Sunday 31 March 2019

Meisen Wood: Middle March



Date: 24 March, 2019
Nets: 130m
Sound: None
Weather: 4C rising to 15C
Ringers:  CS and EB

March’s first session was technically a tad after middle March, but never mind!  The previous three weeks of windy, rainy, snowy, stormy weather had induced ringer’s frustration in us but did not prevent us from delighting in some seasonal changes in Meisen Wood.  It is wonderful how seasonal changes flow, with increasing intensity, into each other.  This fluidity is often marked by sublime juxtapositions: the initially slow opening of leaf buds greening the forest; the nocturnal peeping of migrating Redwing flocks contrasting to the trilling evening song of recently arrived Song Thrushes.  And future seasons are heralded by such moments as: clouds of golden-green hazel pollen drifting on the wind and will hopefully result in a good nut crop next autumn.

This seasonal shift was reflected in today’s catch: a mix of Brambling and Chaffinch with Firecrest and Song Thrush; and a few other beauties for good measure.

Species
Ringed
Retrapped
Totals
Blackbird
1
1
2
Blue Tit
6
13
19
Brambling
9
4
13
Chaffinch
19

19
Dunnock
1
2
3
Firecrest
3

3
Goldcrest
1

1
Great spotted Woodpecker

1
1
Great Tit
3
10
13
Greenfinch
2

2
Hawfinch
1

1
Marsh Tit

1
1
Middle spotted Woodpecker
1

1
Nuthatch

2
2
Robin
1
2
3
Siskin
4

4
Song Thrush
1

1
Wren

1
1
Totals
53
37
90

Bramblings have, surprisingly to us, been present all winter though in the last couple of weeks their numbers have been gradually declining.  The nine new Bramblings included three males whose plumage was close to their stunning full summer attire. Throughout the month the number of Chaffinch have been increasing and slowly surpassing those of Brambling; one day last week we estimated 120 Chaffinch coming to the feeders.  So ringing nineteen new Chaffinches was very pleasing and interesting.  The interest was in their weights and fat scores: several of these finches weighed 25g and had fat scores of 5 and 6, indicating these to be migrating individuals.

Greenfinch numbers have been increasing slowly through the month but have not reached their usual numbers; two new is a low figure for this time of year.  Hopefully this is not symptomatic of another problem; though this indicative role is a valuable contribution that ringing makes to ecological studies.

Song Thrush and Firecrest are two visiting birds we strongly associate with spring and summer; this is clearly shown in the Firecrest’s German name: Sommergoldhähnchen – summer’s golden bird.  Both species nest within the wood and unfortunately, though somewhat perversely interesting, we often witness male Firecrests aggressively displaying at their own images in some of our windows. 

Normally a Hawfinch would be the star bird of any ringing session.  This strikingly coloured finch with a powerful bill – able to crack open hard seeds, as indicated in its German name: Kernbeißer – nutcracker.  Yes that has caused some momentary high excitement in CS when EB has announced that a nutcracker is in the net – the delights of mistranslation!  Usually we catch about ten per annum, mostly in March or April. 

To paraphrase Orwell: all birds are beautiful but some birds are more beautiful than others.  Particularly when it is a new bird for the site which is also a red listed species: Middle – spotted Woodpecker (MISWO).  The pleasure in ringing this bird was not because of its rarity value (okay we don’t believe that either as less than 30 of this species are ringed annually in the Heligoland scheme), but its capture does represent other important ornithological values.




According to the recent Nordrhein-Westfalen Breeding Atlas the nearest breeding MISWO are approximately 40km from here where the breeding population was estimated to be a single pair.  Since the Atlas’s publication a couple of papers have stated that the MISWO population was probably underestimated as surveys using playback lures have indicated the presence of a few more pairs; but still at a good distance from us.

The Atlas’s authors note that in the last thirty to forty years the MISWO has shown a slow range extension.  The authors cautiously applaud this range extension but attach a somewhat damning caveat to why the species remains on the red list of animals of conservation concern.  MISWO’s habitat preference is for forest with a good mix of deciduous trees, particularly oak and beech, including dead trees.  And the caveat applies to the forestry industry’s reckless, and illegal, clearing of dead trees from their plantations.  It is very perplexing why this illegal forestry practice has not been prosecuted!  Aging and sexing MISWOs is not straight forward.  Demongin gives an interesting equation using several discriminating factors for sexing Swiss MISWOs.  

So, the value of capturing this MISWO: it gives definitive confirmation of the species in the area; if this indicates a continuation of the species’ range expansion is for later confirmation.  Hopefully recapturing this individual, or another, in the next few months could potentially indicate breeding i.e., presence of a cloacal protuberance or brood patch; and with that the other biometrics we took could be most useful in aiding our knowledge of aging and sexing this species.  An exciting prospect!

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