Tuesday 20 August 2019

Nature Trail

Grey Seal pups need maximum protection


FEMALE GREY Seals give birth to their pups at this time of year. To afford maximum protection from predators, the mother seals seek out the seclusion of caves and inaccessible beaches on offshore islands and remote, undisturbed areas on mainland shores. Delivery of their offspring sometimes coincides with the gales and rough seas that often occur around the autumn equinox.

In nature, the equinox heralds the change of one season to another. You will remember that there are two equinoxes in the year: autumn and spring. The equinoxes happen each year around September 22nd/23rd and March 20th/21st when, because of Earth's tilt, the Sun appears to be directly over the equator and the length of day and night appears to be approximately equal. Those with the benefit of a classical education will know that, in Latin, 'equi' means 'equal' and 'nox' means 'night' implying that, at this time of year, day and night are equally twelve hours long or thereabouts. There is a widespread belief among mariners that gales are prevalent around the equinoxes but the weather experts tell us that evidence to support that belief is debatable. While the jury may be still out on that particular issue, everyone agrees that the arrival of the autumn equinox signals that summer is well and truly over.

Anyway, back to the seals; pups are born at this time of year and they have white coats and large, doleful, jet black eyes. The last national assessment of the size of the breeding population of Grey Seals in the Republic of Ireland was conducted in 2005 and a detailed report was published in 2008 (available online publications/ irishwildlifemanuals/IWM34.pdf . The number of Grey Seal pups born during 2005 was quantified at 1,574 and the total population size of Grey Seals, all ages, was estimated at between 5,509 and 7,083 animals.

Grey Seal distribution during the breeding season in the 2005 study was found to be concentrated along the Atlantic seaboard from Cork to Donegal. Over half of the national population was associated with breeding sites located in Counties Mayo and Galway, the largest breeding area in the country being on the Inishkea group of islands in County Mayo. The most sizeable colonies elsewhere were located at the Saltee Islands on the south coast, and at Lambay Island and Ireland's Eye on the east coast. The coastlines of all but four counties had some breeding seals.

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