Birds Of Sandy Island: 8. The Sandy Island Monarch

THE SANDY ISLAND MONARCH (Neolalage terrestris)

As with the Dwarf Du, the discovery of the Sandy Island Monarch provides a companion to a species previously considered alone in its clade. In this case, the species in question is the Buff-bellied Monarch of Vanuatu, which the Sandy Island species now joins in the genus Neolalage. Though clearly related, several aspects of its niche and behavior expand the niche packing and behavioral potential of not only the genus but of Monarchidae in general. The Sandy Island bird is the only terrestrial monarch sensu stricto; only the grallinines or “mudlarks”, now generally considered to have joined the family’s ranks though some still gift them their own family, have a similar lifestyle among the monarchids. Slightly larger than the Buff-bellied, the monarch of Sandy Island has a shorter tail and longer, lark-like legs. The color pattern is similar to its congener, but with the black and white of the head nearly reversed: a black head with white hindcrown and supralorals, and a white breast-band. The lower breast and back are both marked with short brown streaks. These pattern and shape differences make the bird almost resemble more a chat, antbird, or bunting than a monarch. Juveniles are patterned similarly to juvenile Buff-bellieds, while subadults resemble adults but with spotted rather than streaked underparts.

The most unmonarchly feature of the Sandy Island Monarch is its nest. Even the terrestrial grallinines build mud nests in trees; the Sandy Island Monarch is the only monarchid that nests on the ground. Its oven-shaped nest is constructed from leaf midribs, and vaguely resembles that of a water ouzel. Both sexes incubate. It is assumed that if Sandy Island had any mud, the monarchs would use that to build their nests instead.

Sandy Island Monarchs walk on the ground with a lilting, stilting gait, hunting for terrestrial and near-terrestrial insects, and are very rarely met with perching in bushes; they are not seen in trees. The monarchs are sassy birds that rank high in the pecking order: above woodswallows, whistlers, and cuckooshrikes, but below Giant Fantails and Robber Starlings. The song is a distinctive slurred whistle, “peeowit-o-weeowit”, but more frequently the bird utters churring scolds not unlike other monarchs along with a tweezy “zeep”.