Extra-pair paternity in a Neotropical rainforest songbird, the White-necked Thrush Turdus albicollis (Aves: Turdidae)

ABSTRACT Over the last two decades, several studies have shown that the mating systems of various birds are more complex than previously believed, and paternity tests performed with molecular techniques have proved, for instance, that the commonly observed social monogamy often presents important variations, such as extra-pair paternity. However, data are still largely biased towards temperate species. In our study, at an area of the Brazilian Atlantic Forest, we found broods containing at least one extra-pair young (EPY) in the socially monogamous White-necked Thrush Turdus albicollis (Vieillot, 1818). Paternity tests using six heterologous microsatellite loci revealed that four of 11 broods (36.4%) presented at least one extra-pair young (EPY). This rate of EPY is within the range found for other studies in the tropics. This is one of the few studies that present detailed paternity analyses of a Neotropical rainforest passerine. Our findings corroborate the early insights that breeding strategies involving cheating can also be widespread among Neotropical socially monogamous songbirds

Hybridization between two recently diverged Neotropical passerines: The Pearly-bellied Seedeater Sporophila pileata, and the Copper Seedeater S. bouvreuil (Aves, Passeriformes, Thraupidae).

The small Neotropical finches called capuchinos are outstanding because they have experienced one of the most recent and explosive avian radiations ever documented for birds. Despite very low morphological and niche divergence among species, many of them are reproductively isolated when in sympatry due to strong sexual selection in plumage traits. However, a specific pair of mostly parapatric species, the Pearly-bellied, Sporophila pileata, and the Copper Seedeaters, S. bouvreuil, has confounded taxonomists because individuals with intermediate color patterns can be found. By analyzing diagnostic COI mtDNA sequences and adult male plumage we provide evidence for hybridization. Paternity tests using microsatellites also indicated that representatives with intermediate plumage pattern can be fertile. Our findings are consistent with the classification of S. bouvreuil and S. pileata as distinct taxa, but we demonstrate that the sexual selection mechanisms involved in the isolation of other reproductively sympatric capuchinos are not applicable to this pair of species, likely because of reduced barriers to mate recognition

Extra-pair paternity in a Neotropical rainforest songbird, the White-necked Thrush Turdus albicollis (Aves: Turdidae)

ABSTRACT Over the last two decades, several studies have shown that the mating systems of various birds are more complex than previously believed, and paternity tests performed with molecular techniques have proved, for instance, that the commonly observed social monogamy often presents important variations, such as extra-pair paternity. However, data are still largely biased towards temperate species. In our study, at an area of the Brazilian Atlantic Forest, we found broods containing at least one extra-pair young (EPY) in the socially monogamous White-necked Thrush Turdus albicollis (Vieillot, 1818). Paternity tests using six heterologous microsatellite loci revealed that four of 11 broods (36.4%) presented at least one extra-pair young (EPY). This rate of EPY is within the range found for other studies in the tropics. This is one of the few studies that present detailed paternity analyses of a Neotropical rainforest passerine. Our findings corroborate the early insights that breeding strategies involving cheating can also be widespread among Neotropical socially monogamous songbirds

Extra-pair paternity in a Neotropical rainforest songbird, the White-necked Thrush Turdus albicollis (Aves: Turdidae)

ABSTRACT Over the last two decades, several studies have shown that the mating systems of various birds are more complex than previously believed, and paternity tests performed with molecular techniques have proved, for instance, that the commonly observed social monogamy often presents important variations, such as extra-pair paternity. However, data are still largely biased towards temperate species. In our study, at an area of the Brazilian Atlantic Forest, we found broods containing at least one extra-pair young (EPY) in the socially monogamous White-necked Thrush Turdus albicollis (Vieillot, 1818). Paternity tests using six heterologous microsatellite loci revealed that four of 11 broods (36.4%) presented at least one extra-pair young (EPY). This rate of EPY is within the range found for other studies in the tropics. This is one of the few studies that present detailed paternity analyses of a Neotropical rainforest passerine. Our findings corroborate the early insights that breeding strategies involving cheating can also be widespread among Neotropical socially monogamous songbirds

Novel and cross-amplified microsatellite loci for the critically endangered São Paulo marsh antwren Formicivora paludicola (Aves: Thamnophilidae)

The So Paulo marsh antwren (Formicivora paludicola) is a critically endangered bird endemic to marshes in the metropolitan region of So Paulo city, Brazil. The total population is estimated to be around 300 individuals, distributed among 15 small (< 50 ha) fragments, suggesting that loss of genetic variability may affect the long-term viability of this species. To develop genetic tools for gaining information on effective population sizes, inbreeding and gene flow between populations, we describe nine polymorphic microsatellite loci isolated from a F. paludicola library using next-generation sequencing. We report on levels of variation in these novel microsatellites and eight additional heterologous loci in these birds. Expected (H (E)) and observed (H (O)) heterozygosities averaged 0.72 and 0.70, respectively, and the number of alleles per locus ranged from 3 to 10. These loci will permit evaluation of whether artificial translocations are necessary for long-term viability of this rare bird.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Marshes as “Mountain Tops”: Genetic Analyses of the Critically Endangered São Paulo Marsh Antwren (Aves: Thamnophilidae)

<div><p>Small populations of endangered species can be impacted by genetic processes such as drift and inbreeding that reduce population viability. As such, conservation genetic analyses that assess population levels of genetic variation and levels of gene flow can provide important information for managing threatened species. The São Paulo Marsh Antwren (<i>Formicivora paludicola</i>) is a recently-described and critically endangered bird from São Paulo State (Brazil) whose total estimated population is around 250–300 individuals, distributed in only 15 isolated marshes around São Paulo metropolitan region. We used microsatellite DNA markers to estimate the population genetic characteristics of the three largest remaining populations of this species all within 60 km of each other. We detected a high and significant genetic structure between all populations (overall <i>F</i>_ST = 0.103) which is comparable to the highest levels of differentiation ever documented for birds, (e.g., endangered birds found in isolated populations on the tops of African mountains), but also evidence for first-generation immigrants, likely from small local unsampled populations. Effective population sizes were small (between 28.8–99.9 individuals) yet there are high levels of genetic variability within populations and no evidence for inbreeding. Conservation implications of this work are that the high levels of genetic structure suggests that translocations between populations need to be carefully considered in light of possible local adaptation and that remaining populations of these birds should be managed as conservation units that contain both main populations studied here but also small outlying populations which may be a source of immigrants.</p></div

<i>F</i>_ST and <i>F′</i>_ST (in parentheses) values between pairs of studied populations (above diagonal), and <i>R</i>_ST values (bellow diagonal).

<p>The overall <i>F</i>_ST, <i>F′</i>_ST, and <i>R</i>_ST values across all populations were 0.103, 0.344, and 0.097, respectively. All P values are < 0.01.</p

Number of analyzed individuals (<i>N</i>), average number of alleles per loci (<i>N</i>_A), allelic richness (<i>A</i>_R), observed (<i>H</i>_O) and expected (<i>H</i>_E) heterozygosities, inbreeding coefficient (<i>F</i>_IS), and its probability of being different from zero (<i>P</i>), across 17 microsatellite loci, found in three populations of the São Paulo Marsh Antwren.

<p>The critical P value after Bonferroni correction was 0.001. (SD: Standard Deviation).</p

Population structure and first generation migrants.

<p><b>(A)</b> Proportional membership (<i>Q</i>) of each São Paulo Marsh Antwren in the genetic clusters inferred by Structure (<i>K</i> = 3). This graphic represents each individual as a bar, and its membership probability in each cluster. Individuals <b>1</b> to <b>26</b>: Mogi das Cruzes population; Individuals <b>27</b> to <b>43</b>: Salesópolis population, and individuals <b>44</b> to <b>57:</b> São José dos Campos. Black arrows identify individuals indicated as first generation migrants. <b>(B)</b> Output graphics from Structure Harvester, indicating the higher value of <i>Ln P</i>(<i>K</i>) (left), and Δ<i>K</i> (right).</p