Here are some characteristics of birds:
- unique feature that distinguishes birds from other animals is their feathers
- forelimbs modified into wings
- hind limbs adapted for walking, swimming, perching
- horny beak
- lay eggs
The CLASSIFICATION of birds
PASSERINES
- smallish birds (except crow)
- feet adapted for perching
- all passerines have altricial young (naked and helpless when hatched and are reared in nest)
NON PASSERINES
- birds with webbed or semi-webbed feet; all non passerines birds
- 2 groups: Terrestrial non-passerines (frequent ground and water); Arboreal non-passerines (frequent trees)
NEAR PASSERINES
- arboreal non-passerines
- appear to be passerines by their size and behaviour
- zygodactylous foot for climbing
- Woodpeckers, Barbets, Parrots, Coucals, Cuckoos
The Food and Feeding Methods
- Fish-eaters (strabbers, grabbers): Herons, Darter, Cormorants, Hamerkops, Yellow-billed Storks, Kingfishers
- Meat-eaters (raptors, scavengers): use bill for the tearing of flesh; owls are raptirs but the bill is insignificant = they don't tear their prey, theu swallow whole.
- Insect-eaters: insects are caught in the air and off firm surfaces; Fork-tailed drongo, Shrikes, Rollers, Woodpeckers...
- Seed-eaters: Parrots, Doves, Weavers, Sandgrouse...
- Fruit-eaters: Turacos, Parrots, Mousebirds, Hornbills, Barbets, Orioles, Bulbuls, Starling and White-eyes...; they supplement their diet with insects and other animal food.
- Nectar-eaters: Sunbirds and Sugarbirds have needle-like curved bills that enable them to suck the nectar from flowers as well as catching insects.
- Filter-feeders: Straining fine particles out of water; Ducks, Flamingos, Prions
- Probers: Have extremely sensitive touch receptors in their bills, to feel the movement of any live prey since they find their food by touch rather than by sight; Ibises, Waders, Woodhoopoes, sugarbirds, Sunbirds...
- Wood-pecking: Can excavate wood and have tongue that can be extended into burrow of wood-boring insect larvae; Woodpeckers.
The NESTS and NESTING BEHAVIOUR
Types of nests:
- Not constructed nests: some owls, kestrels and falcons don't build nests, but use rocky ledges, tree holes, old buildings and nest of other birds; Brood-parasites included.
- Ground nest: very well camouflaged as the parents have to leave the nest unrpotected at various time; Plovers, Terns, Curlews, Ostriches, Nightjars -> scrape in the ground. Sometimes lined with twigs or small pebbles; Young of these birds are precocial.
- Floating nests: Grebes, Coots: collection of reeds and grasses laid one over the other until a fairly substancial platform; eggs are well camouflaged, chicks are precocial.
- Hole nests: because of being well hidden, eggs are often white or light coloured allowing parents to see them easily in the often dark interior. Kingfishers, Bee-eaters -> burrow in sand, glay, mud bank and chisel out tunnels up to 2.5m deep.
- Mud nests: Swallows; vary in terms of architecture of the entrance tunnels and whether or not theu are totally enclosed.
- Cup nests: many passerine or perching birds; usually off the ground in a shrub or tree; Robbins, Trushes, Bulbuls, Wagtails -> cup-shaped nests in shrubs or trees; the White-eyes build nest high-up in trees, Batises and flycatchers camouflage cup nest with lichen they stick with cobwebs.
- Enclosed woven nests with entrance: Weavers; suitable sites, above water, males gathers leaves of green grass and weaves its nest; own entrance design = long tubes, neat hole reinforced for take-off and landing.
- Platform nests: Darters, Herons, Storks, Pigeons, Doves, some birds of prey -> platforms of sticks or twigs, or branches of trees; Lay white eggs and keep them covered and hidden all the time.
- Unusual nests: Palm-Swift -> strange nest of feathers glued together with sticky saliva which is fastens the underside of palm leaves and then builds a lip at the bottom where the 2 eggs are also cemented in place with saliva.
HATCHLING
Newly hatched birds are of 2 types: PRECOCIAL and ALTRICIAL
PRECOCIAL: (Lapwings, Francolins, Spurfowl, Guineafowl, Quails, Ducks, Water birds) Young are covered with down when hatched and can run or swim as soon as their plumage is dry.
ALTRICIAL: are naked and helpless at birth and remain in the nest for 1 week or more. Most non-ground birds.
BROOD PARASITES
A Brood Parasite is a bird that lays eggs in nest of a foster parent or host of another species for rearing and does not involve itself with any kind or parental behaviour.
Hatched young of parasite brooders may respond to the presence of eggs or young of the host in the nest in various ways:
- may hatch 1st and evict the host'eggs or chicks
- may outgrow the host chicks and smother them to death and trample them into the floor of the nest
- may reared with the chicks of the host species
Of the world's about 9000 bird species, only around 1% are brood parasites.
In South Africa, 24 species place their parental responsibilities onto other birds.
3 Families:
- Cuckoos (except Coucal)
- Honeyguides
- Whydahs and widowfinches
Common BIRD BEHAVIOUR
- PREENING
- each day
- Allopreening among most non-passerines occurs when breeding
- SCRATCHING
- counter irritation and groom feathers on the head
- preen oil transferred to head by feet
- SHAKING
- body shake
- rid the plumage of excess water
- shake off any loose material dislodged during preening
- during rain to remove droplets of water
- BATHING
- WATER BATHING: important in fishing birds whose plumage get soiled with mucus from their fish prey.
- DUST BATHING: bird creates a saucer-shaped depression in the ground by using bill, scratching with feet or relating body; remove ectoparasites, lice; Ground birds, Sparrows, Mousebirds
- SUN BATHING: Doves lie on ground with wings and tail spread; Storks, Herons, many birds of preys
- ANTING
Some ressemble sunbathing allowing ants to swarm over the plumage; or birds pick up an ant and pass it rapidly over the feathers; formic acid and ants crawling stimulate skin.
How to IDENTIFY a BIRD?
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