Made available in DSpace on 2014-12-17T15:36:57Z (GMT). No. of bitstreams: 1 DinaLOA.pdf: 757673 bytes, checksum: dfcacad0b099f951e69bc556d1a78317 (MD5) Previous issue date: 2009-08-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Investigamos nesta pesquisa, o papel das rotas e da obten??o de informa??es sobre a efici?ncia no forrageio de Dinoponera quadriceps. Foram observadas duas col?nias numa ?rea de mata atl?ntica secund?ria na FLONA-ICMBio de N?sia Floresta, Estado do Rio Grande do Norte, pelo menos uma vez por semana. Inicialmente, observamos as oper?rias, desde a sa?da do ninho at? o retorno, sem qualquer tipo de manipula??o, numa segunda fase, introduzimos uma placa de acr?lico (100 x 30 x 0,8 cm) diante da entrada observada. Todo o registro comportamental foi feito com a t?cnica do focal time sampling e todas as ocorr?ncias, como complementar; os focais eram de 15 min, com registro a cada minuto, e intervalo de 5 min entre eles. As oper?rias gastaram a maior parte do tempo fora do ninho no comportamento de forrageio. O tempo fora do ninho e a dist?ncia percorrido mostra uma rela??o positiva. Estas vari?veis influenciaram na propor??o do alimento, que requereu mais tempo e dist?ncia na busca. A propor??o tamb?m interferiu no tempo que a oper?ria ficava no ninho antes de uma nova viagem, maior propor??o menor tempo no ninho. Durante toda a pesquisa, as oper?rias individuais demonstraram fidelidade ? rota e a setores na ?rea de uso, mesmo na presen?a da placa, na qual elas desviavam e continuavam seu curso. As caracter?sticas no forrageio quanto ao tempo, dist?ncia, rota fixa e flexibilidade para desviar de obst?culos, apresentadas pelas oper?rias indicam que as decis?es ocorrem em n?vel individual e ? eficiente em rela??o ao balan?o custo-benef?cio. A estrat?gia adotada se encaixa na teoria do ponto central e no teorema do valor marginal, e demonstra ser flex?vel ? presen?a de informa??es novas, o que indica que as oper?rias s?o capazes de aprender novas pistas do ambiente para orient?-las / In this study, we investigated the role of routes and information attainment for the queenless ant species Dinoponera quadriceps foraging efficiency. Two queenless ant colonies were observed in an area of Atlantic secondary Forest at the FLONA-ICMBio of Nisia Floresta, in the state of Rio Grande do Norte, northeastern Brazil, at least once a week. In the first stage of the study, we observed the workers, from leaving until returning to the colony. In the second stage, we introduced a acrylic plate (100 x 30 x 0,8 cm) on a selected entrance of the nest early in the morning before the ants left the nest. All behavioral recordings were done through focal time and all occurence samplings. The recording windows were of 15 minutes with 1 minute interval, and 5 minute intervals between each observation window. Foraging was the main activity when the workers were outside the nest. There was a positive correlation between time outside the nest and distance travelled by the ants. These variables influenced the proportion of resource that was taken to the nest, that is, the bigger its proportion, the longer the time outside and distance travelled during the search. That proportion also influenced the time the worker remained in the nest before a new trip, the bigger the proportion of the item, the shorter was the time in the nest. During all the study, workers showed fidelity to the route and to the sectors in the home range, even when the screen was in the ant?s way, once they deviated and kept the route. The features of foraging concerning time, distance, route and flexibility to go astray by the workers indicate that decisions are made by each individual and are optimal in terms of a cost-benefit relation. The strategy chosen by queenless ants fits the central place foraging and marginal value theorem theories and demonstrate its flexibility to new informations. This indicates that the workers can learn new environmental landmarks to guide their routes

Made available in DSpace on 2014-12-17T15:37:00Z (GMT). No. of bitstreams: 1 IsabelliCM_DISSERT.pdf: 1085220 bytes, checksum: 3e4aaeea15703fb5defff68874553b0d (MD5) Previous issue date: 2010-05-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Food access, territory or reproductive partner can generate conflicts between individuals in many species with occurrence of aggressive behaviors. However some species respond less aggressively to intrusion by neighbors than non-neighbors in its territory to minimize the costs of continuous fight. This difference in aggression is called Dear Enemy Effect described in various vertebrates and invertebrates. To investigate if this phenomenon occurs in Dinoponera quadriceps (Hymenopetra, Formicidae) three colonies, two neighbors and one non-neighbor, were captured in its natural environment then transfered to the laboratory where we did experimental confrontation intra and inter colonies involving one pair of workers. We compared the behavioral frequency exhibited by each worker, the intensity and duration of the confrontation between a neighbor and a non-neighbor referring the place where they were collected. Our results revealed that Dear Enemy Effect does not apply to D. quadriceps due aggressive response is more intense and longest toward neighbor than non-neighbor, probably due intra specific competition, ecological factors and characteristic of the species / O acesso a fonte de alimentos, territ?rio ou parceiros reprodutivos pode gerar conflitos de interesses entre indiv?duos em v?rias esp?cies de animais. Entretanto, v?rios animais respondem menos agressivamente ? entrada de seus vizinhos do que a entrada de n?ovizinhos em seus territ?rios, como forma de minimizar os custos de uma agress?o cont?nua. Essa diferen?a na resposta agressiva ? conhecida por Efeito Inimigo ?ntimo, descrito em v?rias esp?cies de vertebrados e invertebrados. Para investigar se este fen?meno ocorre em Dinoponera quadriceps (Hymenoptera, Formicidae), tr?s col?nias, sendo duas vizinhas e uma distante, foram coletadas em seu ambiente natural e transferidas para o laborat?rio onde foram conduzidos confrontos experimentais intra e entre col?nias, envolvendo um par de oper?rias. Comparamos a frequ?ncia comportamental exibida por cada oper?ria envolvida nos confrontos, assim como a intensidade e a dura??o dos confrontos entre col?nias vizinhas e distantes com refer?ncia do local de coleta. Nossos resultados revelam que o Efeito Inimigo ?ntimo n?o ? aplic?vel ? D. quadriceps, pois resposta agressiva ? mais intensa e duradoura entre oper?rias vizinhas do que entre distantes, provavelmente devido ? competi??o intraespec?fica, fatores ecol?gicos e caracter?sticas da esp?cie.