine causes and consequences of variation in reproductive success of <i>Succisa pratensis</i> on a regional scale. The results suggest that the most important variables, on a regional scale, for reproductive success were population size and habitat quality. The results showed that seed weight variation might be important when assessing reproductive success. In this study, seed weight variation did not seem to be adaptive.</p>

Pollination is one of the most important factors determining the reproductive success of plants. This thesis examines processes associated to varying pollination, with focus on plant responses. The first aim was to examine the possibility and constraints for short-term evolution of flower size in Raphanus raphanistrum. The results showed that there exists a possibility for pollinator-mediated short-term evolution of flower size in the study species. Flower size was strongly correlated to plant size. Since flower size cannot evolve separately from plant size, this correlation may constitute a constraint to the evolution of flower size. The second aim was to determine how varying pollen load affects later flowering, reproduction and growth of maternal plants. High pollen load treatment resulted in larger or more flowers on late flowers, which may enhance pollen dispersal and reproductive success, while the total seed mass was the same between treatments. The results indicate that the study species R. raphanistrum, Sinapis arvensis and Brassica napus have plastic responses in floral traits according to the present pollination level. The third aim was to determine how varying pollen load affects seed quality and offspring vigor. The results suggest that high pollen load had no positive effects on seed quality or offspring vigor due to pollen competition. Instead, seed mass determined seed quality and offspring vigor in the three study species and low pollen load treatment resulted in highquality offspring due to heavier seeds. The fourth aim was to examine causes and consequences of variation in reproductive success of Succisa pratensis on a regional scale. The results suggest that the most important variables, on a regional scale, for reproductive success were population size and habitat quality. The results showed that seed weight variation might be important when assessing reproductive success. In this study, seed weight variation did not seem to be adaptive.

The health of Florida's beaches are vital to the survival of loggerhead sea turtles (Caretta caretta), as nearly half of the world's loggerheads nest on the states beaches. Many of the beaches utilized by the turtles have undergone nourishment projects in hopes of combating erosion of the shoreline, protecting beachfront property, and creating more suitable beaches for tourism. Although it is argued that beach nourishment benefits sea turtles by providing more nesting habitat, the effects of the Pinellas County nourishment projects on loggerhead nesting are unknown. Beach nourishment can alter the compaction, moisture content, and temperature of the sand, all of which are variables that can affect nest site selection and the proper development of eggs. This research has four objectives: (1) to create a GIS dataset using historic loggerhead sea turtle data collected at the individual nest level along the West coast of Florida, (2) to examine the densities of loggerhead nests, the densities of false crawls (i.e. unsuccessful nesting attempts), and the nest-to-false crawl ratio on natural and nourished beaches for the 2006-2010 nesting seasons; (3) to determine the effects of beach nourishment projects on the hatchling success rates and emergence success rates; and (4) to determine areas preferred or avoided by turtles for nesting. The study found that nesting and false crawl densities significantly differed between natural and nourished beaches during three of the five nesting seasons. Nesting densities increased directly following nourishment and false crawl densities were higher in nourishment areas during every nesting season. False crawl densities were higher than statistically expected on nourished beaches and lower than expected on natural beaches. No significant differences were found between hatchling and emergence success rates between natural and nourished beaches. However, when the rates were analyzed by nesting season, the average hatching and emergence success rates were always lower on nourished beaches than on natural beaches. A hotspot analysis on nests and false crawls revealed that turtles preferred natural beaches that border nourished areas for nesting while false crawls were more evenly distributed through the study area. Although this study documents the negative effects of beach nourishment on loggerhead sea turtle nesting, nourishment projects are likely to continue because of their benefits to human populations. Further examining of the impacts that humans have on nesting and developing loggerheads will ultimately aid policy formation as we continue to manage and protect the future of the species.

No description available.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Body size is an important determinant of reproduction in capital breeding animals, including large mammals. However, it is not always practical to hand-measure body size of free-ranging species. In recent years, parallel-laser photogrammetry has been used to obtain remote estimates of body size for some animals, though it remains unknown how well this technique might capture variation in curvilinear body features or if the distance between parallel-laser calipers is altered when projected onto a curved surface. In this thesis, I describe a photogrammetric system that may be useful for obtaining body-size measurements from unrestrained large mammals that permit approach, using domestic horses (Equus ferus caballus) as a model (Chapter 2). I then apply this technique in the field to a wild (feral) population of horses at Sable Island National Park Reserve, Nova Scotia, Canada, where I include body size measurements as variables in a detailed analysis of factors affecting reproduction in females (Chapter 3). Using my parallel-laser photogrammetric system, I show how curvilinear hand-measurements (e.g., across the barrel of a horse) are stongly correlated with their respective linear photogrammetric estimates (R2 ≥ 0.998), and most photogrammetric estimates using my system had high reliability. Using three variables of body size, photogrammetric estimates and hand-measurements explained 86.0% and 96.2%, respectively, of the variation in body weight of a sample of domestic Newfoundland ponies. On Sable Island, Nova Scotia, I examined the relationship of numerous variables (including skeletal body size and body condition) with the probability of yearly reproductive success for female Sable Island horses (years 2008–2012), where I define reproductive success as production of an offspring surviving to one year of age. Age class was a dominant factor predicting reproductive success, as expected from trends previously associated with body size or reproductive experience iii in other populations. Age-class specific energy budgets or social and sexual behaviour caused a more pronounced relationship with body condition at parturition in sub-adults, and body condition at conception and stability of consort relationships were associated with reproductive success in adults. In addition, relationships with local density suggested limited forage around the time of conception and limited water during lactation might also influence reproductive success in adult females. Although relationships were evident for age class, which is correlated with body size, reproductive success was not related to skeletal body size, past reproductive experience, age of primiparity, or band structure. The capital breeding strategy and year-round social associations seen in horses make their reproductive ecology a combination of patterns observed for large ungulates and social primates.

In this thesis, I combined field, common-garden and greenhouse experiments to examine the ecological and evolutionary consequences of plant-herbivore interactions in the perennial herb Lythrum salicaria. More specifically I examined (1) whether resistance and tolerance to damage from herbivores vary with latitude and are positively related to the intensity of herbivory in natural populations, (2) whether effects of herbivory on plant fitness vary with latitude, (3) whether populations are locally adapted and whether herbivory influences the relative fitness of populations, and (4) whether the intensity and effects of insect herbivory on reproductive output vary locally along a disturbance gradient and are associated with differences in plant resistance. A common-garden and a greenhouse experiment demonstrated that plant resistance decreased whereas plant tolerance increased with latitude of origin among populations sampled along a latitudinal gradient in Sweden. Oviposition and feeding preference in the greenhouse and leaf damage in the common-garden experiment were negatively related to natural damage in the source populations. Experimental removal of insect herbivores in three populations sampled along the latitudinal gradient demonstrated that intensity of herbivory and its effects on plant fitness decreased towards the north. A reciprocal transplant experiment among the same three populations showed that herbivory affected the relative fitness of the three populations, but did not detect any evidence of local adaptation. Instead the southernmost population had the highest relative fitness at all three sites. A herbivore-removal experiment conducted in nine populations in an archipelago in northern Sweden demonstrated that insect herbivory strongly influenced among-population variation in reproductive output. However, variation in resistance was not related to differences in intensity of herbivory at this spatial scale. Taken together, the results demonstrate that resistance and tolerance to herbivory vary with latitude but in opposite directions, that intensity of herbivory is a major determinant of flowering and seed output, and that the strength of herbivore-mediated selection varies among populations in Lythrum salicaria. They further indicate that both physical disturbance regime and latitudinal variation in abiotic conditions may strongly influence the performance and abundance of perennial herbs because of their effects on interactions with specialized herbivores.

Roe deer give birth each year in May. At each reproductive event, a female can be in different reproductive statuses: breeder or non breeder and can wean a variable number of offspring. The successive transitions between the different statuses of a given female give its individual reproductive trajectory. The performance of a given trajectory is assessed by its fitness which can be approximated by the total number of offspring weaned during the trajectory. Different individual life-history trajectories can exist in a same population and these different trajectories can reach similar or different fitness. This suggests that different strategies can be chosen by different individuals to reach the same fitness but also that individuals of high quality can reach higher fitness than individuals of low quality. The study of a roe deer population located in North-Eastern France allowed analyzing the sources and the consequences of individual heterogeneity on individual life-history trajectories and on population dynamics. This work showed that roe deer individual reproductive trajectories are consistent for a given female such as high quality females have an annual reproductive success higher than low-quality females. Female quality is partly generated by birth condition such as birth date and environmental conditions at birth. Individual life-history trajectories vary also randomly in relation to annual environmental conditions. In particular, climate change led to a decline in annual mean reproductive success and a decrease of the population growth rate in the last decades in relation to an increase of the mismatch between vegetation phenology and roe deer birth period. This work discussed how individual heterogeneity is generated in a long-lived species and how it influences individual life-history strategies and population dynamics