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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Vliv výchovy psů na jejich chování v dospělosti / The influence of dog education on their behaviour in maturity

VICKOVÁ, Pavlína January 2011 (has links)
The influence of dog education on their behaviour in maturity was described and documented in this diploma thesis. The dog handling and relationship to other members of family and to other dogs were studied. Questionnaire investigation was made in the area of Trhové Sviny town. It was found, that not only the time of removing the puppies from their mother, but also the way of the care for the dog before the removing play important and primary role. The way and the degree of social cognition by the new owner and the knowledge in field of ethology and in dog communication signals of the new owner are important as well.
242

Comportamento de ovinos da raça Santa Inês de diferentes cores pelame, em pastejo / Behavior of Santa Inês sheep of different colors of coat, grazing

SANTOS, Merilene Maria dos 18 February 2010 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2017-05-09T14:41:53Z No. of bitstreams: 1 Merilene Maria dos Santos.pdf: 442992 bytes, checksum: 7e567f24eb03cc395349aa653e81efed (MD5) / Made available in DSpace on 2017-05-09T14:41:53Z (GMT). No. of bitstreams: 1 Merilene Maria dos Santos.pdf: 442992 bytes, checksum: 7e567f24eb03cc395349aa653e81efed (MD5) Previous issue date: 2010-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The experiment was conducted during the summer in the Agreste region of Pernambuco state in order to evaluate the behavior under conditions of grazing sheep Santa Ines of different colors of coat. The experiment lasted from January 12 to 01 March 2008, with two and six weeks to adapt to data collection. The observations were made every 10 minutes during the period of 6 A.M. to 5 P.M. for two consecutive days each week. The experimental design was completely randomized, with three coat colors (white, brown and black) as treatments and 7 replications in a split plot arrangement with the coat color in the plot and period in the sub-plot. The variables analyzed were grazing time (PT), rumination time (RT), leisure time (TO), other activities (OA) and drinking water. No significant interaction (P> 0.05) between period and color of the coat for any of the behavioral traits studied. The periods affected all behavioral activities. The hair coat color influenced only the activity mulling standing at the Sun, the white animals had longer (P <0.05) (19.64 minutes) 51 than the brown and black (11.43 and 14.28 minutes), respectively did not differ among themselves and also in other activities in total (Sun and shade), the animals had longer brown (P <0.05) (8.69 minutes) than whites and blacks (5.00 and 6.19 minutes), respectively, which did not differ. The climatic element most associated with the visit to the water source and the animals stay in the shade was the maximum temperature. The period 4, in general, was the worst for sheep in relation to thermal comfort. / O experimento foi conduzido durante o verão na região Agreste do estado de Pernambuco com o objetivo de avaliar o comportamento, em condições de pastejo, de ovinos da raça Santa Inês, de diferentes cores de pelame. O período experimental foi de 12 janeiro a 01 de março de 2008, com duas semanas para adaptação e seis para a coleta de dados. As observações foram realizadas a cada 10 minutos, no período das 06h às 17h,durante dois dias consecutivos a cada semana. O delineamento experimental foi o inteiramente casualizado, com três cores de pelame (branco, castanho e preto), representando os tratamentos e 7 repetições, em um arranjo de parcela subdividida com cor do pelame na parcela e período na sub-parcela. As variáveis analisadas foram: tempo de pastejo (TP), tempo de ruminação (TR), tempo em ócio (TO), outras atividades (OA) e bebendo água. Não houve interação significativa (P>0,05) entre período e cor do pelame para nenhuma das características comportamentais estudadas. Os períodos influenciaram todas as atividades 19 comportamentais. A cor do pelame influenciou apenas a atividade ruminando em pé ao sol: os animais brancos apresentaram maior tempo (P<0,05) (19,64 minutos) que os castanhos e pretos (11,43 e 14,28 minutos), respectivamente, não diferindo entre si. Também em outras atividades no total (ao sol e sombra): os animais castanhos apresentaram maior tempo(P<0,05) (8,69 minutos) que os brancos e pretos, (5,00 e 6,19 minutos), respectivamente, os quais não diferiram entre si. O elemento climático mais associado com a visita à fonte de águae permanência dos animais na sombra foi a temperatura máxima. O período 4, de modo geral,foi o mais desfavorável para os ovinos com relação ao conforto térmico.
243

Influência de diferentes sistemas de manejo sobre parâmetros comportamentais, produtivos e de qualidade de carne de bovinos confinados / Influence of different handling systems on the behavioural, productive and meat quality parameters of confined cattle

Bruno César Prosdocimi Nunes 06 October 2009 (has links)
O presente estudo teve como objetivo investigar a influência de diferentes sistemas de manejo sobre a reatividade, parâmetros produtivos e de qualidade de carne e carcaça de bovinos confinados. Para isso, foram utilizados 50 novilhos Nelore, alocados em confinamento sob dois sistemas diferentes quanto ao manejo, o tradicionalmente empregado em fazendas (MT) e o baseado em princípios racionais de trabalho e na biologia dos bovinos, conhecido popularmente como manejo racional ou gentil (MR). Os animais de ambos os tratamentos receberam a mesma dieta e ficaram em confinamento por 126 dias (± 18 dias). Foram colhidas, durante os manejos de pesagem em brete, informações quanto ao ganho diário de peso (GDP) e reatividade (através do Escore de Comportamento Composto - ECC). Calculou-se, ao fim do confinamento, o ganho diário médio de peso (GDPtot). Durante o abate, foram colhidas informações quanto à reatividade dos bovinos no bloco de atordoamento (ECCabt). Durante a desossa, foram registradas informações quanto a coloração (L*, a* e b*) das amostras de Longissimus dorsi colhidas, três de cada animal, uma para cada tempo de maturação (0, 7 e 14 dias). Apos o período de maturação, procedeu-se com as análises de perdas de água por exsudação (PAE) e por cozimento (PAC), bem como de força de cisalhamento (MAC). Os resultados indicam que ocorreram influencias dos sistemas de manejo nas características PAE e MAC, com valores superiores e inferiores, respectivamente, em MR. Ocorreram influencias na interação tratamento e manejos ocorridos no GDP, com resultados superiores em MT. No parâmetro MAC ocorreu diferença significativa em relação aos dias de maturação, com diminuição ao longo do tempo de maturação, alem de diferenças nos tratamentos na carne nao maturada, com valores inferiores para MR. As características Contusões (totais, no dianteiro, na ponta de agulha e no traseiro), ECCabt, de coloração (L*, a* e b*) e de PAC não apresentaram diferenças significativas entre os tratamentos ou suas interações. Constatou-se melhor qualidade de carne de animais MR, porém com ganhos de peso ligeiramente inferiores aos do MT. A reatividade apresentou tendência de diminuição ao longo do confinamento, com valores ligeiramente inferiores para animais MR nos manejos de pesagem em brete e mais acentuados no momento do abate. / The present study investigated the influence of different handling systems on the reactivity, production parameters and quality of meat and carcass of confined cattle. The experiment used 50 Nellore steers placed in feedlots that received two different handling systems: the traditionally used in the Brazilian farms (MT) and the based on rational principles of work and in the biology of cattle, known as gentle handling (MR).Both treatments received the same diet and remained in confinement for 126 days (± 18 days). Were taken over the handling in squeeze chute, information about the daily weight gain (GDP) and reactivity (through the Composite Behaviour Score - ECC). At the end of the confinement, the average daily weight gain (GDPtot) was calculated. During the slaughter, was collected information of the reactivity of cattle in stunning pen (ECCabt). During the boning, were recorded information about the color (L *, a * b *) of Longissimus dorsi samples. Three samples from each animal was collected, one for each maturation period (0, 7 and 14 days). After the maturation period, that was preceded with the analysis of water loses by exudation (PAE) and by cooking (PAC) and the shear-force (MAC). The results indicate that there were influences of the handling systems features in PAC and MAC, with values higher and lower, respectively, in MR. Occurred influences in treatment and management occurred in GDP, with superior results in MT. In the MAC, parameter was significant difference for days to maturity, with a reduction over maturation time, and differences in treatment in the meat does not mature, with lower values for MR. The characteristics contusions, ECCabt, meat color (L *, a * b *) and PAC showed no significant differences between treatments or their interactions. It was better quality of meat from animals MR, but with gains weight slightly lower than that of MT. The reactivity, although not significantly different, tended to decrease during the confinement, with slightly lower values for MR in the management of animals weighing more pronounced in squeeze chute and at slaughter.
244

Comportamento e organização social do préa Cavia intermedia, uma espécie endêmica das Ilhas Moleques do Sul, Santa Catarina / Behavior and social organization of the wild cavy Cavia intermedia, an endemic species of Moleques do Sul Island, Santa Catarina, Brazil

Nina Furnari 04 November 2011 (has links)
O preá Cavia intermedia (Rodentia: Caviidae), uma espécie recém descrita encontrada exclusivamente no Arquipélago Moleques do Sul, em Santa Catarina, está entre os mamíferos mais raros do planeta. Esta espécie se diferencia de outros preás por características genéticas e morfológicas, muitas delas decorrentes de sua adaptação ao ambiente insular. O objetivo desta pesquisa foi obter dados comportamentais, tomados dentro da necessária matriz ecológica, para o conhecimento da organização social, distribuição espacial e uso dos recursos em C. intermedia. Nossa abordagem utilizou dados existentes de C. magna e C. aperea para situar os resultados em um contexto comparativo, ressaltando possíveis efeitos do isolamento em ambiente insular. Realizamos 25 viagens mensais à ilha, entre novembro de 2007 e dezembro de 2009, com cerca de oito dias cada. Utilizamos 49 armadilhas em um programa de captura-recaptura, no qual os animais foram marcados, medidos, pesados e conferidos quanto ao seu estado reprodutivo. A observação comportamental foi realizada em turnos de duas horas (scans a cada um minuto) em três áreas de grande avistamento de preás (Clareira da barraca, Campinho I e Campinho II), em um total de 636,7 h. Dos 132 indivíduos capturados, 118 foram marcados, sendo 71 machos e 47 fêmeas. A população foi composta em sua maior parte por indivíduos adultos, os quais possuem alta longevidade. Há maturação sexual tardia em relação às espécies preás do continente, além de uma redução no tamanho da ninhada (apenas um filhote). Os nascimentos se concentraram nos meses quentes e chuvosos, cessando em meses frios e com pouca chuva, quando os animais sofrem com a escassez de alimentos. O repertório comportamental de C. intermedia é rico e semelhante em sua forma geral ao de C. aperea, com diferenças em poucas categorias. O hábito alimentar se mostrou herbívoro generalista e dependente dos recursos alimentares disponíveis em cada uma das áreas amostradas, nas quais preás diferentes foram observados. As agregações dentro de cada área se mostraram fluídas, inexistindo territórios, mas encontramos algumas associações entre machos e fêmeas mais duradouras, além de uma hierarquia de dominância entre machos e entre fêmeas. O aumento no número de indivíduos capturados ao longo dos meses revelou um aprendizado por parte dos preás e a maior captura de machos em relação a fêmeas sugere que haja estratégias comportamentais diferentes nos dois sexos. Nossos resultados monstraram que C. intermedia possui diversas características comuns a outras espécies de roedores insulares (população com indivíduos mais velhos, alta longevidade, maturação sexual tardia e redução da ninhada, resposta anti-predatória reduzida, inexistência de territórios, aumento na tolerância a coespecíficos e na freqüência de interações), fruto de adaptações ao ambiente insular. Por outro lado, características como repertório comportamental, aspectos fisiológicos da reprodução e hábito alimentar se mostraram conservadas ao longo da evolução, sendo comuns a outras espécies de preás do continente / The Cavia intermedia cavy (Rodentia: Caviidae) a newly described species exclusively found in the Moleques do Sul Archipelago in the state of Santa Catarina, Brazil is one of the rarest mammals on the planet. This species is differentiated from other cavies on the basis of its genetic and morphologic characteristics, several of them resulting from its adaptation to an island environment. The objective of this research was to obtain behavioral data taken from within the required ecological matrix to shed light into the social organization, spatial distribution and resource use of the C. intermedia. Our approach used existing data for C. magna and C. aperea to frame results into a comparative context, highlighting possible effects from being cut off in an island environment. We have done 25 monthly trips to the island, of approximately 8 days each, between November 2007 and December 2009. We have used 49 traps for a capture-recapture program in which the animals where tagged, measured, weighted and checked for reproductive state. The behavioral observation took place in two-hour rounds (with intervals scans of one minute) in three areas of frequent cavy sightings (Clareira da barraca, Campinho I and Campinho II) totaling 636,7 hours. Out of the 132 individuals captured, 118 were tagged: 71 males and 47 females. This population was composed mostly of adults which had a long lifespan. There was a delayed sexual maturity in this population when compared to the mainland cavy species, as well as a reduction in litter size. Births were concentrated during the warm and rainy months and halted during the cold and dry months, when the animals struggled with food scarcity. The behavioral repertoire of C. intermedia is rich and generally similar to C. apereas, differing in only a few categories. Their feeding habits matched those of a generalist herbivore and depended on the food sources available in each one of the surveyed areas. The gatherings within each area proved to be fluid, without territorial definitions, however we have observed a few longer-term male-female pairings, besides a dominance hierarchy among males and females. The increase in number of captured individuals over the months indicates that the population became aware of and used to the capture process. Besides, the increase in number of males captured in relation to females signals at gender-specific behavioral strategies. Our results show that the C. intermedia has several characteristics in common with other species of island rodents due to adaptations to island life: older population, longer lifespan, late sexual maturity and reduced litter size in response to reduced predatory activity, lack of territories, increase tolerance with coespecific and increase in interactions. On the other hand, certain characteristics such as behavioral repertoire, physiological aspects in reproduction and feeding habits remained the same throughout the evolutionary process, being shared with other cavy species from the mainland
245

Evolução da memória em aranhas do grupo Orbiculariae / Evolution of memory in Orbiculariae spiders

Vanessa Penna-Gonçalves 01 April 2011 (has links)
A memória é considerada por muitos pesquisadores como um dos produtos mais fascinantes da evolução biológica, justamente por proporcionar aos animais a vantagem adaptativa de se utilizar de uma experiência prévia para a solução de problemas necessários para a sobrevivência. Os animais se utilizam de processos mnemônicos durante o forrageamento, a seleção de parceiros sexuais, seleção de habitat e a preferência alimentar. As aranhas são um modelo interessante em estudos de memória e há evidências do uso de experiências passadas na otimização do forrageio: a teia permite que as aranhas capturem e armazenem mais de um item alimentar. Há carência na literatura de estudos comparativos evolutivos da memória, o que dificulta identificar as possíveis pressões seletivas. O primeiro objetivo deste trabalho foi fazer um estudo comparativo de aspectos da memória predatória em aranhas do grupo Orbiculariae. Este grupo é monofilético e tem como principal sinapomorfia a construção de teia orbicular. Porém, ao longo da evolução, o padrão de teia foi se modificando desde uma estrutura plana até uma tridimensional. Tais modificações podem ter gerado diferenças comportamentais e no sistema de memória dessas aranhas. Por este motivo, o outro objetivo, foi traçar a evolução da memória dentro do grupo. Delinearam-se três grupos de estudo com sete espécies. Na condição natural, observou-se a captura de duas presas sucessivas. Na condição experimental I, ofereceu-se uma primeira presa (p1) à aranha e, em seguida, ofereceu-se uma segunda (p2); durante o deslocamento da aranha até p2, retirou-se p1 da teia. Na condição II, ao invés de se oferecer p2, a aranha foi atraída à periferia (simulando a queda de p2). No deslocamento da aranha até a fonte de vibração removeu-se p1. O indício de memória é observado quando, na supressão da presa, a aranha executa um comportamento denominado Busca. Neste, a aranha executa sacudidas/detecções dos fios no centro/refúgio da teia. A busca por p1 roubada foi observada em todas as espécies estudadas, exceto em Z. geniculata no grupo I. A presença de p2 parece interferir na expressão da memória de p1; deixar p2 na teia enquanto busca por p1, aumenta as chances de p2 também ser roubada por ação dos cleptoparasitas. Zosis apresenta algumas peculiaridades, entre elas a ausência de veneno. Dessa forma, o tempo gasto durante a imobilização de p2 parece ser suficiente para causar o esquecimento de p1. Todas as espécies buscaram por p1 quando não houve oferta de p2, inclusive Zosis. O tempo de busca, na condição I, diminui da base de Araneoidea até as famílias mais derivadas. No grupo II, há uma aparente inversão do sinal filogenético e o tempo de busca aumenta na família mais derivada. A estrutura da teia tridimensional parece ser mais complexa e, por este motivo, exigiria um sistema de navegação espacial também mais complexo quando comparado às aranhas orbitelas. A construção da teia parece ter sido crucial para a captura e armazenamento de presas excedentes, e tal comportamento, juntamente com a diversificação das teias, favoreceu a variação e evolução da memória na Ordem Araneae / Memory is one of the most fascinating products of biological evolution, because it endows animals with the adaptive use a prior experiences to solve survival problems. Animals use mnemonic processes during foraging, selection of sexual partners, habitat selection, and feeding preference. Spiders are an interesting model for studies of memory, and there is evidence of their using of past experiences in optimizing foraging: the web allows the spiders to capture and store more than one food item. In literature, there are few comparative studies, and no one about the evolution of memory, making it difficult to identify the possible selective pressures on memory. The first objective here was to make a comparative study on the aspects of predatory memory in spiders of the group Orbiculariae. This group is monophyletic and its main synapomorphy is building an orbicular web. However, during evolution, the web pattern changed from a flat to a three-dimensional structure. Such changes may have caused differences in behavior and memory. For that reason, another goal was to trace the evolution of memory within the group. We used three experimental groups with seven species each. In natural conditions, there was an observation of the capture of two successive preys. In the experimental condition I, a first prey (p1) was offered to the spider and, subsequently, another prey (p2) was offered; during the locomotion of the spider towards p2, p1 was removed from the web. In condition II, instead of offering p2, the spider was attracted to the periphery (simulating the fall of p2). As the spider moved towards the source of vibration, p1 was removed. The evidence of memory is observed when, in the suppression of the prey, the spider performs a behavior called search behavior: the spider runs plucking on threads in the web hub/retreat. The search for stolen p1 was observed in all species studied, except for Zosis geniculata in group I. The presence of p2 appears to interfere with the expression of p1 memory, and also leaving p2 on the web while searching for p1, increases the chances of having p2 stolen by the action of kleptoparasites. Zosis presents some peculiarities, including the absence of poison glands, leading to a prolonged immobilization of p2, in a time lag that could then be sufficient forget p1. All species sought by p1 when there was no offer of p2, including Zosis. The search time, in condition I, decreases from the base of Araneoidea until the most derived families. In group II, there is an apparent reversal of the phylogenetic signal and the search time increases in the most derived family. The three-dimensional structure of the derived webs seems to be more complex and, therefore, it would require a spatial navigation system also more complex if compared to the flat orbweb. The construction of the web seems to have been crucial for prey capture and storage of surpluses, and such behavior, along with the diversification of the webs, favored the variation and evolution of memory in the Order Araneae
246

Vocal Flexibility and Regional Variation in Free-Tailed Bat Song

Salazar, Israel 07 July 2016 (has links)
While much work has been done on regional vocal variation in birds, relatively few studies have found evidence of similar variation in mammalian vocalizations. This study quantifies individual, colonial, and regional level variation in T. brasiliensis songs in the southeastern United States. Brazilian free-tailed bats (Tadarida brasiliensis) are among a handful of mammals that produce complex, hierarchically structured vocalizations. Their songs are composed of multiple syllables that are combined into three phrases that vary in number and order across renditions. Tadarida brasiliensis songs showed considerable amount of variation, and differed significantly between locations in terms of syllable structure and song syntax. Some of the variation observed was not correlated to geographical distance, and is unlikely to be explained by genetic divergence or differences in habitat use. These results indicate the existence of vocal dialects and a possible role of vocal production learning in dialect formation in this species.
247

Non-Consumptive Effects of Predators in Coral Reef Communities and the Indirect Consequences of Marine Protected Areas

Catano, Laura 05 November 2014 (has links)
Predators exert strong direct and indirect effects on ecological communities by intimidating their prey. Non-consumptive effects (NCEs) of predators are important features of many ecosystems and have changed the way we understand predator-prey interactions, but are not well understood in some systems. For my dissertation research I combined a variety of approaches to examine the effect of predation risk on herbivore foraging and reproductive behaviors in a coral reef ecosystem. In the first part of my dissertation, I investigated how diet and territoriality of herbivorous fish varied across multiple reefs with different levels of predator biomass in the Florida Keys National Marine Sanctuary. I show that both predator and damselfish abundance impacted diet diversity within populations for two herbivores in different ways. Additionally, reef protection and the associated recovery of large predators appeared to shape the trade-off reef herbivores made between territory size and quality. In the second part of my dissertation, I investigated context-dependent causal linkages between predation risk, herbivore foraging behavior and resource consumption in multiple field experiments. I found that reef complexity, predator hunting mode, light availability and prey hunger influenced prey perception of threat and their willingness to feed. This research argues for more emphasis on the role of predation risk in affecting individual herbivore foraging behavior in order to understand the implications of human-mediated predator removal and recovery in coral reef ecosystems.
248

Visual Attention in Jumping Spiders

Bruce, Margaret 19 March 2019 (has links)
The different ways that animals extract and analyze visual information from their environment is of interest to sensory ecologists. Jumping spiders, well-known for visually guided mating and hunting behavior, are an interesting model for the study of visual attention because they quickly and efficiently integrate information from eight eyes with a small brain. Stimuli in front of the spider are examined by two functionally and morphologically distinct pairs of forward-facing eyes. The principal eyes discern fine details and have small retinas and thus a small visual field. However, their position at the back of moveable tubes within the cephalothorax expands this visual field. The anterolateral eyes, one of the three pairs of secondary eyes, have lower spatial acuity and a larger visual field that overlaps with that of the principal eyes. They act as motion detectors, directing the principal eyes to objects appearing in their visual field. In Chapter 1, using a salticid-specific eyetracker, I explore how characteristics of a stimulus influence whether the secondary eyes redirect the gaze of the principal eyes from a principal stimulus to a new stimulus appearing in the visual field. I found that spiders suppressed redirection of the principal eyes when engaged by a salient stimulus, and redirected to moving peripheral stimuli more frequently than to stationary peripheral stimuli. The principal eyes are also known to engage in a complex behavior called “scanning,” involving both dorsoventral and rotational movement. One hypothesis regarding scanning’s function is that it helps spiders identify important lines and angles in stimuli. However, scanning routines are not well understood. In Chapter 2, I measured scanning behaviors when spiders were watching quickly moving versus still or slowly moving images. I found that spiders spent more time overall looking at still or slowly moving images, and that stimulus speed does not appear to affect rotational movement of the retinas. Overall, I conclude that motion in an appearing stimulus elicits the attention of the principal eyes, but it remains unclear how and whether scanning functions in the extraction of detail from moving stimuli.
249

Analýza a komparace boxerských stylů elitních amatérských boxerů Kuby a Kazachstánu / Analysis and comparison of boxing styles of elite amateur boxers from Cuba and Kazakhstan

Čížek, Jakub January 2021 (has links)
Title: Analysis and comparison of boxing styles of elite amateur boxers from Cuba and Kazakhstan Objectives: The main goal of this thesis was to find out whether the frequency of use of punching techniques and the distance from which these punching techniques are used are statistically significant for the style of two the most successful countries in amateur boxing. The countries were compared in the use and success of the strikes and compared to their preference for long or medium combat distance. Methods: The method of quantitative observation was used, in which data was obtained by watching video recordings. Part of the matches was evaluated by recording the results manually on paper, the other part in the BORIS program. All data was then transcribed into a Microsoft Excel spreadsheet, where it was also processed. The source for the data were publicly available video recordings from top competitions in 2010-2020. Results: Differences between countries in the monitored indicators are insignificant and boxing styles do not differ much. In the frequency of the use of striking techniques between the rounds, a significant difference was found only between the first and second round of the Kazakhs. In the case of determining the preference for long and medium distance combat between the rounds, there...
250

Encephalization in Commensal Raccoons: A Unique Test of the Cognitive Buffer Hypothesis

Anderson, Peter M 01 May 2020 (has links)
This study investigated selective pressures associated with encephalization in mammals and discussed broader implications. Relative brain size as measured by EQ (Encephalization Quotient) was compared between ecological categories. Omnivores had higher average EQ than ecological specialists. Since specialists are disproportionately affected by extinction events, selection for ecological generalism is proposed as encephalization mechanism. This mechanism may reinforce the more widely known Cognitive Buffer Hypothesis (CBH)—the idea that possessing relatively large brains has buffered lineages against environmental change. CBH is tested here by comparing EQs in Procyon lotor (raccoon) in urban and rural environments. CBH predicts that raccoons in the most radically altered environment, the city, experience the strongest selection for encephalization. Urban raccoons studied here exhibit a higher EQ. Although results are preliminary, data suggest that encephalization is accelerated during abrupt periods of environmental change. Finally, implications for the evolution of biological complexity more generally are discussed.

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