I was appalled by a gruesome discovery this morning just outside our front
door. The head of one of our magnificent ospreys had been severed and was lying
on the ground. A pair of ospreys has been nesting in a tall Norfolk Island pine
directly over our house for the past 20 years. I immediately suspected that the
perpetrator was one of a pair of great horned owls that have been hooting from
a stand of Australian pines next door. Great horns take over nests of other
bird species and are well known to evict even large birds of prey such as
ospreys and eagles. We had heard a commotion in the early morning hours and
thus surmise that one of the ospreys had been reluctant to abandon its
cherished nest and was attacked and killed by the great horned owls. These owls
are huge and ferocious and completely dominating at night when they can see
clearly while the daytime hunting ospreys cannot.
This is a painful lesson in the ways by which natural events sometimes unfold.
These can seem cruel, but conflicts over territory and breeding sites can be
extremely fierce and terminal for the loser. We are sad for our poor osprey but
have been taught a lesson in nature's classroom.
An interesting evolutionary question would be why great horned owls do not
build their own nests as do most birds? One answer would be that they thus save
themselves some effort and can by their own might usurp the breeding territory
of other birds. There is of course no competition for food between ospreys
(fish eaters) and great horned owls which feed on a wide variety of terrestrial
vertebrate prey (birds, mammals, reptiles). So the competition may be primarily
for scarce nesting sites and/or perhaps even the nests themselves, which
require considerable effort to construct. There is also the fact that an owl
nesting near an osprey or eagle would likely be subject to considerable
harassment during daytime since the owls might prey on the osprey and eagle
chicks. So by removing the nesting osprey the owls eliminate a source of danger
to themselves during daytime when they are most vulnerable.
Bill Dunson
276-233-6364 cell text
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Water view of Osprey nest in Norfolk Isl pine on FL yard Bill Dunson Docks FL lots 11.5.15 Bill Dunson IMG_1498 aa.JPG
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Osprey on nest in Norfolk Isl pine FL yard Bill Dunson IMG_2429 aa.JPG
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Great horned owl FL yard 1.7.16 Bill Dunson IMG_0760 aa.JPG
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Osprey head killed by great horned owl FL yard 1.14.16 Bill Dunson IMG_0880 aa.JPG
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