Palmerio Andrés Gabriel, Miño Carolina Isabel, Massoni Viviana
Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
Laboratorio de Genética Evolutiva, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Posadas, Misiones, Argentina.
PLoS One. 2025 Sep 12;20(9):e0331227. doi: 10.1371/journal.pone.0331227. eCollection 2025.
Life history theory posits negative trade-offs between current reproduction and survival and between current and future reproduction. We tested if the Saffron Finch (Sicalis flaveola), a sexually dichromatic thraupid with age-related plumage coloration, conforms to the expectations under this theory. Previous studies in nest-box systems have shown that both drab young males and bright-yellow older males provide similar parental care and achieve comparable reproductive success. We experimentally handicapped females and males from both age classes by clipping of three primary remiges to manipulate their parental care efforts. We compared mating pairs conformed by handicapped males of both age classes paired with non-handicapped females, handicapped females paired with either handicapped or non-handicapped males of both age classes, against control pairs (non-handicapped individuals). We assessed weight changes, feeding rates, brooding bout duration, nest temperature, and return rates for both adults and nestlings, as well as growth rate, asymptotic weight, time spent at the nest, and fledgling success. Contrary to expectations, none of the experimental individuals adjusted their feeding rates. However, we observed intra- and intergenerational costs for handicapped females mated to second-year males, including shorter brooding bouts, greater weight loss, slower offspring growth, and lighter fledglings. Thus, in our study system, lower-quality females paired with second-year males may be maximizing reproductive success under less-than-ideal circumstances.
生活史理论认为，当前繁殖与生存之间以及当前繁殖与未来繁殖之间存在负权衡。我们测试了具有年龄相关羽色的两性异色裸鼻雀科鸟类——藏红花雀（Sicalis flaveola）是否符合该理论的预期。先前在巢箱系统中的研究表明，羽色暗淡的年轻雄性和亮黄色的老年雄性提供的亲代抚育相似，且繁殖成功率相当。我们通过修剪三根初级飞羽来削弱两个年龄组的雌性和雄性，以操纵它们的亲代抚育努力。我们比较了由两个年龄组的残疾雄性与非残疾雌性配对、残疾雌性与两个年龄组的残疾或非残疾雄性配对的交配组合，与对照组（非残疾个体）。我们评估了成年个体和雏鸟的体重变化、喂食率、育雏时间、巢内温度和归巢率，以及雏鸟的生长率、渐近体重、在巢时间和出飞成功率。与预期相反，没有一个实验个体调整它们的喂食率。然而，我们观察到与两岁雄性交配的残疾雌性存在代内和代际成本，包括育雏时间缩短、体重减轻更多、后代生长缓慢和雏鸟体重较轻。因此，在我们的研究系统中，与两岁雄性配对的低质量雌性可能在不太理想的情况下实现了繁殖成功率最大化。
