de Castro e Souza Andiara Silos Moraes, Del Lama Silvia Nassif, Miño Carolina Isabel
Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil.
J Exp Zool A Ecol Genet Physiol. 2013 Jun;319(5):277-84. doi: 10.1002/jez.1792. Epub 2013 Apr 1.
The white-faced ibis Plegadis chihi Vieillot, 1817 (Pelecaniformes: Threskiornithidae) is a socially monogamous colonially breeding bird in which behavioral and ecological observations suggest the occurrence of conspecific brood parasitism (CBP). We inferred aspects of the genetic mating system of P. chihi in nature, using a genetic approach in the absence of parental information. We used five heterologous microsatellite loci and a multiple-step methodological approach to infer kinship patterns among 104 pairs of nestlings sampled inside 80 nests in a breeding colony from southern Brazil. The estimated effective population size was 69 white-faced ibises (95% CI: 50-98), enough to ensure long-term population survival. Kinship patterns were identified for 38% of the analyzed pairs: 60% of the diagnosed pairs were identified as full-siblings, 2.5% as half-siblings and 37.5% as unrelated individuals. CBP could explain the presence of unrelated nestlings within broods, in agreement with available non-genetic evidence. The presence of half-siblings within broods could indicate extra-pair paternity. Results suggest that a non-strictly monogamous genetic mating system may be present in the white-faced ibis. This study is the first molecular approach to better characterize the reproductive behavior of P. chihi in the wild. Our findings set the stage for further research to investigate the possible causes and consequences of alternative reproductive strategies in this species.
白脸朱鹭（Plegadis chihi Vieillot，1817年）（鹈形目：鹮科）是一种群居繁殖的鸟类，在社会行为上实行一夫一妻制，行为和生态观察表明该物种存在种内巢寄生（CBP）现象。在缺乏亲代信息的情况下，我们采用遗传学方法推断了自然界中白脸朱鹭的遗传交配系统。我们使用了五个异源微卫星位点和多步骤方法，对巴西南部一个繁殖群体中80个鸟巢内的104对雏鸟进行亲缘关系推断。估计有效种群大小为69只白脸朱鹭（95%置信区间：50 - 98），足以确保种群的长期生存。在38%的分析雏鸟对中确定了亲缘关系模式：在诊断出的雏鸟对中，60%被确定为全同胞，2.5%为半同胞，37.5%为无亲缘关系个体。种内巢寄生可以解释巢内出现无亲缘关系雏鸟的现象，这与现有的非遗传证据一致。巢内半同胞的存在可能表明存在配偶外父权现象。结果表明，白脸朱鹭可能存在非严格一夫一妻制的遗传交配系统。本研究是首次采用分子方法来更好地描述白脸朱鹭在野外的繁殖行为。我们的研究结果为进一步研究该物种替代繁殖策略的可能原因和后果奠定了基础。
