Dispersal by animals is fascinating, as the places the plants end up in is closely tied to the lifestyle and movements of the animals involved. Some plants have barbs or similar mechanisms on their seeds. Twinflower (Linnaea borealis) rarely produces seeds, but when it does the seeds have small hooks that adhere to animal fur and bird feathers, allowing them to be carried to new sites. Humans also play a part in this process: we have carried seeds far beyond their normal range on clothes and shoes.
Some seeds are dispersed and pushed into the ground by the hooves of large mammals such as the wild ox.The wild ox is endangered. The loss of plant eaters that are also plant seed dispersers, has deprived the some habitats of an important dispersal method.
The additional weight of nuts and acorns causes problems with moving around, and oak seeds generally do not germinate in the shadow of their parents. They need to germinate away from their parents because they can not compete with the parent tree which does not allow enough light for the young seedling. Blue Jays eat acorns and can carry them (up to five per flight) for several kilometers. These birds store the acorns by burying them, to eat at a later time. They often have a preference for burying them near a tree or shrub, at the edge of the forest. In one autumn a single bird can bury as many as 4,600 acorns, and can remember the locations of them all! Harsh weather and hungry predators, however, will take their share of jays, and this enables some seeds to germinate. Jays play an important part in dispersing oak trees.What other animal is a disperser of acorns?
Birds are among the most mobile creatures, and there are many plants that can hitch a ride with them. As well as sticking to the outside, plants can tempt birds to swallow their seeds, and so carry them in their gut to other areas. Attracting the birds is crucial, and what better way to do it than with energy-rich berries? With bright berries such as these, the color acts as an advertisement for birds, who have good color vision. Birds have a grinding gizzard. This grinding action is actually necessary for some seeds to prepare them for germination. Some of the seedlings are found growing beneath pine trees. In this case, we can deduce that a bird at some point sat in the branches of the tree, and passed the seeds out in its droppings.
Hazelnuts are often spread to new areas by red squirrels and mice, that may store them for later use. While some seeds will be eaten, others aren’t eaten and will be able to grow.
Remarkably, even ants can help to disperse the seeds of plants. Wood anemone seeds have a small food body attached to them and cow-wheat seeds resemble ant cocoons; in both cases the ants carry them off and store them in new areas where they can then germinate.
Cocklebur plants produce little football-shaped burs, about one inch (2.5 cm) long and covered with stiff, hooked spines. Each cocklebur fruit contains two seeds that may still be able to germinate many years after being produced. The prickly burs hook into your clothing and become tightly attached. Often the vicious burs form tangled mats in the fur of animals, and must be cut out of the hair. These prickly burs have enabled the cocklebur plant to hitchhike all over the world.
The second seed is dispersed by animals.What features enable it to be dispersed by animals?
The red berries are dispersed by animals.Which animals might disperse these seeds?Explain how it is done.What features make this seed likely to be dispersed by animals?
The brown seed is dispersed by animals.What features make it likely to be dispersed by animals?What types of animals are likely to disperse this seed?
The picture on the left (pecan tree) is the correct choice. How is this seed dispersed by animals?What features make it likely to be dispersed by animals?
