+FOLLOW

1. • Birds are grouped on the basis of their feeding habits.
• Birds may eat different kinds of food at different stages in their life history.
• For example. Robins feed largely on worms and other invertebrates when
these foods arc available. Robins may feed on berries ( fruits like tomato) in
the winter.
• They can change their diets according to availability of food
• The feeding habits of some birds are harmful to man.
NUTRITION IN BIRDS

2. • Birds damage orchard and grain crops. Millions of
birds arc collected in local area due to flocking and
roosting habits in some birds.
• They destroy fields of grain.
• Birds of prey have minimum impact on populations
of poultry and game birds and on fisheries. It has
been mistaken though that they are responsible for
these loses. Thus human are killing them by poison
or shooting them

3. • Birds feel great appetites. This appetite support a high metabolic rats.
• High metabolic rate is necessary for endotherm and flight.
• For example, humming birds feed during the day. But they can’t maintain
metabolism at night. Therefore, they become torpid at night.
• They reduce temperature and respiration rate. They again become active and
feed in the morning.

4. Bill and tongue
• The bills and tongues of birds are modified for different feeding habits and
food sources.
• The tongue of woodpecker is barbed. It is used or extracting grubs (larvae of
insect) from the bark of trees.

5. • Sap suckers dig holes in trees. It uses a brush like tongue for licking
the sap from the holes.
• Hummingbirds are nectar feeders. Their tongues roll to form a tube
for extracting nectar from flowers