Woodpigeons

Woodpigeon 

I've been wondering about the recent absence of woodpigeons so I've been going through my records to see if I've been missing something. And it looks like I have been:

Period	Percentage of records
	All	November
Past 30 years	11%	7%
2016	7%	5%
2017	6%	4%
2018	7%	3%
2019	8%	7%
2020	10%	6%
2021	14%	13%
2022	15%	7%

Three things:

• These are the number of records, not the number of birds. An individual record might be one bird or a hundred. I'd have to do a lot of deep diving into the data for each year to find out whether I was just not seeing any woodpigeons at all, like this year, or if there were plenty around but only in large flocks.

• I changed my style of recording during lockdown and these days I'm doing more detailed recording on journeys: instead of recording the birds along a line between two points that may be kilometres apart I've split it down so I'm recording the birds within approximately 1km² squares. (They're approximate because I'm dependent on landmarks to mark the boundaries.) There's a bias towards the large and easily identifiable when you're recording what you're seeing in transit so more detailed recording means more records of the large and easily identifiable. That's why pigeons, corvids and gulls make up a greater proportion of records than they used to. They've always been jockeying for position in the top five, mind.

• I don't know why 2021 is an outlier. I'm going to have to have a rummage in the data for clues.

My general conclusion is that I've got to stop thinking of our woodpigeons as a resident population augmented by Winter visitors, like the local blackbirds and robins, and think of them as migrants with a breeding population and a Wintering population, like the starlings, blackcaps and chiffchaffs.