The Great Northern Diver raises its chicks on trout fry and therefore resides on lakes that offer such food. This Diver has one chick which is most common although the eggs are two. The parents can seldom find enough food for two chicks to survive, thus only one lives to become an adult. This bird with its chick was in Veiðivötn Lakes in the southern highlands.
Veiðivötn (Fishing Lakes) are a cluster of lakes in the southern interior of Iceland. Ordinarily there are around 35 to 40 Great Northern Divers there over the summer time and usually 10 – 15 nests. This spring it was very cold and a lot of snow and ice. The Great Northern Divers turned up at their usual time and at least 10 pairs layed eggs by the water edge of lakes. When it at last started to get warmer snow and ice melted and six of the nests went under water and were destroyed. Only three chicks hatched from two nests in the area. This is by far the worst breeding to be seen since I started observing the Great Northern Diver in the area 15 years ago. The nest in the picture went underwater but in recent years this pair has always managed to raise two chicks.
This picture is of the same pair with two chicks last year.
The Great Northern Diver is a characteristic bird on Icelandic mountain lakes. You can hear its a special laughing call on the lakes and in flight its wailing calls resound in rocks and craters, creating an unforgettable atmosphere, memories of quiet summer nights. In USA it is called the Common Loon but in UK it is called the Great Northern Diver.
The Great Northern Diver chooses its nesting place on islands or islets or else by the banks of the lakes. The nests are most often in moss or grass but sometimes on sandy lakeshores. The nests are usually about 1 – 2 meters from the water level. The eggs are usually two.
Big clear mountain lakes full of fish are the Great Northern Divers favourite nesting place. Their main food source is trout. There is usually just one pair on each lake unless the lake is very big.
A nesting pair usually claims a whole lake as its territory and makes sure that no one gets too near and uses force to keep other Divers away.
Most Great Northern Divers stay in the ocean around Iceland over the winter time, a few go to the UK or West Europe.
There are around 300 breeding pairs in Iceland and it is the Great Northern Divers only nesting place in Europe.