Dear All,
I am in the throes of submitting the first Caspian Gull in sub-saharan
Africa, from a bird I photographed in Nairobi National Park back in
2002.
Amongst our flocks of large white-headed gulls as the group is called,
we are regularly getting visits from other races and species that are
not currently recorded from East Africa.

As I am ready to send in the record to be adjudicated by the East
African Rarities Committee (EARC), because this has been such a
complex history as far as the gull awareness and taxonomy is
concerned, I started the report with a time line of the group relative
to East Africa, then thought that if I posted it on kenyabirdsnet,
with all the keen photographic birders out there, maybe it will
unearth some other interesting individuals which would be a pleasure
to see. Any large gull that it not a Lesser Black-backed Gull inland
should be considered interesting and should receive the attention of a
camera. From what I have found one of the other species is several
times more likely than a Heuglin’s, which are now rare away from the
coast.

Hopefully with the knowledge now that not all large gulls are
Heuglin’s and nominate Lesser Black-backed, interest in the group will
be revived.

INTRODUCTION TO WHITE-HEADED GULLS IN EAST AFRICA


SOME HISTORY
Large White-headed Gulls have long been known as Palearctic Visitors
to East Africa. Originally the Lesser Black-backed Larus fuscus was
recorded, shortly followed by a paler-backed bird initially identified
as Herring Gull L argentatus. Subsequently all the non-fuscus were
considered the form heuglini, which then had been given specific
status, and Heuglin’s Gull was now listed for the region and Herring
Gull removed from the list. The race of Lesser Black-backed was the
nominate fuscus and upperparts all black, heuglini was considered as
extremely variable with upperpart colours from pale grey to charcoal
and the birds were considerably larger and heavier than fuscus. But
amongst these were birds almost as pale-backed as the real Herring
Gull. These were at that time identified as Taimyr Gull L taimyrensis
but more on that later. So from very early on, pale-backed gulls were
being recorded in East Africa, and being thought as this form which
was also considered a part of Heuglin’s and not a species apart. As
such it received no attention or was not considered of interest.
Then came another “revelation” which was followed in East Africa, and
that was that Heuglin’s was not even a race of Herring Gull, nor a
species apart but relegated to a race of Lesser Black-backed Gull
where it currently languishes in the regional treatment.
After this final devaluation complete interest was lost in our
visiting gulls, no matter what mantle colour they showed. Before the
absorption of Heuglin’s Gull into Lesser Black-backed, any bird not
that species was just a part of the variation in Heuglin’s, and after
the lumping… all the large white-headed gulls were just widespread
races of the same species, nominate Larus fuscus fuscus, L f heuglini
and L f  taimyrensis, (it should be added here that this race has not
been conclusively identified in the Middle-East or in Africa).

Around the turn of the century more interest was being taken in these
gulls in Western Europe, and a whole series of papers were being
published following some very detailed researching, and with the
Internet this material was freely available to any interested party.
Gulls suddenly became very interesting again and a whole set of new
species were launched that had only subspecific status before then.
One of the first to receive notice was Yellow-legged Gull L
michahellis. Information was now available through studies that
readily identified this form as distinct from Herring Gull (races
argentatus and argenteus). There had been a few records of adults over
the previous century, but now hundreds annually were being found in
the UK, and they have also since bred. Following on from this another
two of the Herring Gull races cachinnans and ponticus, were united
under a new species and called Caspian Gull. Whilst two races are
currently in the literature, it is likely that the two races form a
cline with L cachinnans ponticus being the western end and the
nominate in the eastern part of the range. The first time a Caspian
Gull was identified in the UK only twenty years ago, it caused a
furore of excitement amongst the British birders. So much was then
written on how to identify Caspian Gull, and with a forearmed birding
public it was found that this form that was part of the Herring Gull
tribe was in fact not merely a regular visitor, but over the very next
year lost its rarity status as it was evident that several hundreds of
birds were present in UK annually. Now there are regular spots where
the species can be multiply guaranteed in season. The same awareness
is now almost throughout southern and eastern Europe and so is the
Caspian Gull.

Sandwiched between Caspian and the far northern Heuglin’s Gull
population in the eastern European Steppe lakes is another form, the
Steppe or Baraba Gull L barabensis, this is treated either as a race
of Caspian (to the south), or Heuglin’s (to the north). Some recent
DNA research has shown an alliance with heuglini, but in Kazakhstan
the birds resemble darker-backed Caspian Gulls. So there are two
schools that disagree as to the placement of the Steppe Gull. Authors
of regional and family specific guides are not following either school
and consider Steppe Gull L barabensis a full species in its own right.

In the west another gull was elevated to specific status and that is
Armenian Gull L armenicus, which is a short distant migrant that
visits Israel in large numbers, but is scarce in the rest of the
Middle-East and has not been found to enter the southern Red Sea.
Because of this it is unlikely to reach our region except under
extreme vagrancy (which gulls are very good at)!

The eastern European/western Asian breeding gulls head towards the
Middle East from either to the N or NE. But in Eastern Asia a whole
different line of Gulls has been spawned from Herring Gull. These
include Mongolian Gull L mongolicus, land-locked as a breeding species
on the Mongolian Steppes, Vega Gull, L vegae, breeding in the very
high latitudes in the east, and connecting Vega to Heuglin’s is the
before mentioned Taimyr Gull. All of these forms fly south-east to
winter from western India east to Korea, China and Japan. None have
appeared in Israel, Middle East or North Africa. To the best of my
knowledge, none have ever reached the equatorial zone in their own
longitudes, so the likelihood of any of these west Pacific birds
appearing on our side of the Indian Ocean, and also to continue to the
equator is exponentially unlikely.

The most heavily watched area for gulls in the greater African region
is Israel, there are some gull fanatics who spend all their birding
hours trying to learn more and more about them. Another gull hot spot
as far as study goes is the Middle-East, there are so many birding
expats that are very (if not obsessively) keen and have the latest
information available of the ID of the forms, and also contribute much
to the pooled knowledge. Then there are the people that devote their
time to gull research so there is so much information available now,
equalling if not surpassing any other bird group. In all the research
that has taken place, with daily observations especially during the
migration and wintering periods, as yet no Taimyr Gull has been proven
to wander into the region, which brings us back to the Taimyr Gull
records in East Africa, how unlikely now do these records seem, and it
was even considered regular but is it visiting us at all?

So the likelihood of our pale-backed gulls being something else other
than members of the Lesser Black-backed grouping, has also increased
exponentially!

There is one last irony, in that researchers have studied the Lesser
Black-backed Gulls that almost exclusively winter on the seaboard and
large inland lakes in our region. This is the nominate L fuscus
fuscus. They have found that the race apart from having solid black
upperparts with no grey tones, and the very long wings that would be
expected for such a long-distance migrant, have very different moult
timings and sequences from the two other races of the species graellsi
and intermedius. Some authors, and regional field-guides now treat
graellsi and intermedius as Lesser Black-backed Gull, and the previous
nominate fuscus as a novel species Baltic Gull. This means we have
gone from having everything lumped as Lesser Black-backed Gull to
having no Lesser Black-backed Gulls at all!


WHITE-HEADED GULLS IN EAST AFRICA.
Having established that the pale-backed gulls that visit us are likely
not taimyrensis, this leaves us with a “what are they then?” To answer
this we have to remove ourselves from the “Gull Dark Ages,” and enter
the “Brave New World” of gull identification.

I have during the course of a few years gathered together images of
pale-backed gulls from East Africa, and have for a very long time not
trusted the acceptance that all of them are Lesser Black-backs or even
Heuglin’s. Other gulls are coming here and regularly in small numbers;
they just are not getting identified because we have been blinkered
with erroneous belief. But in all fairness nothing like this was
suspected in early days.

Best for now
Brian