Friday 11 January 2019

Meisen Wood: Year’s End



Date: December 2018
Ringers: CS and EB

After Lynne and Johne’s enjoyable visit in early November little ringing was done until December.  This is usual in November when we typically lose two or three sessions because of The Fall – a wonderfully apt Americanism.  If we were to ring during this period the majority of the time would be consumed with the tedium of extracting gorgeously coloured leaves from the nets.

Despite the dearth of ringing, Meisen Wood is a delightful place to be during this period. The meadow is briefly quilted with rich yellow, gold, brown and scarlet leaves.  The upper woodland paths become thickly carpeted with a plush layer of golden-brown larch needles.  While on the frequent damp, overcast days, the incandescent blotches of golds and reds from the trees not yet stripped of their leaves is accentuated.  This is also a fungally rich time with earthstar constellations, dripping inkcaps, scarlet agarics, rich red-brown boleti and various sulphur coloured toadstools.  Meanwhile the red squirrels are actively burying seeds, nuts and acorns in the meadow; and increasingly birds are coming to the feeders. 

Above all this obvious avian migration continues: with skeins of White-fronted Geese and noisy flocks of Cranes winging their way towards their wintering grounds.  And this year we have observed a major movement of Brambling, on one morning more than two thousand flew over. Two ringing sessions at November’s end, few leaves needed extracting, and the figures (not shown) reflected this Brambling movement with 36 ringed.  The final November session was notable as being the first since early September when the number of re-trapped Great Tits outnumbered new Great Tits.

This autumn we have ringed 413 new Great Tits, such a large number being a consequence, in part, of serendipity.  Inexplicably one of our sound systems slipped to playing Great Tit calls and with the adjacent net containing many of those tits a change in tactics ensued.

The Great Tit captures are intriguing at several levels.  Most Autumns, for two or three weeks, we capture males with notably longer wing lengths of 81 to 83mm compared to the normal 78 – 79mm range; this cohort contained some of the larger winged males.  Thus, according to Bergman’s Rule, these individuals could potentially be migrants from more northerly latitudes.  An intruding caveat to this theory is 63% of the captures were juvenile females which the scientific literature indicates as being dispersal: males stay on territory and unpaired females disperse.  Though many Baltic Ringing Stations this autumn ringed large numbers of Great Tits, therefore do these captures indicate a migratory or an irruptive movement? 

Given the literature’s somewhat equivocal stance and Nature’s delightful capacity to not be easily categorised, the numbers probably reflect a mixture of migration, dispersal and irruption.  Further the Devil’s Advocate’s hand would state: there has always been a Great Tit passage through Meisen Wood but because you did not play the appropriate sound lures you were oblivious to its intensity!  Um, a good point, to be examined in future years!

By Advent we have normally resumed our standardised ringing effort and this year was no exception, December’s totals are shown in the table below:



Species
Ringed
Re-trapped
Control
Total
Blackbird
3
3

6
Blue Tit
59
36
1
96
Brambling
58
6

64
Chaffinch
23
4

27
Coal Tit
12
9

21
Crested Tit

2

2
Goldcrest

1

1
Great Tit
19
81

100
Greenfinch
44
4

48
Long-tailed Tit
1


1
Marsh Tit
1
20

21
Nuthatch
2
2

4
Robin
1
2

3
Treecreeper

1

1
Willow Tit

1

1
Total
223
172
1
396

Good numbers of Brambling, Chaffinch and Greenfinch acquired rings.  Normally throughout the winter we catch a dribble of Chaffinch, a smattering of Greenfinch and it is noteworthy if we see a Brambling before March.  Various sources report a Brambling invasion this winter which is reflected in our catches and observations.  And, superficially at least, it would appear that there has been a good movement ot the other two finch species too.

Entering the year’s final data into the Heligoland data system allows for reflection on some of the data we have collected; or not as the case maybe. 

With 3636 newly ringed birds this has been, for us an outstanding year’s ringing; that figure is more than double our yearly average.  Within that figure it was pleasing to note that we ringed a good number of Blue Tits this year, who unlike in 2017, seem to have had a good breeding season.  A situation reflected across much of northern Europe with high numbers of Blue Tits being ringed in Scandinavia and in the Baltic States; one of which, wearing a Lithuanian ring, we caught in the year’s penultimate session.  The German Ringing Atlas shows many Blue Tits originating from the Courish Spit (shared by Russia and Lithuania) migrating to western Germany and the neighbouring Netherlands.

Sadly our figures show some apparent breeding failures.  During 2018 we hardly ringed any Wrens, Dunnocks or Chiffchaffs!  Within Meisen Woods we found two predated Wren nests.  Despite two Chiffchaffs chiff – chaffing all spring and summer we captured no females or juveniles during the breeding period.  At the time we commented on how long the two males were singing; did they both fail to attract mates?

The 3636th bird was, appropriately, a resplendent male Brambling whose head feathers were already wearing away to their stunning dark head plumage of summer.  Now with each day getting fractionally longer this Brambling, hopefully, augers well for a good ringing year ahead. 

Happy New Year!



No comments:

Post a Comment