Dear All,
Here is the latest bit of excitement, and it's always nicer to find an
interesting breeding bird than a vagrant, and this one doesn't even
require leaving the Lamu airstrip on Manda Island! It was also good to
finally get rid of the myth that there are all black glossy East Coast
Boubous (formerly Tropical Boubou) on the Kenya coast, which has
intrigued me for some time. This is the report as being sent to the
rarities committee. I am working on the rest of Nigel Hunters and my
coastal sortie, and there are some other interesting observations, but
of course nothing quite like this one. It also makes what was probably
one of the most dangerous endemics to search for in Somalia, being as
it is confined south of Mogadishu, now so easily accessible without
the worry of personal safety…………..

I had always been intrigued by the mention in the literature of East
Coast Boubou Laniarius (aethiopicus) sublacteus having a curious black
morph living with the typical black and white birds. I had questioned
a number of observant ornithologists, and none to testify as to ever
having seen a black Boubou on the coast. Throughout the extensive
range of sublacteus the bird is otherwise non-varying, black above
with no white on the wings, and all white below. Why should a
Laniarius suddenly throw a melanistic morph into the mix when it does
not happen anywhere else in the genus in Kenya. It was time to find
out the real story behind this, and BWF suspected that the bird might
be the southern Somali endemic L. erlangeri.
Opportunity had arisen to visit the coast for a few days, and I asked
Nigel Hunter if he might be interested in getting to know the Kenyan
coastal Boubous, and tracking down this mysterious "so-called" black
morph of sublacteus. He was as eager as I, and we started to read the
literature to find out where they had occurred.  I wrote to Colin
Jackson and asked him if he knew of the whereabouts, and he wrote back
to say that he had not heard of any sightings, and in fact had not
heard about the black Boubous. Through the literature it appeared that
the claims originated from Manda Island in the Lamu chain, in fact the
island that has Lamu Airport probably one of the most popular tourist
destinations on the entire Kenyan Coastline. We had invited Colin to
come with us, but he had an obligation in Naivasha for the same
period, however as he passed through Nairobi, he called in at the
Museum and on checking the tray of Tropical Boubou specimens, found no
less than seven black Boubous, six were collected at Manda Island, and
one from southern Somalia. This was great confirmation, and was a good
indication as to where the myth of melanistic Boubous had originated
from.
Armed with this information we set off by road for Manda Island, first
landing on Lamu where we found some excellent contacts for a visit to
Manda Island the next day. We took a speed-boat, and within two
minutes of leaving the bustling wharf of Lamu, were setting foot on
Manda Island.
The incredibly dense low forest/bush was full of birds, and we could
hear sublacteus calling all around us, and called in identical
black/white pairs with playback. Walking along the airfield perimeter
fence, Nigel was the first to spot the first black Boubou moving
through mid-levels but we unfortunately lost it, and playing
sublacteus only succeeded in bringing in more aroused sublacteus. We
birded along the road that takes off from the end of the airstrip, and
after a hundred metres turned right onto a broad track cut through the
forest. A deep throaty call was heard and recorded. The sound was
completely unfamiliar, and on playback an all black Boubou climbed to
the top of a bare tree, and after several minutes of hopping around in
the open, answered the playback call with a completely different and
novel ringing call. On recording this call and playing back to the
bird, it became far more aggressive and flew to the top of another
live acacia and called from the unconcealed perch. Three very
different calls were recorded, all alien to us, and none of them
remotely like anything produced by the familiar sublacteus which were
constantly all around us. Frequently after a bout of calling from a
tree-top it would parachute with slow rowing wingbeats and fully
spread tail to land either in the scrub or another high perch. As well
as recording the vocalisations, BWF both videoed and photographed the
bird.
We continued walking along the road for another two kilometres, and
whilst sublacteus was very common in identical pairs, we only heard a
few of the now familiar calls of the black Boubou some distance away.
On returning a couple of hours later, we went to the territory of the
previously obliging bird and played the call, with the male bird
coming in aggressively and challenging us from the protruding tops of
the trees, and engaging in the parachute display. Whilst the male
called the identical black female would complete the duet with a
throaty churr after every call. More recordings were made and we
returned to the first place where the initial black Boubou had been
seen, and played back the recordings of the cooperative pair.
Instantaneously this pair flew in with the male climbing to the top of
the tree and swearing at us, until attacked by a Bare-eyed Thrush. At
10:30am having first seen the bird at 6:30am we felt that to endure
the heat longer, was unecessary as we had accumulated so much data on
the birds.

DESCRIPTION

A small Boubou, quite smaller when seen perched with African Drongo
Dicrurus adsimilis, and when attacked by the Bare-eyed Thrush  Turdus
tephronotus. Maybe as much as a couple of centimetres shorter than
sympatric East Coast Boubou Laniarius sublacteus.  The only known dark
Boubou species in Kenya is the Slate-coloured Boubou L. funebris, and
compared to this bird the tail was longer and the entire bird appeared
slimmer.
Overall a glossy black bird.
HEAD:
All black and shiny with reflections of blue and green. The black of
the head continued over most of the underparts. The eye was a dull
red, and the hooked bill all grey-black and quite deep.
UNDERPARTS:
Entirely black, in direct bright sunlight sometimes giving a greenish
or at times even a violet wash, and becoming greyer on the vent.
UPPERPARTS:
Upper-back glossy black, remainder of upperparts less shiny black.
Tail entirely black, fairly long, and very broad when fanned.
Wings all black, slightly darker than back. Underwing coverts all
black contrasting in flight with translucency of greyer undersides to
the flight feathers.
LEGS and FEET:
Grey and strong.

HABITS

A bird of mid-levels, spending its time in the canopy, especially when
calling or investigating an intruder. An extravert bird readily
perching for long periods on exposed tops of trees. The tail is
frequently flicked, and carried slightly cocked. Closed it shows as a
narrow tail with a notch, but when calling it raises and slightly
flares it. The female is far less obtrusive, calling from concealed or
less conspicuous perches than the male, though joins him when foraging
through the tops of bushes. Male indulges in a parachute display, with
deep rowing wing-beats making slow progress, tail fully fanned, and
back feathers raised.

CALLS

Four different call were recorded, three of these ringing and loud
with an almost "gonolek" quality to them.

1.    A repeated loud "wee-ooo" given from exposed perch at a rate of
slightly more than one per second.
2.    A loud double "weeerk-weeerk" also from exposed perch, the call
lasting not much more than a second, and the spaces in between sets
slightly more than this.
3.    A throaty four-note set "jhi-jhi-jhi-jhi" lasting a little more
than a second with a second or so pause between each set.
4.    The female answering the male as part of the duet, with a throaty
soft churr starting almost the same time as the males "wee-ooo" single
call, and lasting fractionally longer.

HABITAT

The habitat of Manda Island is quite extraordinary, the floor has much
reddish sandy cover but with some coral rag on the surface. The bushes
only grow to a couple of metres, but are impenetrable where
undisturbed. Only the very occasional tree reaches beyond three
metres. There is much scattered Acacia species and Dichrostachys,
amongst the unidentified broader leaved non-legumes. We are given to
understand that this growth is over much of the island although we
only covered some two kilometres from the airfield.

DISCUSSION

Erlanger's Boubou has been considered a southern Somali endemic,
confined to two rivers where it has been found in gallery forest. On
the Jubba river it is said to occur in two morphs, one black and the
other black-and-white, whilst on the Shabeelle river that runs
parallel with the coast, only the all black bird is found. Because of
its location in a region long torn by civil unrest, there is little
information available on the species. East Coast Boubou (sublacteus)
occurs along the Kenyan coast from the Somali border to south of Dar
es Salaam, it penetrates inland in both Tanzania and Kenya. In Somalia
it only occurs south of the erlangeri populations in the Boni Forest
in the extreme south of the country. The two species have not been
found to occur sympatrically until now.
The perpetuation of mis-information comes to the fore in the history
of the black morph of Tropical Boubou on the Kenya coast. Firstly
collected on Manda alongside sublacteus,  then forever treated as a
black morph of it. It is mentioned in Mackworth-Praed and Grant as
"There is a wholly black colour phase on the coast of Kenya Colony and
Manda Island."
This is followed in Zimmermann & Turner as "… and lacking in
sublacteus which has an all-black coastal morph."
Stevenson & Fanshawe follow suit again without any investigation of
their own with ".. and there is also a glossy all black morph," under
treatment of sublacteus.
The Handbook of the Birds of Africa mentions it as "An entirely black
morph occurs," treatment under Laniarius aethiopicus sublacteus, when
Tropical Boubou encompassed all. Also under "Field Characters" …. "An
all black morph occurs in Somalia and coastal Kenya and Tanzania."
Britton doesn't even mention it as it has no racial identity, having
been shut away in a drawer and left as Tropical Boubou!
And finally  Sinclair & Ryan in "Birds of Africa," under Tropical
Boubou state "… also occurs in all-black morph which is glossy black
(not dark slate-grey, like Slate-coloured Boubou."
I can only imagine that the original collectors on Manda were native,
and merely brought in the specimens with no details of what the birds
said, did or any other vital piece of information. Then as it seemed
unlikely that two species of Boubous would inhabit an offshore island,
concluded without any investigation whatsoever in a most unscientific
manner, to treat them as a melanistic morph of sublacteus.
Not only are these erlangeri distinctively coloured, much glossier and
smaller than sublacteus,  they (like sublacteus) remain in like pairs,
inhabit a different strata, are extravert as opposed to the skulking
intravert sublacteus, have an entirely different set of vocalisations,
have an aerial open  parachuting display, etc. In short not only are
they a different species, but belong in a completely different
grouping within Laniarius. The calls are ringing but not bell-like
suggesting Gonoleks and naturally we experimented with playback, and
known recordings of sublacteus taken in situ, only succeeded in
bringing in other sublacteus, whilst erlangeri showed no interest, and
likewise playback of known erlangeri taken in situ impressively
attracted others of its kind whilst sublacteus showed no interest
whatsoever. The parachute display reminded BWF of the display flight
of Sooty Boubou L. leucorhychus, the churring of the female in duet
and the males penchant for finding high perches (when available) from
which to call is reminiscent of Red-naped Bush-Shrike L. ruficeps,
but nothing is reminiscent of anything to do with the Tropical Boubou
group.
Recently Nguembock, Fjeldså, Couloux and Pasquet published a thorough
revision of the genus Laniarius as "Phylogeny of Laniarius: Molecular
data reveal L. liberatus synonymous with L. erlangeri and ``plumage
coloration" as unreliable morphological characters for defining
species and species groups."
Their work revised the Tropical Boubou complex, breaking the birds in
Kenya into Great Boubou L. major  of the Kenyan uplands and west of
the Rift Valley, East Coast Boubou L. sublacteus on the entire Kenyan
coastline extending inland as far as Garissa, Taita and Makindu, and
along our north north-eastern border the Ethiopian Boubou L.
aethiopicus. In the old treatment of Tropical Boubou there was a
fourth member to the group, and this was erlangeri. Their DNA studies
on Somali specimens from two populations, show that the bird has
nothing whatsoever to do with the Tropical Boubou clade, and is more
closely allied to ruficeps. Whilst treating the Tropical Boubou
complex, they like everyone else state that "within sublacteus,
occasional birds along the Kenya coast are black morphs," but extend
the range to incorporate the Tana delta, and whilst claiming to have
taken DNA material from every race of every Laniarius, they completely
ignored the black Boubou of the Kenya coast stating; "L. a. sublacteus
also has a black morph in the area around the mouth of the Tana River
in Kenya (Stresemann, 1947)." It would be in their interest for
completeness of their study, to get some DNA material from the six
specimens collected on Manda Island that are in the Nairobi Museum.
We have no doubt that the birds of Manda Island living sypatrically
with sublacteus,  represent a Kenyan resident population of what was
thought of as a Somali endemic, Erlanger's Boubou Laniarius erlangeri.
The presence of the bird actually in scrub along the airstrip for Lamu
just goes to show that highly visited locations are not without their
surprises.

Best to all,
Brian