a web page by Don Roberson |
NICATORS Nicatoridae |
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 Nicators are a small group of three species within a single genera (Nicator). Together, their range covers much of forested subSaharan Africa. Eastern Nicator,
sometimes called "White-throated Nicator,"(left in a spectacular photo
by Hugh Chittenden), is patchily distributed in east Africa from
Somalia & Kenya south of Mozambique and easternmost South Africa.
These are shy, skulking, forest undergrowth birds, much more readily
heard than seen. The other two species are Western Nicator N. chloris,
ranging from humid forests of west Africa to the Congo Basin, and the
smaller Yellow-throated Nicator, found locally in the Congo Basin. |
Probably because of the heavily hooked bill, Nicators were initially thought to be shrikes (Laniidae) and then Bush-shrikes (Malaconotidae) when it was released that shrike-like birds were diverse. In the 1920s James Chapin noted the similarities between the nicators and both the bush-shrikes and bulbuls (Fishpool & Tobias 2005). Delacour (1943) placed the genus with the bulbuls (Pycnonotidae). Olson (1989) argued that the genus was more closely related to the bush-shrikes, as the nicators lacked the ossification of the nostril found in all other bulbuls. The pendulum began to swing back toward bush-shrikes until initial DNA-DNA hybridization work (Sibley & Ahlquist 1990) put them closer to bulbuls again. In fact, several features, including the position of the facial bristles (preorbital rather than rictal), their nests and the calls, make the genus unique. This uncertainty led to confusion in the impressive Bird of Africa project. Artists had been commissioned to paint the Nicators among the bulbuls, and did so on Plate 21 of Vol 4 (Keith et al. 1992), but by the publication date the genera was not covered in Vol. 4. So the Nicator artwork in Vol. 4 was left stranded, like a lost soul, labeled with "Nicator subsequently re-classified as incertae sedis, possibly near Laniidae, see Vol. 6." Martin Woodcock's artwork reappeared on Plate 23 of Vol 6 (Fry et al. 2000), with the bush-shrikes. But it was misplaced there as well. |
Eastern and Western Nicators have loud explosive vocalizations, unlike bulbuls or bush-shrikes. The nest is completely different than either, being flat, built of crossed twigs, like a pigeon, and often so small and rudimentary that the egg may fall through onto the ground when buffeted by wind. The nest is fragile only for a few days because then the nest becomes glued to its support by the mycelium of fungi, and becomes so secure that it can be held upside down without falling off (Fry et al. 2000). The mystery about Nicator's taxonomy was not resolved until molecular analysis by Beresford et al. (2005) and Moyle & Marks (2006). By then it was too late for change its location — with the bulbuls — in the Handbook of the Birds of the World series (Fishpool & Tobias 2005). Moyle & Marks (2006) summarized the DNA results: "The African genus Nicator is not part of the bulbul assemblage. Our outgroup sampling is not extensive enough to place this genus with any certainty, but nuclear DNA sequences showed it to be a basal lineage in the Sylvioidea." Jønsson & Fjeldså (2006) more extensive review of the Sylvioidea found that it was a very early offshoot at the base of the Sylvioidea tree, rather, in that sense, like Hyliotas (see Fuchs et al. 2006), but not particularly related to them either. Jønsson & Fjeldså (2006) put the three Nicators in Clade 5 of their 13 clades that revolutionized the world of Old World warblers (see the breakup of the Old World warblers). Only Western Nicator N. chloris was reviewed genetically, but there is no controversy that all three are close relatives. But mysteries remain, included the exact relationships to other early offshoots in the Passerida tree. Rockfowl and rockjumpers are other early "lost lineage." It is hard enough to get a decent view of any nicator. It only adds to our troubles to barely understand its relationships. |
Photos: Hugh Chittenden photographed the Eastern Nicator Nicator gularis at Mkuzi Game Reserve, near Marromeu, Mozambique, in Dec 2005. Photo © Hugh Chittenden, used with permission, with arrangement through Adam Riley; all rights reserved. Bibliographic note: There is no "family book" per se, but a fine introduction to this family, with some fine photos, is in Tobias (2005). Literature cited:
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