1 January 2023

Autumn migration 2022 - summary

Introduction

Autumn could be described as the period between the first returning passage migrant after the summer and the departure of the last. In which case the first and last autumn passage migrant this year was the same species: Yellow Wagtail, with the first on 27 July and the last on 22 October. Of course, different forms of migration and movement continue on into November with finches and the thrushes etc.

August is when autumn migration kicks off for birders, but August 2022 was a relatively disappointing month in Wanstead. We recorded a total of 86 species for the month of August which is dwarfed by the 98 we had in August in the previous year. September performed better and we breached the ton for the second year running (102 for September 2022 versus 104 for the month in the previous year). October was a bit down on average with 88 for the month (whilst each of the three previous years saw the month get over 90 species). In November we recorded 81 species, very slightly up on average, but four down on November 2021.


Highlights

September delivered two significant patch rarities: Tree Sparrow found by Mary on 2 September (our first since 1985!); and the first of two long staying Dartford Warbler (our second and then third ever and first since 2009) found by Marco on 30 September.


Other good birds included: Wryneck (9 Sep); Cuckoo (4 Sep); Short-eared Owl (14 Sep); Yellowhammer (17 Sep); a well twitched Woodlark on the deck (29 Sep); and Merlin (14 October). Merlin would probably have got more column inches devoted to it if it wasn’t the second (or third if you count that the first was seen over two days) record of this patch rarity for the year.


Bob’s NocMig recorder also delivered some incredible results: most notably our first ever Pink-footed Goose (16 Sep), but also Ortolan Bunting (13 Sep); Barn Owl (30 Sep); and Nick heard a Ringed Plover (1 November). All very high quality patch rarities for us.


Autumn Passage Migration

The table below captures the phenological dates and counts of most of our classic passage (non-breeding) migrants. I have been converted to the value of ‘bird days’ as a metric despite it always seeming nonsensical to me before. So, ten Wheatear on one day would be ten ’bird days’ as would one Wheatear every day for ten days.


Almost everything arrived earlier this Autumn than the year before, with some returning birds even appearing in July, including our first Autumn Wheatear on 27 July, compared with 16 August in 2021. The final departures, meanwhile, were not overly early or late, although we did have our latest ever record of Yellow Wagtail on 22 October.


In terms of volume of records Swallow and Whinchat numbers were very materially up on the previous year (223% up for Swallow and 118% increase for Whinchat). Let me try and bring that to life a little: this Autumn, we recorded 185 bird days or records of Whinchat, spread across 44 calendar days from 1 August until 2 October, with the majority of dates in August and September producing Whinchat. Obviously some of these records will be the same birds stopping over for a day or more to re-fuel, but the average count of four birds, across each of the dates when records were registered for this species, is impressive, as is our high count of 13 Whinchat on 9 September.


Spotted Flycatcher, Common Redstart, and Garden Warbler numbers were also up, whilst everything else saw lower numbers of records than the previous year. Sand Martin (68% down on the previous year) and Yellow Wagtail (62% decrease) were particularly notable drops on the year before.


I am well aware that trends cannot be read into a dataset covering two years, but we only have eBird records from October 2020 and I don’t have the patience to trawl through old bird reports or tweets to build a better data set.




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