Hornbills and Tucana

21 Oct 2016

Last night, sitting out in the dark with a cup of tea and watching Tucana’s faint but beautiful sweep of stars take shape as my eyes adapted to the dark, I was musing about the bird it represents.

Tucana was first depicted as a constellation in 1598 when it appeared on a celestial globe published in Amsterdam by the Dutch astronomer and cartographer Petrus Plancius and his associate, Flemish cartographer and engraver Jodocus Hondius. It was based on the observations of Pieter Dirkszoon Keyser and Frederick de Houtman who mapped the southern sky on the first Dutch trading expedition to the East Indies, known as the Eerste Schipvaart.

The new constellations’s first depiction in a celestial atlas was in Johann Beyer’s Uranometeria of 1603.

Both Plancius and Bayer depicted it as a South American toucan. But interestingly, Frederick de Houtman included it in his southern star catalogue the same year under the Dutch name Den Indiaenschen Exster, op Indies Lang ghenaemt – “the Indian magpie, named Lang in the Indies”. He was describing the hornbill, a bird that is native to the East Indies and Malaysia.

The Kalahari is also home to hornbills, the most beautiful being the yellow billed hornbill.

A couple of days ago, as my dog, Waldo and I returned from our early morning walk, I saw a pair of these magnificent birds investigating a hollow in a Camelthorn tree, a mere twenty five metres or so from my little cottage’s back door. What a talkative pair of birds, chatting non-stop as they examined every inch of the tree and the hole. Apparently, they have used that nest for years (they are monogamous birds), and will probably use it again. How enchanting will it be to have these exquisite birds as neighbours?

They have an extraordinary nesting arrangement. The male finds a suitable natural tree hole and lines the inside with grasses and twigs. Once the nest is suitably lined, the female enters the nest, and they both seal the entrance with mud, although the female does most of the work from within, building a wall with the mud brought by her mate. She leaves only a narrow vertical slit, through which her mate delivers food and out of which she ejects remains of food and droppings.

She molts all her flight and tail feathers at once and throws them out the slit. She incubates 3 or 4 eggs which take 25 days to hatch. When the chicks are three weeks old, the female (whose flight and tail feathers have regrown by now) breaks out of the nest in order to help the male in his feeding duties. The parents and young repair the wall with their droppings. Both parents bring food to the chicks for the next six weeks, after which the fully fledged youngsters break out of the nest and, with some tough-love prodding from their parents, learn to fly.

Having watched the beautiful pair pick their nesting site decided me on the constellation Tucana as my observing target last night…

Observations

10″ f/5 Dobs; magnifications of 90x, 144x and 208x

The Small Magellanic Cloud is such a showstopper – so full of goodies and so magnificent an object to explore that it requires a night all to itself – that I realised it would swamp my gentle little hornbill-inspired expedition around Tucana, so I left it aside for this session. Instead I headed straight for Tucana’s other showstopper…