Showing posts with label Chaffinch. Show all posts
Showing posts with label Chaffinch. Show all posts

Tuesday, 12 December 2017

The sum of all parts of the quarry (2): finches

This December, the two roost counts at Berengrave are going to be rather far apart. First half of month was nice and early but, thanks to an operation, second half count will be nice and late. In the meantime, a chance to muse on what else, in addition to all those Magpies and Woodpigeon I keep going on about, gets counted. Yup, OCD muppet that I am, I try to count everything.

Results? All 'normal', but all fascinating, and helping to refine my personal views on the local populations.

How the reserve was promoted 32 years ago. Now? No school visits,
no fieldwork- mind you, no Borough Council, no Police Station.

The Finches
Brambling
Still a close-your-eyes-and-you're-back-there species for me; Berengrave, 1986, more than 200 coming into roost at the southern end around the chalk washing ponds. Snow everywhere, flurries coming down, calling to the left, right and centre of me. Birds staring back at me through the gloom. Wonderful.

Of course, those cold winters were the exception rather than a norm even back then and, although locals always go on about how the regular roosts there have disappeared, were they ever regular?

Certainly a struggle nowadays, in line with sightings for much of the western half of the southern shore- slightly higher around the remaining orchards in the east of the estuary, but a double figure at roost would be something to celebrate. Of course, I now count from the south-west corner of the quarry, so far I've been able to resist checking numbers from the ground in the north-east.



Chaffinch
Those early years of birding (I didn't start until in my twenties) had hundreds of Chaffinch roosting at the southern end of the pit. Today, birds still favour that end, and many arrive from the north and west; a scan of the treeline in the last half-hour of daylight will find numbers perched out, advertising the roost; in the minutes before sunset, they all drop in together; few are late to roost. Small numbers arrive from the south and west of the viewpoint; there are, of course, other local roost sites for townie finks.

The general trend is for fair numbers pre- year-end being followed by a peak at the start of the winter; mid-winters influxes have not been seen the past four winters. By February numbers are dropping off- dead, driven on by weather/food shortages, or when mild, perhaps even heading back toward the continent; by early March it seems to be just a few, most likely local breeders, left.




Goldfinch
All highly irregular. Even in the better years they lead any observer a merry dance, jingling in to the quarry only to jingle out ten minutes later. The deep dip in mid-winter perhaps reflects onward passage during the coldest part of the year. One species for me to watch in the coming years.



Greenfinch
Sadly, I have no recollection of a Greenfinch roost from all those years ago. I have yet to look up roost preferences (got to save some things for the years to come) and can only presume this reflects the population crash in recent years (what, BTO? No 'Birdtrends' webpage for Grefi? I was looking to make a link to there..) Based on ringing, we never see many into the UK each year so that 'monster' count of 16 this autumn may not actually be reflecting passage birds. The biggest hope for local trends is a slow year-on-year increase in numbers. Another good reason to keep dragging myself down twice a month 13 times a year..

Siskin
Finally for the common finches (a species only gets a chart when I've seen it a dozen times to date)
a species that I remember more from the springs than the autumns. A trend not seen now, but as this is an irregular irrupter, why should they? The habitat is just not right, even though they (and Lesser Redpolls) used to like the north-east corner in the days before the birches and alders were routinely removed.



Wednesday, 15 November 2017

Visible migration; Horrid results for the finches

The question- is visible migration worth studying along the south Medway? The results from this year's early morning counts at the point of Horrid Hill (plus, from early October, a second spell on the Mound at the base) have provided some useful support to findings made at other sites on the south Medway since autumn 2013.

The opening quotes for each species are from John Holoway's 'Birds of Gillingham', and then Dave Davenport's chapter on migration from Oliver's 'Bird watching on the North Kent Marshes'. The graphs are this years Horrid Hill figures, whilst the maps, unless otherwise stated, are based on cumulative observations for the whole southern shoreline over the past five autumns.


Chaffinch

Holloway (1985): "..flocks are often seen along the river and on farmland in autumn and winter.."
Davenport (in Oliver, 1991): "..last three weeks of October and first two weeks of November produce the main westerly passage.."

Chaffinch has been an eye-opener for me for many years since first bumbling into the factoid that the majority of 'finks overwintering in the U.K. enter via the south-east (unlike Bramblings that mainly come in further north).



It is certainly a great example of east-west visible migration here. Previous autumns, east and south-east of Horrid, have shown just how strong that movement can be. Often the biggest counts happen the day after east coast sites such as Pegwell have their big arrivals, as if they are putting down within an hour or so of crossing the Channel.


Brambling

Holloway (1985): "..occasionally seen with Chaffinches in the winter months.."
Davenport (in Oliver, 1991): "as Chaffinch.. accompanied by smaller numbers.. main arrivals equally likely to occur in early November.. frequently associated with hard winters.. when.. takes to feeding on the saltings or along the sea walls.."

A species that never regularly turns up in numbers in the autumn, one that is more prone to see cold weather movements later in the year. Whether these later movements are from birds already in the UK, from the north, or further immigration from the near continent, is difficult to say. The autumn birds here are tied in with the onshore Chaffinch pulses and should be considered as 'fellow travellers', as the majority of Brambling arrivals come in over the northern North Sea.


Greenfinch

Holloway (1985): "..widespread.."
Davenport (in Oliver, 1991): not mentioned.


Another species many believe comes over in numbers, but one that ringing evidence says 'no'. Certainly these grounded birds were only coming out to the Point on Horrid to feed; stay long enough and you would see them return to the same spot on the 'mainland' most days. Any peak could just as likely be down to local dispersal.


Goldfinch

Holloway (1985): "..fairly common.."
Davenport (in Oliver, 1991): "..increasing numbers (in October).."


Although the past few years have picked up a definite 'southerly' feel to autumn flights, perhaps indicating a larger element of emigration rather than immigration, the local topography creates a south-west movement inland. Goldfinches at the Point are more likely to be coming in from a northerly vector than most finch species reviewed here.


In previous decades wintering numbers were much lower, so picking up movement late in the season was easier, but there are now several areas where Goldfinches remain in fair numbers throughout the autumn; local ringing has shown some local breeders to be sedentary. To that end, daily roost flights have to be considered when considering possible viz mig; these roosts grow in size from early September onwards.


Linnet

Holloway (1985): "..can be seen along the Medway at any time of the year.."
Davenport (in Oliver, 1991): "..on some October days.. southerly movements of Linnets.."


Very similar general comments to Goldfinch, with a nice southerly trend to flights. However, many more feeding flights to the island saltings, so difficult to pick out viz mig; roosting habitat preferences, such as dense bramble, are not found on many of the islands and the short duration of the main southerly pulse points towards an ability to pick up on viz mig.


Siskin

Holloway (1985): "..very uncommon migrant but in October 1983 there was a large passage.. flocks of 20 or so could be seen flying west.."
Davenport (in Oliver, 1991): "..last three weeks of October and first two weeks of November.. season for (large visible movements) accompanied by smaller numbers of.. Siskins.."


No shocks with this graph; not a Siskin autumn. This species (and the following) have a large element of irruptive nomadism to their seasonal movements. Irruptive, because they work from local food source to local food source- there is no promise of food at the end of a long migration to the same spot as the previous winter; why, for example, Scandinavian breeders might first move south then possibly move west, or east, later into the winter.


Lesser Redpoll

Holloway (1985): "..occasionally seen with other finches in winter.."
Davenport (in Oliver, 1991): Not mentioned.



Siskin and Redpoll could almost be lumped for viz mig comments. Again, feeding further north must have been good at the start of the autumn (ringing has shown that many birds in the south-east in autumn have come from within the UK).

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In conclusion, diurnal movements of finches, although nowhere near as strong as along the Thames, itself nowhere no as strong as further east in the county, is observable on the estuary, and regular watches can turn up the odd 'big day'. Even if these results don't fill you with any urge to rush to the Medway, bear in mind the Thames is woefully under-watched these days; despite the adverse comments places like Grain seem to receive on an annual basis on social media, the birds are still passing there. Lower Hope Point at Cliffe, Allhallows, Sheerness on the island, all spots where viz mig awaits to be recorded fully again.

Monday, 9 October 2017

Horrid autumn- 9/10/17

7:15-9:15
Viz Mig- Marsh Harrier, Peregrine, 14 Skylark, 31 Meadow Pipit, 5 Pied Wagtail, 22 Chaffinch, Brambling, 4 Goldfinch, 4 Siskin, 3 Linnet, 5 Reed Bunting.

Pt- Meadow Pipit 2, Chiffchaff, Redwing 2, Song Thrush 6, Blackbird 4, Chaffinch 6, Linnet 23, Reed Bunting 5.

Time to introduce the mound-shaped secret weapon.

In all probability, the main movement is on a broadfront, just that little bit too high overhead. Some Diurnals have to refuel, come a bit lower. Some diurnals might have drifted that tad off bearing, need to adjust in the first few hours. Some will continue moving for the moment, but looking for the opportunities to feed and rest as they go. Some plough on through staying high, some drop a little lower.

The second hour after dawn is THE time. Forget birds crossing the estuary; some will, most won't. They will be funneled by leading lines. For the rest of the month the viz mig will be split between the Point and the Mound, that lovely man-made viewpoint back on shore. Will the gamble pay off?



The Mound, 9:25-10:25:
(viz mig west) Sparrowhawk 3, Great Spotted Woodpecker 2, Stock Dove 5, Meadow Pipit 6, Pied Wagtail 2, Redwing 13, Song Thrush 12, Blackbird 6, Mistle Thrush 6, Starling 251, Chaffinch 1,052, Brambling 2, Goldfinch 121, Greenfinch 4, Crossbill 3, Siskin 2.

That'll do Kev, that'll do.

Between the uninviting mudflats and railway line by the sprawl of Twydall, greenfield land (for now). Orchards, fields, scrub. Migrant magnet. 'Scope set up south, over the Lower Rainham Road. Most at quite a distance, but worth it. The walk up to Twydall late morning just produced a trickle of late movers, but left me dreaming of watching slightly inland another year. Getting ahead of myself, plenty of 2017 left, will be hitting the Mound hard.




Thursday, 4 February 2016

The Circle of Strife




Tonight was an odd set of roost counts. The birds had clearly been disturbed of late. The Magpies pre-assembled all along the western edge of the chalk pit, avoiding the usual spots. The Woodpigeon had deserted in droves. Many of the passerines didn't show (shockingly, Chaffinch only just made double figures). I might have put it down to the warm weather, but the Magpie numbers were still clearly high. I did wonder if the seventeen youngsters congregated at the viewpoint might have been a regular disturbance of late? Sunset was nearly five- plenty of post-school loitering time now, at least they weren't glued to their computers.

Me being me, I stood my ground, nodded and smiled, and started counting. Then stopped smiling and asked them to stop kindly stop throwing their rubbish down the bank. Then to not throw branches down. After about ten minutes of staring me out and eff-ing and jeff-ing in my general direction, they drifted off, not without the odd taunt hurled from a distance.

Ah, the youth of today.

Exactly the same as the youth of yesterday.

I didn't get into birding until post teens, but a general interest in nature had been stirred a few years earlier, mainly, as I recall, through some nicely illustrated AA books and a set of carefully cut out cardboard nature dioramas, care of the nice people at Weetabix. Which was how, as we trudged our way to Luton Recreation ground forty years ago, I had been able to bore my own local 'gang' by continually pointing out one of the few plants I'd learnt, a jolly patch of Lords-and-Ladies, proudly adding "also called arum maculatum" every time. Every single time until the day they'd been flattened. Smashed to bits. Ground into the ground. Even now I can still hear Magoo (our squinty goalpoacher) laughing "Yer won't be saying yer noncey-poncey Latin anymore now, will yer?".

Thank you for that lesson Mr. Magoo, I've never forgotten it.

I was the one now squinting, adding up the notebook ticks in the twilight. Cumulative numbers were down by about a third on last February but I'd broken the 250 mark for the Magpies again, that'd have to do. Time to go. Now if I could just find my way back out in the dark without landing in the little herberts' broken glass, fag butts and crisp wrappers, that'd be grand.

Friday, 8 January 2016

The Berengrave roost

That Pheasant- a record shot to impress
the Berengrave rarities committee
A new high total of 282 Magpie in tonight, though I was rather more impressed by a Pheasant dropping in, low over my head- the first I've noted roosting here in the three winters I've been counting Berengrave. That's how counting can get you, even the most uber-mundane species can overexcite you just by showing up and doing not a lot a lot.

Redwing numbers were up, and some of them were not quite sure where exactly to go in, circling the chalk pit several times, one or two flying off to the west- recent arrivals from a local movement perhaps? Disturbingly the Chaffinch collapse continued, now less than fifty birds were seen arriving.

But perhaps most interesting to me were the Woodpigeon. Numbers slightly down, perhaps expected after the New Years' Eve fireworks, but more intriguingly the vast majority arrived not from the east and the open countryside, but south and west from the urban sprawl. Local fields lack quality feeding this year, and a switch to the gardens of Medway could be underway.