Predicting climate-driven shifts in the breeding phenology of Varied Tits (Sittiparus various) in South Korean forests

Abstract

Phenological shifts of plants and animals due to climate change can vary among regions and species, requiring study of local ecosystems to understand specific impacts. The reproductive timing of insectivorous songbirds in temperate forests is tightly synchronized with peak prey abundance, and thus they can be susceptible to such shift in timing. We aimed to investigate the effect of future climate change on the egg-laying phenology of the Varied Tit (Sittiparus various), which is common and widely distributed in South Korean forests. We developed the predictive model by investigating their egg-laying dates in response to spring temperatures along geographical gradients, and our model indicated that the tits lay eggs earlier when the average of daily mean and daily maximum temperatures rise. We predicted future shifts in egg-laying dates based on the most recent climate change model published by the Intergovernmental Panel on Climate Change (IPCC), under a scenario with no climate change mitigation and under a scenario with moderate mitigation. Under this outcome, this species might be unable to adapt to rapid climate change due to asynchrony with prey species during the reproductive period. If no mitigation is undertaken, our model predicts that egg-laying dates will be advanced by more than 10 days compared to the present in 83.58% of South Korea. However, even moderate mitigation will arrest this phenomenon and maintain present egg-laying dates. These results demonstrate the first quantitative assessment for the effect of warming temperatures on the phenological response of insectivorous songbirds in South Korea.

Spatio-temporal variation in egg-laying dates of nestbox-breeding varied tits (Poecile varius) in response to spring pre-breeding period temperatures at long-term study sites in South Korea and Japan

“…One of the major drivers of local temperature variability across the globe is altitude (Geiger et al 2009). Air temperature near ground decreases as elevation increases in the troposphere, and thus phenological events such as budburst and the flowering of plants, and breeding of animals in the forest ecosystems progress along with elevational gradient in spring (Hwang et al 2011;Jeong et al 2019). However, recent studies also found that the rate of warming is greater in high-elevation regions around the globe (Rangwala and Miller 2012;Pepin et al 2015).…”

“…Birds in the Paridae family are excellent model species for studying effects of climate change on breeding phenology -(a) since they breed in cavities and readily use nestboxes, (b) shortdistance migrant or resident species thus influenced by local climatic patterns, (c) and heavily rely on seasonal herbivorous arthropod prey, especially lepidopteran larvae for breeding. Many species of birds in this taxa have been studied widely as a model species to understand the phenological response of animals to climate change and its consequences and their fitness (Reed et al 2013;Shiao et al 2015;Yanase et al 2018;Jeong et al 2019).…”