The Little Stint: The mysterious Kinglet Calyptura

This is the story of the mysterious Kinglet Calyptura, which has managed to elude the ornithologists and birders of humanity for over 100 years:
Some of the smallest birds of the world live in Latin America. The Bee Hummingbird (Mellisuga helenae) of Cuba with only 5 to 6 cm and 1.6-2.6 g is likely the smallest of them all, shortly followed by the similarly tiny Short-tailed Pygmy-Tyrant (Myiornis ecaudatus) which is the smallest passerine: It measures 6.5cm, weighs 4.2g and lives throughout much of the continent.

Some readers might have seen these. But I doubt any reader has ever seen the Kinglet Calyptura (Calyptura cristata). At 7.5-8 cm it's not much bigger than the aforementioned species, being even smaller than e.g. the eurasian Goldcrest (Regulus regulus) (9cm) or the north american Golden-crowned Kinglet (Regulus satrapa) (8-11cm). With its yellow-green colouration, two white wingbars on the blackish wings, a stubby tail and especially its black-bordered large orange-red crown patch it actually looks a lot like these two.

Specimen of Kinglet Calyptura (Calyptura cristata), probably a male
taken in Brazil, probably prior to 1890.
Special thanks to the 'Landesmuseum Natur und Mensch Oldenburg',
where these pictures were taken. ©Mathieu Waldeck

Only a very tiny handful of people have ever set eyes on a living Kinglet Calyptura in recent years. Back in late October 1996 the observation of a pair on the edge of Serra dos Órgãos National Park, ca. 60 km north of the city of Rio de Janeiro resurrected the species from the dead for three days and put them back on our radar:

The Kinglet Calyptura was first described to science by Louis Jean Pierre Vieillot in 1818 from a specimen taken in Rio de Janeiro. It was certainly not as rare back then as it is today. Over 55 specimens can be found in museum collections. But it vanished for more than a century after the last specimen was collected in 1890. Many ornithologists believed it to have gone extinct and only few people knew much about it, when suddenly on October 27th local ornithologist Riccardo Parini found what appeared to be the "most anxiously awaited" rediscovery of South America.

After calling some friends and describing what he had just seen they returned the next day to confirm its existence and exclude a misidentification. Bad weather prevented them to find the birds on this day, so on October 29th they returned once again and at 6:30 in the morning a tiny little bird popped up for a few seconds ca. 150-200 m away from the expected place in significantly taller trees than two days earlier (second growth atop some fairly dense, 3-4 m high trees), but soon vanished into a nearby treetop. Hastily the search party relocated to a better viewing spot and after a short search they finally got the views they had hoped for. Four observers had the great luck of being the first observers in over a hundred years of the enigmatic Kinglet Calyptura. After a while they noticed, that there were actually two birds, which they observed on the next day again. Even though professional video and sound-recording gear had been brought no footage could be obtained, as the birds quickly disappeared after their anxiously awaited appearance. Two more people saw the bird this time, while three people missed their chance of seeing it, probably forever, when they decided to walk a little bit down the road and search there.

What they noticed in addition to the known key field marks (size & colouration) were two things that differed from what they had expected: The orange-red crown was held erect like a crest and the bird sat rather upright. This disagreed with the way that Kinglet Calypturas has always been depicted in books before. Unfortunately the birds would not call or do anything other than repeat a routine of flights, with brief pauses to rest on specific treetops. The upright posture actually makes some sense, if you consider that the Calyptura is most closely related to the members of the genuses Platyrinchus and Neopipo, forming a basal branch of the tyrant flycatcher family, which have a fairly erect posture too.

The following 30 days the group returned nine times, but to no avail before the observation was finally announced to the general public in late November. Remember that this was before the era of cell phones, the internet and instant news.

For most people that have heard the story of the Calyptura this is already where it ends. The birds are most probably still out there, though their diminutive size, unknown calls and likely small population has hindered another rediscovery. But there are three more unconfirmed sightings from the general area that bear some credibility:

A report from July 1990 by Tomas Sigrist describes a pair following a mixed flock in subcanopy at Picinguaba near Ubatuba in Sao Paulo. It’s interesting to know that this report (proceeding the sightings from 1996) already mentions the male raising its crest, something that was an unknown behaviour at the time. However it wasn’t published until 2005, which is somewhat surprising given the noteworthiness of this incredible sighting.

A second report on 27^th March 1997 by Ladd Hockey from a place near Ubatuba Experimental Station goes into detail about several key characteristics that were noticed, but unfortunately the observations was short (5 s) and his wife Petra was birding apart from him at the moment and thus couldn’t confirm the observation. Again the raised crest is mentioned.

And finally on 4^th March 2006 Martin Schaefer reported that he and his wife had observed a Calyptura in subcanopy near Ubatuba, again with a mixed species flock. Again the description fits well with Kinglet Calyptura, but some key characteristics like the size or the short tail are left unmentioned and at least one of the accompanying species mentioned (Red-legged Honeycreeper) does not occur in the area.

Recently a two-month survey by Frank Lambert from mid-september to mid-november 2006 sadly ended fruitless, as did another 15-day expedition in search of the enigmatic Calyptura in October 2010 by Luciano Lima. But I’m convinced that it is still out there and will eventually be re-rediscovered!

The Little Stint

Donnerstag, 1. Februar 2018

The mysterious Kinglet Calyptura

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