Overnight mothing saw an increase in immigrant numbers if not variety, with 45 Rusty-dot Pearl, 19 Rush Veneer, 11 Diamond-back Moth, 9 Silver Y, 5 Marbled Piercer Cydia splendana and 1 White-speck making up the tally at the Obs; a Convolvulus Hawk-moth was found by day on the wall of the Bill toilet block. A small arrival of Western Conifer Seed bugs saw 2 caught in a moth-trap at Weston and singles found by day on the Obs front door and on the Bill toilet block. Clouded Yellows by day included 3 at Coombefield and several singles at the Bill.
On the ground, Wheatear remains just about the only routine migrant that could be described as even approaching conspicuous just at the moment © Steve Gantlett cleybirds
Ferrybridge continues to come up with some nice variety, with today's Common Gull and Lapwing both oddities for September © Pete Saunders
Although moth trapping was still uneventful it was interesting to see another little pulse of Marbled Piercers arrive in tandem with an obvious if small influx of common immigrants. Although usually considered a common resident in Britain - with numbers maybe boosted by immigration - we've got no evidence that this species is anything other than solely an immigrant to Portland: standing at just 30, this year's Obs total has been nothing special, but in the past our annual totals have been as high as 734 in 2014 when as many as 201 were trapped in a single night © Martin Cade
We had promised a nocturnal passage update a couple of evenings ago but Nick Hopper's most recent stay with us was so busy that it's taken far longer to go through the recordings than anticipated. Anyway, far better late than never, Nick's now sent us through his report on the first of the two nights - last Sunday, 4th/5th September. As we were hearing whilst we were listening from the Obs after dusk it proved to be a night for waders: 15 species were recorded, with calls heard pretty well throughout the night. The most regular callers were Dunlin, Ringed Plover and Common Sandpiper, with also many Green Sandpiper and Greenshank; Bar-tailed Godwit, Whimbrel, Turnstone, Curlew, Grey Plover, Oystercatcher, Redshank, Knot, Golden Plover and Sanderling were also all recorded on multiple occasions. Trying to get a handle on numbers is proving to be a fascinating issue, with one event illustrating just how difficult it is to be confident about exactly what's going on: whilst we were listening from the Obs patio a particularly low-flying party of Common Sandpipers that we'd taken from their calls to be maybe 2 or 3 birds were suddenly illuminated by the light from one of our moth-traps and revealed to be a flock of 12 birds! Passerines were represented by frequent Tree Pipit calls along with a few Robins, Yellow Wagtails and two each of Pied and Spotted Flycatcher. A single Arctic Tern also went through. More to come from Monday night's session where passerines take centre stage…