Canada Geese 2019

On Thursday (27th) afternoon, Alan L and Jerry prepared the goose catching area ready for the roundup on Sunday 30th. A large contingent of visiting ringers and helpers, joined the reduced numbers from the Group for this annual event. In total, 428 birds were caught, comprising 426 Canada Geese (220 ringed, 177 already with rings, with 29 released unringed) and two Mallard who got mixed up with the Geese on the way in!. In addition, a further c42 Canadas were not rounded up/or escaped. Therefore the number of Canada geese using the Lake to moult has increased a bit from last year but is still well short of  the c600 which were recorded in 2016 and 2017.

The total catch

This years young were caught with the flock this year (this doesn't happen every year), some can be seen in this photo (one being the darker bird in centre of first row). 

A total of 36 ringers/helpers were involved in processing the birds, including a large contingent who came from Dorset. Thanks to all who helped but especially the Lake/landowners Anstey Blackham and Clive Jones, and the canoeists - Tony Grifffiths & the Aberfan Canoe Club, Richard and Kirsty Garner plus many others we didn't get the names of. Alan Ashman, Bob Webber and Ron Clevely brought the pens over from Chew Valley, Matthew Ashman and Peter Jenkins were in the pen, Sue Parkinson and Jerry Lewis scribed, Alan, Bob and Ron did the weighing and Jerry organised the whole thing expertly!

Textbook goose presentation from PJ!

CP queuing to be weighed

All of the ringed Canada Geese were from the Lake, having been ringed in 2018 (76), 2017 (36), 2016 (25), 2015 (12), 2014 (11), 2013 (5), 2011 (5), 2009 (5), 2007 (2). There was no roundup in 2012 because of the algal bloom. Two birds from each of 2017 and 2011, were ringed originally with Radipole rings. For comparison, our oldest Canada Goose is just short of 19 years.

Its been some years since we have recorded the sex of the birds - based on cloacal examination (CE), due to time constraints with processing the increasing size of the flock. This year we thought we might sex them, based on the weight ranges of male/female published in BWP (and repeated in Demongin). The idea being that any bird below the range of male, would be female, and any above the range of female, would be male. Sounded good, but on checking, Peter found that there would be 198 female, 10 male and 186 unsexed (in the overlap range) this year. In addition, 88 (22%) of the 2019 birds fell below the weight range given for the species in the references (lower limit of 3670 gm)!!!! Peter then looked at our historical data, and found over 1000 birds (about 18% of those weighed), were also below this "lower limit" for the species. Of these "small birds" that were sexed (on CE), 234 were female (as one would expect), but 11 were males (and therefore an awfully long way below the lower weight limit for males). 

In addition to this, out of 1443 birds sexed on CE (717 male and 726 Females), 148 birds sexed as male were below the weight threshold given in BWP for males, this means that had we sexed all these birds on size just over 20% of our "historic" males would have been incorrectly sexed as Females. We therefore decided not to try sexing on weight, but have found some useful data to include up in a future report/paper on the Lake's Canada Geese.

It was good to see a couple of youngsters keen to get stuck in and carry some geese

The young lady above also proved to be a dab hand with the camera!

Thanks also go to Lyndon Roberts (first 5) and Molly Pannell (final Photo) for the use of their photo's in our blog.