 The
Magellanic
Plover is an enigmatic shorebird confined to the southern tip of South
America. Although traditionally included among the plovers [Charadriidae],
it is an odd, almost dove-shaped wader that behaves more like a turnstone
than anything else (left; an adult photographed by Alvaro Jaramillo).
It breeds around upland lakes in Tierra del Fuego, preferring shallow saline
lakes with shores laden with salt deposits. It disperses more widely in
the non-breeding season, when small flocks reach to coastal Patagonia (Piersma
1996, Jaramillo 2003). It has a number of features not shared with other
plovers, including the habit of turning seaweed and stones to uncover invertebrates,
and digging in the sand with its short legs for buried prey. Magellanic
Plovers carry food to their chicks in the crop, a pouch which can also
be distended in display (Piersma 1996).
Recent analysis of analysis of morphological and osteological characters
provided initial evidence that this was not a typical plover but, rather,
more closely linked to sheathbills [Chionidae] than any other Charadriformes
(Strauch 1978, Chu 1995). Genetic data (Paton et al. 2003) support this
relationship and "thus also the treatment of Pluvianellus as a monotypic
family
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 The
Magellanic Plover breeds on high-elevation lakes in the austral spring
(Sep-Nov) where pairs are solitary and defend territories vigorously. Generally
two eggs are laid, and incubated by both parents, but if both hatch, the
weaker check usually does not survive (Jehl 1975, Piersma 1996). Juvenal-plumaged
birds (right, in another fine Alvaro Jaramillo shot) are heavily scaled
with white and the legs are yellowish, rather than bright pink-red as in
adults.
It is often said that the elevation of Magellanic Plover to its own
family is a Sibley & Monroe (1990) innovation, but this is not true.
Sibley & Monroe (1990) listed it almost dead-center among the plovers
in family Charadriidae, and cited only Jehl (1975) for its placement. However,
Charles Sibley (1996) elevated it to family status in his diskette update
to Sibley & Monroe after Burt Monroe's death. Yet event the very text
that make this proposal acknowledged that the suggestion was not based
on biochemical evidence (unlike all their other DNA-DNA hybridization work)
but instead was grounded in its unique behavioral characteristics. Sibley's
suggestion was entirely philosophical: "Placing it in a monotypic family
calls attention to its unique or unusual features and may attract additional
study." Clements (2000) then followed Sibley (1996) to consider it a separate
family. Piersma (1996), in the Handbook of the Birds of the World
series, did not. It is only the more recent biochemical evidence
(Paton et al. 2003) that now permits us to support what had been a seemingly
premature family designation in the 1990s.
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| Photos: Both photos of Magellanic Plover
Pluvianellus socialis were taken by Alvaro Jaramillo at Laguna de los
Cisnes, Tierra del Fuego, Chile, on 31 Jan 2004. All photos
© 2006 Alvaro Jaramillo, used with permission; all rights reserved.
Bibliographic notes There is no "family book" for Magellanic Plover but a fine introduction is in Piersma (1996). Literature cited:
Clements, J.F. 2000. Birds of the World: A Checklist. 5th ed. Ibis Publ., Vista, CA. Dickinson, E.C., ed. 2003. The Howard & Moore Complete Checklist of the Birds of the World. 3d ed. Princeton Univ. Press, Princeton, N.J. Jaramillo, A. 2003. Birds of Chile. Princeton Univ. Press, Princeton. Jehl, J.R., Jr. 1975. Pluvianellus socialis: biology, ecology, and relationships of an enigmatic Patagonian shorebird. Trans. San Diego Soc. Nat. Hist. 18: 25-74. Paton, T.A., A.J. Baker, J.G. Groth, and G.F. Barrowclough. 2003. RAG-1 sequences resolve phylogenetic relationships within charadriiform birds. Molecular Phylogenetics & Evolution 29: 268-278. Piersma, T. 1996. Family Charadriidae (Plovers), pp. 384-443 in del Hoyo, J., A. Elliott & J. Sargatel, eds., Handbook of the Birds of the World. Vol. 3. Lynx Edicions, Barcelona. Sibley, C.G. 1996. Birds of the World, on diskette, Windows version 2.0. Charles G. Sibley, Santa Rosa, CA. Sibley, C. G., and B.L. Monroe, Jr. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT. |