Great White Egret (Great Egret, Great White Heron) Ardea alba (Egretta alba, Casmerodius albus)
Great White Egret is a rare visitor to the UK from Europe, although records have increased in the last 15 years or so. Sightings of 2 or even 3 birds together have now been reported a few times but the amazing flock of 8 shown below was completely unprecedented in the UK.
In Europe this species was formerly known as Great White Heron, but this name should be avoided to prevent confusion with the similar all-white form of Great Blue Heron Ardea herodias occidentalis that is known by the same name where it occurs in North America.
This species has an extensive world range and in North America the form that occurs there (race garzetta) is more commonly known as Great Egret. This form is suspected as having occurred in the UK on occasion and the following photos all belong to this form.

