Micahel Viney responds to queries and observations on nature.
In Bushy Park, Dublin, I saw a heron high on a tree calling out and breaking off large twigs and dropping them on the ground. A crow arrived and tried to drive the heron away. It also began to break off twigs. A second crow arrived and they drove the heron away.
Rory Pollard,
Dublin 6
Herons build their nests of twigs high in trees. Your heron's actions were part of a courtship ritual to attract a female in which he grasps a twig and shakes it as if inserting it into a nest. Having attracted a female they both build the nest. He may have intended to build in that particular tree, possibly a site already picked out by the crows.
On February 7th a swallow was flying over Glanmore Lake. Would it have overwintered or was it blown here very early?
Alexander Dowds,
Lauragh, Co Kerry
Swallows have been arriving early this year because of south-westerly mild airflow which brought out flights of insects on the migrant path. Singles and small flocks were seen in the south of England six weeks earlier than normal.
• Michael Viney welcomes observations at Thallabawn, Carrowniskey PO, Westport, Co Mayo; e-mail: viney@anu.ie. Include postal address.