In tropical species, the study of parental care and the description of the intraspecific variation of parental care remain relatively understudied, especially when compared to the vast works dedicated to species from the Northern Hemisphere. In Colombia, the saffron finch Sicalis flaveola, is a species with a wide geographical distribution, and despite its abundance in open habitats and urban environments, little is known about its reproductive ecology. As a small‐bodied, short‐lived passerine, we postulated that the saffron finch should behave according to the ‘reproductive value hypothesis', investing in the current brood at the expense of future survival. Consequently, we predicted: 1) that parental investment would be associated with brood size and 2) parental investment would be positively associated with nestling growth rate and reproductive success (defined as the number of nestlings which reached fledging age). In 2018, two reproductive peaks of S. flaveola flaveola were documented in the Meléndez campus of Universidad del Valle, Cali. Direct observations and video cameras (> 1700 h of recording) were used to monitor the nests from 38 different breeding pairs. We found that feeding visits and the number of regurgitation events were positively related to brood size. In an experiment of simulated nest predation, 85% of breeding pairs responded to the stimulus and parents who exhibited highly responsive behaviours (50%) raised nestlings with a higher growth rate. We also found that egg surface area positively affected the number of incubation bouts per hour. Whilst no relationship was found between overall parental investment and reproductive success, our results appear to show that the intensity of parental investment during reproduction was modulated by brood size. Our findings suggest that there are multiple ecological factors that influence reproductive success in the saffron finch, and reinforce the need for longer term studies of tropical passerines.

中文翻译：

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父母的投资不会直接影响藏红花雀的生殖成功

在热带物种中，对父母照料的研究以及对父母照料的种内变异的描述仍然相对缺乏研究，特别是与北半球物种的大量研究相比。在哥伦比亚，藏红花雀科Sicalis flaveola，是一种地理分布广泛的物种，尽管其在开放的栖息地和城市环境中丰富，但对其生殖生态学知之甚少。作为一个短小，短生命期的雀形目，我们推测藏红花雀应该按照“生殖价值假说”行事，以目前的繁殖能力为代价，以牺牲未来的生存为代价。因此，我们预测：1）父母的投资将与育雏的规模有关； 2）父母的投资将与雏鸟的生长速度和生殖成功（定义为成年雏鸟的数量）成正比。在2018年，两个S. flaveola flaveola生殖高峰记录在卡利大学瓦莱大学梅隆德斯校区。使用直接观察和摄像机（记录> 1700 h）来监视来自38个不同育种对的巢。我们发现进食次数和反流次数与育雏量呈正相关。在模拟的巢捕食实验中，有85％的繁殖对对刺激有反应，表现出高响应行为的父母（50％）以更高的生长率繁殖出雏。我们还发现，鸡蛋的表面积对每小时孵化次数有积极影响。虽然总体父母投资与生殖成功之间没有关系，但我们的结果似乎表明，生育期间父母投资的强度受育雏量的调节。