[ptha]

It seems that putting the test near the nest was done deliberately: Cognition is challenging to assess in wild animals because testing paradigms often require individuals living under similar conditions to be tested repeatedly. Administering cognitive tests where wild animals rear their offspring can overcome this challenge because breeders often return reliably to a known location. [1]

[1] https://royalsocietypublishing.org/doi/10.1098/rsos.211343#d...

[petee]

Thank you, I definitely hadn't read the original. It makes perfect sense, but I am still not sure just dropping a box halfway on the nest could have no impact on the results.

Reading your link, it says that some string tests also use unbaited strings, but it seems they didn't do that here? And I to bust my own argument, it also does say that some gulls didn't even interact with the string...