Give any two examples for each of the following cases where dispersal of fruits and seeds take place : (i) by birds (through excreta) (ii) by human beings
Answers
1. dispersal by Birds are Dandelion, cottonwood tree.
The dispersal of fruits and seeds takes place by various natural modes in general.
Fruits carried and left half un-eaten or thrown away acts as a mode of dispersal of seeds.
The place where fruits are left would let seeds from fruits grow there.
Two of the major sources are by birds’ excreta and by human beings-
• By the excreta of birds- Fruits are dispersed by bird excreta, birds are specifically attracted to brightly coloured fruits and also general fruits that grow around their usual habitat.
The dispersal by this mode allows no damage to the seeds as they clearly pass through alimentary canal of the animals.
Another factor to it is that the seeds are usually dispersed miles away and at quiet a distance from its basic origin eg- dispensed to tree tops, inaccessible corners and nooks of buildings and far off places where birds fly off.
• By Human Beings- The dispersal by human beings is wider in its due to a very high mobility.
Humans move around and travel with new and better means of transport as well eg- cars, ships, trains, busses, airplanes, walking etc.
The dispersal by humans acts both on large and small regional scale simultaneously. Eg- Dispersal on clothes, shoes, cars by spitting or throwing away seeds.
Another way in case of humans is voluntary or deliberate dispersal by humans adding new varieties to new atmosphere and environment.
Another example is commercial dispersal i.e. selling seeds.