While on holidays in west Cork last summer we noticed two crabs on the beach at Barleycove. The larger crab was carrying a smaller one under its body, holding it in position with one of its legs. As we approached to investigate, the large crab raised its claws and the smaller one appeared to make several attempts to escape, but was unsuccessful. Was the small crab a mate, offspring or supper?
Ian McGowan, Tralee, Co Kerry
It was a mate. The male of the green or shore crab is larger than the female. He seeks out a female about to moult and carries her under his body for a few days. When the female moults copulation takes place. The female then burrows in the sand and lays her eggs, as many as 180,000, which attach to her abdomen. She carries these around for several months before they hatch.
I have been reading in Time's Eye (The Irish Times December 17th, 1998) about the predicted extinction of some birds in Britain within the next decade, and of the thrush within five years. In our rural area here, while the blackbird and other small birds are still plentiful, the thrush over the past decade has virtually disappeared. What circumstances have contributed to this loss, as the those associated with extinction in Britain do not to any material degree exist here?
Jim Doyle, Carrigaloe, Cobh, Co Cork
In the Countryside Bird Survey, Interim Report, September 1998, the song thrush was found to be thriving in this country as it appeared in 80 per cent of the squares sampled. On our rather bare hillside, song thrushes have arrived since we provided plenty of cover on our small piece of land. It is very difficult to say what causes local declines in some birds or to know how real these are.
I, too, planted garden centre primroses last spring (Eye on Nature, January 2nd) and looked forward to them heralding the coming of spring, but they have flowered constantly since then. I have noticed the same occurrence in other gardens, but not among wild primroses. Why would the garden ones be more susceptible to global warming and the wild ones not?
Pearse Ryan, Limerick
Indeed. Perhaps the cultivated ones are bred in climates that encourage all- year-round blooming.
Edited by Michael Viney, who welcomes observations sent to him at Thallabawn, Carrowniskey PO, West- port, Co Mayo. Email: viney@anu.ie. Observations sent by email should be accompanied by postal address as location is sometimes important to identification or behaviour.