Chiffs and Chaffs

Heysham Obs
A routine morning again saw conditions a little too windy, certainly for any Grey Wagtail ringing.  I'm confused with Chiffchaffs.  The only time we get the 'swee' or 'swe-oo'-calling birds at Heysham is when there is more than a hint that there has been trans-North Sea migration e.g. a good chunk of the back-end of last autumn and definitely in the post-3J season.  This autumn, which has not been very easterly to say the least, has produced not a single calling Chiffchaff giving other than the usual monosyllabic collybita-type call - yet we have e.g. ringed record numbers by this stage of the autumn, so they are about.  However, peer-reviewed publications insist that the rather strident 'swee' and 'sweoo' calls are given by "young birds" of British origin.   Why not at Heysham, as a fair chunk of the birds ringed have been locally-produced young and 'early' passage youngsters?   Opinions, please, to PMrsh123@aol.com

Ringing/grounded by the office
Chiffchaff - 4 (2 ringed)
Goldcrest - 1
Robin - little obvious evidence of migrants but two 'new' birds ringed
Green Woodpecker - one tank farm

Vis mig 0720-0920
Dominated by an early movement of Chaffinch with some probably missed
Chaffinch - 215 SW
Meadow Pipit - just 20 SE
alba Wagtail - exactly 50 SE
Grey wagtail - 4 SE
Linnet - 1 SE
Redpoll spp - 1 SE
Swallow - 19 S
Goldfinch - just 4 SW
Siskin -  2 SW
Greenfinch - c15 SW

Ocean Edge/Red Nab
Knot - 2,700
Bar-tailed Godwit - 750
Grey Plover - 335
Redshank - 313
Shelduck - 72
Med Gull - adult and 1CY
Little Gull - ad & 2CY
Arctic Tern - seemingly just one juv left on outfalls
Linnet - 72
White Wagtail - at least 3 grounded (& 25 Pied/unspec)

North harbour wall (via Mark)
Med Gull - 2 adults including Czech-ringed bird