Winter Birding: Wintering Lesser Whitethroat in Co. Tyrone by Brian Mccloskey

 

Winter lesser whitethroat by Brian Mccloskey

Siberian Lesser Whitethroat description.

On the 7th of January information about an overwintering Lesser Whitethroat went up online, with two pictures attached. When I saw these pictures, I was very intrigued. It struck me as a Lesser Whitethroat that was possibly of eastern taxa. I wanted to see it but unfortunately the Tuesday and Sunday that were arranged for viewing didn’t suit me with work. John Cusack and Tom McEntee wanted to see the bird as well and we headed up from Monaghan on Saturday the 19th January. We had great views and John managed a record shot of the tail in flight. I left feeling a little disappointed as I knew it couldn’t be identified from the pictures we had gotten. That evening Wilton Farrelly informed me that he had heard a single tack call. With my thinking pushing towards eastern taxa, a tack call would rule out vagrant S.c.halimondendri (Desert Lesser Whitethroat) based on current knowledge, but more information was needed to get this birds identification over the line.

Still intrigued by the bird, Gerard Murray and myself headed up two days later on the 21st. Unfortunately, the weather was a bit rainy and windy and despite good views over 4 hours we had nothing to boost our speculation that it was of the S.c.blythi (Siberian Lesser Whitethroat) subspecies. Cardboard platforms were put under the feeders in hope to collect a DNA sample. We left a little disappointed. 

My third visit was another two days later on the 23rd. I travelled up with Victor Caschera who was hopeful we would clinch it. After good views were had we went outside and attempted to get a recording of its call. Unfortunately, it was keeping its bill closed despite playback. Playback was of no use and the bird never even looked our way when playing Lesser Whitethroat calls. We spent the whole day after this outside trying to hear the call. We lost the bird for approximately half an hour so I wandered up the road and re-found it feeding low in the ditch the opposite side of the road from the house. I signalled to Victor I had it and we had great views. After a few moments the bird hopped into the tree tops and flew onto the feeders. Having had my binoculars on it as it flew, it landed and opened its tiny bill. I could clearly hear the rattle call and in a panic, I started recording while getting Victors attention. Silence followed for a few seconds before… tack tack! The bird gave ten typical tack calls before giving another rattle call and then finishing off with a single tack! I couldn’t believe that it called and better still I had it all recorded. Victor and myself were ecstatic. According to Martin Garners Autumn book the rattle call is typical of blythi. It reminded me somewhat of a Wren as opposed to the Blue Tit like rattle of halimondendri. Had we got enough now? Unfortunately, despite everything pointing towards blythi, DNA was still needed. 

That evening I got contact details of BTO ringers but despite trying to get in contact with them I failed. That was until Declan Coney from Scotstown, Co. Monaghan contacted me a few days later saying he was going to try to ring it and that he had been up that day to see the bird, before contacting the BTO. This was brilliant news to me. Peter Phillips and myself decided to meet him on Tuesday the 29th of January at the house in Omagh. We arrived at about 9.50am and Declan was already there with the nets up. The Lesser Whitethroat showed just before Declan arrived the owners said. At about 10am I picked the Lesser Whitethroat up at the top of the tree opposite the house. It gave lovely views and was the first time Peter saw the bird. At 10.03am it was in the net! My heart was racing as I desperately wanted to see the primaries up close. Declan got the bird out of the net and put it in the bag. Declan gave me the bag with the bird in it while he quickly took down the nets. He took the biometrics and ringed the bird before we got to take pictures. The primaries were perfect for blythi. On the primaries p2 ran through p6 and p7. On S.curruca (European Lesser Whitethroat) p2 would fall between p5 and p6 and on halimondendri it would fall between p7 and p8. The tail was very worn! Not much could be made from it but there was a faded white tip to t5 and the outer t6 was mostly white with the inner web a ‘dirty’ white colour. There was no hint of white on any of the other tail feathers. In the bag there was a few droppings as well as three tiny feathers. I put them into capsules and sent them off to Martin Collinson that evening. 

Age: First-winter. This bird shows many features that age this bird as a first-winter. Firstly, the central tail feathers of this bird are pointed, however the outer tail feathers are somewhat rounded. The fresh feathers indicate first winter and perhaps the roundedness of the outer tail is as a result of wear. The iris colour is grey with no suggestion of warm or tan colour. The primary coverts are weak and abraded and show some moult contrast in the greater coverts. All features indicating first winter. 

Figure 1: shows features that are pro first-winter

Identification: As Lesser Whitethroat but with subtle differences. The upperparts are a sandy like colour suggesting eastern taxa. No hint of a supercilium was visible in the field, however in the hand a very faint white supercilium was visible. The ear coverts aren’t strong at all almost fading into a lighter grey. The tail is very interesting. The first shots of the tail show that t6 is almost completely white with what appears to be a hint of a brown shaft running up the centre, t5 shows a white tip and t4 lacks white. The lack of white on t4 isn’t suggestive of halimondendri. The orbital ring is white but is broken towards the bottom. The alula is black. The bill is quite strong and long which again doesn’t favour halimondendri. The base of the upper and lower mandible is a lighter shade of grey with a hint of green. There is a tiny light tip to the bill. The flanks are buff. Legs dark. The throat is white and has a neat cut off point, which reminded me somewhat of a first-winter Taiga Flycatcher. In some lights the bird had a dark shoulder patch

Call: The bird was only vocal very infrequently. On Wednesday the 23rd of January it opened its bill for the first time. As Victor and myself watched the bird fly from the trees above the road to the feeders it called. I had my bins on it and watched it open its bill. The first call was a Wren like rattle. When I heard the bird call, I alerted Victor it was calling and I started recording straight away. After the original rattle it gave 10 tack calls followed by another rattle and finally one more tack. The rattle was very distinctive and Martin Garner describes the blythi call as like a Spectacled Warbler which sounds very similar. Vagrant halimondendri aren’t known to give the tack calls and therefore as good as rules this out. Just before the Lesser Whitethroat went to roost it gave almost 5 minutes of constant tacking calls. No rattle calls were heard during the tacking in the evening. Poor recordings were taken. 

Figure 2: showing neat cut off on the throat, dark shoulder patch and buff flanks. Mask almost non-existent. White on t6 visible.

Figure 3: John Cusack’s flight shot. t6 appears almost completely white. Small white tip to t5. White on t4 absent. All pro blythi.

Figure 4: on this bird p2 falls between p6 and p7 a feature of blythi.

Figure 5: Showing the tail pattern. Despite being worn looks spot on for blythi.

DNA

Late on the 7th of March 2019, I got an email from Professor Martin Collinson. It read as follows “Good news. Thom has done the Lesser Whitethroat, Omagh, Co. Tyrone, sampled 29 Jan 2018 (our ref LW122), and confirmed it is a Siberian S. c. blythi.  If there’s any question or if you need more info for RC, please let me know.” The DNA sequence was as follows…

LW122 blythi

CtaGGCCTCTGCTTAaTCaCACAAATCGTTACAGGCCTATTCCTAGCAATACATTATACAGCAGATACTTCACTAGCCTTCGCCTCCGTGGCCCACATATGCCGAGATGTCCAATTCGGCTGACTAATTCGCAACCTACACGCAAACGGGGCCTCCTTCTTCTTCATCTGCATCTACCTCCACATTGGCCGAGGAATCTACTACGGATCCTACCTAAACAAAGAGACCTGAAACGTAGGGGTTCTCCTCCTGCTAGCACTTATAGCCACTGCCTTCGTAGGCTACGTTCTGCCCTGAGGCCAAATATCATTCTGAGGGGCTACCGTAATTACAAACCTACTCTCAGCcatCcCATATGTTgGTCAAACACTAGTAgaATGAGCCTGAGG. 

Figure 6: Showing brown upperparts extending up onto the nape.

A fantastic piece of work by my good friend Brian Mccloskey about a wintering lessser whitethroat in Northern Ireland. This is what it takes to discover and learn more about these subspecies.

#Teamwork #Vikingoptical #BirdGuides #Irishbirding #Winterbirding