White-tailed eagle - Haliaeetus albicilla

[OldGreenVulture]

White-tailed eagle



Region: Arctic

Destinations: Lofoten, Fair Isle, Greenland, North Norway

Name: White-tailed Eagle, Sea Eagle, Erne, White-tailed Sea Eagle (Haliaeetus albicilla)Length: 65 to 95 cmWeight: 3 to 7 kgLocation: Northern Europe and Asia, winter in Mid-East and Eastern AsiaConservation status: Least ConcernDiet: Fish, birds, small mammals, carrionAppearance: Greyish-brown with white highlights and a white tailHow do White-tailed Eagles feed?The diet of any one White-tailed Eagle depends very much on its location in the world and on the season.

White-tailed Eagles are opportunistic, snatching food from other birds and otters. They’re excellent fishers, snatching fish near the surface of the water. They will also scavenge – either garbage or carrion from the kills of other animals.

White-tailed Eagles have been known to attack entire colonies of smaller birds, causing the adults to scatter and abandon the young and the eggs. Because of this some smaller birds have been forced to relocate their entire colonies away from White-tailed Eagle ranges.How fast do White-tailed Eagles fly?White-tailed Eagles can reach speeds up to 70km per hour.

What are White-tailed Eagle mating rituals like?White-tailed Eagles mature sexually around 4 years of age.

Courtship involves aerial displays culminating in the male and female locking talons and spinning toward the earth together, breaking off only at the last moment.

The Eagles bond for life. They’ll build a nest with sticks in trees or on cliffs. Being territorial, the Eagles will often return to the same nests year after year, and once one pair dies out another pair may take up residence in the empty nest.

The female will lay 1 to 3 eggs per year in March or April. The incubation, performed by both adults, takes about 40 days. The female takes up the majority of the protection of the chick while the male goes off to hunt and bring back food.

Once hatched, the chicks can feed themselves starting around 5 weeks old, and they fledge (grow flight-worthy feathers) at about 11 weeks of age.How long do White-tailed Eagles live?White-tailed Eagles live about 20 to 25 years on average.How many White-tailed Eagles are there today?There are over 12,000 White-tailed Eagles in Europe.Do White-tailed Eagles have any natural predators?White-tailed Eagles do not have any natural predators, making them an Apex Predator.7 Wonderful White-tailed Eagle Facts
White-tailed Eagles are closely related to Bald Eagles. They hold the same niche in the ecology of Eurasia that the Bald Eagle holds in North America.
On average the White-tailed Eagle has the largest wingspan of any Eagle.
The largest population of White-tailed Eagles in Europe is found along the coast of Norway.
A White-tailed Eagle’s territory can range as far as 70km. They’re almost always located around bodies of water.
A White-tailed Eagle appears in Germany’s coat-of-arms and is Germany’s national bird.
White-tailed Eagles are the largest Eagles in Europe.
The White-tailed Eagles found in Europe are mainly sedentary, while the White-tailed Eagles found in Russia and northern Asia are migratory.

oceanwide-expeditions.com/to-do/wildlife/white-tailed-eagle

[Eaglehawk]

Proximity to paths and roads is a burden for white-tailed sea eagles


by Forschungsverbund Berlin e.V. (FVB)


White-tailed sea eagle with fledgling in nest. Credit: Oliver Krone

The white-tailed sea eagle is known for reacting sensitively to disturbances. However, research into which factors have which effects on the animals and how these impacts influence breeding success has so far only just begun. A research team led by Dr. Oliver Krone from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) has now measured concentrations of the hormone corticosterone and its metabolic products in white-tailed sea eagles in northern Germany and correlated these values with potential causes of "stress". They found that the levels of corticosterone in the birds' urine are higher the closer a breeding pair's nest is to paths or roads. From this, the scientists derive implications for the management and protection of white-tailed sea eagles, in particular for protection zones around the nests. The study was published in the journal General and Comparative Endocrinology.
Important areas of distribution of the sea eagle in Germany—such as the Mecklenburg Lake District or the Baltic Sea coast—are also attractive tourist regions. As a result, visitor numbers in core breeding areas are high and continue to rise. Since typical tourist activities—hiking, cycling, and water sports—focus on experiencing nature, researchers see a potential conflict between visitors and the sensitive animals. "In order to either confirm or refute this assumption, we measured the level of the hormone corticosterone in urine samples of 52 white-tailed sea eagles in the Usedom Island Nature Park in spring and early summer," explains Dr. Oliver Krone of Leibniz-IZW, head of the study.
For this, they use excrement samples from 6 to 8 week old young sea eagles, which they collected from leafs in the direct vicinity of the nests. Long-term data of the Leibniz-IZW sea eagle project were also used to determine the population density of the white-tailed sea eagles in the respective area, the breeding success of the sites and the distance of the nests to the nearest road or path. "By means of statistical tests, we were able to check the relationship between these long-term data and hormone levels," says Krone. "We were able to detect lower levels of corticosterone in samples collected at sites greater in distance from roads or paths." The relationship is statistically highly significant, demonstrating the negative effect of the "stress factor" road or path. At the same time, Krone could not prove any negative influence of this factor on breeding success. "Whether breeding is successful at a given location does not seem to depend on the corticosterone level or the proximity to roads and paths," says Krone. Rather, there is a correlation between sea eagle density and breeding success: In already densely populated regions (more than two pairs per 121 square kilometres), the chances of having offspring are significantly lower than in regions thinly populated by sea eagles.
To prevent negative effects on the breeding performance, the scientists regard adjustments of the protection zone regulations as necessary. These regulations in the German federal states of Brandenburg and Mecklenburg-Vorpommern, for example, restrict forest and agricultural use within a radius of 300 metres of an eagle's nest. "Hiking trails or riding paths have not been affected by this regulation so far," Krone adds. Yet, intensive tourist use, as is the case on Usedom for example, is proving to be just as "stressful" for sea eagles. "We suggest to exclude tourist use and development within a radius of 100 metres around the nests and to prevent any leisure activities off the beaten track, paths or roads in breeding regions", Krone adds: "Car traffic on the road is not disturbing sea eagles at all, the animals can get used to it well. However, pedestrians and cyclists who pass too close to the nest pose a potential danger to the eagles."
Intensive protection efforts over the last 100 years have saved the sea eagle from extinction in Germany. They were placed under protection in the 1920s, after hunting in particular had reduced the population to a critical level. Meanwhile the population of white-tailed sea eagles has grown back to a stable level. However, the use of leaded ammunition in hunting still has a negative effect on the birds, which in winter feed on the carcasses of animals left behind by hunters. Currently there are about 800 breeding pairs of the white-tailed sea eagle in Germany, projections assume a potential of 1200 breeding pairs for Germany.

phys.org/news/2019-10-proximity-paths-roads-burden-white-tailed.html

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Journal Reference:
Oliver Krone et al. Monitoring corticoid metabolites in urine of white-tailed sea eagles: Negative effects of road proximity on breeding pairs, General and Comparative Endocrinology (2019). DOI: 10.1016/j.ygcen.2019.113223

Abstract
The white-tailed sea eagle (Haliaeetus albicilla) is known to be sensitive to disturbance. To better understand potential stressors, we measured corticosterone metabolite levels in H. albicilla excreta and recorded the nest success of breeding pairs. We tested the ability of four enzyme immunoassays (EIA) to measure urinary glucocorticoid metabolites (uGM) in the excreta of one adult female eagle subjected to a controlled physiological stress treatment. We identified corticosterone-21-HS to be the most sensitive EIA to changes in uGM concentration. To exclude a sex bias, we confirmed the assay’s applicability with samples collected from similar stress treatments in two juvenile males. We used the identified EIA to measure uGM in wild breeding pairs and tested effects of disturbance. Breeding pairs nesting closer to roads and paths had higher uGM concentrations (p = 0.02), which is likely an effect of human recreational activity and disturbance. There was no difference in uGM concentrations between failed and successful nests. Our results highlight the potential impact of road and path proximity on white-tailed sea eagles, with potential importance for species management and conservation, particularly with respect to nest protection zone legislation.

www.sciencedirect.com/science/article/pii/S0016648018304258?via%3Dihub