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Birds, Bowels, Bush - Classroom Teacher Notes
Curriculum Links
- Social Studies
Place and Environment (Level 2)
- Technology
Technological Capability (Level 2 & 3)
- Science
Living World (Level 2, 3 & 4)
There are many types of seed dispersal-
Wind
Some very light seeds such as sycamore are designed to be carried by the wind. They are shaped like a propeller and can be carried on the wind for great distances.
Birds
In New Zealand, birds are the main seed dispersers. They swallow the fruit or berries, and as they can cover great distances, so can the seeds. Some seeds cannot germinate unless they have passed through a birds gut!
Water
Plants that live near water may drop their seeds into the water. The water will carry the seeds far from the parent plant. It will germinate when it gets caught in the mud.
Mammals
Some mammals eat fruit to disperse seeds. They may eat the seed and, unable to digest it, pass it out the other end. Or they may eat the fruit and discard the seed. Other types of seeds will get caught in their fur and travel with the mammal until it grooms itself, often far from the parent plant.
Explosion
Plants such as gorse disperse their seeds by exploding. When the weather warms up, you can hear them popping open. This shoots their small seeds around.
Fire
Many plants in the Australian bush can only disperse their seeds in the intense heat of a bush fire. The fire will kill the parent plant, but the seeds will germinate in the new fertile soil.
Key Question
- What happens if the method of seed dispersal is removed i.e. birds?
The number of trees will gradually decrease, and the animals of the bush/forest will have less to eat. This is the case in New Zealand. Many of our seed dispersing native birds are extinct or endangered.
- How can we help to encourage native birds back?
Plant more native trees. Leave feed or nectar stations in your garden to invite birds in. Put a bell on your cat, and lock them in at night.
- Why do seeds need to disperse far from the parent plant?
It will cause overcrowding if seeds fell just below the tree. They would be competing for light, space, food.
- What seeds can you find? How do you think they are dispersed, and how can you tell?
Key Words
Disperse, seed, fruit, berry, germinate, digest, bird, native, endangered, extinct, parent plant.
Other useful information-
Online-
http://www.countrysideinfo.co.uk/seed_dispersl/index.htm
http://www.zephyrus.co.uk/seeddispersal1.html
School journal stories-
Part 1, Number 1, 1995, Hidden Seeds.
Part 1, Number 5, 2003, Seeds that wear life jackets.
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