The dear enemy effect is a widespread behavioral phenomenon that promotes selective pacifism in order to minimize costs of territorial defense. The dear enemy hypothesis predicts heightened aggression towards unfamiliar conspecifics compared to familiar neighbors where territorial boundaries are established. The purpose of this study was to test the dear enemy hypothesis in Neolamprologus multifasciatus, a social cichlid fish endemic to the shell beds of Lake Tanganyika. They establish breeding groups that control distinct territories, each governed by a dominant male. Territories can be very densely spaced, and conspecific border intrusions generally trigger aggressive responses from the focal group. The dominant males are responsible for the majority of territory defense. In this field experiment, 27 breeding groups were each given two treatments, each consisting of artificial introduction of an out-of-group dominant male. One male originated from an immediately neighboring group, the other from a distant group.  A downward-facing camera recorded group members’ aggressivity exhibited towards the experimentally presented male. The behavior was manually scored according to a behavior ethogram and analyzed with either linear mixed effects models or generalized linear mixed effects models. No clear dear enemy effect was detected within Neolamprologus multifasciatus. Several reasons are proposed for this result. Firstly, a contingent “ceiling effect” in terms of aggressive behavior imaginably deterred efforts of dear enemy detection. Conversely, perhaps negligible necessity of stranger-neighbor recognition within Neolamprologus multifasciatus has resulted in discriminatory behavior being absent. In conclusion, no dear enemy effect was detected and future research will address possible alternative explanations.

This study investigates the song-based recognition of individual songbirds with the main focus on the chiffchaff (Phylloscopus collybita) as a model species. The introductory part deals with vocalization-based recognition in birds in general.The following parts summarize our knowledge of individual recognition in songbirds based on song, namely the limitation of recognition ability caused by repertoire size or song sharing and how songbirds encode their identity in song. In the field study, we also proved the ability of the chiffchaff and willow warbler (Phylloscopus trochilus) to recognise particular neighbours based on one particular song from their repertoire. Our findings are interesting because chiffchaff and willow warbler differ in repertoire size and song organisation. We also analysed the repertoire size of chiffchaff males and the potential for identity encoding by basic voice characteristics (timing and frequency). We have found that chiffchaff song is unstable from year to year and that basic voice characteristics are useful for identification only when the same song type is used in the short time period. The last part of the thesis answers the question of whether there are some general voice characteristics independent of song content that might represent the structure of the sound organ and thus carry the identity of a bird independently of song content. We used ASRNI (Automatic system for the recognition of bird individuals) to identify particular birds based on unprocessed (raw) recordings of song without song preparation or manual measurements. This method also allows work with the data as an open set, so that the number of birds analysed does not have to be known in advance. Based on the parameters automatically extracted, we were able to recognise individuals with satisfactory accuracy. Based on such findings, we proved the existence of individually specific voice qualities that are independent of voice content and which may be used by birds for recognition. By using ASRNI we also introduced an approach that has great potential to be used in the effective acoustic monitoring of bird populations.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-20T19:43:49Z No. of bitstreams: 1 tatianearchanjodesales.pdf: 1871876 bytes, checksum: 6bdeefe279a3c1e633ba1cbae84bdf3c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-02T11:28:21Z (GMT) No. of bitstreams: 1 tatianearchanjodesales.pdf: 1871876 bytes, checksum: 6bdeefe279a3c1e633ba1cbae84bdf3c (MD5) / Made available in DSpace on 2016-07-02T11:28:21Z (GMT). No. of bitstreams: 1 tatianearchanjodesales.pdf: 1871876 bytes, checksum: 6bdeefe279a3c1e633ba1cbae84bdf3c (MD5) Previous issue date: 2012-02-23 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Buscando identificar os mecanismos formadores das assembleias de formigas em campo rupestre, este estudo foi dividido em três partes. A primeira investigou a habilidade das espécies em descobrir recursos alimentares e a influência dos comportamentos na sua permanência nos mesmos. Iscas atrativas foram oferecidas em uma área de campo rupestre no Parque Estadual do Ibitipoca, MG. Foram realizados 60 registros, referentes a 10 iscas/quadrante, totalizando 40 horas de filmagem. Das nove espécies mais freqüentes Pheidole obscurithorax, Pheidole radoszkowskii, Pheidole sp.6 e Crematogaster sericea foram as que apresentaram maiores valores para habilidade de descoberta e tenderam a permanecer por mais tempo nas iscas; Camponotus crassus, Camponotus renggeri, Ectatomma edentatum, Camponotus genatus, Pachycondyla striata foram espécies com menores taxas de permanência, podendo ser consideradas como submissas devido à menor habilidade competitiva. Os comportamentos também influenciaram na permanência e variaram entre agonísticos e de coexistência em função da espécie e do contexto no qual ocorreu a interação. As duas espécies com maior habilidade em descobrir os recursos - C. sericea e P. obscurithorax - foram selecionadas para a segunda parte do estudo. Objetivando avaliar mecanismos competitivos em locais distantes e próximos aos seus ninhos, foi averiguada a influência da distância do recurso ao ninho na agressividade e abundância, bem como o status hierárquico durante o forrageamento. Foi estabelecido um plot de observação para cada ninho composto por oito iscas: quatro localizadas a 1,5m de distância dos ninhos e quatro a 0,5m. As iscas foram observadas uma por vez, totalizando 256 registros/espécie. Os comportamentos registrados foram ataque e avançar. Para ambas as espécies a distância do alimento ao ninho não influenciou na agressividade (Z= 1,44; p=0,07 C. sericea; Z= 1,44; p=0,07 P. obscurithorax); a abundância de P. obscurithorax foi maior nas iscas próximas ao seu ninho (F= 7,30; p<0,01), enquanto que para C. sericea não diferiu entre iscas próximas e distantes (F=2,19; p=0,14). Apesar de fortes competidoras, C. sericea e P. obscurithorax forragearam de acordo com seus status hierárquico, sendo a primeira territorialista e a segunda agressiva não territorialista. Na terceira parte foram investigados os padrões comportamentais de agressividade entre colônias de C. sericea e P. obscurithorax localizadas próximas (2,40m) e distantes (15,60m) entre si baseado na Hipótese do Inimigo Querido. Foram capturados 50 indivíduos/colônia para execução de encontros diádicos. Foram realizados 10 encontros/tratamento: controle, interespecífico próximo e interespecífico distante. Os comportamentos observados foram: inspeção, toque de antena, auto-grooming, viii evitar, avançar, abertura de mandíbula, morder, curvar o gáster e luta. Para cada ato foi atribuído um valor, utilizado no cálculo do índice de agressão. Verificou-se maior agressividade de C. sericea quando confrontadas com P. obscurithorax provenientes da colônia próxima (t=-4,935; p<0,001). Em contraste, não houve diferença significativa na agressividade exibida entre operárias de P. obscurithorax e C. sericea provenientes da colônia distante (t=0,617; p=0,995). A agressividade de C. sericea direcionada aos seus vizinhos atesta que, além de haver o reconhecimento entre diferentes espécies, P. obscurithorax pode ser considerada uma forte competidora, não sendo aplicável a hipótese do inimigo querido a estas espécies. / In order to identify the mechanisms that form the ant assemblages in the rupestrian, this study was divided into three parts. In the first was investigated the species ability to find food resources and the behaviors influence of their permanence in the same resources. Baits were offered in a rupestrian area in Parque Estadual do Ibitipoca, MG. Were made 60 records, on a 10 baits/quadrant, totaling 40 hours of recording. Of the nine most common species Pheidole obscurithorax, Pheidole radoszkowskii, Pheidole sp.6 and Crematogaster sericea showed highest values for discovery ability and tended to stay longer in the baits. Camponotus crassus, Camponotus renggeri, Ectatomma edentatum, Camponotus genatus, Pachycondyla striata were species with lower permanence rates, may be considered as submissive species due to lower competitive ability. The behavior also influenced the permanence and ranged between agonistic coexistence depending on the species and the context in which the interaction occurred. The two species with greater ability to find resources – P. obscurithorax and C. sericea – were selected for the second part of the study. In order to evaluate competitive mechanisms in places far and near to their nests, has been investigated the influence of distance from the resource until the nest in the aggression and abundance, and the hierarchical status during the foraging. We established an observation plot for each nest, composed by eight baits: four located 1.5m away from the nests and four 0.5m. The baits were observed one at a time, totaling 256 records/species. The behaviors recorded were attack and advance. For both species, the distance of the food to the nest had no effect on aggression (Z= 1,44; p=0,07 C. sericea; Z= 1,44; p=0,07 P. obscurithorax); the abundance of P obscurithorax was higher in the baits near its nest (F = 7.30, p <0.01), while for C. sericea did not differ between near and far baits (F=2,19; p=0,14). In spite of being strong competitors, C. sericea and P. obscurithorax foraged according to their hierarchical status, being the first territorialist and the second aggressive not territorialist. In the third part, we investigated the behavioral patterns of aggressiveness among C. sericea and P. obscurithorax colonies located near (2.40 m) and far (15.60 m) from each other based on the Dear Enemy Hypothesis. We captured 50 individuals/colony to perform dyadic encounters. Were conducted 10 meetings/treatment: control, near interspecific and far interspecific. The behaviors observed were: inspection, antenna touch, self-grooming, avoidance, forward, open jaw, bite, bend the gaster and fight. For each action was assigned a value, used to calculate the aggression rate. Was found more aggressiveness of C. sericea when confronted with P. obscurithorax from the nearby colony (t=-4,935; p<0,001). In contrast, there were no significant difference in x aggressiveness displayed between workers of P. obscurithorax and C. sericea from the far colony (t=0,617; p=0,995). The aggressiveness of C. sericea directed to their neighbors certifies that, in addition to the recognition between different species, P. obscurithorax also can be considered a strong competitor, then Dear Enemy Hypothesis cannot be applicable to these species.

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.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-09T13:11:45Z No. of bitstreams: 2 Tese - Alessandro Ribeiro de Morais - 2014.pdf: 2129232 bytes, checksum: 5d68ebb0d660653aee9fe82ab86a6237 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-09T14:13:07Z (GMT) No. of bitstreams: 2 Tese - Alessandro Ribeiro de Morais - 2014.pdf: 2129232 bytes, checksum: 5d68ebb0d660653aee9fe82ab86a6237 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-09T14:13:07Z (GMT). No. of bitstreams: 2 Tese - Alessandro Ribeiro de Morais - 2014.pdf: 2129232 bytes, checksum: 5d68ebb0d660653aee9fe82ab86a6237 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-06-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Acoustic signals are a key element in social interactions in anuran amphibians. Accordingly, different types of vocalizations can be emitted in specific social contexts. Thus, this study investigated the influence of conspecific individuals on the vocal behavior of Hypsiboas goianus. Field observations and playback experiments were conducted at the Silvânia National Forest, Silvânia, Goiás, central Brazil, in the breeding season between 2011 and 2013. We used playback experiments of pre-recorded advertisement calls to test the influence of conspecific calls on the acoustic behavior of males of H. goianus. We found that males change their acoustic behavior after stimulation by conspecifics calls. Specifically, males decrease the interval between calls, the emission rate of advertisement calls, and the duration of pulses. Additionally, we tested whether males of H. goianus use acoustic signals to discriminate large- from small-sized conspecifics. We used an experimental approach with playbacks of synthetic advertisement calls built with different dominant frequencies. We used calls with low frequency (3,123 Hz) to simulate large-sized individuals, and calls with high frequency (3,573 Hz) to simulate small-sized individuals. Males of H. goianus significantly altered their acoustic behavior in response to high-frequency calls by shortening the duration and emission rate of advertisement calls, but increasing the duration and number of pulses of the short aggressive call. Conversely, there were no changes in the acoustic behavior of males when stimulated by low-frequency advertisement calls. Finally, we tested whether males of H. goianus respond less aggressively to close neighbors than unknown intruders. To test this, we used playback experiments to stimulate males of H. goianus with calls of both adjacent neighbors and distant individuals. However, there was no change in the acoustic behavior of males. Our results show that males of H. goianus not only modify their acoustic behavior in 13 response to conspecific males, but also asses their competitors by using acoustic signals. Thus, the acoustic plasticity of males of H. goianus not only maximizes signal transmission, but also overcome the acoustic interference of conspecifics. / As interações sociais em anfíbios anuros são mediadas principalmente pelos sinais acústicos. Neste contexto, os indivíduos apresentam diferentes tipos de vocalizações, que podem ser emitidas em contextos sociais específicos. Desta forma, este estudo investigou a influência de indivíduos coespecíficos no comportamento vocal de Hypsiboas goianus. O presente trabalho foi realizado na Floresta Nacional de Silvânia, município de Silvânia, estado de Goiás, Brasil. Primeiramente, para testar a influência de cantos coespecíficos no comportamento acústico de machos de H. goianus, utilizamos experimentos de playback a partir de cantos de anúncio gravados previamente. Neste contexto, observamos que os machos alteram seu comportamento acústico, uma vez que estes indivíduos, ao serem estimulados por cantos coespecíficos, diminuem o intervalo entre cantos, taxa de emissão de cantos de anúncio e duração dos pulsos dos cantos de anúncio. Adicionalmente, testamos se os machos de H. goianus utilizam os sinais acústicos para discriminar o tamanho corporal entre indivíduos coespecíficos. Para tal, utilizamos uma abordagem experimental em que realizamos experimentos de playback a partir de cantos de anúncio sintéticos com diferentes valores de frequência dominante. Assim, para simular indivíduos com grande tamanho corporal utilizamos cantos com baixa frequência (3123 Hz), enquanto os cantos com alta frequência (3573 Hz) simularam indivíduos com pequeno tamanho corporal. Os machos de H. goianus testados alteraram significantemente o comportamento acústico em resposta aos experimentos de alta frequência, uma vez que diminuem a duração e a emissão do canto de anúncio, porém aumentam a duração e o número de pulsos do canto agressivo curto. Por outro lado, não observamos alterações no comportamento acústico dos machos quando estes foram estimulados por cantos de anúncio de baixa frequência dominante. Finalmente, testamos se machos de H. goianus respondem menos 11 agressivamente a indivíduos coespecíficos que sejam vizinhos próximos do que a intrusos desconhecidos. Neste contexto, utilizamos experimentos de playback para estimular os machos de H. goianus com cantos dos vizinhos adjacentes e também de indivíduos distantes. No entanto, não observamos qualquer alteração no comportamento acústico dos machos testados. Os resultados obtidos neste estudo demonstram que os machos de H. goianus são capazes de alterar o comportamento acústico em resposta a machos coespecíficos e, adicionalmente, tais indivíduos podem discriminar os seus respectivos competidores a partir dos sinais acústicos. Assim, a plasticidade acústica apresentada por machos de H. goianus é um mecanismo que maximiza a transmissão dos sinais por estes indivíduos e, consequentemente, superar a interferência acústica causada por coespecíficos.