It looks like the Great Northern Diver has finally departed after its 118 day visit. There was no sign this morning or late afternoon. I still need to check pre 1999 records but it's looking like its got the record for the longest staying bird in GM.
When it first appeared on January 27th it was very flighty between the top and lower reservoirs but settled on the lower reservoir for several weeks as it moulted and became flightless. In the last few weeks it started to make small flights across the lower reservoir then became flighty between the 2 reservoirs again for the last couple of weeks.
So does the diver look exactly the same as when it was first seen or is it showing signs of adult plumage? It's being reported on birdguides as a juvenile but it's about a year old now!
The bird is showing signs of moult and should be classed as an immature by now. See Gary Crowders images further down this thread from April 2016 and note the moult in upperwing coverts and scapulars. Some second calendar year birds moult into an adult non-breeding type plumage which this bird is well into; note its much more square shaped new scapulars complete with pale greyish internals on both webs. Other birds moult into something similar but with slightly more adult breeding type features apparently.
I was up there about 3 weeks ago and the bird didn't look to have progressed from juvenile plumage at all, but I'm no expert. It was pretty dark over the back but there was no hint of the beautiful patterned plumage of a summer adult. I had expected some sort of transition. That said, the only summer plumage bird I've ever seen was in mid-November, so presumably there is lots of variability in the timing of the moults.
So does the diver look exactly the same as when it was first seen or is it showing signs of adult plumage? It's being reported on birdguides as a juvenile but it's about a year old now!
Great Northern Diver absent when I arrived but flew in over the lower reservoir, over top bank and was back on the lower reservoir when I left.
Also seen: two pairs Common Sandpiper, 3 Redshank, Great Crested Grebe, one Oystercatcher, pair Tufted Duck, Mallard with ten ducklings as well as one with two.
Great Northern Diver still on the lower resvr. I went around 6am and couldn't find it. Mark Rigby saw it at some point later in the morning. I went again around 5pm and it wasn't on view (starting to get a complex.....!). Then it flew in from the Delph end of the valley! 1pr Oystercatcher 1 Redshank 1 Curlew 4+ Common Sandpipers 1 Cormorant 1 White Wagtail on top dam 2 Swallows 1 Willow Warbler 1 Reed Bunting
2 Great Crested Grebe 6 Common Sandpiper 2 Oystecatcher 2 Redshank 5 Mallard, one female with 9 duckling
Is the great northern diver showing any difference in plumage? I don't know anything about ageing of divers or how soon the reach adulthood, but presumably it can't stay a juvenile for ever so perhaps it's showing signs of adult, sub-adult or 2nd calendar year plumage?
In addition to Graham's sightings (8.30-10am) 1 Wheatear hiding out of the strong easterly Another Buzzard 3 Redshank 1 Curlew 1 House Martin 1 cracking male Linnet on the top dam 1 Lesser Black-backed Gull Willow Warbler in car park Chiffchaff around Low Bank
2 Ring Ouzel Yellow Wagtail (fem) 2 Wheatear Dunlin 2 Common Sandpiper Redshank 2 Oystercatcher Curlew 2 Raven Sparrowhawk 2 Tufted Duck Great Crested Grebe Hirundines moving through with each shower so hard to estimate numbers but at least 1 Sand Martin amongst them.
A walk around in glorious sun 3 - 4pm Great Northern Diver showing well on lower reservoir 1 Buzzard 2 Redshank 6 Lapwing 2 pairs Tufted Duck 2f Goosander 2 Wheatear 2 Swallows 1 Mistle Thrush 1 Pied Wagtail
The Great Northern Diver was still enjoying life on a somewhat calm lower reservoir.
Several meadow pipits flitting about, I counted 8 but I think more. 1 Male reed bunting on the wall near the pumphouse. 2 Pied wagtail 1 Grey wagtail chasing a Swallow, plus an earlier sighting making 2 swallows. 2 Oystercatchers 2 Redshank