Monday, 25 April 2011

Self-found lifer: White-billed Diver

I spoke to Ken Shaw briefly after a Lothian SOC meeting a few weeks ago. "If you are in the Outer Hebs for 10 days in mid-April you will definitely see White-billed Diver", he confidently asserted. He shared his gen willingly, letting me know the various best vantage points on Lewis for this species that has transformed from mythical rarity to scarce migrant in the last decade or so. Since Ken was one of those involved in the hours of seawatching required to reveal the regular presence of this species off Lewis and elsewhere in Scotland, I listened and took careful notes. Nevertheless, as I set off a couple of weeks ago for the Outer Hebrides, I couldn't help but feel that my chances of success were lower than predicted - after all family holidays are not always compatible with hours of seawatching off exposed and remote headlands...

Sure enough the trip to Port of Ness and Skigersta drew a blank, thanks in part to the poor weather on the day we made the haul up to the Butt of Lewis. As most of the holiday was spent on North Uist, I knew that its shallow bays held little chance of White-billed Diver which seems to prefer deeper waters for feeding. Instead, Great Northern Divers fished these waters and I spent time carefully checking each of at least 50 individuals encountered in the Sound of Harris and North Uist's shores. Small numbers of Red-throated and Black-throated Divers added to the mix, but as the trip drew to an end I knew that the Lochmaddy-Uig ferry was my only real chance of connecting.

As it turned out persistence paid off. Colin McF and I spent the journey constantly scanning for birds. Three-quarters of the way through the trip, somewhere off Waternish Point of Skye, a massive diver came into view. Having such fresh experience of so many Great Northern Divers certainly paid off as this bird's bulk was instantly striking - appearing another 50% bulkier than any other diver seen on the trip, and dwarfing the Red-throated Diver we had seen a little while earlier. The bird's neck appeared particularly powerful, and what was more, the bird had a massive pale yellowish-white upturned bill... a winter plumaged White-billed Diver!

Quickly I pulled out the SLR and started firing away trying to switch between AF and manual focus to try to ensure some recognisable shots of the increasingly distant target. The shot above has captured the upturned bill and also shows hints of the neck collar. Unfortunately all of the bird was not visible all of the time though due to its size its head could be picked out most of the time.

The shot below shows the distinctive head pattern of the species with a pale side to the head and darker cheek patch.

This shot gives some idea of the bulk of the bird and the thickness of its neck. It is facing away and downwards and is just dipping its bill (which is just visible to the left of its body) into the water as it dips its head to look for prey.

What a great bird - a brief but conclusive sighting (the photos do not do the bird justice obviously and were taken once the bird was beginning to be lost from sight as we passed - initial views were much better as the bird was spotted just before we drew level with it). For me, this is a personal target met as I have been hoping to self-find a lifer in Scotland for a few years and I knew that this species was most likely to provide the best opportunity but it was certainly worth the wait.

So, many thanks to Ken Shaw for his prediction, which provided the determination to keep searching until the end. Now of course I would like to see a summer plumaged individual and hopefully not be on a rapidly moving ferry when I do so...

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