Archivos de diario de enero 2023

02 de enero de 2023

A thrushful winter season

One feature which keeps the Hong Kong avifauna interesting is the way the winter visitors vary from one year to the next. In some years, particularly cold winters, thrushes are especially numerous. It appears that cold weather in China and Japan forces thrushes to winter further south, thus reaching Hong Kong. While 2021-22 was the year of the Eyebrowed Thrush, the winter of 2022-23 has been particularly 'thrushful', with Brown-headed, Pale and especially White's Thrush being unusually common. Grey-backed and Japanese Thrushes are also around in good numbers, along with Chinese Blackbirds which are also thrushes (Turdus sp.). Apart from thrushes themselves, robins and their relatives seem to be especially common in 'thrushful' years. Red-flanked Bluetails and Rufous-tailed Robins have been numerous this season, joined by an unusual influx of Japanese Robins.
At the Chinese University in the first week of January, a White's Thrush at Chung Chi stream and a Red-flanked Bluetail in a ravine were the first eBird records for this site. The Red-flanked Bluetail and Daurian Redstart share the peculiarity that more females than males are seen in Hong Kong, though the balance varies from one winter to the next. This appears to be because males winter further north than females in order to reach their breeding grounds earlier and establish territories in advance. In the case of the Red-flanked Bluetail the apparent imbalance is magnified by the fact that immature males resemble females. Based on my local observations, female Daurian Redstarts outnumber males by around 3:1 this year, though this imbalance is not reflected in observations on i-Naturalist, probably because the males are both more visible and more photogenic (for birds in general, online media show a strong bias towards the more colourful males, as do museum specimens).
The less common Plumbeous Water Redstart is a regular winter visitor which shows strong 'site fidelity', returning each year to favoured riverside spots such as Mui Shue Hang where a female recently took up residence. A male in a quiet corner of Sai Kung Harbour was in a less usual salt water environment.

Publicado el 02 de enero de 2023 por stephenmatthews stephenmatthews | 9 observaciones | 0 comentarios | Deja un comentario