Beak and bill are names for the same hard, pointed part of a bird's mouth and both names have alternative meanings. Since bill is defined as the beak of a bird, we will just use beak from here…
Every part of a bird has evolved over time to "fit the bill" for surviving. Just looking at the beak of a few of our local birds, there are some incredible structures that could have been designed by an engineer.
Curlew – The long down curved beak is longest in females and they can probe down deepest to find worms on the shore, saltmarsh or in grassland. But it can also be used upside down to get underneath stones and vegetation to pull out small crabs.
Avocet – similar feeding style, but a very long, fine up curved beak for catching small shrimps and worms in wet mud. Their food is tiny, so they have to feed for long periods.
Snipe – the end of their very long beak is soft and sensitive so that they can feel for worms deep down in soft mud, the tip can also move like fingertips to grab their prey – this is called rhynchokinesis
Wigeon – most ducks have short beaks for grazing grass or eating water weed.
Shoveler – have a massive beak that is used for taking in water and plankton and straining it out through a filter along the edge in a similar way to flamingos.
Red-breasted Merganser (photo) – is in a group of ducks known as “sawbills” that also includes Smew and Goosander. They eat slippery fish and have “teeth” along their beaks to catch and hold them.
Spoonbill – now a regular visitor to the reserve their beak is used to catch small fish and invertebrates that are swimming in the water. They feed in shallow water and move their open beak from side to side until they feel something between, then they snap it shut and toss the item into their throat. This must be effective because Spoonbill spend so much of their time asleep.
Little Egret - many fish-eating birds, such as herons and terns have dagger like beaks, not to spear the fish, but to break through the water when they break the surface. This video is slowed down 20 times to catch the action.
Green Woodpecker – their dagger like beak is good at breaking open ant nests, but it contains a very long barbed tongue that extends much further to get at the ants living down their tunnels.
For an article about the Green Woodpecker click here
Swift – at first glance their beak looks tiny, but when feeding it has a huge gape, edged with long bristles that act like a large net to take individual insects out of the air, while flying swiftly.
I could go on with many more examples of specialised beaks, but I want to finish by suggesting that every time you look at a bird just consider how it uses its beak to feed. Then remember the beak is also extremely important in caring for feathers, for preening the finely divided feathers to enable efficient flight and to keep warm and dry.
Enjoy 5 minutes and 41 seconds with this preening Common Tern.