Meisen Wood: At Last

January 25th 2019

Nets: 39m

Weather: -2C rising to 3C

Ringers: CS

Well, the weather here has been miserable since the New Year: consistent rain and drizzle occasionally punctuated by snow whose accompanying frosts have plummeted the temperatures to -9C; a typical dreary start to a new year on the north German Plain. 

Despite the persistent precipitation Meisen Wood has not been without avian interest.  Tawny and Eagle Owls have been regularly calling at sunrise and sunset; male Black Woodpeckers have started their territorial drumming on dead beech trees; and a host of passerines have started singing.  The activity around the feeding stations has been frenetic with the movement of tits, finches, nuthatches and woodpeckers being reminiscent of speeded up footage of aeroplane arrivals and departures at a major airport; a most welcome blizzard of colour on dreary grey days.

With the weather forecast indicating a minor respite in the gloomy weather for Friday, CS took the opportunity to stretch some nets for the first time this year.  And though unpredicted sleet brought an early close of play, the year’s first session was a decent one:

Species	Ringed	Re-trapped	Total
Blackbird	1		1
Blue Tit	2	9	11
Brambling	18		18
Chaffinch	1	2	3
Great Tit	4	11	15
Greenfinch	1	2	3
Long-tailed Tit		2	2
Marsh Tit		3	3
Nuthatch		3	3
Redpoll	1		1
Robin		2	2
Total	28	34	62

The ratio of new to re-trapped birds was on a par with previous years; though this year’s new ringed birds were bolstered by a good catch of Brambling.  Recently there have frequently been eighty to a hundred of these colourful finches at the feeders; and locally at least there seems to have been a small invasion of Brambling; though these numbers do not compare to those currently being recorded in central Europe where counts of five to ten million have recently been noted. 

Catching these northern finches is a pleasure at two levels: aesthetically because of their stunning colours; and scientifically as we often control birds from both ends of their migratory path – south west France and northern Scandinavia.  Despite their nomadism it is pleasing to know that Meisen Wood is on their migratory route.  The day’s Brambling data was interesting too in that most individuals had fat scores from two to four but quite a number had muscle scores of zero.  Potentially this indicates that these birds are not yet physiologically prepared to move on.

Of particular interest in today’s totals were several re-traps, particularly: two Greenfinch, and one each of the Long-tailed, Blue and Great Tits. 

Both the Greenfinches had been originally ringed in spring 2017, with one of them being re-trapped last spring.  Clearly, for this species, we are on their migratory route too; though quite where this route’s terminals are remains unresolved.  The German Migration Atlas shows many Greenfinch wintering in Belgium down to southern France; also these birds include German and southern Scandinavian breeders.  Several Greenfinch ringed by us have been controlled near Hamburg but whether these individuals were still on passage or breeding is unclear. 

The Long-tailed Tit had originally been ringed in September 2016 and has not been re-caught since.  Back then it had been aged as a 2.  This does not mean it was two years old.  The age code 2 means that ringers cannot say with certainty when that individual hatched.  Some ringers derisorily, and unfairly, describe this age code as a cop-out. Ageing birds is based on moult: when a bird moults; which moult strategy that species follows (of which there are several); and as a simple corollary to those points, the time of year.  Long-tailed Tit adults perform a complete post-breeding moult which is finished by late summer.  Juvenile Long-tailed tits undergo a complete post juvenile moult also finished by late summer.  Thus by early autumn there is no plumage difference between adults and juveniles so the ornithologist cannot say that the bird was born that year or in a previous year. That is not a cop-out but an honest recording of the in-hand observations.  So this re-encountered Long-tailed Tit was at least two and half years old, and possibly older, pretty impressive for such a small bird.

Two other birds extended the theme of being re-trapped for the first time since their initial ringing: a Great Tit and a Blue Tit.  Both had been ringed as nestlings in May 2015.  Their recapture the other day is interesting at several levels: it illustrates that mist netting, can be in certain circumstances, considered as a random sampling technique which gives strength to any statistical analysis through removing bias.  Also these two re-captures beg the question: where have these birds been in the interim years?  This question is a prime example of the fact that there is still much we do not know about the lives of birds, including common ones.  This, and other simple questions, will eventually be answered through ringing studies.

The weather forecast for the week ahead is mixed, mixed precipitation that is, with perhaps a small window of opportunity for ringing mid-week.  Fingers crossed!

Foot-note:  during Lynne and Johne’s visit in early November we captured a Swedish ringed Goldcrest.  We have just received notice that this individual was ringed nineteen days earlier at Hammaron Ringing Station, on Lake Vänern some 858km distant from here.