Saturday, 28 April 2012

A day of two controversial sightings!

It's 2.30 am again, so it must be Friday! This week it is Oscar & myself who are hammering it over to Fujairah National Dairy Farm. We arrive and start to rack up the migrants. First we work the road & see Masked; Woodchat, Turkestan and Lesser Grey Shrike.

Lesser Grey Shrike

A female White-throated Robin & 2 Rufous Bush Robins, skulked in cover and 16 Pale Rockfinch fed out in the open. The Goat Farm produced at least 130 Eurasian Turtle Doves and a host of migrants including 3 Whinchat; 4 Northern Wheatear; 32 Isabelline Wheatear, around 45 Turkestan Shrike; a Grasshopper Warbler and 2 Ortolan Buntings. Four Masked Shrikes was a particulary fine total.

Part of a flock of Eurasian Turtle Doves

Both Purple Heron and Little Bittern were in the long grass and a couple of Pallid Harriers cruised around, with at least 16 Lesser Kestrels overhead. Huw was around, trying to photograph more or less everything!

Huw getting ready for action!

Then a buteo flew over. For me, it was clearly a Steppe Buzzard, but others did not agree with the identification.

Steppe Buzzard

Look at the underwing & underbody patterning.
 Also look carefully at the tail.

A buteo like this can only be one of two things: either a Steppe Buzzard or a Long legged Buzzard. Steppe Buzzard, is an eastern race of the Common Buzzard complex. It is slightly smaller than the nominate race, with a rufous tail. Records of Long legged Buzzard in the UAE, fall into two groups:
the rufinus race which is widespread to the north of us and the cirtensis race of north Africa and parts of Arabia. This latter race is rare in the Middle East and is thought to be resident and only undertaking local movements. There are at least two pairs breeding the the southern UAE, but they are declining, with increased development of the virgin desert. The nominate race is widespread and some more northern populations move south to avoid the harsh winters and pass through the UAE, although they are uncommon.
Now, why did I identify this bird as a Steppe Buzzard instantly? It is all to do with the structure of the bird: Steppe Buzzard is a compact buteo, it is smaller than the nominate Common Buzzard. It has a samll head, with a short neck and crucially, the wings are not long for the size of the bird. The tail is of medium length. On the othe hand, Long legged Buzzard is a large bird. It may be confused with the smaller eagles. At no time could this bird be confused with an eagle! The nominate race, rufinus, is a brute of a bird (the females, in particular being huge). The have very long wings, so long infact that the front & hind wing edges appear parallel to each other. They soar on eagle-like bowed wings and broad splayed fingers. The tail is also quite long. This is a large bird, much larger and bulkier than a Common Buzzard. Now the situation here is complicated by the smaller race of Longlegged Buzzard, cirtensis. This race is smaller than the nomiate race, but is still a large bird, in compaison with Common Buzzard. And it still has the same proportions ie long wings and reasonably long tail. The size of cirtensis and Common Buzzard can overlap, because of differences in the size of the sexes. But Common Buzzard has never been recorded in the UAE. Steppe Buzzard is a smaller bird again than Common Buzzard. On this individual, the size could be gauged against nearby Lesser Kestrels. We are talking of a size difference of ten percent here, between cirtensis race of Long legged Buzzard and Steppe Buzzard. To conclude,structural differences between the species are: Long legged Buzzards are long winged and quite long tailed, they have parallel looking wing shape with very splayed primaries. The head is quite large, with a noticeable neck. Even in the smaller race the proportions do not change, cirtensis still looks a large bird. On a side note, I have never seen this race way from the deep desert. All Long legged Buzzards I have seen at migration sites have been of the nominate rufinus race. (The exception to this are birds within the city of Abu Dhabi which are escapes from captivity - you can walk up to some of them)!
Regarding plumages: these are variable and complex in both species. However, Steppe Buzzard is much less variable than the nominte Common Buzzard. Basically, there are three colour phase groupings in this race. Long legged Buzzard is also quite variable in colour, but there are plumage constants (see below). The cirtensis race is much less variable, being basically a mixture of rich rufous and cream with very contrasting black carpal spot on the underwing and very black primary tips (appearing as fingers).
If you look at the bird above, the underwing pattern is pure Steppe Buzzard. Then look at the head and underpart colouration: the head and throat are all dark. There is no cream or white headed effect and no rufous colouration so it can't be a rufous morph Long legged Buzzard. Then look at the underbody colouration. Can you see any combination of a white chest and darker belly? On nominate, the chest is very pale or bright rufous and the belly is dark sometimes black. The cirtensis race is even more strikingly rufous and cream and is much less variable. The underpart colouration seen here only fits Steppe Buzzard, there is not a race or age, or colour morph of Long legged Buzzard that this could fit. Finally, lets look at the tail colouration & patterning. Pretty bland, pale rufous with a multitude of small darker bars. Long legged of all races is much more rufous (apart from juvenile, which this bird isn't) and the rump should be much paler. In the smaller cirtensis race this feature is even more enhanced. Again the tail colouration & patterning are pure Steppe Buzzard. There are more features that I could discuss which separate these two species, but there seems little point in doing so. This bird is a second calendar year Steppe Buzzard (notice the moult in the primaries).

We then motored down to Kalba, to catch Abdullah's boat out to the great blue yonder. We had a quick stop off at Fujairah Port Beach and we  noted a Sooty Shearwater and 5 Arctic Skuas. Around 1450 Common Terns were also flying north.
The sea was calm as we left harbour and immediately we saw another Sooty Shearwater, a few Red-necked Phalaropes and a scattering of Persian Shearwaters. An Arctic Skua raced by. It was another quiet trip, with just a third Sooty Shearwater flying by. But then we saw a small skua sat on a buoy.

Sooty Gull & Long tailed Skua

Notice the general clouration of this bird.

Heavily thick barred rump; large underside wing flash.
Restricted wing flash on upper primaries.

Showing the extensve white underwing pattern very nicely.

The bird was small, with a small head & bill. The bill was quite stubby and for the size of the bird it had a deep chest. General clouration was a grey brown, with heavily barred rump. Wing pattern on upper & lower sides pure classic, Long-tailed Skua. This record is the earliest ever and the question asked must be wat is it doing here at this time of year? From our limited experience off the east coast of the UAE, it looks likely that first year birds of all three smaller skua species, just hang around in the northern Indian Ocean. Most probably don't undertake the full migrations that adults undertake each year. Certainly, when you record skuas in January/February, they are virtually all first summer birds. Several other predominantly pelagic species also do this: shortened migrations when immature, only undertaking the long migrations when adult. Common Tern is a classic example of this, with many juvenile/first winter birds hanging around the east coast beaches and only migrating relatively short distances.
Two very fine species for my year list in the bag!
2 species added (282 species total): 620 kms travelled.

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