A red-breasted nuthatch hides 22 seeds in half an hour

The fir seed is falling hard on the ridge road this week, and a red-breasted nuthatch that finds a good cone does not eat all of it. It hides it, one seed at a time, in bark.

Half an hour of hiding

I followed one bird with glasses from 09:20 to 09:50 and recorded every cache: 22 in 30 minutes, one every 82 seconds on average.

• Trees used: three Douglas-firs, all with deep, scaly bark and no moss on the north face. The bird never cached on the two mossy hemlocks it passed.
• Heights: between 2.1 m and 9.4 m, with 15 of the 22 between 4 m and 7 m.
• Technique: the seed was wedged into a crevice with the bill, then tapped two or three times with the bill, which is how the bird makes sure it is tight.
• Revisits: two caches were revisited inside the half hour, both of them emptied.

A cache in bark is not buried and not defended. It is a bet that the bird will remember where it put it, and that nothing else will find it first. The two empty revisits in half an hour suggest the memory is good.

Why the crop matters

Red-breasted nuthatches stay or leave depending on the conifer crop, and the trees on this plot are having a good year: 31 cones per square metre under the sample firs on the ridge, against 4 in 2024. When the crop fails, these birds move downslope and south in numbers; when it holds, they stay and cache all autumn.

Eight minutes after the nuthatch moved off, a Steller's jay worked the same three trees. I did not see it take a cache, but a jay watching a caching nuthatch is a jay that knows where the food is.

What to check next time

• Count caches in the same 10 m of trunk in December to see how many are still being used.
• Look for a second bird caching nearby, which would mean a pair holding this plot for the winter.
• Note whether the bird caches in the same three trees or switches after a hard frost.