Page 320 - Microsoft Word - LessonPlan-Overview.doc
P. 320
Unit 18: Biology Part 1 Page 35 of 60
South to the tropics when the eat fruit, help to spread seeds,
weather becomes too cold. Birds since they often fly to a different
use natural landmarks such as location to eat the fruit they got
riverbeds, or look at the direction from a plant. This helps ensure
of the sun to assist them in their that plants are spread out, and less
migration patterns. By doing this, likely to compete with each other
birds ensure that they follow the for limited resources, as they
same path every year. would if they were all in the same
Birds migrate South, in order to place.
find warmer weather.
Introduction to Mammals
Birds are useful to human beings in
a number of ways. Some, such as Mammals are endothermic
vertebrates. They have many
turkeys and chickens are a food
source. Guano, which are bird characteristics in common,
droppings, are used as a fertilizer, including the presence of hair, the
both in a manufactured state and presence of sweat glands, and the
naturally as birds lay their presence of three middle ear
bones. They also have a four-
droppings on the areas above
which they fly. Bird watching or chambered heart and specialized
listening to birds sing provides a teeth for ripping, tearing, and
source of recreation and fun for chewing foods. Finally, mammals
have a gland called a mammary
many people.
gland. This gland produces milk,
Chickens can serve as an early which adults provide for their
warning system for diseases such offspring.
as West Nile Virus. Mosquitoes
bite young chickens, infecting them One small group of relatively
with the disease. Usually, about primitive mammals are known as
three months later, an outbreak the monotremes. These animals
will start in humans. By examining share several characteristics with
the sick birds, public health officials birds and reptiles. Along with
having only one body opening for
can prepare for humans to be
struck by the disease in advance. urinating, defecating, and
reproduction, the monotremes
Birds also help plants. Some birds, reproduce by laying eggs,
such as hummingbirds, pollinate something no other mammals do.
plants by spreading pollen when
they drink plants’ nectar. The leathery eggs of monotremes
Frugivores, which are birds that are similar to those laid by lizards
© 2011 Supercharged Science www.ScienceLearningSpace.com
722
