Showing posts with label Plane Tree. Show all posts
Showing posts with label Plane Tree. Show all posts

Tuesday, 8 December 2020

Carrion Crows feeding on Plane Tree fruits

This morning I took a walk near a local park. On a square lined with Plane Trees, some pollarded, a flock of Goldfinches fed on the bauble-like fruits, often hanging from them acrobatically, as they often do.


Then I noticed the crows. They flew to the tip of the branches, where the plane tree fruits clustered, once they gained their balance they moved to the tip of the branch, and picked on the fruits, pulling at their stem. Then they purposefully hanged down from their legs, then only one leg while holding the fruit on the other and attempting to break the stem. What complex thing to do! Some of the fruits had frayed stems, like they had been chewed a few times. If a crow breaks the stem but drops the fruit, the other crows will be quick to go and steal the price. I didn't see this, but I did see chases and close guarding of the fruit by the owner crow, often flying to a safer place holding onto it.

All three crows did this, often the three of them hanging from branches at the same time. At least twice I saw they were successful, and then they flew with the fruit on their bill, once transferring it to their feet before landing and starting breaking the fruit open for their seeds. I'm always amazed at crows, I have covered how they crack mussels and periwinkles at the beach.

Today's behaviour, however, really topped it up. Were they copying the Goldfinches? Crows are always to the alert, they must have noticed the Goldfinches feeding on these fruits and had a go at getting them!

This is a video made with three clips I took from them


And a few photos of the behaviour.

Hanging from one leg, holding onto the fruit with the other.






Crow with its prize.
The pink gape suggests this is a young crow, feeding on the plane fruit. I wonder if this is a family, with the young copying the adults in learning this skill.
I'll be very interested to head from anyone that have seen this behaviour in their local crows!

Thursday, 24 November 2011

Planes and goldfinches

This morning coming into work I heard the unmistakable chirps of squabbling goldfinches. There was a large flock feeding on a line of plane trees. While I climbed the stairs I thought delightedly that the window in our lab overlooks the trees, so I could have a level view of the feeding goldfinches. There they were, hanging from the bauble-like seed balls or balancing from the thin stems holding them. London plane trees (Platanus x acerifolia) is an important food resource for goldfinches, as it provides seeds during the autumn months into the winter. The photos didn't come brilliant - I blame the dirty windows - but I think the one on top captures the atmosphere of the feeding flock. I count seven, how many can you see?

More information
Sachslehner, L. M. (1998): The significance of Plane-trees Platanus x hispanica M. as a food resource for Goldfinches Carduelis carduelis L. in Vienna. Egretta 41: 90-101.