Meisen Wood: Siskin Swarms

18 – 2 – 18

Nets: 45m

Sounds: none

Weather: -4C at start, 2C at finish

Ringers:  CS and EB

Species	Ringed	Re-trapped	Totals
Robin	1	1	2
Great Tit	4	5	9
Chaffinch	1		1
Blue Tit	4	2	6
Dunnock		1	1
Siskin	72	24	96
Marsh Tit		1	1
Greenfinch	5		5
Brambling	5	1	6
Coal Tit	1	6	7
Treecreeper		1	1
Short-T- Treecreeper		1	1
Redpoll	1		1
Blackbird	2		2
Totals	96	43	139

Sometimes you just inexplicably know from the off that it is going to be a good day; today was such an occasion.  We commented, while setting the nets in the dark, how good the air felt: fresh, clear, clean; and the crisp crunch of frozen leaves beneath our feet as we walked along the net rides had a satisfying quality.  Even the problem of pushing the pointed ends of the sectional poles into the frozen earth was but an insignificant tribulation.

This pleasant experience was enhanced by the Buing of the resident male Eagle Owl and the trilling songs of Robins and Dunnocks; though we did question the wisdom of a Tawny Owl pair calling in an Eagle Owl’s territory.  Eagle Owl, the apex predator here, frequently prey on Tawny Owls.  Then, while setting the final net, near a stand of majestically tall spruce trees, we were regaled by the delightful chattering of numerous Siskins; a twittering that was to continue through the whole session.  Siskins, dapper little finches in their colourful yellow, gold, green and black livery were to be the bird of the day.  Indeed our nets were colourfully adorned with Siskins, and other resplendent finches: Greenfinch, Brambling, Chaffinch and Redpoll every net round.

During the last three weeks the number of Siskins in the wood has been increasing; and now large “swarms” of this diminutive finch are seen, and heard, daily moving through the tree tops. “Swarm” is used advisedly.  Swarm is German for flock and the etymology of swarm in English stems from an old Saxon/low German base.  Siskins form small winter flocks which in years of food shortage (conifer and alder seeds is their dietary preference) merge into substantial flocks and become very mobile.  This mobility often results in them wandering substantial distances; this is not an annual event but does occur frequently. 

Our short ringing history in Meisen Wood reflects this behaviour.  In 2016 we ringed slightly shy of six hundred Siskins; in 2017 we ringed just seven.  Today’s number took our 2018 figure, to date, to one hundred and fifty-two.  Hopefully the swarms will remain for some time, not just for ringing studies but for the pure enjoyment we get from listening to their continuous, pleasant twittering in the winter woodland.  Interestingly, today’s oldest re-trap Siskin was originally ringed as a 6M in February, 2016, which makes him, minimally, nearly four years old.  How many kilometres has that old boy flown? 

Brambling are present in good numbers too.  Our normal ringing figures average ten per year; so far this year we have ringed fifty-five.  Like several, predominantly northern European birds, Brambling populations sometimes overflow from their normal winter range in movements called irruptions.  Such irruptive movements are usually a response to a combination of local over population, food shortage and, or, extreme cold weather.  From our limited data it is not possible to conclude if this is an irruptive year, or not. 

Interestingly many German ringers have commented on catching substantial numbers of Redpoll, another irruptive species.  Though that maybe, the Redpoll we captured today was the first ever caught in Meisen Wood; and was the first that EB has ever handled. 

So birds are definitely moving, the seemingly sedentary phase of winter is passing.  In the last ten days, or so, we have noticed a decrease in the number of Marsh Tits visiting the feeders.  This decline is reflected in today’s captures and is probably indicative of this species dispersing back to their breeding territories; which will probably be fairly local.

Similarly other birds are signalling their increasing readiness for the coming breeding season.  Sitting at our ringing table it was a delight to listen to Stock Doves cooing; the nasal calls of Greenfinches; and Black woodpeckers proclaiming their territorial rights with staccato drum beats on dead beech trunks.  So despite the cold, the annual cycles of life are, as ever, inexorably continuing.