Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-07-31T21:39:35Z No. of bitstreams: 1 Disserta??o Final_Fernando Flores.pdf: 2552427 bytes, checksum: 56e64e9a4e8e38fa82bdf2d85f521c8b (MD5) / Made available in DSpace on 2015-07-31T21:39:35Z (GMT). No. of bitstreams: 1 Disserta??o Final_Fernando Flores.pdf: 2552427 bytes, checksum: 56e64e9a4e8e38fa82bdf2d85f521c8b (MD5) Previous issue date: 2014-03-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Mixed flocks of birds are clusters of two or more species whose formation and cohesion depend on behavioral interactions among members. This study investigated the specific composition of mixed flocks in the Atlantic Forest area of Bahia, Brazil, considering the seasonal dynamics of flocks, the vertical distribution of their species, and the determination of species-nucleus, which are responsible for attracting and maintaining the cohesionof other species flocks. From August 2012 to August 2013, monthly expeditions of five days were conducted at the region of the Ecopolo I,in Pratigi Environmental Protection Area (Ibirapitanga, Bahia).The following data were recorded for each mixed-flock contacted: the specific composition, the number of individuals of each species and, when it was possible, the height of foraging, the occurrence of agonistic interactions, estimated intensity of movement and vocalization for each species. Furthermore, the contacts of mixed-flocks component species were recorded when they were seen out of the flocks, observing the foraging height and evidences of reproductive behavior.Was registered 113 contacts with mixed flocks, with a total of 51 species of birds, representing about 30% of the species recorded in the study area.In flocks, the most representative families were Thraupidae and Thamnophilidae - counting this one with two endangered species. Mixed flocks occurred throughout the whole year, being more frequent in August and less frequent from September to April.Due to the constantly rainfall throughoutyear in the study area, there was no correlation between frequency, richness and size of flocks with the monthly pluviosity. There was a negative correlation with the frequency of flocks and temperature. The richness and the size of flocks did not correlate with the temperature.The average richness in flocks was 5,1 ? 2,6 species, and the average size of 5 ? 5,2, individuals, these two variables were correlated positively (r = 0.81, p = <0.0001). The richness was different between the vegetation strato, being the understory flocks richer than the ones in canopy. However, in relation to size of individual numbers, the understory and canopy flocks didn?t present significant difference, because the canopy flocks were composed by a great number of Thraupidaespecies, that happened in large intraspecific group. Inside or outside of mixed flocks, all species foraged in the same height range of vegetation.Among the five most frequent flocks species, three were considered to be species-nucleus(Herpsilochmus rufimarginatus, Lanio cristatusandMyrmotherula urosticta),presenting a higher degree of associations between all species, and capable of recruiting more species for flocks when they took place; flocks where these species-nucleus occurred were richer, indicating that, when put together, these species increased the ability to recruit other species. / Bandos mistos de aves s?o agrupamentos de duas ou mais esp?cies cuja forma??o e coes?o se devema intera??es comportamentais entre seus integrantes. Este estudo investigou a composi??o espec?fica dos bandos mistos em uma ?rea de Mata Atl?ntica da Bahia, considerando a din?mica sazonal dos bandos, a distribui??o vertical de suas esp?cies e a determina??o das esp?cies-n?cleo, que s?o as respons?veis por atrair e manter coesas as demais esp?cies nos bandos. Foram realizadas, de agosto de 2012 a agosto de 2013, expedi??es mensais de cinco dias para a regi?o do Ecopolo I da ?rea de Prote??o Ambiental do Pratigi (Ibirapitanga, Bahia), quando eram registrados os dados de cada bando misto contatado: composi??o espec?fica, n?mero de indiv?duos de cada esp?cie e, sempre que poss?vel, a altura de forrageamento, a ocorr?ncia de agonismos e intensidades estimadas de movimenta??o e vocaliza??o de cada esp?cie; al?m disto, eram registrados os contatos com as esp?cies participantes de bandos mistos quando vistas fora destes, sendo observadas suas alturas de forrageio e evid?ncias de comportamentos reprodutivos. Foram feitos 113 contatos com bandos mistos, dos quais 51 esp?cies de aves, que representam cerca de 30% das esp?cies registradas na ?rea de estudo, participaram. Nos bandos, as fam?lias mais representadas foram Thraupidae e Thamnophilidae ? dentre esta ?ltima, duas esp?cies amea?adas de extin??o. Os bandos mistos ocorreram durante o ano todo, sendo mais frequentes no m?s de agosto e menos frequentes nos meses de setembro a abril. Devido ? ocorr?ncia de chuvas ao longo do ano todo na ?rea de estudo, n?o houve correla??o entre frequ?ncia, riqueza e tamanho dos bandos com a pluviosidade mensal; houve correla??o negativa entre a frequ?ncia dos bandos e a temperatura, n?o havendo correla??o da temperatura com riqueza e tamanho dos bandos. A riqueza m?dia nos bandos foi 5,1? 2,6esp?cies e o tamanho m?dio de,5 ? 5,2, indiv?duos, sendo estas duas vari?veis correlacionadas positivamente(r = 0,81; p = < 0,0001). Houve diferen?a na riqueza entre os estratos da vegeta??o, sendo que no sub-bosque os bandos eram mais ricos que os de dossel. No entanto, quanto ao tamanho, em n?mero de indiv?duos, os bandos de sub-bosque e dossel n?o apresentaram diferen?a significativa, pois os bandos de dossel eram compostos por um grande n?mero de esp?cies de traup?deos que ocorriam em grupos intraespec?ficos grandes. Dentro ou fora dos bandos mistos, todas as esp?cies forrageavam na mesma faixa de altura da vegeta??o. Das cinco esp?cies mais frequentes nos bandos, tr?s foram consideradas como esp?cies-n?cleo (Herpsilochmus rufimarginatus, Lanio cristatus e Myrmotherula urosticta), apresentando um maior grau de associa??es entre todas as esp?cies e capazes de arregimentar mais esp?cies para os bandos onde ocorriam; os bandos onde estas esp?cies-n?cleo ocorriam eram mais ricos, indicando que, quando juntas, estas esp?cies aumentavam a capacidade de arregimentar outras esp?cies.

The urbanised environment provides ecologists with unique situations in which to undertake ecological study. It has been said that urbanisation is like a natural experiment; we often have populations of animals that have gone from living in natural or semi-natural environments to living in a highly modified anthropogenic environment. These situations provide ideal settings to study the ecological and behavioural differences that may develop in populations located in different habitats. Urbanisation typically results in a minority of species dominating the fauna, and this thesis aimed to examine one such species, the Australian magpie. Despite the magpie being a common and well-liked suburban bird, the majority of previous research on this species has been undertaken within rural or exurban locations. This thesis aimed to examine what actually happens to the species when it lives in the suburban environment. In particular I focused on specific behavioural and ecological features, to see if there were any particular adaptations the suburban magpies showed and also if the suburban habitats provide certain resources favourable to the magpies and what ecological effects these may have. Comparisons of the territory structure and resources of rural and suburban magpies showed that although many features of the territory are similar between rural and suburban locations, notably the choice of native nest trees, magpie territories within suburban areas were smaller and contained more anthropogenic features. The reduced territory size may possibly be related to a greater abundance of key food resources also evident within suburban areas. Furthermore, suburban magpies are more successful in their foraging attempts, again possibly reflecting a more abundant food supply in suburbia and also the simplified nature of suburban foraging areas might facilitate more successful foraging. The increased foraging success is likely to explain the greater provisioning rate to nestling suburban magpies. Suburban magpies also utilised human provided foods. I quantified the extent of wildlife feeding within many of the suburban study sites of this thesis (through the use of questionnaire surveys). In each of the locations it was evident that at least one person (usually more) was providing a regular supply of food to wildlife and magpies appeared to be the main recipients of this food. Previous ecological studies suggest the provision of extra food to avian populations is likely to affect the breeding ecology, and this was so for magpies. The suburban populations initiated breeding significantly earlier than rural magpies. To test the influence of food, supplementary food was provided to rural magpies, not currently receiving any additional human provided foods. The fed rural magpies initiated breeding before control rural magpies (i.e. not receiving any additional food) but suburban magpies still initiated breeding before all other groups. This suggests additional factors present within suburbia, such as warmer temperatures, may also control the timing of breeding in magpies. Magpies in rural and suburban locations lived within different vertebrate communities. Within suburban magpie territories a greater number of intrusions were made by domestic animals, notably dogs (Canis lupus) and cats (Felis domesticus). The frequency of raptors entering the territorial areas occupied by magpies appears to suggest such events are more common in rural areas. The number of humans entering magpie territories was obviously greater in the more populated suburban areas and the majority of magpies responded neutrally to humans. However a group of magpies that previously exhibited extreme aggression towards humans were found to have a greater frequency of aggressive interactions with potential predatory intruders, which were primarily humans. Subsequent examination of the level of corticosterone from this aggressive group of magpies found that a high level of aggressive interactions with potential predators and humans is reflected in higher level of corticosterone, which may have implications for further behavioural and even physiological changes. An ability to habituate to human in urbanised areas is a key attribute of successful synanthropic species. Comparisons of magpies disturbance distances at different points along the urban gradient (the gradient that runs from the urbaised city to natural wildlands) found suburban magpies only responded to humans when they had approached to a close distance (often less than one metre) and many simply walked away to avoid the approaching human. Rural and exurban magpies responded to humans at greater distances than suburban magpies. The distance at which they responded to the human was usually 100 meters plus, and these magpies always flew away. A continuation of this investigation over a temporal scale again found the large difference in response to humans, with suburban magpies exhibiting a decreased response towards humans. However, a certain proportion of responses from suburban magpies were also aggressive. The examination of disturbance distance over the breeding season found that in suburban magpies the responses of most disturbance distance variables remained similar between breeding stages. Rural magpies, however, exhibited variation in their responses towards humans depending on the stage of breeding. It is suggested that the response of rural magpies may be a typical fear response towards an unusual potential threat. The studies presented in this thesis show that magpies have the behavioural capacity to take advantage of resources in suburban landscapes that are not available or are in lessor supply in rural landscapes, it is these abilities that facilitate the magpies synanthropy.

<p>This thesis is a summary of enclosure and microcosm experiments that aimed to study the impact of allochtonous subsidies on food web dynamics in a heterogeneous food web. In the enclosure studies, a three trophic level littoral food web was used. The food web consisted of two growth forms of primary producers: phytoplankton and periphyton and their associated herbivores: scraping and filtering herbivores. The predator used, YOY perch, affects both pathways in the food web. Manipulation of the openness for the different trophic levels showed that the inflow of phytoplankton and cross-habitat foraging by the herbivore level reinforced the compensatory response between the two growth forms of primary producers </p><p>In the microcosm experiment, the response of an herbivore food web and a microbial community to inflow of resources and food web configuration was studied, using a model food web. The model food web consisted of two forms of primary producers, i.e. phytoplankton and periphyton, and two herbivores, i.e. <i>Daphnia pulex</i> feeding on phytoplankton, and <i>Chydorus sphaericus</i> feeding on both periphyton and phytoplankton. Three different food web configurations, all having the phytoplankton and periphyton, but either one of the herbivores, or both, were set up. The flow regimes consisted of an open treatment receiving a constant supply of phytoplankton, and a closed treatment with an initial resource pool. The effect of the inflow of phytoplankton was affected by the food web configuration. In the presence of <i>D. pulex</i>, the inflow of phytoplankton was made accessible to periphyton, and indirectly to <i>C. sphaericus</i>, which increased to such high densities that <i>D. pulex</i> was negatively affected. The inflow of phytoplankton had an indirect negative effect on the microbial community, since the biomass of herbivores increased, which imposed a higher grazing pressure on all parts of the microbial community.</p>

<p>About 70% of the plant species in the temperate zone are characterised by clonal growth, clonal species are also in majority in the Arctic and Subarctic where they affect the structure and composition of the vegetation. It is therefore of great importance to increase our knowledge about clonal plants and their growth and life histories. I have investigated how ramets of the stoloniferous plant <i>Linnaea borealis</i> are affected by the naturally occurring variation in environmental factors, such as: light, nutrient and water availability. Moreover, I examined the seed set and how supplemental hand pollination affects seed set in <i>L. borealis</i>, and also investigated the significance of the apical meristem for shoot population fitness. All studies were performed under field conditions in northern Sweden in a Subarctic environment and most are experimental.</p><p>The results show that nutrient resorption from senescing leaves is not significantly affecting the growth and nutrient pools of the ramet. This implies that the growth of<i> L. borealis </i>ramets is not governed by micro-site resource availability. However, removal of light competition resulted in increased branching and number of lateral meristems produced, reduced growth, and decreased root:shoot ratio on a per ramet basis. Thus, ramets of <i>L. borealis </i>can efficiently exploit favourable light patches through plastic growth. Apical dominance exerts a significant effect on shoot population fitness and can be lost through rodent grazing. However, loss of apical dominance is dependent on the timing of grazing, if the apical meristem is removed early in the autumn the ramet can repair the loss until the next summer. If grazing occur during spring the dry weight and leaf area production is affected negatively. Seed production in <i>L. borealis</i> in the Abisko area varies between years and sites, and was unaffected by supplemental hand pollination treatment, implying that there is no lack of pollinator activity.</p>

About 70% of the plant species in the temperate zone are characterised by clonal growth, clonal species are also in majority in the Arctic and Subarctic where they affect the structure and composition of the vegetation. It is therefore of great importance to increase our knowledge about clonal plants and their growth and life histories. I have investigated how ramets of the stoloniferous plant Linnaea borealis are affected by the naturally occurring variation in environmental factors, such as: light, nutrient and water availability. Moreover, I examined the seed set and how supplemental hand pollination affects seed set in L. borealis, and also investigated the significance of the apical meristem for shoot population fitness. All studies were performed under field conditions in northern Sweden in a Subarctic environment and most are experimental. The results show that nutrient resorption from senescing leaves is not significantly affecting the growth and nutrient pools of the ramet. This implies that the growth of L. borealis ramets is not governed by micro-site resource availability. However, removal of light competition resulted in increased branching and number of lateral meristems produced, reduced growth, and decreased root:shoot ratio on a per ramet basis. Thus, ramets of L. borealis can efficiently exploit favourable light patches through plastic growth. Apical dominance exerts a significant effect on shoot population fitness and can be lost through rodent grazing. However, loss of apical dominance is dependent on the timing of grazing, if the apical meristem is removed early in the autumn the ramet can repair the loss until the next summer. If grazing occur during spring the dry weight and leaf area production is affected negatively. Seed production in L. borealis in the Abisko area varies between years and sites, and was unaffected by supplemental hand pollination treatment, implying that there is no lack of pollinator activity.

This thesis is a summary of enclosure and microcosm experiments that aimed to study the impact of allochtonous subsidies on food web dynamics in a heterogeneous food web. In the enclosure studies, a three trophic level littoral food web was used. The food web consisted of two growth forms of primary producers: phytoplankton and periphyton and their associated herbivores: scraping and filtering herbivores. The predator used, YOY perch, affects both pathways in the food web. Manipulation of the openness for the different trophic levels showed that the inflow of phytoplankton and cross-habitat foraging by the herbivore level reinforced the compensatory response between the two growth forms of primary producers In the microcosm experiment, the response of an herbivore food web and a microbial community to inflow of resources and food web configuration was studied, using a model food web. The model food web consisted of two forms of primary producers, i.e. phytoplankton and periphyton, and two herbivores, i.e. Daphnia pulex feeding on phytoplankton, and Chydorus sphaericus feeding on both periphyton and phytoplankton. Three different food web configurations, all having the phytoplankton and periphyton, but either one of the herbivores, or both, were set up. The flow regimes consisted of an open treatment receiving a constant supply of phytoplankton, and a closed treatment with an initial resource pool. The effect of the inflow of phytoplankton was affected by the food web configuration. In the presence of D. pulex, the inflow of phytoplankton was made accessible to periphyton, and indirectly to C. sphaericus, which increased to such high densities that D. pulex was negatively affected. The inflow of phytoplankton had an indirect negative effect on the microbial community, since the biomass of herbivores increased, which imposed a higher grazing pressure on all parts of the microbial community.

Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to the significance of their role as pollinators in managed and native ecosystems. As a result, conservation efforts have been undertaken to preserve them. While considerable attention has been given to honey bees, relatively little is known about many native bee species. Of particular interest is the family Halictidae, which can comprise the majority of observed individuals in many habitats. These, often small, bees are difficult to identify, and, as a result, relatively little is known about their preferred floral hosts. Because bee species assemblages vary significantly from region to region, it is important to have an understanding of local populations and their floral hosts. It is also important to understand factors which affect the quantity and quality of floral resources, such as anthropogenic disturbance. The Pacific Northwest is a diverse landscape, with rich agricultural and wildland environments that require pollinators in order to continue to thrive. Two studies examine the interface between these two systems, the first explores how roadside disturbance, which is prevalent across the world, impacts native pollinators across habitat types, and the second explores the diet of common native species, and how that diet changes across habitat types. In these studies, it was found that roadside disturbance was associated with reduced native bee diversity and abundance in the seasonally wet Willamette Valley of Oregon, but not in the more xeric Central Oregon. Bee abundance was positively correlated with temperature. Bee diet was more diverse in areas of scarce floral resources. In both regions, exotic plants were important floral hosts, representing nearly half of observed floral visitations. This thesis presents results of species analysis, floral richness and density correlations, and comparisons of floral resources used by different bee species. Implications and recommendations for land management are discussed. / Graduation date: 2013

This collection of research examines how changes in the sensory landscape, mediated by both odor and hydrodynamic properties, impact odor-mediated predator-prey interactions in salt marsh communities. I approached this research using an interdisciplinary framework that combined field and laboratory experimentation to address issues of scale and make connections between predator behavior and patterns of predation in the field. I explored a variety of interactions mediated by changes in the sensory landscape including; indirect effects of biotic structure on associated prey, predator responses to patches of prey with differing density and distribution, and dynamic interactions between predators and prey distributions. I found that biotic structure (oyster reefs [Crassostrea virginica]) has negative indirect effects on associated hard clam prey (Mercenaria mercenaria) through the addition of oyster reef odor cues that attract predators (blue crabs [Callinectes sapidus] and knobbed whelks [Busycon carica])and increase foraging success near the structural matrix. Variation in the structure of patch-scale prey odor plumes created by multiple prey results in predator-specific patterns of predation as a function of patch density and distribution which are mediated by differences in predator sensory ability. There is a potential negative feedback loop between blue crab predators and hard clam prey distributions; clam patches assume random within-patch distributions after exposure to blue crab predators, making the detection of patches by future blue crab predators more difficult. Sensory landscapes are also mediated by water flow, which transports prey odor plumes downstream to predators. Characterization of water flow in small-scale estuary systems indicates that values of turbulent flow parameters are highly context specific and depend on both tidal type (spring, neap, normal) and site. Wind and tidal range seem to be good predictors for wave components and turbulent components of fluctuating flow parameters, respectively, although the strength of their predictive ability is dependent on time scale. Modifications of the sensory landscape through changes in structurally-induced turbulence, mixing of individual plumes from multiple prey, and bulk velocity and turbulence characteristics need to be considered when formulating predictions as to the impact of predators on naturally occurring prey populations in the field.

Plant-pollinator interactions figure as key elements promoting the natural regeneration of terrestrial vegetation, as most plants depend on animals to transfer their gametes between flowers and produce seeds. Bees are the most common pollinators of plants and their interactions with flowers have served as model systems for the study of specialized mutualisms since Darwin's time. While most plants offer nectar as a reward and attract a variety of floral visitors, others produce distinctive types of resources which are sought by particular groups of pollinators. Such associations may involve specialization at the morphological, behavioral, or physiological levels and are especially common in tropical habitats. The interactions between oil-producing flowers of Neotropical Malpighiaceae and oil-collecting bees are an example of a specialized mutualism in which plants offer lipids to attract pollinators that use the resource to build nest cells and feed their offspring. Although several studies have focused on specialized pollination at the species level, their effects on the organization of tropical communities remain largely unexplored. This dissertation aims to help fill this gap through an analysis of the mechanisms of pollinator partitioning in multi-species assemblages of specialists as well as a study of the organization of communities in which they occur. The motivation for pursuing the study of specialized interactions using Neotropical species of Malpighiaceae as a model system is outlined in the first chapter. In Chapter 2, I present an evaluation of the structural properties of a plant-pollinator community from the Cerrado, a seasonal ecosystem that hosts a large diversity of oil flowers. The third chapter analyzes pollinator partitioning and reproductive strategies promoting the coexistence of closely related Malpighiaceae. A possible outcome for the selective pressures imposed by the coexistence of specialists is presented in Chapter 4 by a case study providing evidence for a shift from specialized to generalized pollination in a Neotropical Malpighiaceae species. The last chapter includes reports of active floral oil foraging by males of Tetrapedia and a description of an oil storage structure without precedence among bees and unique to males of this genus suggesting that floral oils may also play a role in bees mating systems. / text

Behaviors can exhibit a wide degree of plasticity depending on the environmental context in which they are expressed. Despite this, repeatable differences have been found among and within individuals across a wide range of taxa. For my thesis, I investigated individual differences in foraging and parental care. In the first experiment, I assessed house sparrows (Passer domesticus) for domain-generality among neophobia, habituation and associative learning as they are all responses to novelty. While the results of the study find individual differences in each of these contexts the conclusion supported separate mechanisms for each response (domain-specificity). In the second experiment, I examined how the loudness of brood begging vocalizations influenced parent trip time, food load size brought to the nest and the amount of time spent in the box. The results of this study found individual differences in trip time and the time spent in the box with regard to the initial five seconds of begging loudness during a parent’s visit. Additionally, trip time was also influenced by the change in loudness within a visit. My findings reveal that individual variation may depend on the context in which individuals are measured.