Greetings Japanese boys (Charles and Stu)
Firstly Charles, the nests are at undisclosed locations to keep them away from the attentions of egg collectors. There aren't many in Iceland but one would be enough. As for unscrupulous twitchers - perhaps, although it would have been a long way to go and I don't think anyone would have bothered, even though I really want to see Long-tailed Skua. There are also people who just like to shoot rare birds so that they can have them stuffed. Don't even try and think of an explanation for that one.
Secondly Stu, there are few species in Iceland but as you say quantities are often huge although I think "quality" is a relative term. Many birders based in Britain would consider Harlequin, Barrow's Goldeneye, Grey Phalarope, Gyrfalcon, White-tailed Eagle and Brünnich's Guillemot fairly decent quality.
Our regularly breeding passerines are Redwing, Redpoll, Wren, Snow Bunting, Wheatear, White Wagtail, Meadow Pipit, Goldcrest, Blackbird, Starling and House Sparrow (one location). However, we get plenty of vagrants in the autumn, ranging from the common (Blackcap) to the mega (Cerulean Warbler - only WP record). I saw for example 14 warbler species in Iceland last year (Sedge, Reed, Blyth's Reed, Icterine, Barred, Lesser Whitethroat, Whitethroat, Garden, Blackcap, Yellow-browed, Wood, Chiffchaff, Willow and Goldcrest) and a friend of mine saw these and Marsh and Sykes's. Of course our year lists are tiny compared to those in Europe, above 120 is considered pretty good and c. 165 is the record but it's all relative. So although the distribution maps show a real paucity of species, they don't always tell the whole story.