Wednesday, November 18, 2009

EA Bee-eaters

many thanks Don
Nobby, this should be in Scopus !!
yet another example where blood samples are vital if these basic questions are ever to be answered.

Neil

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Subject: EA Bee-eaters


Dear Brian; The following may be of help in the very complex arrangement of Blue-breasted vs Cinnamon- chested Bee-eaters in East Africa, and whether our oreobates is in fact correctly named.
With very best wishes
Don Turner




Prior to Fry's major contribution on the evolution and systematics of bee-eaters (hereafter referred to as Fry 1969), it had been generally accepted by most authors including Jackson & Sclater (1938), Chapin (1939), Peters (1945), Boetticher (1951) and White (1965) that Merops oreobates (Sharpe 1892) was nothing more than a race of Merops lafresnayii Guérin-Méneville 1843.

However Grant & Mackworth-Praed (1937) had considered (on mainly morphological grounds) that lafresnayii more closely resembled Merops variegatus Vieillot than M.l.oreobates, and so proposed that lafresnayii be considered a race of variegatus, thus leaving oreobates a distinct monotypic species of the East African highlands. This position was later followed in Mackworth-Praed & Grant (1952) though clearly rejected by White (1965). More recently Fry (1984), Fry et al (1988) and Dickinson (2003) have all followed Grant & Mackworth-Praed (1937) and Fry (1969) in considering lafresnayii a race of variegatus.

Throughout the greater part of its range in West, Central and Eastern Africa variegatus is a bird of damp lowland grasslands and lakeside vegetation (Chapin 1939, Benson et al 1971, Britton 1980, Zimmerman et al 1996, Dowsett et al 2008), but the race bangweoloensis does reach 2000m in swampy areas of the Ufipa Plateau in sw Tanzania (D.Moyer & R.J.Dowsett pers.comm.). This is in direct contrast with oreobates which throughout its range is a montane species of open forest, forest edges and woodlands between 1600 and 2300m (Zimmerman et al 1996). In Ethiopia lafresnayii is largely confined to the Rift Valley and adjacent highlands, favouring a variety of forest habitats between 1200 and 3200m (Urban & Brown 1971).

Morphologically lafresnayii is intermediate between variegatus and oreobates, being closer to the former in colouration, but closer to the latter in size and choice of habitat. Vocalisations of lafresnayii are said to be identical with those of oreobates, and totally unlike variegatus (B.Finch pers. comm.). In Chappuis (2000) some calls of variegatus are either a rather hard "klup, klup" or slightly softer and more prolonged (as in the case of a pair displaying), in contrast to the calls of oreobates which are much higher pitched. Some years earlier Van Someren (1922) had commented that specimens of M.l.oreobates from the Turkwell (Gorge) area of nw Kenya were sometimes very like the Ethiopian birds, having the blue forehead and supercilium and blue neck-patch. Meanwhile recent photographs of birds in typical oreobates habitat taken at Malewa River Lodge at 2200m in the central Rift Valley of Kenya north of Lake Naivasha, and from the Kakamega Forest (alt. 1700m) in western Kenya show individuals with a prominent blue supercilium and in the case of the Malewa bird a bright violet-blue neck band.

Fry (1984) posed the question: "is the large blue-gorgeted bird in the highlands of Ethiopia (lafresnayii) conspecific with the large black-gorgeted one in the highlands further south (oreobates), or with the small blue-gorgeted one of neighbouring lowlands (variegatus). " Being clearly inclined to the latter view he felt that the two highland forms were independent derivatives of the lowland Blue-breasted Bee-eater (M.variegatus), the Ethiopian population more recently so than the East African form on account of it showing similar characters (colour of forehead, supercilium and neck band). Nevertheless Fry doubted that unanimity would ever be reached with this problem, and that further revision may be necessary in the future.

While it is likely that oreobates and lafresnayii are independently derived from variegatus, with components of variegatus appearing in both highland forms (not just lafresnayii as earlier thought by Grant & Mackworth-Praed and Fry), and with clear vocal and habitat differences between variegatus and the other two, the question that now arises is whether oreobates can be truly considered a monotypic species confined to the montane forests of Eastern Africa.


References:
Benson, C.W., Brooke, R.K., Dowsett, R.J. & Irwin, M.P.S. 1971. The Birds of Zambia. Collins.
London.
Boetticher, H. von, 1951. La systematique des Guepiers. L'Oiseau 5 (21): 194-199.
Britton, P.L. (Ed).1980. Birds of East Africa, their habitat, status & distribution. EANHS. Nairobi.
Chapin, J.P. 1939. The Birds of the Belgian Congo. Vol 2. Bull.Amer.Mus.Nat.Hist. 75: 1-632.
Chappuis, C. 2000. Oiseaux d'Afrique (African bird sounds), 2. West and Central Africa. (11 CDs).
Paris: Société d'Etudes Ornithologiques de France.
Dickinson, E.C.(Editor) 2003. The Howard & Moore Complete Checklist of the Birds of the World.
Third Edition. Christopher Helm. London.
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Handbook. Tauraco Press & Aves. Liege. Belgium.
Fry, C.H. 1969. The evolution and systematics of bee-eaters (Meropidae). Ibis 111: 557-592.
Fry, C.H. 1984. The Bee-eaters. T & A.D. Poyser, Calton, England.
Fry, C.H., Keith, S., & Urban, E.K.1988. The Birds of Africa. Vol 3. Academic Press. London.
Grant, C.H.B. & Mackworth-Praed, C.W.1937. On the relationship of Melittophagus variegatus
and Melittophagus lafresnayii. Bull. Br. Orn. Club 57: 129-130.
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Mackworth-Praed, C.W. & Grant, C.H.B.1952. African Handbook of Birds. Series 1. Eastern and
North-eastern Africa. Vol 1. Longmans. London.
Peters, J.L.1945. Check-list of Birds of the World. Volume 5. Cambridge, Massachusetts.
Urban, E.K. & Brown, L.H. 1971. A Checklist of the Birds of Ethiopia. Haile Sellassie Univ. Press.
Addis Ababa. Ethiopia.
Van Someren, V.G.L. 1922. Notes on the Birds of East Africa. Novitates Zool. 29: 1-246.
White, C.M.N. 1965. A revised check list of African Non-Passerine Birds. Govt. Printer. Lusaka.
Zimmerman, D.A., Turner, D.A. & Pearson, D.J. 1996. Birds of Kenya and Northern Tanzania.
A & C Black. London.

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