Survivorship Curves
Energy Pyramid
- Type I- Low death rates during early and middle life, increased death rates among older age groups, few offspring, good parental care.
- Bobcats, Foxes
- Type II- Constant death rate over the organism's lifespan.
- Squirrels, Chipmunks
- Type III- High death rates for young, lower death rates for older age groups, large numbers of offspring with little or no care.
- Grasshoppers
Flying Squirrel Food Web
Ecological Relationships
Limiting factors
Flying Squirrel Food Web
By Maya, Jenny, and Lauren
- Limited amount of food, water, shelter, and space create a competition for resources between different species and also within a species which can lead to lower populations of certain species like the squirrel or mouse
- Predation lowers the amount of prey like mice and also creates competition for food in between predators if they consume the same prey
- Disease lowers the populations of producers (trees), primary consumers (squirrels), and secondary consumers (foxes) of Herrick Lake
- Mutualism- An interaction that benefits both species
- Fungus and Other plants (Fungus decomposes dead plants and creates nutrients.)
- Parasitism- An interaction where the parasite derives its nourishment from its host which is harmed.
- A parasite within an animal like a tapeworm within a fox or external parasites like fleas and ticks on a bobcat.
- Commensalism- An interaction that benefits one of the species but neither harms nor helps the other species.
- Lichens and Trees
Different types of species
Density Dependent vs. Density Independent
- Dominant species: the most abundant or have the highest biomass, exert control over occurrence and distribution of other species
- Density Dependent Factors: a limiting factor that depends on population size
- Indicator species: shows the ecosystem's health through its presence, absence, or abundance
- Examples: competition for limited resources like food, trees, water, and space, disease, predation (Hawk eating chipmunk)
- Keystone species: exert strong control on community structure through their pivotal ecological niches
- Density Independent Factors: a limiting factor that does not depend on population size
- Examples: harsh winter (extremely low temperatures), natural disasters (flood from increased rainfall), pollution (toxins and garbage in water)