Liza Cole, senior Ranger at St Abbs Head nature reserve was the speaker at the January meeting of the Berwickshire Group of the Scottish Wildlife Trust in Duns.
The National Trust for Scotland owns 77 hectares at St Abbs Head where it protects and manages this spectacular site for wild flowers and insects as well as the vast numbers of sea birds.
The geology at St Abbs Head is very obvious with the rocks exposed in dramatic cliffs and the contrast between the volcanic rocks which make up the Head and the folded and contorted Silurian Greywacke as seen at Petticow Wick is striking. The sheer cliffs provide both wide, safe ledges for the Guillemots and small discrete nesting sites for the Kittiwakes to build their nests.
About 45,000 sea birds now nest at St Abbs but in its prime there was 80,000 pairs. The crash in numbers is mostly made up in the decline in the numbers of Kittiwakes, there are some 3,000 pairs nesting now compared to over 20,000 in the 1960s.
Kittiwakes are surface feeders far out at sea and their food supply has dwindled as sea temperatures have risen by 2c in the past 20 years.
For many years few chicks fledged and it was sad to see chicks dying of starvation in the nests. Kittiwakes build a nest with grass which they often gather on the steep grassy banks and in a good year lay theee eggs and can raise three chicks.
Guillemots, in contrast, prefer wide ledges where it is easy to land and take off in flight, they do not build nests and just lay their pointed, single egg on the bare rock. The brooding bird must protect it from rolling over the edge and marauding gulls at all times.
Guillemot chicks leave the nest before they can fly and the jumplings just jump at dusk from the cliffs and glide down to the sea where the parent birds will be waiting and calling to them, they then guide them out to sea and safety from predators.
Guillemots feed on small fish like Sand-eels and can dive very deep in pursuit of their prey. The numbers of small fish must have remained constant as the Guillemot numbers have remained at a staggering 33,000 pairs.
Razorbills resemble Guillemots but their backs are jet black, about 1,800 pairs nest and like Guillemots do not build a nest, they tend to nest solitary or in small groups which are scattered over the cliffs rather than densely packed together on ledges or the top of sea stacks.
The numbers of large and noisy Herring Gulls nesting on the coastal sea cliffs has declined but they have tended to move into towns such as Eyemouth and prefer to nest on rooftops rather than cliffs. Here they feel safe and there are scraps of food to be picked up on the streets or they can try and steal your fish and chips.
Shags and Fulmars also nest on the cliffs but in much smaller numbers.
‘Natural Engineers – Bringing the Beaver back’ is the title of the talk tonight, Thursday, February 2, by Susan Davies, Director of Conservation for the Scottish Wildlife Trust, in Duns Parish Church Hall. Doors open 7.10pm, visitors and friends welcome.