Have you noticed the bee and wasp activity on the late flowering Ivy? I enjoy watching this generous plant feed a variety of insects who feed on it’s calorific rich nectar and pollen, fattening themselves up before they hibernate for winter. Fugivourous (fruit feeding) birds such as song thrush, starlings, fieldfares, wood pigeons etc. also rely on the berries of the Ivy in winter when other food sources are scarce.
According to the RSPB the berry of Ivy contains, weight for weight, as many calories as a Mars Bar! (though the Berries are can be poisonous to humans so don’t try this at home).
For more info these are some great articles on IVY