Thursday, 1 November 2007

October summary

Heysham Obs
Three key observers unavailable today and the weather in northern England was what was supposed to be in southern Scotland (e.g. A1 awful between Angel o.t.n. and S. Corner early afternoon, never mind the west coast) so ringing was not an option. The only news item so far was a Light Brown Apple Moth and Angle Shades in the moth trap. Am I really going to trail up to North Uist this evening/early morning.......[Mourning Dove at Clachan]

Here is a summary for October:

Systematic observation took place at Heysham Obs on all but two days (4th, when Flamborough was a better option and 11th when the weather was rubbish). This usually involved an attempt to census grounded night migrants (+/- mist netting) and an average of two hours per day counting visible migrants. Also the usual routine checks of the coastal areas counting Mediterranean Gulls, checking for Black Guillemot etc..

The theme of this month was the rapid transit by many of the migrants as periods of clear weather on most nights allowed birds to move on, as did a fair nunmber of clear, calm sunny days. Therefore I would be extremely wary of wording such as Redwing and Fieldfares "arrived at" as opposed to "passed through" when assessing the nature of this month's migration. For example, there were several mornings late in the month with "50+ or 50-60 Blackbird" and it would be easy to dismiss them as being "in residence, having discovered the hawthorn berries". Careful observation, however, especially of those within range of the vis mig site by the office, revealed that there was a continuous 'through-put' of birds with individuals occasionally taking off and flying high inland, others moving, usually in a generally SE direction through the bushes to be replaced by a new gang of berry eaters.....and so on. This period was punctuated by much larger influxes on 21st and 28th which helped to confirm the impressions as four Blackbirds at any one time in a given hawthorn bush suddenly became eight on those two mornings!

Another theme was a few species which are not normally conspicuous on vis mig. In this respect, only the high-flying individuals were logged - some of the other sightings may also have been birds on more than a 'local circuit'. The main species were Great Spotted Woodpecker, Coal Tit, Jay and especially Bullfinch. See vis mig list below for actual total.

One species which IS conspicuous on vis and which occurred in good numbers (although nothing like nearby Walney) was Jackdaw - this species does not nest at Heysham and therefore migrants can be easily discerned The other noticeable theme concerned the number of species which were either way above par or conspicuous by their absence - very few species seemed to be occurring in "average" numbers for the 27 year dataset Species conspicuous by their absence on the ground were: Wren (usually a noticeable passage early-mid month), Blackcap (no birds accompanying the thrush passage late in the month) and Goldcrest (just no mornings producing more than 20 individuals - this was most unexpected following a good spring passage and does imply a very poor breeding season) Conspicuous by their absence on vis mig were Redwing and Fieldfare, yet there were plenty flying over more inland sites - this is the way it goes some autumns - the grand total for both species has been beaten by single migratory flock on many occasions in previous Octobers

It was quite a good month for scarce species without coming up with a major rarity: Treecreeper - one on 10th, Yellow-browed Warbler - one ringed on 7th, almost certainly another on 8th (almost certainly not ringed). Suitable conditions for one often produce another with this species - indeed the first record for Heysham involved three individuals. Garden Warbler - late bird on 7th. Black Redstart - one for a couple of hours on 15th. Lesser Whitethroat - latest ever records for here - one ringed on 14th and perhaps the same on 18th - sadly not one of the eastern forms. Common Buzzard - one on 20th . Reed Warbler - late bird on 19th. Firecrest - male with a LTT flock on 18th. Woodcock - migrant on 27th. Ring Ouzel - 1st winter male with migrant Blackbirds on 26th

Vis mig totals for the month saw record numbers of common finch species. Most of these birds were flying S or SW:
Pink-footed Goose 4593
Starling 3019
Chaffinch 2322
Greenfinch 1028
Meadow Pipit 742
Goldfinch 611
Redwing 503
Siskin 497
Jackdaw 452
alba Wagtail 405*
Woodpigeon 190
Fieldfare 164
Skylark 122
Linnet 116
Blackbird 115**
Song Thrush 102**
Mistle Thrush 96
Carrion Crow 87
Brambling 76
Rook 71
Long-tailed Tit 68***
Bullfinch 42
Swallow 36
Grey Wagtail 32
Reed Bunting 31
Collared Dove 29
Coal Tit 29***
Great Spotted Woodp. 13
Jay 12
Crossbill 11
Dunnock 10***
House Martin 7
Kestrel 4***
Whooper Swan 4
Sparrowhawk 4***
Cormorant 4***
Pintail 3
Tree Sparrow 3
House Sparrow 3
Grey Heron 1
Twite 1
Merlin 1
Rock Pipit 1
Green Woodpecker 1
Golden Plover 1

* many specifically identified as White
** many more than usual either flying over high or rising out of bushes and heading off general SE high. These were all, of course, presumed to be continental birds
***Only the most obvious "purposeful high-flying birds" included in this category. Cormorant are very rare over this site and all 4 were together and this is the first Pintail record actually over the 'vis' site.

In conclusion, Heysham is not a particularly special location for migrants but it is a good site for combining all aspects of migration (seabirds/vis/ringing/counting grounded birds) and the systematic coverage provides very useful comparative information which can be entered on national or even international visible migration sites and, at the end of the year, it provides consistent annually-comparative data which can be used in county and local bird reports

Thanks to the team for ensuring such good coverage this autumn - pity about the (lack of) Leach's Petrels and other storm-blown seabirds - no storms!