The Little Grebe is a small diving duck, also known as a Dabchick. It spends a lot of time in the reeds, but seems to also spend a long time underwater. When it finally surfaces it's in a completely different place to where it dived down! It is much smaller than most ducks (dwarfed by a Mallard). This one is in its winter plumage, with fairly muted colours.
The next photo was in March, and it's now getting close to summer plumage. It has a chestnut neck and the characteristic bright patch on the base of its bill. They have distinctive call in the summer - a loud whinnying trill. This one was fishing on the Garden Pond, and has been overwintering there for several months.
