As the begins to change from summer to autumn, we can notice a shift in the ages of birds being caught along their migration routes, the beginning of autumn normally shows the arrival of juveniles en masse, this is because: 1, there are more juvenile birds present at this time of year than at any other, compared with ratio to adults. 2, Juveniles disperse from their nesting grounds earlier and undertake shorter hops (a slower migration) than the adults which arrive later on as they surge for their wintering grounds.
Saturday morning however, I noticed a shift amongst Garden Warblers, Lesser Whitethroats and the Whitethroats with regards to their ages; after weeks of only catching juvenile birds today we caught the 2nd,3rd and 4th Adult Lesser Whitethroats of the autumn, the same trend was shown by the other species.
|Garden Warbler-2cy+ note the worn (and 1 replaced) Tertials. Craig Brookes|
Louis Hansen: "05:15 - 17:25 : Teal 800, Arctic Skua 60, Long-tailed Skua 5-7, Little Gull 265, Black Tern 15, Osprey 4, Shoveler 310, Red-Throated Pipit 1" also a Juv Mediterranean Gull was seen.
Photo and Blog : Craig Brookes