Blackbirds, Song Thrushes and Mistle Thrushes are very common all over the Gainsborough area. All three are resident in Mercers Wood, and can be seen in many other places, including along the Riverside, Castle Hill Wood and Gainsborough Cemetery.
Blackbird (male and female) and Song Thrush (pictures from Wikipedia)
Two good places to see Mistle Thrushes is on the Levellings and Rose’s Sports Field. While Blackbirds and Song Thrushes tend to keep around the edges of these places, Mistle Thrushes will boldly wander right out into the open.
Mistle Thrushes are one of the first birds to start singing in the year, and I have heard them singing in Mercers Wood and Castle Hill Wood as early as January.
Mistle Thrush (picture from Wikipedia)
The Trent Valley is a natural avenue for migrating birds from the east, and many Fieldfares and Redwings pass through in the autumn as they arrive in this country, and again in early spring when they leave. Plenty of them stay in the area and both species can be regularly seen in many places.
Field Lane between Morton and Walkerith is a particularly good place to see Fieldfares in winter, and flocks of 100 or more can be seen there. I have seen them in smaller numbers on the riverside at Gainsborough and Morton, and on Walkerith Road.
There were 12 in Mercers Wood on November 20th 2016.
On March 14th 2018, while walking on the riverside footpath, I saw about 25 Fieldfares fly into Mercers Wood from the adjacent allotments.
Fieldfare (picture from Wikipedia)
I have occasionally seen Redwings in small numbers around Mercers Wood and Castle Hill Wood, and in larger numbers around Morton. They are a common sight along the riverside and along Field Lane at Morton. I have seen the odd one or two on the Levellings in Gainsborough.
This year (2018) there were still a few Redwings around in early spring, with six outside the Parish Church in Gainsborough on March 21st, and two on Field Lane in Morton on April 5th.
Redwing (picture from Wikipedia)
The overgrown field at the Morton end of the riverside is an especially good place to find thrushes. Blackbirds, Song Thrushes and (in winter) Redwings are very common there, with occasional sightings of Mistle Thrush and Fieldfare.