Friday, 13 November 2009

Hiding acorns

Do jays hide acorns? I have watched this one for about a month now. It appears to collect acorns from the old oak trees nearby and then fly down to the field and push them into the earth. Is it a sign of a hard winter to come? And - more importantly- will it remember where to find them??
Apologies for the poor picture but I was getting dressed and just noticed the jay, over the fence in the field, so snapped it through my window.


Wipso said...

Just so you know.... :-)
Garrulus glandarius

The Jays transport of acorns away from the shade of the tree may play a very important part in the regeneration of oak woodlands. Acorns can germinate in the dark, but oak seedlings require light environment to grow past the seedling stage. – A mature tree produces deeper shade than its seedlings can regenerate in.

Jays collect ripe and undamaged acorns for their winter stores to which they return for their food during the winter & early spring.

Some of the Jay’s acorns are eaten on the spot; but many are pouched, carried away and hidden in the ground to form a winter storehouse. They bury them individually in the soil carrying between 1 and 5 acorns per flight (one in its beak and the rest in the throat and oesophagus). Often they will carry the acorns distances of 100m to a few kilometres.

Jays hide acorns undamaged, so that some acorns have the chance to grow if left, (unlike the Grey Squirrel who often chews out the embryo of the nut before burying it, so even if it misses a nut store, the acorns are unlikely to grow).

By the time the Jay rediscovers the acorns they have usually stated to germinate, the bird generally only removes the cotyledon (1st leaves, not true leaves) and the young plant continues to grow.

The Jay remembers where they have planted the individual acorns, (they do not search by smell, simply remember where they are and can even locate them under 300mm of snow).

Like that of fox and squirrel, the Jay’s habit of hoarding seems to be a response to a super-abundance of food.

bayou said...

Well researched! That's why it is called "Eichelhäher" in German :-)
In French, it does not disclose any relation to acorns, neither, c'est un geai.

Twiglet said...

Oh what it is to have clever friends and relatives - thank you both!!

PG said...

I thought they did it on purpose, lucky you being able to watch it in action - they are suce shy birds. (I'm glad someone else had a fuller explanation)

BumbleVee said...

I saw a wildlife show once that talked about a Nutcracker that collected pinecone seeds... it could carry many at a time... buried them in exact numbers.. and apparently could later find 70% of them...even under plenty of snow in the winter...I don't remember the name...but, it had something to do with golden... that was either the tree or the bird..I forget...
I am sure plenty of them germinated and grew... and as Wipso mentioned... helped perpetuate the trees...

Jackie said...

ks for your lovely comment. My husband is working in your area at the moment. Good luck with the felting.

Frances said...

Again, may I say thank you for telling me something I would not otherwise have known.

I just thought it was squirrels who squirreled away all those acorns, and did not remember where they'd hidden them.