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!

Marsworth Reservoir 18th March 2019 - The Chiffchaffs are here

After weeks of wet and windy weather today was the first chance for ringing.
With five nets and tape lures we caught 15 birds including 5 new Chiffchaff and a Blackcap. The Chiffchaff were not carrying any fat. All but one of them were birds more than one year old and probably male based on wing length. This is expected because the males usually arrive ahead of the females. We also trapped a 4 year old Song Thrush with very pointy tail feathers. The area of reed cleared in the autumn has flooded as the water level at the Reservoir has risen. We caught a new Water Rail at the edge of the flooded area. Two Red Kites circled all morning and two Goldcrests sang piercingly from two ivy-covered trees either side of where we sit. The reed buntings are still using the hopper for seed and we trapped two that were already colour-ringed. No sign of any Cetti's Warbler.

Flooded cut reed bed

Chiffchaff

Adult Song Thrush showing unusually pointed tips to tail feathers. 

Meisen Wood: Feb’s Figures

Ringers:  CS and EB

After January’s poor weather, February’s aberrant warm weather allowed us to fit in a full set of ringing sessions.  Fitting in all scheduled sessions is important because it allows purposeful year on year comparisons, and for us to identify variations in local population dynamics. 

February’s totals (in table below) were essentially in line with year on year expectations, with two exceptions: the Brambling and Siskin numbers.

Species	Ringed	Re-trapped	Control	Total
Blackbird	10	8		18
Blue Tit	47	67		114
Brambling	69	5	1	75
Bullfinch	1			1
Chaffinch	20	2		22
Coal Tit	2	6		8
Dunnock	3	1	1	5
G S Woodpecker	2	4		6
Goldcrest	1	1		2
Goldfinch	1			1
Great Tit	35	72		107
Greenfinch	23	3		26
Long T Tit	3	2		5
Marsh Tit	1	7		8
Nuthatch		3		3
Redpoll	2			2
Robin	3	6	1	10
Short T Treecreeper	2			2
Siskin	8	1		9
Wren	2	3		5
Totals	235	191	3	429

This year’s Brambling figures, combined with those from last autumn, mean we have this autumn-winter ringed 416 Brambling; hopefully this will generate some good control data.  These above average numbers reflect the current Brambling invasion. 

Conversely the Siskin total is low particularly given that last February we ringed 435 Siskins.

Despite small, delightfully noisy flocks in the tree tops they are not descending to net level; clearly they are finding sufficient food amongst the larch cones to meet their requirements.  In certain ways this is to be expected as Siskin numbers and movements fluctuate widely on an annual basis; essentially a response to breeding success and food availability.

It is always a joy to add a new species to a site’s ringing list, particularly when that species is a gem in the form of a Goldfinch; we are not a hundred percent sure but we think this was a first for EB.

Three controls: a Swedish ringed Brambling, a Dutch ringed Robin and a Dunnock ringed elsewhere within the Heligoland region were most welcome and will contribute to our knowledge of the birds which use Meisen Wood or simply pass through.  The controlled Dunnock, along with a co-specific, were large birds for their species.  Extracting them from the net they felt like plump, feathery sausages.  Both birds’ masses were a tad over 23g while their fat and muscle scores were 5 and 2, such biometrics indicate these Dunnock were simply passing through.

Sadly we caught a Chaffinch whose right leg had a thick warty encrustation probably caused by an infection of the fringilla papillomavirus, while its left leg was incomplete - the length below the tibia-tarsus joint was missing.  Some of the literature states that a consequence of this infestation is the natural amputation of the infected limb – this may then contribute to the bird’s demise through affecting its foraging abilities.  Whenever we catch a Chaffinch with these symptoms we immediately release the bird and disinfect our hands.

We were intrigued by a new Blue Tit whose mandibles were like crossed scimitars.  The bird was ringed and fully processed with its computer entry noting its bill deformity.  This was done because we both have vague memories of a friend, a veterinary nurse, to our incredulity telling us that such birds often develop a weak point where the bill’s excesses will drop off and then re-grow normally.  If we ever re-trap this Blue Tit we will be able to check that statement out and have our doubts dismissed.  Apart from the deformed bill all the bird’s other biometric were what would be expected of a Blue Tit in mid-February.

Towards the end of the month the Brambling numbers were gradually declining, presumably these beautiful finches are winging their way back to their northern homelands.  Meanwhile the numbers of Greenfinch and Chaffinch were slowly increasing.  Through March and into early April we normally catch good numbers of these later two finches.  Sadly, looking at weather maps for the western Atlantic many low pressure systems are being generated there with those being replaced with more of the same.  Therefore the weather prognosis for early to mid – March is looking decidedly stormy and wet which means few, if any, ringing opportunities.  As they say here: schade (pity)!