ML419491061

Age

Not specified

Sex

Not specified

Observation details

A dark intermediate bird seen at distance in the PM whilst underway. Called as a distant jaeger given apparent light build and rapid active flight that culminated in it stealing food from a Crested Tern. Pale flashes in the upperwing were seen in flight but at the time these were assumed to indicate primary moult and visible pale webbing of some jaeger primries. Photos reviewed later demonstrate the bird was in fact a Cartharacta Skua with the obvious ID being South Polar given above outlined mis-ID in the field (ie 'light' structure and dynamic flight) and strength of pale flashes in upperwing. Collating images across 4 photographers resolved the ID as a South Polar Skua on the basis of evidence of golden nape, cold dark grey body that contrasted abruptly with adjacent darker upperwings, large white primary panels visible in both upperwing and underwing. The strength of the pale flashes alone was sufficient to strongly suggest SPS, the paler body contrasting with upperwings clinched the ID. 6 Feb is too early for a juv, strength of pale primary panel and apparent absence of primary moult (inferred not certain given tiny size of available images) suggests this may have been an immature (ie 2nd cycle bird)

Technical information

Model

Canon EOS 5D Mark IV

Lens

EF100-400mm f/4.5-5.6L IS II USM

ISO

640

Focal length

400 mm

Flash

Flash did not fire

f-stop

f/8.0

Shutter speed

1/2500 sec

Dimensions

4500 pixels x 3000 pixels

Original file size

846.64 KB