We have lots (and lots) of really big trees in our yard, most of them some kind of nut tree -- oak, hickory, etc. There's also a large squirrel population, as you might imagine.
We noticed this weekend that, although the leaves are falling, there are NO nuts. None. Normally you can barely walk upright on the driveway by now because of all the acorns rolling around underfoot. Whether it is because of a freeze one night in early spring that killed a lot of new growth on trees, or because of an unusually dry summer, or both, or something else that we don't know about ... there doesn't seem to be any nuts. Maybe they just haven't fallen yet ... but I don't think so. It kind of makes me sad.