Glaucous Gull

Glaucous Gull

Larus hyperboreus Hvítmáfur

Glaucous Gulls occurred in single numbers in the survey area during April and May, and then were absent until 6th September. A peak count of 96 Glaucous Gulls was recorded on 9th October. However, due to difficulty accurately differentiating Glaucous and Iceland Gulls (which share identical plumage characteristics and differ only in body proportions), during surveys when observation conditions were suboptimal or when the birds were being observed at considerable distance, these two species were recorded as ‘Unidentified Glaucous /Iceland Gull’ (see below).

Number of individuals 120 100 80 60 40 20 0 Low-tide Rising-tide

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 Mar Apr May Jun Jul Aug Sep Oct Week number and month

Figure 3-115. Number of Larus hyperboreus recorded during weekly low tide and rising tide estuarine surveys in the Andakíll Ramsar site between 12th March and 25th October 2017.

Figure 3-116. Relative abundance of Larus hyperboreus during weekly (a) low tide and (b) rising tide estuarine surveys in the Andakíll Ramsar site between 12th March and 25th October 2017. Dots are randomly positioned within each subsite. While each dot refers to a single bird, it refers to the bird’s presence in that subsite only, and not the bird’s actual location.

(a) Low tide (b) Rising tide

(a) Autumn

Figure 3-117. Relative abundance of Larus hyperboreus during autumn (6th September– 25th

October), counted on twice-weekly estuarine surveys in the Andakíll Ramsar site in 2017. No map is provided for spring due to the low numbers recorded. The number of dots in each subsite refers to the total number of bird-records (from weekly low tide and rising tide surveys), and reflects the species’ abundance, not the specific location of birds.

Figure 3-118. Proportion of foraging and roosting Larus hyperboreus during weekly (a) low tide and (b) rising tide estuarine surveys in six subsites in the Andakíll Ramsar site between 12th March and 25th October 2017.

(a) Low tide (b) Rising tide