Wednesday, 22 January 2014

Doing the splits!

We spent our Christmas and New Year holiday period thousands of miles apart.  While June divided her time between the UK and Portugal, Peter was in Florida leading a tour for Avian Adventures.  It isn’t what we planned and it certainly wasn’t what we wanted but circumstances conspired against us and that’s what happened.

The tour in Florida was enjoyable enough although the self-styled “Sunshine State” fell some way short of living up to its name.  As with the Algarve, winter birding in Florida gives the opportunity to see lots of interesting resident birds as well as a great many that are from further north and only there to escape the cold.

For many birders, however, particularly Americans, the reason to visit Florida is that there are quite a few exotic species that are now sufficiently established there as permanent residents that they are now deemed ‘countable’ by the American Birding Association.  What that means is that if your motivation is to make a list of the birds that you have seen in the USA, species such as Red-whiskered Bulbul, Spot-breasted Oriole, White-winged Parakeet and Nanday Parakeet will at some point have to be targeted and Florida is the only corner of the country where they can be found.  There are currently about a dozen such species and several more amongst the many other non-native breeding birds are potential additions to the official American Ornithologists’ Union (AOU) Check-List.

Our tour in Florida was most definitely not about searching for exotic species!  However we did want to see Snail Kite and Limpkin that are at the northern edge of their natural range in Florida and not normally found elsewhere in the USA.  Others such as Painted Bunting, Roseate Spoonbill, Crested Caracara and Wood Stork, which all of us had previously seen in Texas, would also be good to find.  And it wasn’t just birds!  West Indian Manatee, a huge herbiverous, marine mammal, was also on everyone’s ‘wish list’.  In the event, all of these targets were seen without much difficulty.

Although we didn’t at any time find ourselves agonising over what was and wasn’t countable, there were a few questions raised, not about ‘exotics’ but about the differences in the way that the various ornithological authorities treat taxa such as Wilson’s Snipe, Common Gallinule, Cabot’s Tern, American Herring Gull and Hudsonian Whimbrel.

Wilson’s Snipe (Gallinago delicata) is regarded as a species separate from Common Snipe (Gallinago gallinago) by the AOU, by the British Ornithologists’ Union (BOU) and by the International Ornithological Committee (IOC) but it is not recognised as such by BirdLife International (BLI).

Cabot’s Tern (Sterna acuflavida) and American Herring Gull (Larus smithsonianus) are treated as separate species by the BOU and the IOC but not by AOU and BLI which list them as subspecies of Sterna sandvicensis and Larus argentatus respectively.

The BOU haven’t so far had to worry too much about Common Gallinule as none have yet made it to Britain.  It’s a bird that looks very much like a Common Moorhen but, mostly it seems because it sounds very different from Gallinula chloropus, the AOU are now, since 2011, calling it Gallinula galeata, a distinct species.  So far, the ever-conservative BLI are not going along with this.

At the moment it seems that only the BOU are persuaded that the Whimbrel that occurs in the Americas should be called Hudsonian Whimbrel (Numenius hudsonicus) and recognised as a species separate from Numenius phaeopus.

It’s all very confusing!  When the so-called ‘experts’ can’t agree, what chance is there for the likes of us?
Of course, there are other pairs that may or may not be separate species.  One thinks of the two Black Terns and Hen and Northern Harriers, for example.

What we do know for sure is that we ourselves were definitely split up over the holidays and we didn’t much like it!  As for all these species splits, you’ll just have to make up your own mind whether you like them.

Incidentally, can you see which of our photographs is the odd one out in that it doesn’t feature the American half of a split? 

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