Saturday, April 23, 2011

Is This Your Goldfinch?

Will and I have caught a number of Goldfinch at Out Rawcliffe so far this year, almost 120 in fact, but from the start of our effort with Goldfinches as spring migrants at this site we hoped that one or two might prove to be arrivals from further away. We got one today, ring number X707467, an adult female, but not our ring.

Goldfinch X707467

Goldfinch X707467

For non-ringers out there the system works something like this: Each registered ringer uses sequences of rings allocated to them and then enters details of each ring used onto an Integrated Population Monitoring and Recording (IPMR) database. Periodically the ringer sends electronically to the BTO a file of their records for the BTO to enter onto its master database. The BTO runs regular programs to match records of individual birds ringed but subsequently found in different locations, and then notifies both the original ringer of the bird and the ringer/finder of the bird of the separate details. Obviously it can take some weeks for the two sets of information to emerge so as to match both together; with ringers ever impatient to receive such information, there is always a desire to retrieve such information earlier than the BTO systems can possibly do it, and thus the reason why ringer’s blogs regularly feature incomprehensible ring numbers.

Our catch this morning was 25 birds, 10 new and 14 retraps, with the one Goldfinch X707467 classed as a control.

New birds: 4 Goldfinch, 2 Willow Warbler, 2 Sedge Warbler our first of the year, 1 Reed Bunting and 1 Whitethroat. Retraps: 6 Willow Warbler, 3 Goldfinch, 2 Whitethroat, 1 Great Tit, 1 Reed Bunting and 1 Chaffinch.

Sedge Warbler

Sedge Warbler

Our Willow Warbler captures here this spring now number 23 birds, 13 completely new for this year plus 10 individuals from previous years. With the plantation being such a discrete, detached area of vegetation and whilst allowing for the fact that some of the Willow Warblers have moved on, it looks like we may have established the extent of the very local population as slightly more than we imagined; but possibly not, judging from the amount of Willow Warbler song and general activity here today with birds moving around constantly in establishing their tight territories. The Reed Buntings caught today were in the net next to each other and so released together, the male was also caught last week.

Reed Bunting - female

Other than the ringing, there is nothing to report. Overnight rain and murk from a westerly left cloud about from first light, which didn’t bode too well for any visible migration, and none was seen apart from several Swallows and a handful of Meadow Pipits.

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