Climate change continues to affects birds and plants, changing resource availability. This is causing problems for both the common and oriental cuckoos. Ornithologists in Kazan, Tatarstan completed research over a 1200km2 area between 1988 – 2023. The sub-taiga area includes forests, farms, lakes, rivers and other human settlements. They recorded arrival times, visual and audio observations several times per week during each spring. They also recorded arrival times and observations of their insect prey. They noted that if they arrived ahead of time, it would not support laying eggs in the host nests because these were not yet available. They supported their findings with statistical analysis.
They found that common cuckoos were arriving up to 10 days earlier by 2020 and oriental cuckoos up to 15 days earlier by 2020. The common cuckoos arrived ahead of the oriental cuckoos. Both species have begun arriving ahead of thrush nightingales, red-backed shrikes, greenish and garden warblers, Eurasian blackcaps and common whitethroats, in particular.
Both common and oriental cuckoo populations have been declining which the researchers believe is due to the lower responsiveness to climate change compared with other bird and plant populations, missing breeding opportunities, prey as well as hosts. Their research can be used to support conclusions of other ornithologists recording climate change responses to species arrival and disappearance.
P. Mikula et al., “Climate change is associated with asynchrony in arrival between two sympatric cuckoos and both host arrival and prey emergence,” Royal Society Open Science, vol. 11, no. 1, Jan. 2024, https://doi.org/10.1098/rsos.231691
Russian Climate Research 