A small bird that nests in gaps in roofs and walls. In Japan it is closely associated with settlements and can be recognized by black cheek patches.
It has a large black patch on each cheek.
Both male and female Eurasian tree sparrows have a black throat patch. When feeding in flocks, they may peck or displace companions during contests over feeding positions.
A study published in 2022 examined tree sparrows living around the University of Debrecen, Hungary. Birds received individually identifiable colour rings, and researchers measured throat-patch areas from photographs. During the winters of 2015 and 2016, they filmed feeding contests at platforms where corn grit was placed in only ten of 121 holes.
The analysis used 466 contests with clear outcomes and information from 32 identified birds. Among females, larger black throat patches were associated with a greater probability of winning. Female winning probability also declined as the density of birds on the feeding platform increased. Despite the similar appearance of the sexes, the association between patch size and contest outcomes differed between males and females.
An extinction-risk assessment has not been added yet.
In October 2024 Japan’s Ministry of the Environment reported declining tree sparrow records in satoyama landscapes and forest/grassland surveys under the long-term Monitoring Sites 1000 programme. Researchers and citizen surveyors continue monitoring familiar natural environments, providing information for conservation policy. The ministry also described its effort to recognize privately supported biodiversity conservation areas, including satoyama sites, through the Nationally Certified Sustainably Managed Natural Sites scheme and to expand these efforts.