a web page by Don Roberson |
LONG-TAILED TITS Aegithalidae |
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There are 11 species in 4 genera but the heart of the family is comprised of the 7 species in genus Aegithalos. One is widespread in northern Eurasia (it is actually called "Long-tailed Tit"); most of the rest are birds of the Himalayas and related mountains east into China. On a visit to mid-elevations in the Himalayas of Bhutan, we found pairs and little flocks of colorful Black-browed Tit (below), often in mixed species flocks. Of the various tits in this family, some are pine-and-oak forest birds (like Black-browed Tit) while others specialize on habitats dominated by juniper, birch, or oak. |
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The Aegithalidae was traditionally considered to be close relatives of the tits, titmice, and chickadees (Paridae). Although Bushtits in California often occur together with chickadees in the same general habitat, the closely knit family units of Bushtit tend to forage most often in single species groups. Molecular studies early this century place the Aegithalidae nearer to various families within the massive Sylvioidea radiation [e.g., the "break-up of the Old World Warblers"]. Long-tailed Tits are now thought to be close to leaf-warblers (Phylloscopidae) and bush-warblers & cettids (Scotocercidae; e.g., Beresford et al. 2005, Alström et al. 2006, Alström et al. 2011, Oliveros et al. 2019). |
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In the mountains of west and central Java, the endemic Pygmy Tit Psaltria exilis is reasonably common. However, it looks and behaves very much like Bushtit in North America, except for its yellow or fleshy legs. Its sibilant calls also recall Bushtit. It feels as if the ancestor to each species was perhaps widespread but went extinct, leaving these two isolated populations, now assigned to different genera, now separated half-a-world apart.
In most species there are "helpers" at the nest (often the young from prior years) although this is not common in Bushtit. Addicott (1938) gave many details of the breeding biology of Bushtits. I rather like her description of the fledging process:
Youngsters, and sometimes the entire family, huddle together for warmth or companionship (below). |
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Small flocks of Bushtit are readily found because they are constantly vocalizing with soft conversational call-notes. In winter in California, bushtit flocks range from about 5 to 25 birds but most often when I've counted them individually they run 12-13 individuals. Adult females are pale-eyed but adult males and youngsters are dark-eyed. It is engaging watching a flock in our birdbath (above, both photos). You can pick-out the pale-eyed female in the right-hand photo. There are three separated populations of Bushtit in North America: the "Plain Bushtit" [minimus] of coastal and foothill oaks west of the Sierra Nevada (all photos on this page); "Lead-colored Bushtit" [plumbeus] in the Great Basin — these are much grayer and seemingly specialize on junipers; and the "Black-eared Bushtit" [melanotis] of west Texas to the mountains of Guatemala. Sibley & Monroe (1990) thought it possible that these might represent separate species. In fact, when I started birding in the early 1970s, the "Black-eared Bushtit" was split from the others as a species. The "black-eared" character proved to be relatively unimportant since young male "Lead-colored Bushtit" could also share this feature. Raitt (1967) showed a narrow zone of secondary intergradation around the U.S./Mexico in west Texas. It is still possible, though, that the coastal and interior populations might prove to be separate species. |
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Photos: The first photo of Bushtit Psaltriparus minimus, of the "Plain" group, was at Salinas River NWR, Monterey Co., California, on 8 Mar 2015. All photos of Black-browed Tit Aegithalos iouschistos iouschistos, of the "Rufous-fronted" group, were taken at Thrumming La, Bhutan, on 24 Mar 2019. Blake Matheson took the photo of Long-tailed Tit Aegithalos caudatus at Port Meadow, Oxfordshire, UK, on 2 Feb 2005. Ron Saldino took the photo of Black-throated Tit Aegithalos concinnus at Naini Tal, northwestern India, in February 2001. The Sooty Tit Aegithalos fuliginosus was at Foping Reserve, Shaanxi, China, on 11 Nov 2010. The Przewalski's Nuthatch Sitta przewalskii was at Huzu NP, Ganzu, China, on 14 June 2004. The Bushtit Sitta oenochlamys nest was at Laguna Grande Park, Seaside, California, on 21 Mar 2017. The packed-together fledglings were at Frog Pond Reserve, Monterey Co., California, on 15 Sep 2018, and those in the birdbath were in my Pacific Grove, California, yard on 17 Nov 2013. Photos © Blake Matheson and © Ron Saldino, as credited; remaining photos © Don Roberson; all rights reserved. Family book: Rating
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The Aegithalidae is a small family of tiny passerines found mostly in the Palearctic, but with a single species in western North America and another isolated in the mountains of Java. The one New World representative is Bushtit (left), whose ancestor is hypothesized to have reached North America via the Bering Strait land bridge 10–12 million years ago (Sibley & Ahlquist (1990). Bushtits roam actively through trees and bushes in family parties and small flocks, and if you have any tinge of anthropomorphism in you, you'll think they are "cute." As are all members of this family.
The European representative, whose range stretches all the way across Eurasia to China, is Long-tailed Tit (right; in a nice photo © Blake Matheson). They, like most of the species in the family, move quickly through the woods in small, noisy parties. I say "noisy" because they are very vocal, but the sound is soft an sibilant, and is likely heard only by the "tuned-in" birders. These little flocks usually move rapidly and, if you're not quick, suddenly they are gone. In woods near the Great Wall of China, we had great trouble showing them to members of our tour because of these attributes. On the other hand, they are a standard feature of suburban parks and gardens in Europe, and were among the first birds I saw in France during my teenage wander through the Bois du Bologne way back in 1969. -24Mr19ThrumingLa9688f.jpg)
The sole North American representative is Bushtit, a tiny long-tailed bundle of nervous energy in western oak or riparian woodlands. Bushtits build a very impressive pendant nest (right) — an elaborate pocket hung from a hood of woven spider web from an overhanging branch. Eurasian members of the family also build impressive woven handing nests and line them with feathers (usually feathers of other species). One Long-tailed Tit nest had 2,379 feathers in its lining! 
