Right outsideBirds
Blue jays carrying and hiding acorns in fall
When: September to October
Those loud jay parties in the oaks are a harvest crew: a blue jay carries up to five small acorns at once, three in its throat, one in its mouth, one in its bill, and a single jay may hide 3,000 to 5,000 nuts in a season.
Why this time of year
Acorn harvest is a fall job, and through the season jays commute between the oak canopy and caching grounds up to a mile and a half away, planting next century's oaks with every nut they forget.
How to notice it
- Follow the noise: loud groups of jays calling in the treetops this time of year are probably working acorns.
- Watch for the commute, a jay flying a purposeful straight line with a bulging throat.
- You will rarely see the burial itself; the harvest happens in the treetops and the hiding happens far away on the ground.
- Time the round trips: how long before the same direction of flight repeats?
Try this with kids: Watch a flying jay: does its throat look puffed out with hidden acorns?
caching means hiding food to eat later; forgotten caches become new trees
Sources
- westboroughlandtrust.orgIn autumn jays are busy harvesting acorns; blue jays prefer small acorns and can carry 5 at a time, three in their throat, one in their mouth, and one in their bill; a single blue jay may hide 3,000-5,000 nuts in a season, traveling to a chosen spot on the ground up to a mile and a half from the oak; loud groups of blue jays calling in the trees at this time of year are probably feasting; by planting and forgetting some acorns, blue jays help spread and regenerate forests.
- extension.illinois.eduA cited study found 50 jays transported and cached 150,000 acorns in 28 days, about 110 acorns per day per bird; jay-stashed acorns had a higher germination rate than those carried by other species and were planted at an ideal depth; jays are credited with spreading oaks after the ice age.
In the guide for September, October