The study of the relationships of organisms to their environment and to other organisms.
ecology
Why is ecology important?
It helps us understand:
Why animals live in certain places.
Why they eat specific foods.
How they interact with other animals.
How human activities harm animal populations and how to preserve resources.
What does an animal’s habitat include
All living (biotic) and nonliving (abiotic) characteristics of its environment
Give examples of abiotic habitat factors
Oxygen, inorganic ions, light, temperature, current/wind velocity
The range of environmental values an organism can live within
tolerance range
How do animals obtain energy?
By ingesting other organisms (heterotrophic).
An accounting of an animal’s total energy intake and how it is used or lost
energy budget
How do endotherms and ectotherms differ?
Endotherms regulate temperature internally; ectotherms depend on external sources
List four responses animals may have when food is scarce
Torpor (daily lowered metabolism/temperature).
Hibernation (weeks/months, small mammals).
Winter sleep (weeks/months, larger mammals like bears).
Aestivation (inactive during dry periods, common in invertebrates, reptiles, amphibians
What factors cause animal populations to change over time
Birth, death, and dispersal
Population increases by the same ratio per unit time
exponential growth
Why can’t exponential growth continue indefinitely
Space, food, water, and resources are limited
The limits imposed by climate, food, space, and other factors
environmental resistance
The maximum population size that an environment can support
carrying capacity (K)
Affect populations regardless of density (e.g., extreme cold, deforestation).
density-independent factors
More severe when population density is high (competition, disease, predation, parasitism)
density-dependent factors
Competition for resources among members of the same species
intraspecific competition
Give examples of interspecific interactions
Herbivory, predation, competition, coevolution, symbiosis
Animals feed on plants without usually killing them
herbivory
Reciprocal evolutionary changes between interacting species
coevolution
What is symbiosis? Name its 3 types
Intimate, continuing relationship between species:
Parasitism (one benefits, host harmed).
Commensalism (one benefits, other unaffected).
Mutualism (both benefit)
Color patterns that help animals hide
camouflage
Animal takes on patterns of its environment
cryptic coloration
Darker top and lighter underside for concealment
countershading
