Agree with Peregrine (of some sort) but I can't see it being a calidus with that moustachial stripe! To me it looks like one of the smaller subspecies
E.L.Schiøler in "Danmarks Fugle vol. 3" states that peregrinus and calidus are practically similar*, with only a clinal trend for birds to become larger and paler the more Northeasterly the origin (breeding place)
The
huge individual variation within
peregrinus makes it impossible to ascertain whether any of the skins in the C.N.M. belong to calidus, and that's why the latter subspecies has never been officially recorded in Denmark, even though it undoubtedly occurs here regularly.
There's a tendency for birders - in an almost Pavlovian response to every pale, juvenile (or even adult) Peregrine - to exclaim:
"wow, a calidus!" , but
it's a myth that is hard to get rid of.
But at least we should
try
If someone will look up the matter in Forsman's new book, I'll be very surprised if he advocates determination of calidus in the field (and in the hand) on the width of the moustachial stripe. Not to easy a measurement to obtain when a bird passes at 200 meters overhead3
Adult calidus is (on average) paler grey on the upperside, and the bird in the OP seems quite pale (the newly acquired first adult feathers on the mantle and scapulars), so it
might be a genuine calidus since that race is a longdistance migrant, and probably more prone to be found at such a location in the migration seasons.
The unavoidable conclusion, however, is that we
shall never know for certain, because calidus
cannot be determined with certainty in the field.
Which brought me to back to The Calidus Myth...and I don't really like to go there.........so, over and out.
Peter
* the width of the moustachial has litte significance, since this character is hugely variable within the distribution of the nominate form, and whether individuals are collected in Denmark, UK or Sweden, one can find birds with paler forehead, narrower streaking on underparts (and face markings), side by side with birds that are more densely streaked underneath, and have broader moustachial stripes. On the face of it, completely the same as accounts for the huge individual variation in all plumages of the Eurasian Sparrowhawk. Or Long-eared Owl as well as in many, many more species......
