Associative breeding of waders: We always wondered about the nesting situation of waders. Specifically, do different species nest together in the tundra? For example: Curlews, Sanderling, Knots, how close do they build their nests to each other? Karina and Bruno – Peruíbe Brazil

The Guru’s answer: Of the species you mentioned, among the tundra breeding Curlews (Numenius), the Little Curlew N. minutus forms loose colonies. The Bristle-thighed Curlew N. tahitiensis has just a small population that only breeds in two areas. In those areas the Curlews nest close enough to one another that several broods will join together in creches, guarded by a small number of adults, sometimes only one male, but that group will always include the male of at least one of the broods involved. Hudsonian Whimbrels N. hudsonicus and Eurasian Whimbrels N. phaeopus tend to be solitary nesters. Sanderlings Calidris alba too are solitary and do not travel far with the chicks from their breeding site and Red Knots Calidris canutus, whilst also solitary, range beyond the breeding site for feeding once the chicks have hatched. Read full answer here.

Mystery wader: I’m not very good at wader identification, but I’ve seen a mystery wader at my local reservoir (Thornton Reservoir) that I just can’t seem to spot with my very poor scope, but I hear it calling really loudly! I mistook it for a Kingfisher but when it flew out of the reeds it was definitely wader shaped! It flew just above the water, it had white underneath and greyish on the top, it flew with a stiff but manic flapping in action. It surprised me to see it as Thornton reservoir has no mud flats or anything (I call it a blue desert) so was totally shocked to see it there. Even with the water low, there are some mud flats but its easily accessible to dogs, unfortunately. Kirsty – Leicester UK

The Guru’s answer: You mentioned the Kingfisher-like call and the call of the Common Sandpiper does sound a bit like that. Read full answer here.