ML370275431
Colaborador
Data
Localização
- Idade
- Não especificado
- Sexo
- Não especificado
Detalhes da observação
Previously submitted as jaeger sp. so I could first look at photos on the computer. I first heard some commotion north of J3 as I was making checklist notes and when I looked I saw an adult jaeger pop above the tree line in the channel harassing a gull; the black cap and apparent penchant for harassing gulls led me to believe this. Exciting!! But would it come back? A few moments later it came darting down the channel that goes from the NE end of Sturgeon Lake out towards Oak Island. It soon gained altitude above the gull roost and almost all gulls in the area took flight as it continued to fly south over Sturgeon Lake. Goodbye Sabine's! Goodbye Franklin's! Goodbye Bonaparte's! The gulls pretty much all got chased out to the NE corner of Sturgeon where the jaeger came from. It then continued to fly southwest and I lost it. I compared my observations and photos to the Kaufman Field Guide to Advanced Birding and landed on Parasitic Jaeger along with the support of a few people on the Portland WhatsApp chat and looking through the Macaulay Library for each of these birds which all came together to solidify this hunch. The flight style of the bird was not tern-like which would usually point away from Long-tailed, but as I understand it this can be variable if the bird is in chase mode which I believed this one to be. What I did notice was that the bird did spend some time gliding with strong yet not as rapid wingbeats as a PEFA. This shift to gliding between wingbeats seemed to have happened once the gulls all began to disperse. The wings also did not seem that broad yet not totally slim, somewhere in the middle. All of these details seems consistent for Parasitic on a normal day while looking at my photos and scrolling through the Macaulay Library. The bird had a longer bill compared to that of Long-taileds and not as heavy as a Pomarine, nor did the overall size of the bird seem to be as bulky as Pomarine's from comparing pictures on Macaulay Library. The shape of the central tail feathers also seem to exclude Pomarine. From my understanding, the length of the central tail feathers are not always a good indicator of jaeger sp. between Long-tailed and Parasitic since they could be broken or lacking completely, but that doesn't seem to be the case with the feathers on this bird as they each seem to come to a tapered end. The white shafts on the primaries seem to be very bold on this bird for at least the last 4 which is very surprising that I could discern this from a distant photo. The white base of these primaries on the underside of the wing also seem to point away from Long-tailed and toward Parasitic. With all of this evidence, Parasitic seems to be the right choice here for this very awesome bird that capped off an exciting morning at J2!
Informação técnica
- Modelo
- Canon EOS 90D
- Lente
- 100-400mm F5-6.3 DG OS HSM | Contemporary 017
- ISO
- 1600
- Distancia focal
- 400 mm
- Flash
- Flash did not fire
- f-stop
- f/8.0
- Velocidade do obturador
- 1/3200 sec
- Dimensões
- 998 pixels x 998 pixels
- Tamanho do ficheiro original
- 131.02 KB