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Subject facts
Why you need to know these facts.
Vocabulary Amazing facts
Common Misconceptions
Questions
Teaching Ideas
Subject Facts
Beaks
The shape and size of a bird's beak (or bill) can provide an insight into its feeding behaviour (Figure 1). A long, thin beak can be used to probe down into soft mud for food, while the greater leverage of a short stocky beak is better for cracking open small seeds, It is possible to infer the diet of a bird from its beak/
By speciatising in particular foodstuffs, birds become much more effective and efficient feeders — but this has to be balanced against the risks of becoming dependent on one kind of food. Very few species can survive for long if they are dependent on a single food source, uniess that source is especially abundant , a change in the habitat might lead to the loss of their food source and thus to extinction.
Feet
Just as the beak can tell you about the diet of a bird* the feet and Eegs can tell you things about its habitat and how it moves.They can be speciafly adapted for any one of severat purposes, including perching, climbing, grasping prey, walking on mud. paddling or swimming (see Figure 2),
Ducks, who spend much of their time in water, tend to have short, powerful legs situated towards the rear of their bodies, with webbing between their toes. The fowl (or chicken) is adapted to movement on land, as is the emu. But while the emu inhabits open spaces, the fowl (before it became domesticated) lived in semi-jungle areas; it has retained the ability to perch and to fly up to its perch.
The tit can perch by lockng its rear-facing toe into a gripping position, much as a hawk does in gripping its prey but the hawk's talons are much more powerful. Like the emu, the heron has long legs; but they are much more slender since they don't need the power to run, only the length to keep the herons body out of the water.
Why you need to know these facts
Birds provide many fine examples of the specialisation of nature. By studying the beaks of birds, it is possible to determine quite a lot about their eating habits and from that the habitat in which they live.The design of their feet can also tell us a great deal about their lifestyle: Do they walk or swim? Grip or perch? Birds provide excellent material for a case study of adaptation for a purpose.
Vocabulary
Beak - an elongated appendage around a birds mouth, made from a material similar to human fingernails.
Bill — a name given to a beak of the flatter (duck-like) type or the smaller (pigeon-iike) type
Talons- the grasping ciaws of a bird of prey
Web - skin between toes to aid swimming.
Amazing facts
The fastest-swimming bird is the gentoo penguin, which can swim at just over 27k.m/h. The human swimming record (over 50m) is almost 9km/h. The fastest-running bird is the ostrich which can reach 65krn/h. A human Olympic sprinter can run at 37.8km/h.
The bills of some swifts are almost too small to be seem. The bill of the Australian pelican is over 45cm long. The bill of the sword-billed hummingbird, at i10cm, is longer than its body.
The wandering albatross has the largest wingspan of any bird alive, with an average span of approximately 3.5 metres. As a result of its wingspan, it is capable of remaining in the air without beating its wings for several hours at a time.
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Common Misconceptions
Only birds have beaks.
This is not quite true: there are a few other animals that use a beak (or rather; a bil) for specialised feeding, including aquatic mammals such as dolphins and the duck-billed platypus.
Questions
Do birds have teeth?
Strictly speaking, the answer is no, They rely on the sharpness of the edge of the beak to tear and cut. There are a few birds, such as the merganser; which have a serrated edge to their beak but this is not a true set of teeth. Nor is the 'egg tooth' that chicks break through their shell with a real tooth: it is just a sharp spike on the beak.
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Teaching ideas
Food (identifying, inferring, sorting)
Ask the children to look at pictures of birds, assess the size and shape of their beaks, then sort the birds according to what they might eat. They can use books to check whether they were right.
Build a bird (identifying, inferring)
Give each group of children a different set of cut-out bird part shapes. Ask them to identify all the parts and assemble them to build a bird. From what they know about bird beaks and legs, can they say what food the bird might live off and what place it might inhabit?
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