Certainly swallows (birds) are being seen in increasing numbers in Devon. Cattle egrets are also being increasingly seen. The cattle egret sightings remind me of the first little egret sightings in Devon 30-40 years ago.
I suspect several species will become far more common in the years to come e.g. bearded tits, bee-eaters. At the same time, some will be lost. Before 1955 to see a collared dove in the UK would have been amazing. Nowadays they are one of the most common birds in our garden.
See https://en.wikipedia.org/wiki/Bee-eater .