PIPITS & WAGTAILS Motacillidae
The Motacillidae is a reasonably large family of (mostly) ground feeding birds found throughout open country across the globe. They occur from desert grasslands to alpine meadows to remote oceanic islands (e.g., South Georgia). About two-thirds of the species are pipits in the genus Anthus (taxonomy is subject to considerable debate; for the moment I use the list in Clements 1991). One example is Sprague's Pipit (left) of the northern prairie grasslands in the interior of North America. This juvenal-plumaged bird was a rare vagrant to Death Valley, California. Normally a very shy and retiring species, I was able to get this shot by crawling on my belly on a golfcourse where it was feeding.
Another 13 species are wagtails, 12 of them in the genus Motacilla (including the recently discovered Mekong Wagtail M. samveasnae). The remaining wagtail is Forest Wagtail Dendronanthus indicus of the eastern Palearctic. About half of the wagtails are long-distance migrants but others, like Mountain Wagtail (right) of the African tropics, are mostly resident birds. Mountain Wagtail, and a fair number of other wagtails, are long-tailed motacilids adapted for feeding along rushing streams, surging rivers, or other wetlands, rather than the open grasslands used by many pipits.
Here is another of these "river wagtails": the White-browed Wagtail (left) of the Indian subcontinent. Over half of the world's wagtails are crisply patterned in black, white, and grays, making for striking patterns among the river-edge boulders. In this particular shot, note the long shadow cast by the late afternoon sun. But there are "river wagtails" that are patterned in black, white, and yellow, such as the widespread Gray Wagtail M. cinerea of the Old World. It is often found along rushing torrents and, like some of the species shown here, is proportionately long-tailed. It (as do many wagtails and pipits, although not Sprague's) bob their tails as they walk.
Those wagtails and pipits breeding at high latitudes are very migratory, and because they have long migration routes, mistaken trajectories by individual birds can spin off vagrants. Such birds can present significant identification challenges. For example, this first-year White Wagtail (right), found along the Big Sur River in coastal central California (where any wagtail is extraordinary), was identified by us local birders as White Wagtail of the race ocularis. Some experts disagreed, and the California rarities committee rejected it, some even opining this was a Black-backed Wagtail M. lugens. Yet, when Per Alström and Krister Mild, authors of the new state-of-the-art book on Holarctic motacilids (Alström & Mild 2003), reviewed photos, they were "100% certain" it was an ocularis White Wagtail as initially proposed. I have an entire page devoted to this controversial wagtail. Indeed, Monterey County has now recorded all four wagtails that have reached North America, and I have a page on "Monterey wagtails."

Taxonomy in wagtails is in flux. The AOU (1998), for example, considered Black-backed Wagtail of northeast Asia a different species than the rest of the White Wagtail complex. As the two taxa are very similar and have a variety of plumages by age and sex, this created the identification controversies referred to above. The biochemical evidence presented by Alström & Mild (2003) does not support this split. Rather, their biochemical evidence shows that Black-backed is not significantly differentiated from other White Wagtails races. Rather, the most diverse groups are Citrine Wagtail (below left) and Yellow Wagtail (below right; a rather grisly shot of one sitting on the head of a rotting cow in India).

In Citrine Wagtail, mitochondrial DNA results suggested that the two subspecies (M. c. citreola and M. c. calcarata) were not closely related nor even each other's closest relatives, with the latter more closely related to some races of Yellow Wagtail. Yet this finding was contradicted by review of nuclear DNA evidence, and Alström & Mild (2003) note that only adult males are diagnosable. They believe that the mitochondrial DNA results are misleading; this situation presents a useful cautionary example when various "splits" are proposed solely on mitochondrial DNA evidence.

In contrast, all the biochemical evidence presented by Alström & Mild (2003) suggests that there are two biological species of Yellow Wagtail: Western Yellow-Wagtail M. flava (including subspecies flavissima, flava, beema, thunbergi, iberiae, cinereocapilla, pygmae, feldegg, lutea and leucocephala) and Eastern Yellow-Wagtail M.tschutschensis (including subspecies tschutschensis, taivana and macronyx). Under a phylogenetic species concept, the evidence could support ten (!) "species," many of them unrecognizable except as adult males. Alström & Mild (2003) do not actually make any of these splits: they (quite properly) note that the biochemical evidence is very recent and needs confirmation. But birders should be aware that there are potential "splits" in at least the Yellow Wagtail complex down the road. The Yellow Wagtail pictured above is likely of the race beema ["Sykes's Yellow Wagtail"], breeding in Kazakhstan and sw. Siberia, wintering in India, and thus one of the "western" group of Yellow Wagtails.

Taxonomic and identification problems also abound in the Old World pipits. Alström & Mild (2003) actually cover only 18 Holarctic pipits (only 44% of pipit species worldwide), but still account for over 200 pages of detailed text on taxonomy and identification. It can be an interesting challenge to distinguish between, for example, Red-throated Pipit (below left) and Tree Pipit (below right) on migration in the Sinai.

There are dramatic identification difficulties, and taxonomic uncertainties, in Africa pipits as well. And speaking of Africa, the final group of motacilids in the family are seven species of Macronyx longclaws and the closely related Golden Pipit Tmetothylacus tenellus.

Certainly the best known is Yellow-throated Longclaw (left), resident in grasslands south of the Sahara and celebrated in books and museums for its resemblance to North America meadowlarks, completely unrelated icterids. It is a textbook case of convergent evolution. Other longclaws, such as Orange-throated (Cape) Longclaw (below), look much less like meadowlarks and more like a bright-throated pipit. It is a species of short-grass plains in southeast Africa.
Other longclaws have limited distribution and frequent Brachystegia woodlands (e.g., Fuelleborn's M. fuellebornii) or montane grasslands (e.g., Abyssinian M. flavicollis, endemic to Ethiopia).

Together, the pipits, wagtails, and longclaws present an interesting and challenging group. It is comparatively uncertain just where the Motacillidae fit in the grand scheme of bird families. Sibley & Ahlquist (1990) and Sibley & Monroe (1990) said that biochemical evidence showed they were closest to sparrows and weavers, and even downgraded them to a subfamily of a huge Passeridae assemblage. The AOU (1998) has them between thrashers (Mimidae) and waxwings (Bombycillidae). On these web pages, I'm following the Handbook of the Birds of the World sequence, which puts them at a completely different spot: near the front of the passerines, next to larks (Alaudidae) and swallows (Hirundinidae), and before the great corvoid assemblage of families. Because these arrangements are so different from each other one near the end of the checklist, one sort-of in the middle, and the other near the front of the passerines it is often hard to locate the pipits and wagtails on checklists, particularly in regions that have only a couple species. Obviously, much is left to be learned about the relationships of the motacilids.

So, in the end, we have an enigmatic family of uncertain affinities that present a host of taxonomic and identification challenges.

In the Great Indian Desert, we came upon this pipit (right) and battled with its identification. Now, with Alström & Mild (2003) in hand, I think it is a Tawny Pipit. Yet, we had seen a bunch of Tawny Pipits when we encountered this one, and this one sure seemed different to us. In this photo, I think I can see molt limits in the greater coverts: the outer three are worn and unmolted while the inner greater coverts have been replaced (e.g., note the more rusty tone to the edgings at the tips of each of them). This March bird can thus be aged as an adult.

Pipits and wagtails often have a habit of flying off or bob-tailing their direction away from the observer, leaving one puzzled. And here, at the end of this web page, that is just where I am left. Puzzled. But engaged by these enigmatic birds.

Photos: The juvenal Sprague's Pipit Anthus spragueii was a vagrant at Furnace Creek Ranch, Death Valley Nat'l Park, California, on 11 Oct 1997. The Mountain Wagtail Motacilla clara was sunlighted over a dark river at Naro Maro on Mt. Kenya, Kenya, on 11 Nov 1981. The White-browed Wagtail M. madaraspatensis was in Corbett Nat'l Park, Uttar Pradesh, India, in March 2001. The vagrant White Wagtail M. alba ocularis was along the Big Sur River, Monterey Co., California, on 28 Sep 1998. The Citrine Wagtail M. citreola was at Bharatpur, Rajasthan, India, in March 2001; theYellow Wagtail M. flava was at Haipur, just to the northwest, that same month. The Tree Pipit Anthus trivialis and the Red-throated Pipit A. cervinus were both photographed at Sharm-el-skeik, on the tip of the Sinai Peninsula, on 7 Nov 1981. The Yellow-throated Longclaw Macronyx croceus was in the Masai Mara of Kenya in Nov 1981. The Orange-throated (or Cape) Longclaw M capensis was near Walkerstroom, South Africa, in July 1996. The Tawny Pipit A. campestris was in Desert Nat'l Park, Rajasthan, India, or 28 Mar 2001. All photos © 2003 Don Roberson, all rights reserved.

Literature cited:

Alström, P., and K. Mild. 2003. Pipits and Wagtails. Princeton Univ. Press, Princeton, N.J.

American Ornithologists' Union. 1998. Check-List of North American Birds. 7th ed. A.O.U., Washington, D. C.

Clements, J. 1991. Birds of the Word: a Checklist. 4th ed. Ibis Publ., Vista, CA.

Sibley, C. G., and J. E. Ahlquist. 1990. Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale Univ. Press, New Haven, CT.

Sibley, C. G., and B. L. Monroe. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT.




Page created 13 Dec 2003