Semipalmated versus Ringed Plover

Here's a few images of 'Ringed Plovers' from Terceira, the Azores,  last week. There is a well known small (resident and migrant) population of Semipalmated Plover at Cabo da Praia quarry on Terceira, a site that also regularly hosts Ringed Plover, so it's a great place to practise separation/identification between the two species. We've had a least one case (on Corvo in 2016 see appendix) where a bird that had a loral stripe pattern like a Ringed Plover and was identified as such but later responded well to 'tape' and called repeatedly like a Semipalmated Plover and we also occasionally come across other less obvious birds too.

As a re-cap the features for Semipalmated Plover are 1) Loral stripe reaches above gape line 2) Yellowish eye-ring 3) Short and stumpy bill with an orange/red base 4) Semipalmations between front toes, conspicuous between middle and outer (Ringed can have semipalmations between inner and middle toe) 5) Small round head 6) Thin but unbroken breast band 7) Two-toned legs in first winter/juvenile 8) Unmarked and white underwing in flight and last but first in importance 9) 'Spotted Redshank-like' call.   

Here's a sample of birds from last week of both species (if identified correctly- calls not heard on all birds and really need call to nail it home as we have seen puzzling birds in past where calls and field characteristics were not matches). A few less obvious birds below too . I had at least 4 of each Semipalmated and Ringed Plovers. 

Semipalmated Plover 

Loral line above gape line, semipalmations showing between middle and inner toe and thin unbroken breast band. Not much of an eye-ring visible in this image and legs not really two toned either. In this image not looking too round headed or stumpy-billed too. A good starting case of how many birds do not show the full suite of features. I'm working on if a bird has at least two or three features it's going in one box or the other but to be more towards certain need to confirm with call too. 

Loral line above gapeline and hint of a yellow eye-ring. Stumpy billed and round headed. Quite a pale bird.

A nice short stumpy bill, round head, loral line above gape line, quite a prominent eye ring and also looks like that's a muddy semipalmation between the middle and outer toe. Looks like breast band is complete but need a better angle really. Same bird below. 

Another relatively pale bird, loral line over gapeline and semipalmations shown between middle and inner toe. Not seeing this two toned legs on these birds. Again not particularly round headed in this image but bill is short and stumpy. Breast band thin and complete. 

A bird in strong light probably accentuating the apparent relative darkness of the upperparts. Loral line where it should be, hint of eye ring and thin complete breast band.  

A real classic- short stumpy bill, bright eye ring, rounded head, loral stripe above gape line, thin apparently unbroken breast band 

Ringed Plover

A wide breast band, relatively thick loral stripe which seems to just about meet gape line. Zoom in to see but looks like no palmations even between middle and inner toe (which Ringed Plover can have sometimes) 

A pale bird, a paleness which presumably contributes to the washed out loral stripe (which does seem to meet gape line). Same bird below. Quite stumpy billed but 'angular' head, relatively broad breast band at sides. Called several times as expected from Ringed Plover too.

Thick loral line which meets gape line. We have however had Semipalmated Plovers (or birds that called identical to Semipalmated Plovers with this loral line pattern in past though). The call is the really hammer home. Quite stumpy billed and a thin breast band. I think the image below is same bird. 

Another image of a bird I'd like to hear call but with a loral line that meets the gapeline its going in the Ringed Plover box. No eye ring either but the breast band is narrow and structurally it quite stumpy billed and round headed. With resident Semipalmated Plovers in the quarry which could be breeding or even mix-pairing (no evidence I believe of anything along those lines) we perhaps don't need to summon the hybrid possibility but worth noting the haunting thought. 

I'd say it's hammer time for something like this. Thick loral line that meets the gape line, quite a wide breast band, long necked and no hint of an eye ring. Quite a dark bird too. I generally assume the Ringed Plovers on the Azores are Tundra Ringed Plovers (Tundrae) as many look pretty dark (like this bird) on the upperparts. Also according to Duivendijk (2010) Tundra Ringed Plover moult into a more distinct winter plumage compared to Taiga Ringed Plover, hiaticula , which also seems to be the case here. Of note in Spring more fresh looking dark Ringed Plovers are more likely Tundra birds as they moult into a fresh spring plumage unlike Taiga birds. 

Above and the others below- for all the reasons I keep repeating above I'm sticking these in the Ringed Plover box 

Semipalmated or Ringed ?

Zoom on the face of this- not sure where that loral line and gape line meet and there seems to be an eye ring. The breast band is wide. Not sure what box to stick this one in. Again as always really need to hear the call on all of these birds. Same thing going on around the face of the bird below. 

The loral line seems to meet the gape line but cant see eye ring or palmations between middle and outer toe and the breast band is quite wide at side too 

This could be one the same birds above. Several 'Ringed Plovers' kept flying around the quarry so I was presumably coming across the same birds as I went round. 

Hint of an eye ring and not sure what's going on with those lores. Wide sided breast band too. Bung it in the TDB  (too difficult box). 

Reference:

Advanced Bird ID Guide, The Western Palearctic. Nils Van Duivendijk, 2010. 

Appendix

Semipalamated Plover on Corvo 2006 (Vincent Legrand). Called repeatedly like a Semipalmated Plover but lores not great (seem to meet just above gape line with a bit of imagination) and semipalmations not much to sing and dance about either. Eye ring present. Legs are two-toned. Most of us thought this was a Ringed Plover until it called. 

Ring-billed Gulls at Praia da Vitoria, Terceira, the Azores

The story of the Ring-billed Gulls on the Azores and across the Western Palearctic is told in Josh Jones' article, 'The Rise and Fall of Ring-billed Gull HERE. An extract from that article reads:

"Given its geographical position, it is no great surprise that the Azores has traditionally produced the highest counts of Ring-billed Gull within the Western Palearctic. While a small number of new vagrants appears across the archipelago each year, Terceira Island is unique in that it has traditionally attracted a sizeable wintering flock. Data prior to the turn of the century is scant, although maximum counts since then include 56 in February 2001, 33 in 2003, 25 in 2004, 46 in 2005 and 26 in 2007.

What is telling is the gradual but nonetheless noticeable drop from 2005 onward. While the flock still regularly peaked in the low twenties in the late 2000s and early 2010s (for example, 23 on 22 February 2011), such figures have grown increasingly scarce as the 2010s have progressed. Twenty-two were tallied on 16 February 2014, but nothing has come close since. Winter 2017-18 produced a maximum of 12 birds, including just two first-winters (the rest adults), with early 2019 counts peaking at 14. Therefore, though a sizeable wintering population still remains, the story is a familiar one to that encountered across mainland Europe – a diminishing number of individuals and an ageing population among those returning birds"

This year I could only find 10 birds at the usual pre-roost site on the beach at Praia da Vitoria although there were reports of up to 13 birds earlier in the winter, so it seems like this unique small wintering population is hanging in there. The population this year comprised 6 adults and 4 first-winters indicating renewal of the population.  It would be fascinating to know where these birds spend the rest of the year. 

Adult Ring-billed Gulls (above) 

First-winter Ring-billed Gull, bird #1 (above and with a first-winter Common Gull below). A distinctive bird with rather plain greater coverts. 

First-winter Ring-billed Gull, bird #2 (a more typical plumage with mottled coverts with some greater coverts also moulted. Common Gulls on similar age tend to not moult their greater coverts) 

First-winter Ring-billed Gull, bird #3.  This individual had a relatively dark bill. 

First-winter Ring-billed Gull, bird # 4 

First cycle Ring-billed Gull (#3) showing the distinctive mid-underwing pale panel

First-winter Ring-billed Gull (#1) in flight

Adult Common Gull. There were four Common Gulls on the beach and also up to 12 Mediterranean Gull and a hybrid Mediterranean x Black-headed Gull (pictured again below) in the local area this year. Both Mediterranean Gull and Common Gull have been increasing on the Azores over the last couple of decades as Ring-billed Gulls have decreased which may indicate a change in the source populations. More photos of the other Common Gulls on the Beach HERE all of which were confirmed as nominate canus with reference to Peter Adriaens et al, Gulls of Europe.  

Ring-billed Gulls and first-winter Mediterranean Gull on Praia da Vitoria Beach

The Azores Rare and Scarce Bird Report 2018

 

The latest Azores Rare and Scarce Bird Report can now be viewed and downloaded from HERE

THE AZORES RARE AND SCARCE BIRD REPORT 2018

The Azores Winter Trip 2022, Other Wildlife

While scanning for the Swift at the viewpoint over the airfield I had this Vagrant Emperor. The first record for the Azores was as recent as 2019 on Corvo. As far as I know this is the only record since, so one of rarest finds of the trip. It could well coincide with the arrival of the two House Martins and the Pallid Swift candidate. I was doing a bit more investigation into the presumed Pallid. The previous earliest Common Swift record on the Azores was April 1st and Simon Tonkin who is based on the Straits of Gibraltar reported House Martins and Pallid Swift arriving there in the last week. Also James Siddle who was based in Algarve reported that mid-Feb was the typical arrival time for House Martins and the first Pallid Swifts there. Common Swifts generally don't arrive in the Southern Mediterranean until weeks later.   

I had the LED moth trap out one night at Cabo da Praia quarry. The only moth I had was this Pearly Underwing which is resident. Really want to do some more moth trapping out here so will need to come back in high summer when birds are not such a welcomed distraction. 

More Madeiran Wall Lizards- these are numerous on the boardwalk at Cabo da Praia. What sounded like Marsh Frogs are actually Perez's Frogs (Iberian Water Frog) - the Iberian counterpart of Marsh Frog. 

Bermuda Buttercup, Oxalis pes-caprae. This was all over the place. A naturalised South African species. 

Common Broomrape- a lot of this around. A clover parasite. It's not listed for Terceira in Schafer but is on GBIF for the island. 

More Bermuda Buttercup with the new Cabo da Praia mural which is the best wader location on the Azores and hosts a breeding population of Kentish Plover. 

View over the US military base and airfield. 1000 US families used to be based here but now that has been reduced to just over 150 individuals. 

The Azores Winter Trip 2022 , Days Four and Five

Ebird trip report updated HERE. Had 67 species in total. Highlights since last post include a new Azores tick, Jack Snipe, and also managed to see one of the suspect Egrets that have been around. These birds were considered Little Blue Herons when they first appeared but there is a possibility that they might be white morph Western Reef Egrets, hybrids, 'grey phase' intermediate Little Egrets or aberrant Little Egrets. Several birds have got various strange features including grey-pale legs and bill and dark markings on the neck and greyish wash on the upperparts. There were up to four suspects at one point. 

Despite searching for the last two days I failed to locate the Snowy Egret (there were three on the island earlier on in the winter), so once again my Azores bogey bird (that and Meadow Pipit) continue to allude me. 

So in total I got six Azores ticks (now on 248 species for the region) ; Belted Kingfisher (WP tick), Jack Snipe, Marsh Harrier, Water Rail, Common Crane and Pallid/Common Swift. With supporting cast of Bonaparte's Gull, Ring-billed Gulls, possible nearctica Greater Scaup, Lesser Scaup, Green-winged Teal, Ring-necked Ducks, Least Sandpiper, Semipalmated Plovers, 2 Spotted Crakes, record numbers of Med Gulls and nearly 100 Glossy Ibis, it's been a great little mid-Atlantic break. A few other wildlife highlights also to follow plus a closer look as the Common and Ring-billed Gulls and the Ringed and Semipalamted Plovers.  

Egret sp. I'm leaning towards aberrantly marked Little Egret. I presume the all black legs in this photo is due to soiling. 

Jack Snipe- not an easy Azores bird. There have been up to eight this winter which constitutes a good winter (usually 2-3 birds year) 

Adult Mediterranean Gull x Black-headed Gull (thanks Peter Adriaens for identifying this- the black confined to the tips is the main feature to separate from second cycle Med). Considering there are only a handful of Med Gulls on Terceira, it's interesting that this small sample should contain a hybrid. Ruben and I were discussing what appears to be a high frequency of hybrids on the Azores. It's possible that hybrids mix up the genetic code for orientation and navigation and thus makes hybrids more prone to vagrancy? Also see Teal caption below (a bird also confirmed by Peter- thanks Peter, what would I do without you :-) ) vagrancy itself can lead to hybridisation which can 'force' mixed pairings which in part could also account for a higher frequency of hybrids in vagrant traps like the Azores. Off the top of my head I can think of Brewster's Warbler, Stilt Sand x Pec Sand, Black Duck x Mallard, Med x Black-head, Little x Snowy Egret (plus other unusual hybrid egrets including a Western Reef Heron-type) and numerous hybrids gulls, which have all been recorded on the Azores. 

Lesser Scaup, Gadwall, Ring-necked Duck and Great Scaup

House Martin- still flying over the Paul da Praia ridge with 50+ Azores Noctules. Unfortunately no further sign of the Swift sp. From what we saw of that almost certainly a Pallid Swift which is an Azores monster. Was hoping we would see it again, Ruben continues the hunt today. There were two House Martins originally which arrived the same day as the Swift, an incredible occurrence of uber early Spring migrant mid-Atlantic vagrancy. The timing alone also strongly suggests Pallid Swift which is a classic early Spring and late autumn vagrant to northern parts of Europe. 

Snow Bunting with Sanderling and Starling. 

Male and female Scaup- this is the second pair on Terceira. They came in at a different time to the Praia da Paul pair and associated with European birds. The female certainly looks a lot more of a typical European bird. 

Male Scaup 

The female European Teal again. The tertial which has a dark border and a white edge that broadens towards the tip indicates a European origin. The fact that it has paired with a male Green-winged Teal is a vagrancy phenomenon where extra-limital birds pair with their closest congener. We've seen this several times on the Azores before- hybrid Black Duck x Mallard and also seen American Coot and European Coot displaying to each other.  

Western Azores Goldcrest. This is the local race inermis. There are two other island forms, Santa Maria Goldcrest (sanctamariae) and Sao Miguel Goldcrest (azoricus) which occur on their island namesakes. More on endemic birds on the website HERE. 

Adult Mediterranean Gull with Ring-billed Gulls. There has been up to 13 Med Gulls  this winter which indicate an increase in occurrence 

Adult Ring-billed Gull (above and below)

Female/juvenile Belted Kingfisher- has to be bird of the trip. Unlike adult male, females and juveniles have the red-rufous on the underparts making this the ultimate Belted Kingfisher too. Absolute stunner.