The redpoll is an attractive small finch which breeds in Scotland, northern England and Wales. It was formerly split into three different species (lesser, common and arctic) but taxonomists have now amalgamated these three into a single species. Redpolls are on the red list of conservation concern due to a sharp population decline in the late 20th century. In summer their diet consists mainly of invertebrates, but outside the breeding season they are largely dependent on the seeds of birch, Alder, larch and spruce. In years when these seed crops are locally plentiful redpolls are largely sedentary, but when these food sources fail they will move south to southern England, with some birds even crossing the channel to winter in France and the low countries.
Redpolls react well to recordings of their song, and large numbers can be caught in mist nets when this is played in areas of low trees and shrubs to bring birds down from the treetops. We also had success when playing the song in a reedbed where we presume birds were coming to drinking pools to access water (Figure 1).
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Figure 1. A catch of redpolls coming to drinking pools at Loch of Leys in September 2025 (Innes Sim). |
The majority of birds ringed during 2023-25 were ringed during the main dispersal period in September, October and November (hereafter autumn; 93 – 98%; Table 1). Recovery rates outside Grampian were 1 in 330 (2023), 299 (2024) and 281 (2025); movements into Grampian were a lot higher in 2024 (1 in 187) than in 2023 (1 in 1,320) and 2025 (1 in 561; Table 1).
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Table 1. Total numbers ringed, numbers ringed during autumn, number of birds recovered outside Grampian and number of birds ringed elsewhere and recovered in Grampian. |
The majority of redpolls were ringed at four sites: Brathens, Slack Wood, Loch of Leys (all Aberdeenshire) and Tiendland Forest (Moray). All of these sites are mixed birch, larch and spruce forests, except for Loch of Leys which is dominated by birch trees. 2023 and 2025 were birch mast (heavy seeding) years and 62% and 94% of redpolls were ringed at Loch of Leys in those years. In contrast, 2024 was not a birch mast year and only 0.5% of redpolls were ringed at Loch of Leys, with 92% ringed at the other three sites. Birch trees mast every 2-3 years, while spruce and larch mast every 3-5 years, and presumably redpolls adapt to feed on the most plentiful seed in each year. So, it appears that redpolls particularly targeted birch seeds in the mast years of 2023 and 2025, but then switched to feed on spruce and/or larch seeds in 2024. Presumably redpolls will remain close to their breeding areas as long as the seed food source remains abundant, and only move south in autumn in response to diminishing seed resources.
It appears that most of the birds that pass through Grampian in autumn travel as far as southern England by late autumn/winter, with only a single Belgian control recorded during 2023-25 (Figure 2). The majority of birds appear to migrate down the eastern half of England with only two birds being controlled in Gloucestershire, close to the Welsh border. There are only two records of birds ringed during the winter of 2023/24; one from Belgium in December 2023 and one from Nottinghamshire in February 2024 (which may have already been heading north). So, we don’t have a clear idea yet of where these migrants actually winter – perhaps we might get some more information on this in the coming winter. And we also have little information on where these autumn migrant redpolls breed, although one bird ringed on South Uist in late May may indicate that at least some birds breed on the west coast of Scotland. There is clearly still a lot to discover on redpoll movements!
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| Figure 2. Map of North East Scotland Redpoll Movements |
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