Date of the interview: 10 March 2011
In this interview Alv Ottar Folkestad talks about White-tailed Eagles and their current situation in Norway, what threats the eagles face or why the European Otter is import for the Sea Eagles.
Norway has by far the biggest population of White-tailed Eagles in Europe and that population is crucial for the future survival of Europe’s largest eagle.
Markus Jais: How many pairs of White-tailed Eagles do currently breed in Norway.
Alv Ottar Folkestad: In Norway we estimate the population in “number of territorial pairs”. This is so because even among old and well settled White-tailed Eagle pairs the frequency of actually “breeding” pairs may differ from year to year even though the pairs are displaying territorial behaviour and defending their territory year round. At the moment our estimates of territorial pairs is 3500-4000.
Alv climbing nest tree
© Roger Engvik
Markus Jais: How has the population developed since the 1950s?
Alv Ottar Folkestad: The Norwegian White-tailed Eagle population was declining until the beginning of the 1970-ies. The species (together with the Golden Eagle) had no protection at any time of year until September 1968. The estimate made by Willgohs by 1956-60 was only 350 pairs. However, recent recalculation on the basis of his data rather clearly concludes that this was an under estimate and that it is reasonable to believe that the population had to be 7-800 pairs at the lowest.
Markus Jais: What do you think are the main reasons for the population increase in Norway?
Alv Ottar Folkestad: Quite clearly the main reason for the population increase of White-tailed Eagle in Norway was the decision of fully protection made by the Government, and that people rather soon got to accept this decision. Later on the recovery of Otter’s population in Southern Norway has provided the White-tailed Eagles with left over from the otter’s diet. This is a rather important part of the breeding eagle’s food.
Markus Jais: Which habitat do the eagles use in Norway? Where are most eagles found?
Alv Ottar Folkestad: In Norway the White-tailed Eagle is mostly a coastal bird, breeding traditionally along the seashore. By now the population has obviously reached the capacity along most of the Norwegian coast including the fjords. An increasing number of pairs are settling by inland lakes and water courses. However, the bulk of the population is still in the northern part of the country.
White-tailed Eagle chick in nest
© Alv Ottar Folkestad
Markus Jais: In some European countries, at least some White-tailed Eagles seem to get more used to people. There are more and more nests in open agricultural areas or close to busy streets, villages or cities. Do you notice a similar trend in Norway?
Alv Ottar Folkestad: We can clearly see a similar trend in Norway. An increasing number of eagles are including areas with rather heavy human activity into their territory, and immature birds are gathering and feeding around fishing harbours. Some White-tailed Eagle pairs are now nesting very close to people, down to 110 m from inhabited houses, and even closer to summer houses. However, the vast majority is avoiding human activity close to their nest and is nesting at least more than 500 m away from human activity.
Markus Jais: What is the main food of White-tailed Eagles in Norway?
Alv Ottar Folkestad: By far the most dominant part of the food is fish, tentatively 70-80% or more. Mostly it is either dead fish floating in the sea or washed ashore, left over from otters and sea gulls, from fisheries and so on. A rather important part of the food is gained by klepto parasitism, and the main target species for stealing food is the Golden Eagle, the Greater Black-backed and the Herring Gulls, ravens or crows. More occasionally they are chasing gannets, herons and goshawks.
Markus Jais: How important is carrion for White-tailed Eagles in Norway and do you think that they might benefit from an increased Wolf population which could provide carrion during winter?
Alv Ottar Folkestad: Currently carrion may be an important part of the White-tailed Eagle’s food year round, but mostly so during winter. During summer the species has become the main scavenging bird on sheep and lamb carrion in Norway, associating with ravens, Golden eagles and hooded crows. From autumn onwards onto spring the most important carrion is different cervide species. In northern parts of Norway it is Reindeer and Semi-domestic Reindeer, in Western Norway mostly Red Deer, and in the forested parts of Norway the Moose may be the most abundant carrion species. The Wolf population in Norway is still very low, and is no important factor for providing carrion and in that way influencing wintering survival of White-tailed Eagles in our country.
Markus Jais: What is known about predation on livestock like lambs or chickens?
Alv Ottar Folkestad: Traditionally the White-tailed Eagle has not been regarded as a real threat to livestock in Norway. Written sources from the 1700-eds have not livestock of any kind on the prey list of the White-tailed Eagle, quite opposite of what is written about the Golden Eagle. Studies made by the Sea-eagle Project Norway 1974-2010, together with a national scheme on making autopsies and studies of suspected livestock kills made by eagles and legally protected mammals of prey in Norway 1987-2010, has not confirmed a single incidence of White-tailed Eagle kills on lambs or other livestock. A critical re-analysing of former data on the subject has concluded the same: The White-tailed Eagle is making no problems to sheep farming in Norway. Not even the rapidly growing practice of the old and traditional hill sheep farming along the Norwegian coast with sheep grazing in the hills year round and lambing freely on open grounds and not in bye, has got any problems with White-tailed Eagle attacks. Occasionally White-tailed Eagles may kill chickens, domestic ducks, and even domestic geese, but neither is this regarded as a real problem. The Norwegian studies have confirmed that Golden Eagles are killing lambs regularly, all together about 2500 cases of a total number of more than 115 000 autopsied carrion suspected by the farmers to be killed by different legally protected predators in Norway during the period 1987-2011.
Markus Jais: What is the relationship with White-tailed Eagles and fishers and fish farming?
Alv Ottar Folkestad: There has long been, and during recent years even a growing tradition to feed the White-tailed Eagles with fish and fish offal when fishermen are doing their catches on the return from fishing grounds. Several fishermen are feeding “their” White-tailed Eagle pair. So are mostly even the relations with fish farmers, who very often have a pair of adult eagles, together with visiting groups of juvenile and immature birds around their farms. Some fish farmers are even trying to attract White-tailed Eagles to their farms to get the eagles chasing away seagulls, cormorants, herons, and crows around the fish cages.
Markus Jais: Is there competition for food or nest sites with other raptors like Golden Eagles or Ospreys?
Alv Ottar Folkestad: In some situations there may be an apparent competition between White-tailed and Golden Eagles e.g. on carrion, and the White-tailed may chase the Golden Eagle to take over their prey from time to time. How far this is a real competition, however, is difficult to say. In general there is no indication that the one species is excluding the other. The same is more or less the situation concerning their nests. Sometimes the two species may use the very same nest alternatively, and perhaps more often the White-tailed Eagles are taking over Golden Eagle nest than opposite. However, the general trend of nest site selection in the two species in Norway is different. The White-tailed is mainly a tree breeder whenever trees are available, and the Golden Eagle predominantly a cliff nester. There have been cases of successful breeding in neighbouring pairs of White-tailed and Golden Eagles down to a distance of 134 metres apart, cliff nesting on each side of a gorge. White-tailed Eagle and Osprey are overlapping to a very small degree in Norway, and we have no indications on potential interference.
Markus Jais: What is known about the dispersal of juvenile birds?
Alv Ottar Folkestad: More than 4000 White-tailed Eagle nestlings have been ringed in Norway since 1976. Ringing recoveries show a very wide variety of behaviour and dispersal, ranging from Ijselmeer in Netherlands (immature bird) to inland Kola peninsula, Russia (adult bird). Generally there is a tendency in juveniles and immature to be moving SW along the coast during late autumn and winter, and a corresponding movement north during spring and summer, even including birds born in Southern Norway. Most recoveries of adult birds are within 60-90 km from their native area, but some obviously emigrating up to 700 km.
Markus Jais: Do adult birds leave the colder areas during the winter and do eagles from other countries visit Norway during the winter?
Alv Ottar Folkestad: There are no indications that Norwegian adult birds are leaving their territories even during spells of very cold weather. May be this is because most of the breeding population is spread along the seashore and most of the population has a short way to go for ice free waters. During winter we have a number of visitors from other countries, mostly so from Swedish and Finnish Lapland populations, but even some from the Baltic populations further south. Of special interest is an eaglet taken from Northern Norway 1993 to be introduced to the Scottish west coast population, and who returned to Norway the next summer migrating over Orkneys and Shetland to Mid-Norway. Later on she ended up in South-western Norway as a breeding female and has stayed there since as a very reproductive bird!
Markus Jais: How many birds die from illegal poisoning and electrocution?
Alv Ottar Folkestad: The White-tailed Eagle once suffered from poisoned bait long before they were protected, when e. g. strychnine was used for exterminating predators and scavengers. After the decision of fully protection only very occasionally it has been suspected that White-tailed eagles may have fallen victims for illegal poisoning, even though during recent years there have been some few cases confirmed of poisoned Golden Eagles. Electrocution and collision with power lines is by far the dominant death cause in ringing recoveries in first year Norwegian birds. Even the next 2-3 years this is a high ranging cause of death. However, from their fourth year of life electrocution and collisions is reduced to a low frequency, and is staying so in adult birds.
Markus Jais: How many birds die from lead poisoning? Are there efforts to make lead ammunition illegal or are hunters encouraged to use non lead ammunition?
Alv Ottar Folkestad: Neither has lead poisoning showed up to be any frequent problem in the White-tailed Eagles in Norway, actually more so in Golden Eagles. Use of lead ammunition for shotgun is banned in Norway.
Markus Jais: Are pesticides still a threat to the species in Norway?
Alv Ottar Folkestad: Pesticides have never been any serious threat to Norwegian White-tailed Eagles, though locally there may have been some odd incidents, including high mercury level, even lethal, and sometimes chlorinated hydrocarbons (PCB for instance). Therefore pesticides have not been regarded as any big problem in the Norwegian White-tailed Eagle stock.
Markus Jais: What other threats to White-tailed Eagles do exist in Norway?
Alv Ottar Folkestad: During the history it has time and again been demonstrated that the main threats to the White-tailed Eagle are connected to human activity, directly or less directly. For about a century and a half it was persecution. Today it is land use in different ways, forestry, tourist industry, boating, and hiking, but what to me is a really scaring prospective is the way wind power development has been introduced in this country. The first wind power plant of significant size in Norway, on Smøla, is localized into the most spectacular performance of nesting concentration of White-tailed Eagles ever known. There are plans for making wind power into huge dimensions, and most of them localized in the most pristine coastal landscape of the most important areas of the White-tailed Eagle. During the last five and a half years, the wind power plant on Smøla has been killing 40 white-tailed eagles, 27 of them adult or sub adult birds, and 11 of them during 2010. There are no mitigating measures taken so far, and hardly any to think of, and there is no indication of adaptation among the eagles to such constructions.
Markus Jais: What needs to be done so that the population can continue to increase or remain stable where the full capacity of the ecosystem has already been reached?
Alv Ottar Folkestad: The only way to secure a good and healthy population is to realize that the existence of the White-tailed Eagle, like a number of other wild creatures, fully is in the hand of the humane race. They need to have their nesting areas free from human disturbance during the period from long before egg laying and half the way to fledging chicks to secure a good reproduction.
Markus Jais: What lacks in our knowledge of the species do still exist and where should research focus in the future?
Alv Ottar Folkestad: There is a lot of knowledge gathered worldwide on the White-tailed Eagle during the last decades, drawing up a picture of the species that may be a bit different from what we used to think of fifty years ago. However, personally I would like to have the focus much more on which role the species has to play in the ecosystems where it belongs, to fully understand how it functions as a scavenger much more than a hunter in the communities of coastal, marine or wetland dwellers, not as a threat to other species, but a co-player well adapted to fill its place
Markus Jais: How do you see the future of the White-tailed Eagle in Norway?
Alv Ottar Folkestad: By now we have a very strong and mostly healthy White-tailed Eagle population in Norway. If the current situation continue, the coastal areas even in southern parts of the country will be filled up to capacity during rather few years, and an inland population will reach that level in due time. But another prospective may be scaring close. It took us less than 100 years of persecution to exterminate the species from the southern parts of the country, and exploitation of the last areas of pristine coastal nature where the White-tailed Eagles have their strongholds may very well reverse the positive situation of today.
Markus Jais: What was your most amazing experience with White-tailed Eagles?
Alv Ottar Folkestad: It is very difficult after four decades of living with White-tailed Eagles to pick out just a few. There are so many, but to mention a couple of them burned into my mind forever:
The pair I had been watching on a daily basis for eight years from their first indications of becoming a pair. They had been building their nest, laying their eggs every year, and every year failing until their eight year when they finally had a downy chick in their nest. And then one morning after a day and a night of pouring rain. The male was coming in with fish, tearing up pieces by pieces to feed the small downy one, but no response. Male was taking to his wings to his perch in a dead and silvery tree top close by. The female looking into the nest cup, bowing down and carefully and tenderly taking up the chick, hanging dead in her beak, then laying it carefully, very carefully back, walking slowly with careful footsteps along the nest rim to the opposite side of the nest, standing upright with her head on her shoulders and her beak lowered. So far from the blood stained stories told about the eagle’s behaviour and character.
And another: One of those light northern summer nights. I was coming up to a White-tailed Eagle’s eyrie on top of a small crag surrounded by 3-4 metres high aspen trees. There just in front of me the female sitting sleeping on the branch of a silvery grey dead aspen tree, only one short metre away, her huge, yellow beak borrowed deeply into her shoulder feathers, her eyes closed. At the base of the trees her huge nest with her two fully feathered chicks, even they laying sleeping with their heads hidden into their shoulder feathers. The scenery was so peaceful and beautiful that it was impossible for me to break into it and disturb the birds and their privacy. I had to redraw and leave the birds alone, and wait until later to ring the chicks, which was my errand for the nest visit that night.
Markus Jais: Alv, thank you very much for the interview.