The parental food compensation hypothesis suggests that parents may compensate for the negative effects of parasites on chicks by increased food provisioning. However, this ability differs widely among host species and may also depend on ecological factors such as adverse weather conditions and habitat quality. Although weed management can improve habitat quality, management measures can bring about a temporary decrease in food availability and thus may reduce parents’ ability to provide their nestlings with enough energy. In our study we investigated the interaction of parasitism and weed management, and the influence of climate on feeding rates in a Darwin’s tree finch species, which is negatively impacted by two invasive species. The larvae of the invasive parasitic fly Philornis downsi ingest the blood and body tissues of tree finch nestlings, and the invasive Blackberry Rubus niveus affects one of the main habitats of Darwin’s tree finches. We compared parental food provisioning of the Small Tree Finch Camarhynchus parvulus in parasitized and parasite‐free nests in three different areas, which differed in invasive weed management (no management, short‐term and long‐term management). In a parasite reduction experiment, we investigated whether the Small Tree Finch increases food provisioning rates to nestlings when parasitized and whether this ability depends on weed management conditions and precipitation. Our results provide no evidence that Small Tree Finches can compensate with additional food provisioning when parasitized with P. downsi. However, we found an increase in male effort in the short‐term management area, which might indicate that males compensate for lower food quality with increased provisioning effort. Furthermore, parental food provisioning was lower during rainfall, which provides an explanation for the negative influence of rain on breeding success found in earlier studies. Like other Darwin’s finches, the Small Tree Finch seems to lack the ability to compensate for the negative effects of P. downsi parasitism, which is one explanation for why this invasive parasite has such a devastating effect on this host species.

中文翻译：

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小树雀雀Camarhynchus parvulus中的寄生虫和环境因素的父母照料

父母的食物补偿假说表明，父母可以通过增加食物供应来补偿寄生虫对雏鸡的负面影响。但是，这种能力在寄主物种之间差异很大，并且还可能取决于生态因素，例如不利的天气条件和栖息地质量。尽管杂草管理可以改善栖息地质量，但管理措施可能会暂时减少食物供应，从而可能降低父母为雏鸟提供足够能量的能力。在我们的研究中，我们调查了寄生虫和杂草处理的相互作用，以及气候对达尔文树雀科物种摄食速率的影响，这受到两种入侵物种的负面影响。入侵性寄生蝇Philornis downsi的幼虫摄入雀科幼鸟的血液和身体组织，侵入性黑莓悬钩子会影响达尔文树雀的主要栖息地之一。我们比较了在三个不同区域的寄生和无寄生巢中的小雀科Camarhynchus parvulus的父母食物供应，这在侵入性杂草管理（无管理，短期和长期管理）方面有所不同。在减少寄生虫的实验中，我们调查了“小树雀”在被寄生时是否会提高雏鸟的食物供应率，以及这种能力是否取决于杂草的管理条件和降水量。我们的结果没有提供证据证明小树雀在被P. downsi寄生时可以补偿额外的食物供应。。但是，我们发现在短期管理领域，男性的工作量有所增加，这可能表明男性通过增加配置工作来弥补较低的食品质量。此外，在降雨期间父母的食物供应较低，这可以解释降雨对早期研究发现的育种成功的负面影响。像其他达尔文雀科一样，小树雀似乎缺乏补偿P. downsi寄生虫负面影响的能力，这就是为什么这种侵入性寄生虫对这种寄主物种具有如此破坏性作用的一种解释。