The wren appeared on the Farthing from 1937 to 1956 inclusive.
What might be described as an eagle appeared on the 1977 Silver Jubilee 25 Pence Crown coin.
A dove appeared on one type of the 1995 Two Pound coins commemorating the 50th anniversary of the end of World War II.
Apart from that, birds have not been very common on British coins.
There are no birds on British 50 Pence coins.
The wren appeared on the reverse of all British Farthings from 1937 until it was last issued in 1956.
The last British Farthing was minted in 1956.
A Penny Farthing was a 19th Century bicycle invented in 1871 by British engineer, James Starley. It was named for the disparate size of the two wheels, the Penny being very much larger than the Farthing.
The 1937 to 1956 British Farthing features a wren on the reverse. All documentation refers to nothing more than simply "Wren". It is suggested by one source that the designer, Thomas Humphrey Paget, probably did not know the type of wren himself, and merely engraved a wren from a picture.
The wren.
The last British Half-Farthing coin was issued in 1868.
Either coin might get up to £4 GBP in absolute mint condition. If it has been circulated, not much.
It's a wren
The Woodcock was on the reverse of the Eireann/Eire (Irish) Farthing coins from 1928 to 1966.
The farthing was last produced in Great Britain in 1956.
The image on a British Farthing was - From 1937 to 1956, it was a wren. From 1672 to 1937, it was various representations of Britannia.
Such a coin does not exist. The last British Farthing was minted in 1956 and they were demonetised in 1960.
The Royal Mint produced no Half-Farthing coins after 1856.