Monday 21 August 2017

Sweet blackbird inspires poetry

THE blackbird, impudently sweet, half of him passion, half conceit . . . That's Francis Ledwidge, from Poet of the Blackbird. "Dom-fharcai fidbaidae fal fom-chain loid luin-luad nad cel huas mo labran, ind linech fom-chain trirech inna n-ein". That, I gather, is Old Irish as distinct from the first national language. It was written by a hermit called Marban -- he was brother of Guaire, a king of Connacht -- and was found in the margins of a ninth century MSS.

Not to be blinded by scholarship, one translation goes: A wall of forest looms above/ And sweetly the blackbird sings/ All the birds make melody/ Over me and my books and things."

The monk sitting with his psalter looking out over a dawn woodland bursting with song is an image of paradise. The Garden of Eden it is not but it was pleasant enough for me this week to be watching a blackbird pair busy food-searching in an old garden, thick with shrubs. A bluetit or two has followed the blackbirds, who forage separately, like gulls to the plough, seeing what small morsels might be uncovered. The blackbirds are not gathering nesting , so their home must be built, somewhere in the depths of a thick cypress or a recess in an old wall heavily gowned with generations of ivy.

There are magpies here, including one very large bird, intruding and scavenging as nature intends. Survival of fledglings will be a gamble. Depending on weather and predator attacks, blackbirds can produce up to four broods in a season.

When I was a schoolboy, birds nests were robbed and eggs 'blown' for hoarding in cotton wool as a matter of course, to boast about like collections of foreign postage stamps with one-upmanship over scarcity and colour. There were illustrated books in the local library showing the various egg sizes. This practice has thankfully disappeared -- it is illegal to steal the eggs of rarer species although in the UK there is a trade in this, despite fines and jail sentences.

The eggs of the blackbird are blue, as are those of the robins now in policeman mode of territorial defence of their garden domains. Egg shapes are determined, scientists tell us, by the numbers laid and the need to pack together as many as possible in a nest to get incubating cover from a parent. There is also the matter of space for more sustenance in the pointed ends.

A mathematician, Dr Tamas Szekely, of Bristol University, concluded this after research as to why the eggs of shore birds such as plovers (which lay four) were so pointed. Such eggs provide extra survival material for chicks hatched on exposed coastlines than spherical eggs -- as well as snuggling closer together. Egg shape is part of the need to benefit from losing heat more slowly when the parent birds are absent and to pack hatched chicks together for heat cover from the parents.

Eggs are rounded in one-egg species such as the albatross but there is a puzzle with another seabird, the guillemot, which produces a pear-shaped egg. The theory here is that as these birds nest on sheer cliff-faces, the eggs are so shaped as to stop them rolling off!

The biggest bird eggs are laid by ostriches (which I have watched and wondered how they hatched as parents wandered; sun and sand heat must help). These eggs are five to six inches in diameter. The smallest eggs are laid by the vervain hummingbird of Jamaica, at about one-third of an inch across.

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