1 May 2018

1 May 18 - West African Pelagic - Day One: At Sea Around Cape Verde

The first day at sea on the West African Pelagic had got off to a good start for many, although clearly a number of the joining passengers were suffering from the movement of the Plancius due to the strong winds & choppy seas. We had been lucky enough to see one or more Razo Larks from the zodiacs which was great news. While we were stationery off Razo Island, we had a steady movement of Cape Verde Shearwaters, as well as, a few Brown Boobies & Red-billed Tropicbirds.
Brown Booby: I saw at least fifteen during the day which was a Western Palearctic Tick
Brown Booby: This is the nominate leucogaster subspecies which is the same subspecies that we saw around St Helena & Ascension Island
Brown Booby
Cape Verde Shearwaters were the commonest species seen during the day. I estimated I saw around 2500 during the afternoon.
Cape Verde Shearwater: We disturbed large rafts of Cape Verde Shearwaters sitting on the sea
Cape Verde Shearwater: Another large raft
Cape Verde Shearwater: I like the way Shearwaters follow each other in a line. There must be an aerodynamic benefit
Cape Verde Shearwater: I really like this photo
Cape Verde Shearwater
We had seen a few Bulwer's Petrels on the final day approaching Cape Verde, so it was already on my Western Palearctic list. Although, I saw around thirty during the afternoon, I only photographed one individual. I was clearly concentrating on finding new Seabirds.
Bulwer's Petrel: This was to become one of the regular species until we left Madeira
I also saw at least thirty Boyd's Little Shearwaters & this was the only day I saw them. Due to the inconsistencies of taxonomy, this was a World Tick, but not a Western Palearctic Tick. Little Shearwaters taxonomy has changed significantly over recent years. Originally, Little Shearwaters were regarded as a widespread species with populations breeding around the remote offshore islands of Australia & New Zealand, as well as, Tristan da Cunha & Gough Island. Additionally, there was a North Atlantic population that bred on Cape Verde, the Azores, Desertas, Salvage Islands & the Canary Islands. Studies showed that the Atlantic populations renamed Macronesian Little Shearwater were a separate species, from the Little Shearwater that we saw on the approach to South Georgia & Gough Island. More recently, Clements & the IOC have split Macronesian Little Shearwater into Boyd's Little Shearwater & Baroli's Little Shearwater, with Boyd's Little Shearwater breeding on Cape Verde & Baroli's Little Shearwater on the Azores, Desertas, Salvage Islands & the Canary Islands. As always in Birding there are a number of different authorities all vying to define the boundaries on the Western Palearctic & their version of taxonomy. I follow the boundaries as laid down in the Handbook of Western Palearctic that were agreed about the time I started getting serious with my Birding in the late 1970s. The AERC checklist that follows those boundaries, is based upon a common position from the different countries rarities committees that make up the Western Palearctic (effectively the AERC provides an EU or UN equivalent for rarities committees). However, there are some taxonomy differences between the AERC taxonomy & Clements/IOC taxonomy. Currently, the AERC checklist only recognises Macronesian Little Shearwater. Hopefully, they will come in line with Clements & the IOC taxonomies in time & I will get an armchair Tick. Still it's the best Western Palearctic checklist. It is much better than following a self-appointed individual like Shirihai who uses a different set of boundaries to generate a larger Western Palearctic total. In my opinion, is designed to help him sell his books. I don't have a lot of time for mavericks who think they know better than the agreed consensus in Birding. One of my mates tried to support Shirihai's boundaries in a discussion down the pub a few years ago. He argued 'it is good as it adds lots of vagrants onto the alternative Western Palearctic checklist'. Adding vagrants isn't a valid argument. Anyway, back to Boyd's Little Shearwater.
Boyd's Little Shearwater: They are a small Shearwater compared to a Manx Shearwater & similar in size & shape to the Little Shearwaters we had seen in the South Atlantic on the Odyssey & the couple of Baroli's Little Shearwaters that I saw (but didn't photograph) off Madeira on 5 May. The dark markings around the elbow on the underwing is more extensive on a Boyd's Little Shearwater, compared to the whiter elbow on a Baroli's Little Shearwater
Boyd's Little Shearwater: The fluttering flight & stiffer wings were similar to the two other species of Little Shearwaters. The hand is dark on the underwing (like a Manx Shearwater), whereas the white extends further into the centre of the hand on a Baroli's Little Shearwater
Boyd's Little Shearwater: They have a white eye ring and white extending onto the ear coverts
Boyd's Little Shearwater: They have longer, darker undertail coverts than either Baroli's Little Shearwater or Manx Shearwater. Unfortunately, I don't have any photos to show this feature
Boyd's Little Shearwater: Overall, they are darker than the Little Shearwaters that we saw in the South Atlantic which were more of a blue-grey colouration
One of the key species I was looking for during the afternoon was Cape Verde Storm-petrel. As previous discussed for Band-rumped Storm-petrel posts from St Helena & Ascension Island, the taxonomy of the Band-rumped Storm-petrel complex in the central Atlantic is complicated. The latest understanding appears that there is one species of the Band-rumped Storm-petrel complex breeding on Cape Verde between Oct to June & that is Cape Verde Storm-petrel. I saw about thirty Cape Verde Storm-petrels during the afternoon, but failed to get more than a handful of half presentable photos.
Cape Verde Storm-petrel: All photos are of the same individual. Note the broad & clean white rump & slightly forked tail. Leach's Storm-petrel would be longer & narrower-winged with a more curved white rump & likely to have a dark line through the centre of the rump (parallel to the body). The dark line is variable in how obvious it is. Leach's Storm-petrel also have a much deeper forked tail
Cape Verde Storm-petrel: The white continues down the sides of the rump much further on Cape Verde Storm-petrels than on Leach's Storm-petrels. This is a consistent feature with the other Band-rumped Storm-petrels we had seen around St Helena & Ascension Island
Cape Verde Storm-petrel: The tail hardly looks forked in this photo
Cape Verde Storm-petrel: The flight action of the Cape Verde Storm-petrels was similar to the Band-rumped Storm-petrels we saw earlier & later on the Plancius. The flight action of the Cape Verde Storm-petrels was steadier, whereas the Leach's Storm-petrels were always more erratic & constantly changing direction. To me, the flight action of Leach's Storm-petrels is how a Storm-petrel would fly if drunk
Cape Verde Storm-petrel: Again, there is a prominent underwing band & the tail doesn't look vary forked
Cape Verde Storm-petrel: The tail appears a little deeper forked in this photo, but the rump patch still looks like a Cape Verde Storm-petrel. Photos of the Band-rumped Storm-petrels at St Helena, showed that the depth of the rump could vary between photos on the same individual. Separating a Cape Verde Storm-petrel from one of the other Band-rumped Storm-petrel complex is best done by seeing them around the breeding islands
I also saw three White-faced Storm-petrels during the afternoon. Unfortunately, none were close. The combination of the pale grey colouration & a feeding action much close to the water surface compared to the Cape Verde Storm-petrels & Leach's Storm-petrels, made them tricky to pick up & stay on to them. I picked up at least one, by catching a glimpse of something, which I immediately lost behind a wave. Persistence finally revealed it as it re-emerged from behind a wave. They often had their long legs down, so clearly were feeding right on the water's surface. It wasn't helped by the choppy seas with lots of white caps to the waves. It was another good Western Palearctic Tick.
White-faced Storm-petrel: They are a very distinctive Storm-petrel species with their black-edged white underwing, dark undertail, white supercilium & dark grey mask around the eye
White-faced Storm-petrel: Another view of the same individual. This is the eadesorum subspecies which breeds on Cape Verde
White-faced Storm-petrel: A second more distant individual showing the long legs noticeable projecting beyond the tail
White-faced Storm-petrel: The upper side of the second individual showing the distinctive upperparts. Although, they were tricky to pick up in this choppy sea state, they were immediately identifiable
The highlight of the afternoon occurred around four. For many, this was the time of the late afternoon cake appearance in the Observation lounge. But not for me as I was on the deck chatting to Colin: another of the Wildwings punters who had stayed on from the Odyssey. Colin stopped the conversation when he said 'Get onto this'. It was several hundred metres out, but as soon as I picked it up, it was clear it was a Pterodroma, having watched several hundred Soft-plumaged Petrels in the Southern Oceans. Only one species breeds at Cape Verde: Fea's Petrel. I shouted to alert other Birders, but there were only a few around & lifted the camera. Probably a number had gone down to the Observation lounge for a drink or the afternoon talk. Frustratingly, it never came close & it was the only one I saw. There were only two others seen. Henrik, one of the new Wildwings punters, had seen one at lunchtime when he was the only person on deck. Roy & Lorraine had one off the stern the following day.
Fea's Petrel: Identification is based on location as the other two local breeding species breed around Madeira & the Desertas Islands
Fea's Petrel
I hadn't had the best of views of all the new Seabirds, but at least I had seen all the target species & I had got some record photos at least. Many of the passengers had missed one or both of the White-faced Storm-petrels & Fea's Petrels. So, I felt I had done fairly well by the end of the afternoon on the Bird front. There was still one more highlight during the afternoon, but I will cover that in the next Post.