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<p>In the fifteen-spined stickleback, <i>Spinachia spinachia</i>, males provide females with direct benefits by fanning, cleaning and guarding the offspring. Males announce their parental skills through intense body shakes during courtship. Females preferred to mate with more intensely shaking males. As a result, females got better fathers for their offspring, as such males achieved a higher hatching success. Not only did male behavioural cues attract females, but males also used their nests as extrabodily ornaments. The nest is held together with shiny secretional threads consisting of a glycoprotein. Females chose to spawn in nests with more secretional threads. A likely reason for this is that the threads are metabolically costly for the male to produce and the amount of secretion indicates a male's nutritional status, which is of great importance as parental duties are energetically costly. Moreover, females preferred nests built high up in the vegetation, as such nests were safer from egg predators. Competition with other males for females favoured males building higher nests than did their neighbours, probably because females preferred high nests. Male-male interactions, such as sneaking and egg stealing, caused decreased paternity among males in nature as assessed by a microsatellite analysis. Males adjusted their paternal effort according to their previous investment in the brood, but not according to paternity. Thus, female choice is based on multiple cues and results in better paternal care. Males invest in courtship, male-male competition, nest construction and paternal care, the outcome determining their success in mate attraction.</p>

In the fifteen-spined stickleback, Spinachia spinachia, males provide females with direct benefits by fanning, cleaning and guarding the offspring. Males announce their parental skills through intense body shakes during courtship. Females preferred to mate with more intensely shaking males. As a result, females got better fathers for their offspring, as such males achieved a higher hatching success. Not only did male behavioural cues attract females, but males also used their nests as extrabodily ornaments. The nest is held together with shiny secretional threads consisting of a glycoprotein. Females chose to spawn in nests with more secretional threads. A likely reason for this is that the threads are metabolically costly for the male to produce and the amount of secretion indicates a male's nutritional status, which is of great importance as parental duties are energetically costly. Moreover, females preferred nests built high up in the vegetation, as such nests were safer from egg predators. Competition with other males for females favoured males building higher nests than did their neighbours, probably because females preferred high nests. Male-male interactions, such as sneaking and egg stealing, caused decreased paternity among males in nature as assessed by a microsatellite analysis. Males adjusted their paternal effort according to their previous investment in the brood, but not according to paternity. Thus, female choice is based on multiple cues and results in better paternal care. Males invest in courtship, male-male competition, nest construction and paternal care, the outcome determining their success in mate attraction.

In 1996 and 1997, I studied the nest site selection of the yellow-billed cuckoo (Coccyzus americanus) in the George Washington National Forest, southwestern Virginia. Data were collected from nine 30 ha plots. I compared the habitat features of nest sites with two types of nonnest sites (nonuse and systematically random). Habitat features were measured at 3 spatial scales: nest tree, nest tree area (0.0049 ha centered on the nest), and nest stand (forest stand surrounding the nest). Yellow-billed cuckoo nests were oriented in a nonrandom direction (mean angle = 114°, r = 0.43, P = 0.05) with respect to the bole and were concealed more from above than from below (n = 14, M = 5, p = 0.01) or from the side (n = 14, M = 4, p = 0.04). Slope aspect was nonrandom at yellow-billed cuckoo nest sites (mean angle = 143°, r = 0.52, P < 0.05). Small stem density in the nest tree area was greater (P = 0.029) at nest sites than nonuse sites but species composition was similar. The density of grape (Vitus spp.) and dogwood (Cornus spp.) snags was greater at nest sites than random sites (P < 0.001). Total basal area at yellow-billed cuckoo nest stands was lower than nonuse or random sites with (P = 0.033, and 0.016, respectively) or without (P = 0.014, and 0.004, respectively) snags. Nest sites also occurred in areas with less (P = 0.008) canopy cover but more (P = 0.038) ground cover than random sites. Yellow-billed cuckoos appeared to select nest sites based on the structure and composition of the understory vegetation. Periodic disturbance that promotes the growth of shade intolerant species, but maintains the general structure of the stand may be beneficial for this species that appears to select disturbed areas in mature forests. / Department of Biology

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-01-15T13:48:19Z No. of bitstreams: 1 carlosmagnodossantos.pdf: 1171016 bytes, checksum: 843d57bbd25fe33ba51f921168d70aaa (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T17:40:14Z (GMT) No. of bitstreams: 1 carlosmagnodossantos.pdf: 1171016 bytes, checksum: 843d57bbd25fe33ba51f921168d70aaa (MD5) / Made available in DSpace on 2016-01-25T17:40:14Z (GMT). No. of bitstreams: 1 carlosmagnodossantos.pdf: 1171016 bytes, checksum: 843d57bbd25fe33ba51f921168d70aaa (MD5) Previous issue date: 2015-09-28 / (Avaliação da atividade de escavação de ninhos em Acromyrmex subterraneus (Hymenoptera, Formicidae): estímulos e divisão de trabalho). Formigas cortadeiras dos gêneros Atta e Acromyrmex são conhecidas por sua organização social e capacidade de construir ninhos de arquitetura complexa. A construção do ninho é importante ecologicamente, pois altera as propriedades químicas e físicas do solo, contribuindo para o crescimento da vegetação. Além disso, o processo de escavação permite compreender os padrões comportamentais fundamentais na organização social em formigas cortadeiras, constituindo base relevante de estudos ecológicos vinculados à dinâmica comportamental das atividades coletivas organizadas nos insetos eussociais. Sabe-se que para algumas espécies de formigas cortadeiras, fungo simbionte e prole atuam como estímulo para a escavação, exercendo influência sobre a complexidade das estruturas emergentes (túneis e câmaras). Este estudo investigou quais são os estímulos para o comportamento de escavação em Acromyrmex subterraneus durante a construção do ninho, tendo como hipótese que a presença do fungo jardim e/ou prole constituem estímulos para a escavação de túneis e câmaras. Além disso, investigou a divisão de tarefas a fim de verificar se o nível de atividade das operárias para a tarefa de escavação se altera em função da presença do fungo e da prole. O experimento consistiu no registro da frequência de escavação de operárias individualmente marcadas colocadas em cilindros plásticos preenchidos com solo, em que foram aplicados quatro tratamentos: FB - 30 operárias médias, 5g de jardim de fungo e 30 itens de prole (larvas ou pupas), FG - 30 operárias médias e 5g de jardim de fungo, LP - 30 operárias médias e 30 itens de prole e WK - 30 operárias médias, sem jardim de fungo e prole. Após 24 horas foram registrados os parâmetros morfométricos do ninho (comprimento e largura de túneis e câmaras em cm) e o volume de solo escavado, assim como a atividade de escavação individual de cada operária. Em contraste com o esperado, não houve variação da estrutura morfológica, frequência de escavação ou volume de solo escavado em função dos tratamentos. No entanto, verificaram-se diferenças no nível de atividade das operárias gerando uma distribuição desigual de tarefas com metade das operárias permanecendo inativa em detrimento de outras que realizaram a tarefa de escavação de forma intensa e repetitiva. / (Evaluation of nest’s digging activity in Acromyrmex subterraneus (Hymenoptera, Formicidae): stimuli and division of labor). Leaf cutting ants from Atta and Acromyrmex genera are known by their social organization and ability to build nests with a complex architecture. Nest building has a great importance in the field because it alters the chemical and physical properties of the soil, contributing to the growth of vegetation. In addition, the excavation process allows us to understand fundamental behavioral patterns in social organization in cutting ants, constituting relevant basic ecological studies related to behavioral dynamics of group activities organized in eusocial insects. It is known that for some species of leaf-cutting ants, symbiotic fungus and offspring act as a stimulus for the excavation, exerting influence on the complexity of the emerging structures (tunnels and chambers). This study investigated what are the stimuli for digging behavior in Acromyrmex subterraneus during nest building, testing the hypothesis that the presence of the fungus garden and/or brood are stimuli for the excavation of tunnels and chambers. In addition, we investigated the division of labor to verify if the level of activity of workers for excavation task changes due to the presence of the fungus and brood. The experiment consisted in recording the frequency of excavation of individually marked workers placed in plastic cylinders filled with soil, in which were applied four treatments: FB - 30 medium workers, 5g of fungus garden and 30 brood items (larvae and pupae) FG - 30 medium workers and 5g of fungus garden, LP - 30 medium workers and 30 items of brood and WK - 30 medium workers without fungus garden and brood. After 24 hours we registered nest morphometric parameters (length and width of chambers and tunnels in cm) and the volume of excavated soil, as well as the excavation activity of each worker. In contrast to the expected, there was no change in the morphological structure, digging frequency or volume of excavated soil among the treatments. However, we verified differences among the activity level of the workers, leading to an unequal distribution of tasks with half of the most workers remaining inactive while the others performed the excavation intensely and repetitively.

In April of 1990 the Sebastian Inlet Tax District received a long-term (25 year) permit to conduct maintenance dredging of the navigation channel at Sebastian Inlet, Florida. Approximately 105,150 cubic meters of sediment will be removed every two years and pumped to a feeder beach immediately south of the inlet. The renourished beach, a high density nesting beach for loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtles, is within the proposed Archie Carr National Wildlife Refuge and will play a critical role in the long-term maintenance of Sebastian Inlet as a navigable waterway. A turtle monitoring program was implemented by the District at the request of the U.S. Fish and Wildlife Service. The monitoring program was designed to investigate nesting behavior, reproductive success and physical characteristics of the nesting habitat on the renourished beach at Sebastian Inlet and on a control beach (Wabasso Beach). Daily nesting surveys were conducted to record all sea turtle nests and non-nesting emergences in each study area. All nests were marked, monitored throughout incubation and inventoried to determine hatching and emergence success. Data on physical parameters were collected in monthly profiles of each beach. Compaction values were recorded with a cone penetrometer along transects from the dune to mean high water line. Temperature of the ambient beach was recorded at 30 and 60-cm depths along two transects from the dune to mean high water line. Moisture and sand grain analysis were conducted monthly in 1991. Sea turtle nesting and hatching success were similar on the renourished and control beaches in 1990 and 1991, suggesting that renourishment had no adverse effect on sea turtle reproductive success. Nesting success on the renourished and control beaches, respectively, was 42.0% (N = 104) and 45.0% (N = 65) in 1990, and 62.9% (N = 165) and 62.4% (N = 118) in 1991. Hatching success on the renourished and control beaches, respectively, was 80.7% (N = 85) and 79.3% (N = 59) in 1990, and 69.1% (N = 118) and 66.7% (N = 102) in 1991. Compaction values averaged 500 PSI on the renourished beach, while values on the control were approximately 250 PSI. The higher level of compaction on the renourished beach resulted in a lack of complete nest covering, and aberrant nest chamber configurations on the renourished beach. Grain size and moisture content were similar on the renourished and control beaches. Compaction levels were not related to incompatible fill, implying that the manner in which the material was deposited resulted in the increased compaction. Beach temperatures measured at 30-cm and 60-cm depths indicated that the renourished beach was consistently 0.5°C warmer than the control beach. If the physical parameters of a subsequent renourishment project are within the findings of 1990 and 1991, there should be no adverse effect on sea turtle nesting and hatching success. The results of this project cannot be applied to other beach renourishment projects however, but should be restricted to future dredging projects at Sebastian Inlet. Although the results are not applicable to other locations, the methodologies developed to study the effects of renourishment on sea turtles could be applied to other beach renourishment situations. Future research should focus on how the physical parameters of a renourished beach affect the micro-environment within the actual nest chamber and embryonic development. / Master of Science

Made available in DSpace on 2016-06-02T20:21:24Z (GMT). No. of bitstreams: 1 3223.pdf: 1875073 bytes, checksum: da879cb2bcfcd8ac244156eec8eca3ad (MD5) Previous issue date: 2010-08-05 / Universidade Federal de Minas Gerais / Genetic architecture of a phenotype represents the total number of genes, independent effects (additivity), the interactions between alleles (dominance and epistasis), and its effects on other phenotypes (pleiotropy). An enormous debate about general types of genetic architectures relates the importance of independent and interactive variation in the adaptive process. Because natural selection reduces additive variation, we expect, of fitness related phenotypes, lesser additive than interactive variation and relatively more genes with moderate effects. Maternal care is a phenotype with enormous importance to fitness. Of the maternal care behaviors, the nest building highlights itself improving pups survival by protection against predators and temperature maintenance. We investigated the genetic architecture of nest building in mice and tested the hypothesis that this behavior has a genetic architecture related to fitness, also verifying possible associations with anxiety and weight. For that, we checked the relation between all phenotypes and tested, using the QTL analysis, the phenotypic association with regions (microsatellites markers) spread about all genome of F2 females at maternal stage from the intercross of inbred strains SM/J and LG/J. We found 23 QTLs which, individually, are associated with phenotypic variation on nest building, weight and anxiety (15 QTLs at the 6 nest building phenotypes). The nest building s individual QTLs have moderate effects (from 4 to 13%), and the numerous epistatic QTLs add to increase this explained variation. There are common regions for nest building with anxiety and weight and, searching for candidate genes, we found genes with effects already described for these phenotypes. Hence, we corroborate our hypothesis of the genetic architecture type related to fitness for nest building behavior, of genes with bigger effects and high interactive variation. The identification of regions associated with maternal care in mice and the knowledge of the related genetic architecture can help in identifying genes for these behaviors in other mammals, and in the comprehension of general patterns in adaptive process and life evolution. / Arquitetura genética de um fenótipo representa o número total de genes, os efeitos independentes (aditividade), as interações entre alelos (dominância e epistasia), e o efeito destes em outros fenótipos (pleiotropia). Um grande debate entre tipos gerais de arquitetura genética está no papel da variação independente e de interações no processo adaptativo. Pela seleção natural reduzir a variação aditiva, esperamos de fenótipos ligados ao fitness menor variação aditiva relativa a variação de interações e genes com efeitos médios relativamente mais comuns. O cuidado materno é um fenótipo com grande importância para o fitness. Dentre os comportamentos de cuidado materno, a construção de ninho destaca-se aumentando a sobrevivência dos filhotes pela proteção contra predadores e manutenção da temperatura. Investigamos a arquitetura genética da construção de ninho em camundongos e testamos a hipótese que esse comportamento tem a arquitetura genética relacionada ao fitness, verificando também possíveis associações com ansiedade e peso. Para isso, checamos as relações entre os fenótipos e testamos, com a análise de QTL, a associação dos fenótipos com regiões (marcadores microssatélites) por todo o genoma de fêmeas F2 em fase materna do intercruzamento das linhagens endogâmicas SM/J e LG/J. Obtivemos 23 QTLs que, individualmente, estão associados com a variação nos fenótipos de construção de ninho, peso e ansiedade (15 QTLs para os 6 fenótipos de construção de ninho). Os QTLs individuais de construção de ninho têm efeitos moderados (de 4 a 13%), e os muitos QTLs epistáticos colaboram aumentando essa variação explicada. Existem regiões em comum para ninho com peso e ansiedade e, na procura de genes candidatos, descobrimos genes já descritos com efeitos nesses fenótipos. Assim, corroboramos a hipótese do tipo de arquitetura genética relacionada ao fitness para o comportamento de construção de ninho, de genes com grandes efeitos e alta variação genética de interações. A identificação de regiões associadas ao cuidado materno em camundongos e o entendimento da arquitetura genética envolvida poderão contribuir na identificação de genes para esses comportamentos em outros mamíferos, e na compreensão do padrão geral do processo adaptativo e da evolução dos seres vivos.

Loggerhead and leatherback sea turtles nest on the beaches of the north-eastern portion of Kwazulu-Natal within the iSimangaliso Wetland Park. Loggerheads place ~60 percent of all nests within an 8 km stretch of beach, whereas leatherbacks tend to space their nests more evenly along the entire length of the monitoring area. The study aimed to determine nest site fidelity of loggerheads and leatherbacks (using four decades of nesting data housed by Ezemvelo KZN Wildlife) and the factors that influence nest site selection of both species within the 56 km of turtle monitoring area (32N to 100S) and the 5 km area of high-density loggerhead nesting (0N to 12N). The effectiveness of nest site selection was then determined through the hatching success of loggerheads over the 5km area (0N to 12N). Results showed that loggerheads show a high degree of nest site fidelity (~3 km) with nest site fidelity of individuals increasing over subsequent seasons of nesting, as well as these individuals using the same stretches of beach for nesting (the most popular area being 1N to 4N for repeat nesters). Leatherbacks displayed nest site fidelity of ~9 km and this did not increase over successive seasons of nesting. In terms of nest site selection, loggerheads and leatherbacks both avoided areas where low shore rock was present, whereas both species preferred nesting on beaches of intermediate morphodynamic state. Leatherback nesting was significantly higher in areas with wider surf zones. Both species were able to surpass the high water mark when nesting as nests below this point would be almost certainly doomed. Hatching success of loggerheads was comparative to high (83 %) relative to other studies, however, nest success varied across the beach from beacon 1N to 12N. Areas where highest nest success was observed were not areas of highest nest density presumably due to artificial lighting. Results from this study increase our understanding of the evolutionary biology of loggerhead and leatherback turtles in South Africa and the effectiveness of loggerhead nest site selection through hatching success.

La construction du nid chez les fourmis génère des structures assumant de nombreuses fonctions, qui sont en grande partie dépendantes de l’architecture produite. L’omniprésence de ces fonctionnalités contraste avec la forte diversité intra et inter-spécifique de la morphologie du nid. Ce travail a pour objectifs de déterminer d’une part la morphogenèse du nid durant son excavation par les fourmis (Chapitre 3), et d’autre part de quantifier l’impact de la taille du groupe (Chapitre 3) et de la qualité de l’environnement (qualité du matériau, gravité; Chapitres 4 & 5) sur cette séquence. Pour répondre à ces questions, nous avons utilisé un dispositif de creusement en deux dimensions (2D) afin de suivre la dynamique d’excavation et l’évolution de la morphologie du nid au cours du temps. Nous avons tout d’abord mis en évidence (Chapitre 3) un changement brutal de la morphologie du nid au cours de sa croissance. Durant une première période d’excavation homogène, le nid est constitué d’une seule cavité de forme circulaire et au contour régulier. Par la suite, le pourtour de la cavité devient plus irrégulier, l’apparition de ‘‘bourgeons’’ lui donnant une apparence plus plissée. Enfin, la cavité centrale cesse de croître lorsque des ramifications se déploient depuis certains des ‘‘bourgeons’’. Nous avons qualifié de transitions morphologiques ces brusques changements de forme, dont la fréquence d’apparition augmente avec la taille de la population. Notre analyse et le recours à la simulation semblent indiquer que ce phénomène soit basé non pas sur un changement de comportement des ouvrières excavatrices mais sur la densité d’activité au front de creusement. Lorsque celle-ci est importante, des phénomènes d’encombrement se manifestent et le nid est excavé de manière homogène. À l’inverse, lorsque l’encombrement diminue les ouvrières peuvent focaliser leur travail et excavent des galeries. Un modèle analytique (Chapitre 6) a permis d’étudier les conditions d’apparition de cette transition morphologique. Nos autres résultats indiquent que le matériau de construction influence très fortement la morphogenèse du nid (Chapitre 4) : les nids excavés dans un milieu cohésif sont plus fréquemment ramifiés et la transition morphologique apparaît à des surfaces de nid plus petites que dans un milieu granulaire. Il semblerait qu’à nouveau, il n’y ait aucune variation comportementale impliquée, mais que l’environnement joue un rôle de ‘‘médiateur’’ des interactions entre les fourmis: le milieu change le temps d’extraction et donc la probabilité individuelle d’excavation, cette variation est exacerbée par les mécanismes d’amplification à l’œuvre, modifiant alors sensiblement la dynamique collective de creusement et la structure du nid. Enfin, une série d’expériences (Chapitre 5) nous a permis de déterminer l’influence de la gravité sur la morphogenèse. Il apparait que la gravité sert de gabarit à la construction, puisque les nids excavés dans un dispositif à l’orientation verticale sont tous dirigés vers le bas. Aussi, si le nid prend directement une forme de long puit vertical sans jamais présenter de chambre, le mécanisme de transition morphologique reste visible, sous forme de bifurcation des galeries à leur extrémités. Ce phénomène de tip-splitting semble aussi apparaître sous la contrainte de la densité d’ouvrières excavant au fond des galeries. Notre travail a donc mis en évidence un phénomène de transition morphologique capable de produire les modules de base de tout nid - chambres et galeries -, et qui semble découler non pas de modifications comportementales, mais de la seule interaction de l’amplification de l’activité et de l’encombrement au front d’excavation. Ce phénomène ubiquiste propose une explication à la grande variété de structures observées sur le terrain, en lien notamment avec la diversité et l’hétérogénéité des milieux, et la dynamique des colonies. Enfin, les similitudes de la transition morphologique avec les instabilités de croissance observées dans de nombreux systèmes biologiques et physico-chimique invitent à considérer ces derniers phénomènes à la lumière de nos résultats.