Nest of a Strange Bird?
No. Earthball fungi feed on dead wood and these, by chance, are in a nest-like hollow.
Scleroderma citrina can be found in considerable numbers in our woods at this time of the year.
Olympus EM-1 (aperture priority), Olympus 4/3 x2 TC, Olympus 4/3 50mm f2 macro, 1/25 at f11 ISO 800, hand-held.
The stereos are crosseye.