Norwick: 2 Tree Sparrows.
Haroldswick: 9 Whooper Swans & Black Redstart.
Uyeasound: 7 Taiga Bean Geese & Greenland White-fronted Goose.
Whooper Swan on the sea at Haroldswick
Otter with prey
Greenland White-fronted Goose with Greylags at Uyeasound
Taiga Bean Geese at Uyeasound
A flock of jumpy Bean Geese that were first seen by Brydon on Sunday. We today obtained a series of rather distant and brief views as they proved incredibly wary in very stormy weather but at least we were watching them in nice light between the heavy showers!
It’s fair to say that I’ve never found the identification of Taiga and Tundra Bean Geese straightforward but that’s probably no surprise given:
Separating Taiga and Tundra Bean Geese from each other is often difficult, or even impossible, due to the occurrence of individuals with intermediate features (the extent to which these intermediate features are a result of hybridisation is not known. Family groups can be easier to identify due to their more or less homogenous features. (van Duivendijk 2024).
Here's a few annotated images...
As for comparative size, based on the following two images I think it's safe to say that you would estimate a 20% weight difference...
Greenland
White-fronted Goose (centre) and 2 Taiga Bean Geese
Comparative average
weights per BWP: Taiga 2843-3198, Tundra 2374-2668 & Greenland 2526-2543
Taiga Bean Goose
and Greenland White-fronted Goose
Alongside the Greenland White-fronted Goose it’s
easy to appreciate not only the overall larger size but also the longer,
thicker neck and more attenuated rear end of the Taiga Bean Goose.
Greylag Goose (left)
and 6 Taiga Bean Geese
Clearly the two species appear comparable
in size.
Average lengths are given for Greylag Goose as
79cm and Taiga Bean as 83cm (van Duivendijk 2024).
Taiga Bean Geese at Uyeasound
Whilst distant, it's hard to imagine Tundra Bean Geese ever taking on the long-necked appearance, head shape and bill shape profiles of the left two individuals and the long attenuated bodies of the left and right individuals.
But, as so often is the case with Bean Goose identification, not everything appeared quite so straightforward...
I was less keen on the appearance of the left individual. Whilst it appears little different in size to the accompanying Taiga, it consistently appears to have a more triangular, thicker-based, less slender bill with a slightly swollen base to its lower mandible, albeit its culmen appears concave. Additionally, its bill pattern resembles that of a Tundra, although c.10% of Taiga show similar bill patterns (van Duivendijk 2024). I wouldn't have wanted to see it as a lone individual and can easily imagine considering it a large gander Tundra or a so-called 'Dutch intergrade'...
