Further to James Ndungu's, Brian Finch's and
Marlene Reid's remarks on Common Sandpipers.
Although I've never seen this species in East Africa
in June (i.e., overwintering), I have always thought of it as a very
early returning migrant and believed this to be well-known and accepted.
Individuals certainly arrive in Kenya in July: I find my first "autumn" record
is of one bird on 8 July at Naivasha in 1972 but most of my July records are
from 20th onwards.
Britton (Birds of East Africa, 1980) and Zimmerman et al. (Birds of Kenya
and northern Tanzania, 1996), for arrival dates say,
". . . being especially numerous from late July to early
September.",
and
"common and widespread from mid-July . .
.", respectively.
Urban et al. (The Birds of Africa vol 2, 1986) also note, "1st adults
penetrate south of the equator by mid-July", so the species' early arrival is
well documented.
Further, Chapin (Birds of the Belgian Congo, vol 2, 1939) writes (of the
Belgian Congo, now DRC), "The astonishingly early arrival of birds from the
north has often led to the assumption that they have bred near the equator."
He goes on to give July (from 21st) and August records down to 7° S. His
remarks make it quite clear, though, that he does not think much of the claims
that it has bred in tropical Africa, "Of its nesting in tropical Africa I
am still skeptical. The van Somerens have published a photograph taken in
Uganda of a bird supposedly sitting on its nest, and Colonel Meinertzhagen,
too, reported young common sandpipers with their parents on the Kagiado River
in Kenya Colony." Well, now we all know about Col Meinertzhagen and his
records . . .
Many northbound Common Sandpipers caught for ringing in early May carried
a lot of fat.
Best
wishes,
Graeme Backhurst