Employees of the Icelandic Institute of Natural History found 96 dead Arctic tern chicks in the colony in Hliðsnes in Álftanes, the capital region, this week. They were on a routine expedition—they have tagged more than 100 chicks in a period of three weeks.
An Arctic tern. Photo by Geir Ólafsson.
The situation is believed to be caused by lack of food. Sandeels, which are the tern’s main source of food, have been on the decline and as a consequence the bird’s nesting has been poor in the past years, Morgunblaðið reports.
However, this year, the Arctic tern nesting in Hliðsnes was off to a good start. “These were adolescents, about to become fully-fledged,” said Aron Leví Beck of the dead chicks.
He has been monitoring the situation in the nesting colony and noticed that recently, the adult birds have been unusually calm. “They haven’t been as aggressive as usual […] and we noticed that they haven’t been bringing food to their chicks.”
Under normal circumstances, adult birds constantly fly back and forth to their nests with small fish in their beaks. There is news of dead chicks in Arctic tern nesting colonies around the country, including by Ísafjarðardjúp in the West Fjords.
The reason is considered to be the same everywhere. New studies indicate that sandeels in Icelandic waters aren’t fattening because of competition over food with mackerel, which also feeds on sandeel.
In other bird news, the 2012 sea eagle nesting is largely proving to be a failure. Most of the 45 eagle couples that laid eggs in the spring were unable to raise chicks due to the cold spell that hit in May, Fréttatíminn reports.
“Eagles nest in early or mid-April and the chicks won’t become fully-fledged until mid-August. In the first part of the nesting season, eagles are sensitive towards cold spells and disturbances by humans,” said Kristinn Haukur Skarphéðinsson, divisional manager in zoology at the Icelandic Institute of Natural History.
Kristinn stated that one of the main tourism companies by Breiðafjörður has offered illegal sailing trips to eagle nests and disturbed the birds early in the spring.
“No chick survived in the northern Breiðafjörður and only one chick is currently about to become fledged in the West Fjords,” he said.
However, the eagle nesting by Faxaflói in the west was fairly successful, Kristinn added. The institute knows of 21 eagle couples with 28 chicks in Iceland that are set to start flying in two to three weeks.
The good news is that in spite of this setback, the sea eagle population in Iceland is growing, albeit slowly, currently numbering 69 couples, up from 66 in 2011.
Click here to read more about the study on sandeels and the condition of seabirds in Iceland.