Thursday, October 27, 2011

KE, Recaptures And Fingers Crossed

An hour or two at Knott End (KE) this morning proved very rewarding for seeing a good selection of birds, but not for photography on the grey, overcast morning.

A walk up river and then near the jetty produced 9 Red-breasted Merganser, 15 Eider, 30+ Wigeon, 4 Grey Heron, 2 Little Egret, 6 Pied Wagtail, 1 Rock Pipit, 4 Cormorant and 1 Kestrel.

The incoming tide pushed waders and wildfowl to the shore, with 1900 Oystercatcher, 1400 Knot, 145 Redshank, 28 Turnstone, 140 Dunlin, 40+ Curlew and 35 Shelduck. A Peregrine dived once or twice at the assembled Knot before the tide ran in so quickly that I didn’t get to accurately count the many birds which flew either up river to the Wyre roost or along the sands to the Preesall/Pilling roost.


Rock Pipit


It rained later so I turned my attention to trying to answer a question from a blog reader from the US who asked about ringing recaptures.

I keyed WILWA into our Fylde Ringing Group IPMR database and came up with the example below to illustrate how full life histories are gleaned from multiple recaptures of the same individual, in this case a small migratory warbler, the Willow Warbler. British Willow Warblers spend the summer here before migrating to central Africa for the winter.

IN1795 was first captured as a juvenile (age code 3) in July 1990, almost certainly a bird whose parents bred within the ringing site. It spent its first and subsequent winter somewhere in Africa, returning to exactly the same UK location in years 1991, 1992, 1994, 1995, and 1997, when we recaptured and identified it as a breeding male (code 4M) in most years. The bird was almost certainly present during the summers of 1993 and 1996, the reason for the non-recapture being that it simply escaped us ringers that year. In 1997 it went off the radar and may have died from old age, an unknown cause, or possibly on migration south during the autumn of 1997, in its Africa winter, or even on the way back to the UK in the spring of 1998. Willow Warblers, indeed most small birds are not especially long lived, but in its 6+ years the recapture history of IN1795 provided lots of valuable data.

Age 3, First ringed - 14/07/1990 Inskip, Lancashire
Age 4, Recaptured - 20/04/1991 Inskip, Lancashire - 280 days
Age 4M, Recaptured - 18/05/1991 Inskip, Lancashire - 308 days
Age 4M, Recaptured - 14/05/1992 Inskip, Lancashire - 1 year 305 days
Age 4, Recaptured - 01/05/1994 Inskip, Lancashire - 3 years 291 days
Age 4, Recaptured - 14/04/1995 Inskip, Lancashire - 4 years 274 days
Age 4M, Recaptured - 06/05/1995 Inskip, Lancashire - 4 years 269 days
Age 4M, Recaptured - 03/05/1997 Inskip, Lancashire - 6 years 293 days

Willow Warbler

The forecast isn’t looking too bad for a ringing some new birds tomorrow, and maybe even a few more recaptures. Fingers crossed.


Kay L. Davies said...

I love the work you're doing, Phil. The more we know about the various species on our planet, the more we care, and the more we care, the more likely we are to want to preserve both the planet and its creatures.

Kay, Alberta, Canada
An Unfittie’s Guide to Adventurous Travel

Mary Howell Cromer said...

The Rock Pipit and Turnstone, stunning delights they are!!!
The recapture statistics are so interesting!
Oh to be a bird and to be able to fly off and migrate to a warmer climate when the winds blow in the cold of winter...

grammie g said...

Hey Phil...I am total impressed with your ringing and what is accomplished by doing so!
Interesting the info you provided about the ringed bird!!
Had a great morning ..thats good!!
See that a whole comment without be silly!! : }


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