Intermediate forms of Hairy-breasted Barbet Tricholaema hirsuta in the Lesio-Louna Reserve, Congo-Brazzaville

2008·1.5 MB·

by  Tony King

Intermediate forms of Hairy-breasted Barbet Tricholaema
hirsuta in the Lesio-Louna Reserve, Congo-Brazzaville
TonyKing
Formes intermediaires du Barbican herisse Tricholaema hirsuta dans la Reserve de Lesio-
Louna, Congo-Brazzaville. Des photos sont presentees d’un couple de Barbicans herisses
Tricholaemahirsutadans laReserve de Lesio-Louna, Congo-Brazzaville. Chezlepremieroiseaula
moustache estlarge et distincte, tandis quele sourcil ne comprend que quatre petits traits blancs.
Chezledeuxieme, lesourcil estbeaucoup plus net, bienqu’il ne consisteegalementquedequatre
traits, tandis que la moustache se limite a une grande tache au-dessous des parotiques, ne
s’etendant par vers le bee. Les deux oiseaux sont densement tachetes de jaune sur le front, la
nuque et le dos. Les parties superieures du premier individu apparaissent plutot brunes,
contrastant peu avec les parties inferieures, tandis que le second est plus noir au-dessus et plus
jaune en dessous. Les deux oiseaux ont la gorge blanchatre mouchetee de noir. Les oiseaux
presentent ainsi des caracteristiques intermediaires entre la sous-espece ansorgii et les formes
flavipunctata ou angolensis.
T
heaimofthis noteis to discuss thesubspecif- significantly reduced. In one of the pair (Figs.
icidentityofapairofHairy-breasted Barbets 2-3), the moustachial stripe was rather broad and
Tricholaema hirsuta present in the Lesio-Louna distinct, whilst the supercilium comprised just
Reserve, 140 km north of Brazzaville, on the four small white streaks. In the other (Figs. 4-5),
Bateke Plateau of Congo-Brazzaville (03°16’S thesuperciliumwas much moredistinct, although
13°29’E). Between2 and3 December2005 oneof still broken into four streaks, whilst the mous-
the pair was observed excavating a hole within a tachial stripe was non-existent anteriorly, but is
branch ofa dead tree, in anarrowstrip ofdegrad- apparent as a large spot below the ear-coverts.
ed forest inwooded grassland between two gallery Bothbirds possessedstrongyellowspottingon the
forest patches. On 13, 15 and 28 December, one napeandback(Figs. 2and5), andontheforehead
ofthe pairwas observedwith its bill and forehead (Figs. 3 and 4), a feature characteristic of
emerging from the hole. On the next visit, on 28 flavipunctata and angolensis rather than ansorgii.
January2006, nonewasseen, butanotherindivid- The upperparts ofone bird appearedfairlybrown,
ual was observed singing 600 m north ofthis site offering rather little contrast with the underparts
on 15 February 2007, and its song was subse- (Figs. 2-3), in this being suggestive ofangolensis,
quentlyheard in the same area until at leastApril. whilstthe otherindividual appearedblackerabove
The racial identity ofthese birds is not obvi- and yellower below (Figs. 4-5), thereby agreeing
ous. T. hirsuta is the most morphologically more closely withflavipunctata or ansorgii. Both
variable of all Afrotropical barbets and, conse- hadawhitish throatmottledblack (Fig. 4), typical
quently, has caused much confusion amongst ofall three races.
taxonomists. Four subspecies are generally recog- The single bird observed at some distance in
nised: hirsuta in the west, ansorgii in the east, 2007 appeared to have an overall blackhead, with
angolensis in the south-west, andflavipunctata in only the suggestion ofa white supercilium, some
the north-centre of the species’ range (Short & yellow speckling on the nape, a motded whitish
Horne 1988, 2001, 2002, Fishpool 2005; see Fig. throat, a blackish-brown back and yellowish
1). Intergradation between the subspecies is well underparts. Again, these characters suggest an
known (Short & Horne 1988, 2001, 2002), and intermediate form.
photographs of an intermediate hirsuta / It seems probable that the grassland-
flavipunctatawere published in Fishpool (2005). dominated Bateke Plateau separates the two
Ofthe pair observed in 2005, both birds had subspecies generally regarded as occurring in
black head-sides and white facial stripes, charac- Congo-Brazzaville, namely ansorgii to the north
teristic ofansorgii although the facial stripes were andangolensisto thesouth-west. However,westof
,
IntermediateformsofHairy-breastedBarbet:King BullABCVol15No2(2008)-245
the Bateke Plateaulie theforests ofcentral Gabon,
where the transition occurs fromflavipunctata in
the north to angolensis in the south (see Fig. 1).
Rand et al. (1959) believed this transition to be
abrupt, and to be located at c.02°S. It is conceiv-
able thatflavipunctata extends from the forests of
central Gabon, south-east through the gallery
forests ofthe Bateke Plateau. I tentatively suggest
that the Lesio-Louna birds reported here are prin-
cipally ofansorgii /flavipunctata origin, although
the possible influence of angolensis cannot be
discounted.
Whilst most recent texts claim yellowspotting
&
on the forehead to be absent (Short Horne
2002, Fishpool 2005), or only occasional (Short
&
Horne 1988), in T. h. ansorgii examination of
,
69 specimens ofthis taxon at the Royal Museum
for Central Africa atTervuren, from three regions
246-BullABCVol15No2(2008) IntermediateformsofHairy-breastedBarbet:King
of Congo-Kinshasa, revealed that 15 (22%) had Acknowledgements
yellowspotsontheforehead.Thereappearedtobe I thank the Ministere de l’Economie Forestiere et de
regional differences, with 45% (five of 11) from l’Environnement ofthe Republic ofCongo, and The
the Ubangi region exhibiting yellow spots on the Aspinall Foundation ofUK, for their continued com-
forehead, 29% (5 of 17) from the Kunungu mitment to the joint management project for the
region, andonly 12% (5 of41) from theEquateur Lesio-Louna Reserve; Michel Louette and the staffof
region. Two (3%) ofthe 69 specimens examined the Royal Museum for Central Africa at Tervuren,
appeared to have slightly reduced facial stripes. Belgium, foraccesstotheirspecimencollection; Robert
Again, cases ofpartial or reduced facial stripes are Prys-JonesandthestaffoftheNaturalHistoryMuseu&m
not generally discussed in recent texts. (Tring) forprovidingaccess to theirlibrary; Richard
Phyllis King for their help with literature; Franchise
Interestingly, whilst the intermediate bird pho-
Dowsett-Lemaire, Robert Dowsett and Hugo Rainey
tographed in Fishpool (2005) possessed a
for providing useful background information and
conspicuous white supercilium, on closer inspec- advice; and Lincoln Fishpool and Ron Demeyfor con-
tion this appears to comprise fourseparate streaks, structive comments on the manuscript.
rather than asingle continuous one, in asimilar if
less obvious pattern to the two Lesio-Louna birds References
illustrated here. Fishpool, L. D. C. 2005. An intermediate form of
Hairy-breasted Barbet Tricholaema hirsuta. Bull.
Captions to figureandphotos onoppositepage ABC12: 172-173.
Rand, A. L., Friedman, H. & Traylor, M. A. 1959.
Figure 1.Approximatedistributionsofthefourraces of Birds from Gabon and Moyen Congo. Fieldiana
Hairy-breastedBarbet Tricholaemahirsuta,withthe
ZoolA1:221-411.
ABiarteeskedePldaitsetaruibruetgiiononapdeplrionxeiamtaetdiviensredde.squatresous- Short, L. L. & Horne, J. F. M. 19&88. Family
ePslpaetceeasuddeusBBaartbeikceandehleirmiistseeeTnrircohuoglea.emahirsuta, avecle CK.api(etdosn.i)daTeh.eIBnirFdrsy,ofCA.frHi.c,a.KeViolt.h,3.S.LondUornb,anU,KE:.
FTirgiucrheosla2e-m3a.hiOrnsuetao,fLaespaiior-LoofuHnaairRye-sberrevea,stCeodnBgaor-bet ShorAt,caLd.eLm.ic&PrHeossr.ne, J. F. M. 2001. Toucans, Barhets
Brazzaville, December2005 (TonyKing) andHoneyguides. Oxford: Oxford UniversityPress.
Un membred’uncouplede Barbicansherisses Short, L. L. & Horne, J. F. M. 2002. Famil&y
Tricholaemahirsuta. Reservede Lesio-Louna, Congo- Capitonidae(barbets).IndelHoyo,J.,Elliott,A.
Brazzaville, decembre2005 (TonyKing) Sargatal,J. (eds.) HandbookoftheBirdsoftheWorld.
Figures4-5.ThesecondofapairofHairy-breasted Vol. 7. Barcelona: LynxEdicions.
Barbet Tricholaemahirsuta, excavatingaholeinadead The Aspinall Foundation, BP 13977, Brazzaville,
tree, Lesio-LounaReserve, Congo-Brazzaville, December RepublicofCongo. E-mail:[email protected]
2005 (TonyKing)
L’autremembred’uncoupledeBarbicans herisses Received 23 November 2006; revision accepted 4
Tricholaemahirsuta, creusantun troudans un arbre February2008.
mort, ReservedeLesio-Louna, Congo-Brazzaville,
decembre2005 (TonyKing)
IntermediateformsofHairy-breastedBarbet:King BullABCVol15No2(2008)-247