a web page by Don Roberson |
THRUSH-TANAGER Rhodinocichlidae |
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Clark (1913) was the first to suggest that this unusual bird — then known as the "Panama Thrush-Warbler" —was a tanager. Skutch (1962) — using a long name, "Queo," and citing habit and behavior — suggested it was related to thrashers [Mimidae]. Eugene Eisenmann (1962) published multiple reasons it could not be a mimid, but was most likely an aberrant tanager. He argued that the "hyphenated English name 'Thrush-Tanager' ... seems adequately to suggest the taxonomic uncertainty and the appearance of the bird." He agreed that "unless we are prepared to cut up the traditional tanager family into a number of families, there seems no over-all gain in erecting a separate monotypic family for Rhodinocichla -- at least without anatomic basis." We are now in the era when "cutting up the traditional tanager family" is underway apace. Barker et al. (2013), using genetic evidence, "recovered 5 major lineages traditionally recognized as avian families [one was the tanagers, Thraupidae], but identified an additional 10 relatively ancient lineages worthy of recognition at the family level." One of those lineages that Barker et al. (2013) felt "worthy of recognition at the family level" was Rosy Thrush-tanager, now proposed as the sole member of the Rhodinocichlidae. |
The use of the tem "relatively ancient" by Barker et al. (2013) is curious. Normally when taxonomists speak of "ancient" lineages, those go back to the Eocene Epoch (about 34-56 million years ago), or at least the Oligocene (about 23-34 mya), The lineages set out in Barker et al. (2013, 2015) are no older than 15 mya, and some proposed as families are as recent as 9 mya. Whether elevated all such lineages to Family status has yet to be sorted out by the AOU and SACC. Using the data presented by Barker et al. (2013, 2015), we can retain the five "traditional" families [Parulids, Emberizids, Tanagers, Grosbeaks, Icterids] by adding just 5 new families (rather than 10), and one of them [Calcariidae, the longspurs and allies] has already been adopted by the AOU. Based on the evidence, though, the "most necessary" new family is the Rhodinocichlidae. Barker et al. (2013, 2015) present evidence that it is sister to the longspur/Snow Bunting family [Calcariidae], and together these are sister to a huge assemblage that includes the New World warbler [Parulidae], cardinals & grosbeaks [Cardinalidae] and tanager [Thraupidae] families. In short, at about 14 million years old, the Rosy Thrush-tanager lineage is the oldest and earliest of the offshoots among these New World passerines. Rhodinocichla does exhibit behavioral features adapted to its habitat niche, not reported of any of other tanagers. It is sexually dimorphic. Most distinctive is the antiphonal singing by both members of a pair. This is characteristic of certain other tropical birds (notably a number of tropical wrens), which skulk in the undergrowth and remain paired for all or most of the year (Eisenmann 1962, Ridgely & Tudor 1989, Hilty 2011). There are currently five generally accepted subspecies of Rosy Thrush-tanager within a fragmented pattern of occurrence. Each may be geographically isolated. To the eye the populations differ mostly in the color of male's back, ranging from gray to blackish in a 'leap-frog' pattern (Hilty 2011). Although large and loud with, Rosy Thrush-tanager can be a very difficult bird to see in the dense understory it inhabits. World birders will surely wish to prioritize viewing this brilliant species. Currently it is not considered at risk, but its terrestrial habits within threatened tropical deciduous forests could mean that it faces heightened risk for the future. |
Photos: Adam Riley photographed the Rosy Thrush-tanager Rhodinocichla rosea in Panama in August 2015.
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The Rosy Thrush-tanager Rhodinocichla rosea
is a beautiful and enigmatic Neotropical specialty (left, a lovely shot
of a singing male by Adam Riley of Rockjumper Tours). The species has
an oddly disjunct range, mostly along the coast, in western Mexico,
Costa Rica and Panama, Colombia, and Venezuela. It lives in pairs on or
near the ground in thick undergrowth in arid to semi-arid forests,
scrub, or overgrown habitat that has previously been cleared. Males are
slaty above and rich raspberry-red below; females are similar but the
red is replaced by orange. Pairs sing a flutey song in antiphonal duets.