Mmm, ivy berries

The cedar waxwings are getting used to me.
I was sitting on a chair on the patio, and suddenly they were fairly close, above the Meyer lemon tree, eating ivy berries.
In the above image one of the waxwings has an ivy berry in its beak.

There are three waxwings in this photo.
And another has just plucked a berry, holding it in its beak.

See how one of the waxwings with its back to us, is holding onto a blackberry vine as it reaches for a berry.
I'm learning a lot, observing different birds here.
First, I just never knew that ivy plants produce berries.
And second, how important a food source these berries are for birds.
So far I've seen robins, towhees, sparrows, mockingbirds and the waxwings flock to these berries for a meal.