Плавают ли орланы? я в смятении...

Вот пара ссылок, одна - с фотографиями.
http://www.ketchikanphotos.com/Wildlife/Bald-Eagle-swimming.html
http://elibrary.unm.edu/sora/Auk/v086n03/p0561-p0561.pdf
Могут, если очень надо.

Ну, судя по наблюдениям, - сами в воду лезут без фанатизма, но и без лишних комплексов перед водной стихией.
Под "очень надо" - я имел ввиду, что в норме они при охоте так делают нечасто - об этом свидетельствет и сам факт появления об этом публикаций и фотографий,  - ибо регулярно так охотиться для орланов энергетически достаточно затратно. Но если что - то перед водой не робеют. Экстремальным для них попадание в воду не является.
Для курицы же это уже будет именно "выплыть" из экстремальной для нее среды.
Ну, а насчет нормы жизни и регулярности времяпровождения - опубликованной статистики нет. Думаю, что в определении "нормы жизни" найти какие-то базовые цифры - что считать нормой, а что нет - очень сложно. Раз в день, (неделю, месяц, год) для одной особи - это "регулярно"? В этом ключе вопрос, действительно, интересный. И не знаю, исследованный ли. Здесь, как раз, можно у Владимира Мастерова спросить - часто ли они так делают вне охоты и в каких ситуациях это наблюдается.

Плавают, но при необходимости. Поймав слишком крупную добычу, при экстремальных ситуациях, когда невозможно быстро взлететь с воды. При плавании одновременно загребают обоими крыльями (в стиле кроль), ноги при этом вытянуты вдоль хвоста и выполняют роль руля. Этим стилем я плаваю медленнее   Намокнуть орлану очень трудно, вода его выталкивает. Скорость плавания достаточно большая, несколько сот метров вполне преодолеть по силам.

Наши ребята наблюдали, как белохвост утопил черноголвого хохотуна (чайка размером с небольшого гуся), посидел на нём в воде, а потом унёс. Так что орлан - очень серьёзная птица и достаточно жизнестойкая.

Обсуждение плавания хищных птиц в мэйлинг-листе Raptors-Conservation:

Stanley Moore
I cited a case where my own great horned owl once jumped into a pond and was easily able to make it back to shore.  And an ornithologist from Peru described seeing a Cooper's hawk that had attacked a thrush and forced it into water then entered the water and had no trouble swimming with its prey back to shore.
Some time ago I heard of a report of a storm over one of the North
American Great Lakes in which perhaps millions of migrant passerines,
especially warblers, were driven into the large body of water during
a severe storm. Many birds washed up dead on the shores of the storm
for days afterwards, and fisherman who caught large lake trout on the
lake also found carcasses of small birds in the stomachs of the trout
which had exploited the temporary food resource. I could envision
something like this happening to small raptors such as sharpshinned
hawks or sparrowhawks and perhaps even large raptors including eagles
could be taken by orcas or crocodiles or other large predators when
they were trying to row to shore after entering the watery domain.

I also recall speaking with raptor bander Daniel Berger once about
his trapping of ospreys using a live great horned owl and dho-gazas
on a floating platform near osprey nests on snags in the water. Dan
would wait in a boat and recover the ospreys if they got caught in
the dho-gaza, but I asked him if he was worried about the ospreys
drowning before he could get there. He told me it was not a major
problem because the birds were very buoyant and it makes sense to me
now that any bird adapted to flight in the earth's atmosphere would
be extremely buoyant on the much denser aqueous environment. There
are photos of this sort of trapping in Hans Bub's book "Bird Trapping
and Banding: Techniques from around the world" published in the
1970's (I believe) by Cornell University Press.


Pat Redig
Interesting query - I can cite three instances of raptors swimming - rowing
might be a better term as the locomotion involved the wings. Case
1: Adult goshawk (falconry bird) flies down and captures a female mallard
about 30 meters off shore - submerges for a moment, then resurfaces and
rows to shore with still alive duck in tow - I intercepted them about 3
meters offshore. Case 2: Juvenile bald eagle - bailed out of nest when
climbers approached rim of nest - flew down shore of a lake a short
distance and ended up in shalloow water - attempts to "rescue" the bird
resulted in it swimming (rowing) across a shallow bay for about 100 meters
where it hauled out on shore. It was captured and returned to the
nest. Case 3: Juvenile peregrine falcon on first flight attempt from a
nest site on a bridge over the Mississippi river where there was about 150
meters of open water. The young male was seen to fly away from the bridge,
then attempt to circle back and land on the understructure. He
miscalculated, stalled, and fluttered down the side of a columnar piling
into the water, which had a pretty good current. He rowed to shore, about
half the distance of the open water, and hauled out quite some distance
downstream from the point of entry. He was seen to dry out on the rocks
and later flew to a nearby tree - no further reports after that.

Rick Harness
I watched an osprey catch a large fish on the Flathead River in Montana.  The osprey couldn’t lift the fish and thus swam about 30 yards to shore with it…

Bob Ritche
I have seen an adult Bald Eagle swim into shore in Prince William Sound, Alaska, after missing an attempt at a fish.  It actually used a small cresting wave to get 'thrown' forward and fly briefly ahead of the surf.

Ivano Angelov
Some 7-8 years ago during mid-winter watefowl census in Bulgaria in Jrebchevo reservoir we observed a male Goshawk catching Black-headed Gull (L. ridibundus) over the water surface and it falled into the water with it. The gull very soon get drown and the hawk swimmed with it to the shore a distance of about 150 meters for about 5 minutes taking small breaks from time to time. As it reached the shore it immediately started plucking and later feeding at the gull.

Gordana Pavokovic
In Croatia, Eurasian Griffons are nesting on cliffs above sea. During summer, tourist come next to the cliffs and claps their hands, or scares them on another way, to see how they fly. Inexperienced young birds often fall to sea. Also, poisoned birds sometimes fall to sea. They are able to swim for 30-45 minutes. Sometimes, they are able to climb on the rocks under cliffs, or have to be taken on the boat. Thanks to good Vulture protection campaign, local people and tourists often call rescues from Vulture Recovery center on the Island of Cres.
Rescued Griffons often show signs of diarrhea and vomiting.

Marge Gibson
Bald Eagles are excellent swimmers.  I've trapped many balds in Prince Wm Sound, AK.  They displayed their swimming prowess often.
A few years ago we had a case of a fledgling bald, blown from the nest by straight line winds.  They eaglet landed in the middle of a large lake and swam to shore where he was rescued.  Residents of the lake that made the observation thought he was a huge snapping turtle coming ashore.