The evolution of sex similarities in social signals: Climatic seasonality is associated with lower sexual dimorphism and greater elaboration of female and male signals in antbirds (Thamnophilidae).

Selection on signals that mediate social competition varies with resource availability. Climate regulates resource availability, which may affect the strength of competition and selection on signals. Traditionally, this meant that more seasonal, colder, or dryer-overall harsher-environments should favor the elaboration of male signals under stronger male-male competition, increasing sexual dimorphism. However, females also use signals to compete; thus, harsher environments could strengthen competition and favor elaboration of signals in both sexes, decreasing sexual dimorphism. Alternatively, harsher environments could decrease sexual dimorphism due to scarcer resources to invest in signal elaboration in both sexes. We evaluated these contrasting hypotheses in antbirds, a family of Neotropical passerines that varies in female and male signals and occurs across diverse climatic regimes. We tested the association of sexual dimorphism of plumage coloration and songs with temperature, precipitation, and their seasonality. We found that greater seasonality is associated with lower sexual dimorphism in plumage coloration and greater elaboration of visual signals in both sexes, but not acoustic signals. Our results suggest that greater seasonality may be associated with convergent elaboration of female and male visual signals, highlighting the role of signals of both sexes in the evolution of sexual dimorphism.

Third-party conflict interventions are kin biased in captive white-lipped peccaries (Mammalia, Tayassuidae).

Third-party interventions may regulate conflicts to reduce aggression and promote cohesion amongst group members, but are rarely documented in ungulates. The white-lipped peccary (Tayassu pecari) lives in mixed-sex herds of hundreds of individuals in Neotropical forests, which are likely to benefit from mechanisms that sustain social cohesiveness. We examined third-party conflict interventions between individuals in captive groups of white-lipped peccaries. During a period of 60 days, we recorded agonistic interactions and occurrences of third-party conflict interventions, and estimated the genetic relatedness between the individuals involved using multilocus microsatellite genotypes. Most third-party conflict interventions were by the dominant male of each group, resulting in conflict termination 100% of the time. Our results also revealed that white-lipped peccaries favour their closest relatives and that individuals showed lower levels of aggression towards kin than to non-kin, and interventions on behalf of kin were more frequent than on behalf of non-kin. Our findings support the idea that genetic relatedness is fundamental in both social structure and third-party conflict interventions in this species, allowing us to suggest that kin selection could have a key role in the evolution of social behaviour of white-lipped peccaries.

The population genetic structure approach adds new insights into the evolution of plant LTR retrotransposon lineages.

Long terminal repeat retrotransposons (LTR-RTs) in plant genomes differ in abundance, structure and genomic distribution, reflecting the large number of evolutionary lineages. Elements within lineages can be considered populations, in which each element is an individual in its genomic environment. In this way, it would be reasonable to apply microevolutionary analyses to understand transposable element (TE) evolution, such as those used to study the genetic structure of natural populations. Here, we applied a Bayesian method to infer genetic structure of populations together with classical phylogenetic and dating tools to analyze LTR-RT evolution using the monocot Setaria italica as a model species. In contrast to a phylogeny, the Bayesian clusterization method identifies populations by assigning individuals to one or more clusters according to the most probabilistic scenario of admixture, based on genetic diversity patterns. In this work, each LTR-RT insertion was considered to be one individual and each LTR-RT lineage was considered to be a single species. Nine evolutionary lineages of LTR-RTs were identified in the S. italica genome that had different genetic structures with variable numbers of clusters and levels of admixture. Comprehensive analysis of the phylogenetic, clusterization and time of insertion data allowed us to hypothesize that admixed elements represent sequences that harbor ancestral polymorphic sequence signatures. In conclusion, application of microevolutionary concepts in genome evolution studies is suitable as a complementary approach to phylogenetic analyses to address the evolutionary history and functional features of TEs.

The mitochondrial genome of the sooty swift (Cypseloides fumigatus).

We assembled the mitogenome of Cypseloides fumigatus based on off-target sequences from ultraconserved elements sequencing. We found a total length of 16,850 bp, including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and one control region, organized in the standard avian gene order. We have built a phylogenetic tree including 26 species of swifts that suggested C. fumigatus as sister species of C. cryptus, and indicated exciting opportunities for biogeographic inferences involving most continents, including Neartic vs Neotropical disjunctions and local radiations across the globe. Finally, we found cases of lack of reciprocal monophyly between named species and high intra-specific divergence, suggesting that population-level studies are warranted.

Ultraconserved Elements Sequencing as a Low-Cost Source of Complete Mitochondrial Genomes and Microsatellite Markers in Non-Model Amniotes.

Sequence capture of ultraconserved elements (UCEs) associated with massively parallel sequencing has become a common source of nuclear data for studies of animal systematics and phylogeography. However, mitochondrial and microsatellite variation are still commonly used in various kinds of molecular studies, and probably will complement genomic data in years to come. Here we show that besides providing abundant genomic data, UCE sequencing is an excellent source of both sequences for microsatellite loci design and complete mitochondrial genomes with high sequencing depth. Identification of dozens of microsatellite loci and assembly of complete mitogenomes is exemplified here using three species of Poospiza warbling finches from southern and southeastern Brazil. This strategy opens exciting opportunities to simultaneously analyze genome-wide nuclear datasets and traditionally used mtDNA and microsatellite markers in non-model amniotes at no additional cost.

Social structure of collared peccaries (Pecari tajacu): does relatedness matter?

Relatedness is considered an important factor in shaping social structure as the association among kin might facilitate cooperation via inclusive fitness benefits. We addressed here the influence of relatedness on the social structure of a Neotropical ungulate, the collared peccary (Pecari tajacu). As peccaries are highly social and cooperative, live in stable cohesive herds and show certain degree of female philopatry and high mean relatedness within herds, we hypothesized that kin would be spatially closer and display more amicable and less agonistic interactions than non-kin. We recorded spatial association patterns and rates of interactions of two captive groups. Pairwise relatedness was calculated based on microsatellite data. As predicted, we found that kin were spatially closer than non-kin, which suggests that relatedness is a good predictor of spatial association in peccaries. However, relatedness did not predict the rates of social interactions. Although our results indirectly indicate some role of sex, age and familiarity, further studies are needed to clarify the factors that shape the rates of interactions in collared peccaries. This article is part of a Special Issue entitled: Neotropical Behaviour.

Comparative analysis of microsatellite variability in five macaw species (Psittaciformes, Psittacidae): Application for conservation.

Cross-amplification was tested and variability in microsatellite primers (designed for Neotropical parrots) compared, in five macaw species, viz., three endangered blue macaws (Cyanopsitta spixii [extinct in the wild], Anodorhynchus leari [endangered] and Anodorhynchus hyacinthinus [vulnerable]), and two unthreatened red macaws (Ara chloropterus and Ara macao). Among the primers tested, 84.6% successfully amplified products in C. spixii, 83.3% in A. leari, 76.4% in A. hyacinthinus, 78.6% in A. chloropterus and 71.4% in A. macao. The mean expected heterozygosity estimated for each species, and based on loci analyzed in all the five, ranged from 0.33 (A. hyacinthinus) to 0.85 (A. macao). As expected, the results revealed lower levels of genetic variability in threatened macaw species than in unthreatened. The low combined probability of genetic identity and the moderate to high potential for paternity exclusion, indicate the utility of the microsatellite loci set selected for each macaw species in kinship and population studies, thus constituting an aid in planning in-situ and ex-situ conservation.

Comparative analysis of microsatellite variability in five macaw species (Psittaciformes, Psittacidae): application for conservation

Cross-amplification was tested and variability in microsatellite primers (designed for Neotropical parrots) compared, in five macaw species, viz., three endangered blue macaws (Cyanopsitta spixii [extinct in the wild], Anodorhynchus leari [endangered] and Anodorhynchus hyacinthinus [vulnerable]), and two unthreatened red macaws (Ara chloropterus and Ara macao). Among the primers tested, 84.6 percent successfully amplified products in C. spixii, 83.3 percent in A. leari, 76.4 percent in A. hyacinthinus, 78.6 percent in A. chloropterus and 71.4 percent in A. macao. The mean expected heterozygosity estimated for each species, and based on loci analyzed in all the five, ranged from 0.33 (A. hyacinthinus) to 0.85 (A. macao). As expected, the results revealed lower levels of genetic variability in threatened macaw species than in unthreatened. The low combined probability of genetic identity and the moderate to high potential for paternity exclusion, indicate the utility of the microsatellite loci set selected for each macaw species in kinship and population studies, thus constituting an aid in planning in-situ and ex-situ conservation.

Estrutura social e alo-amamentarão de catetos(Tayassu tajacu) em cativeiro / Social structure and allonursing of collared peccaries (Tayassu tajacu) in captivity

A estrutura social é a rede de relações estabelecidas entre os indivíduos do grupo e essa estrutura pode ser afetada por fatores como o parentesco e a condição nutricional. Um comportamento intrigante, que foi associado ao parentesco e à condição nutricional, é a alo-amamentação, em que uma fêmea amamenta filhotes de outras fêmeas. Este estudo teve por objetivos determinar a influência do parentesco e da condição nutricional na estrutura social de catetos (Tayassu tajacu) em cativeiro e descrever os eventos de alo-amamentação, buscando verificar variáveis que possam ajudar a compreender o comportamento nesta espécie. Para tal, foram observados dois grupos de animais cativos, um com dez indivíduos (grupo B2) e outro com sete (grupo B3). O grupo B2 foi submetido a uma dieta com 16 por cento de proteína bruta e o B3, com 12 por cento. Os animais dos dois grupos tiveram seu sangue coletado para a análise de parentesco, que foi feita utilizando-se marcadores moleculares microssatélites. Como ainda não tinham sido desenvolvidos primers de microssatélites para catetos, foram testados primers desenvolvidos para suínos. Essa metodologia mostrou-se eficaz para acessar locos de microssatélites em catetos e foi possível, através dela, estimar o coeficiente de parentesco entre os indivíduos. As interações afiliativas e agonísticas e os eventos de alo-amamentação foram registrados pelo método de todas as ocorrências. A proximidade espacial foi obtida registrando-se o padrão de subgrupos formados pelos indivíduos por meio de varredura instantânea. No geral, o grupo B2 apresentou maior ocorrência de interações agonísticas e afiliativas do que o B3, e foi caracterizado por uma estrutura igualitária quanto às relações de dominância, enquanto que o B3 se apresentou mais organizado hierarquicamente. O parentesco não pareceu influenciar diretamente a freqüência das interações agonísticas, mas foi possível associar esta variável com a freqüência de interações afiliativas e proximidade espacial. Os indivíduos aparentados ficaram mais próximos na estrutura espacial e, principalmente no B3, interagiram mais afiliativamente. Os eventos de alo-amamentação foram pouco freqüentes e não pareceram acarretar muitos custos para a fêmea. Foi levantada a questão de que tal comportamento possa ser um comportamento afiliativo e possibilitar a formação de vínculos entre os filhotes e as fêmeas alheias (AU)

Amamentação da prole e amamentação cooperativa em catetos (Tayassu tajacu): uma análise exploratória / Offspring and cooperative nursing in collared peccaries (Tayassu tajacu): an exploratory analysis

Sendo a amamentação uma atividade custosa, esperar-se-ia que as fêmeas de mamíferos apenas cedessem seu leite aos próprios filhotes. O comportamento de amamentar filhotes alheios foi, contudo, observado em muitas espécies de mamíferos. Neste estudo, investigou-se a amamentação em catetos com especial atenção aos padrões de amamentação cooperativa em contraste com os de amamentação da própria prole. Foram observados quatro fêmeas e seis filhotes de um grupo de 26 catetos mantidos em cativeiro, utilizando os métodos de animal focal e varredura instantânea. Todas as fêmeas amamentaram filhotes alheios, porém a freqüência de amamentação cooperativa foi menor do que a esperada para catetos. A amamentação cooperativa e a dos próprios filhotes foram caracterizadas em termos da aceitação da fêmea, do número de filhotes mamando, da posição dos filhotes, e do modo de finalização das mamadas. A maioria dessas características foi semelhante nos dois tipos de amamentação(AU)

Being a high-cost activity, nursing should be restricted to own young. The behavior of nursing alien offspring has however been observed in many mammal species. In this study, nursing was observed in collared peccary, with special attention to the patterns of cooperative nursing in contrast to offspring nursing. Four females and six young of a group of 26 collared peccaries were observed in captivity, throughout focal animal and scan sampling methods. All of the females nursed alien young, but the frequency of cooperative nursing was lower than that expected for collared peccaries. Offspring and cooperative nursing events were assessed in terms of female acceptance, number of young sucking, young postures, and finalization patterns of nursing bouts. Most of such features were similar in offspring and cooperative nursing(AU)

A amamentação cooperativa em catetos (Tayassu tajacu) / The cooperative nursing in collared peccaries (Tayassu tajacy)

O comportamento em que uma fêmea amamenta os filhotes de outras fêmeas foi investigado em cateto. Procurou-se verificar: a freqüência do comportamento e caracterizar seus eventos; a influência do parentesco das fêmeas e do sexo dos filhotes nessa freqüência; a existência de reciprocidade a curto prazo. Houve também, um interesse teórico em compreender os processos subjacentes ao comportamento. Para tal, foram observados quatro fêmeas focais e seis filhotes de um grupo de 26 catetos mantidos em cativeiro. Os métodos de observação utilizados foram o de animal focal e de 'scan sampling'. Embora a freqüência observada tenha sido menor do que o esperado, verificou-se que todas as fêmeas amamentaram cooperativamente, com uma reciprocidade aparente entre duas delas. As interações sociais do grupo exerceram certa influência na existência do comportamento. A aceitação das fêmeas as solicitações dos filhotes para mamar e as finalizações dos eventos pareceram ser determinados tanto pelas motivações delas quanto pela insistência dos filhotes. Filhotes machos e fêmeas demonstraram ter estratégias diferentes para mamar sendo que os machos mamaram com maior freqüência e os fêmeas com maior duração. Observou-se também, que a familiaridade e o parentesco entre as fêmeas podem influenciar a ocorrência do comportamento. A exploração realizada neste trabalho criou condições para permitir planejamentos experimentais elaborados para investigar hipóteses causais e funcionais da amamentação cooperativa (AU)