Ecology

1. Ecology Next test Ch 51-56

2. Ch. 52 Overview of Ecology • Ecology-the study of the interactions of organism and their environment • Abioticfactos-non-living • Biotic factors-living factors • Please recognize the role ecology plays in evolution • Organism, population, community, ecosystem • Terrestrial Biomes (1150-1152) • Tropical Forest, Savanna, Desert, Chaparral, Temperate Grassland, Temperate Deciduous forest, Coniferous Forest (Tiaga), Tundra. • Know them

3. Ch. 51 Behavioral Ecology (1123-1139) (know examples)

4. Behavior • Proximate behavior-response to a stimulus • Ultimate behavior-evolutionary significance of behavior • Both genetic and environment influence all behaviors • Innate behavior • Those that seem to be uniform among varying phenotypes and environments • Ultimately you can see that those that did not show innate behaviors, died • Ethology (proximal behavior)-1930s • Fixed action pattern (FAP) • Sequence of behavior that is essentially unchangeable and is usually carried to completion once initiated. • Triggered by a sign stimulus

5. Behavioral ecology (ultimate behavior) • Optimal foraging theory • Benefits vs. costs of obtaining food • Learning • Modifications of behavior resulting from specific experiences • Most innate behaviors can improve with learning • Maturation-change in behavior as an adult where it is not learned. • Habituation-ceases to respond to stimulus • Imprinting-bond formed with “parent” • Time sensitive only in the first few days of birth, but parents imprint with children as well • Associate Learning • Classical conditioning • Pavlov with his dog drooling • Operant conditioning • Trial and error

6. Cognitive ethology-connects thinking with behavior • Kinesis-changing rate of activity • Taxis-movement to (positive) or away from (negative) stimulus • Using landmarks • Cognitive maps-more complex use of landmarks • Migration • Use Piloting (landmarks), orientation (compass), or navigation (both) • What other animals might be aware of their existence and the world around them

7. Social behavior • Sociobiology-how is social behavior evolutionarily significant • Agonistic behavior-aggressive behavior among species • Leads to a dominance hierarchy • Territorial behavior • Courtship behaviors • Parental investments • Male-more partners is better • Females-selective of partners • Promiscuous, monogamous, vs polygamous relationships • Polygamous • polygyny-single male mates with many females • polyandry-single female mates with many males • Certainty of paternity-how much parental care is given based on how certain they are the parent • Communication • Use visual (waggle dance), auditory, tactile, electrical, chemical (pheromone) • Altruism-sacrifice themselves for the species • Inclusive fitness-helping a kin by altruism • Coefficient of relatedness (Hamilton’s rule)

8. Ch 53 Population ecology (know how to analyze the graphs and equations in the chapter)

9. Measuring Density • Random sampling (plants) • Count random grids, find average, then multiply • Mark-recapture method (animals) • N(number in population) =(number marked in first catch x total number is second catch)/(number recaptured in second catch) • Capture, mark and release some, then set more traps and recapture more. Those that have tags are the recaptured. • Only works if there have been no deaths or births in the population. • Dispersion patterns • Clumped (most common)-individuals in small groups • Uniform-evenly spaced • Random (least common)-unpredictable pattern

10. Demography-study of population growth • Life tables and survivorship curves* • Constructed by the number of individuals that die at specific ages • Table 53.1 and fig 53.6 • Type 1-individuals die at old age more • Type 2-individuals die throughout life evenly • Type 3-individuals die at young age more • Reproductive table • Summary of reproductive rates in a population (only looks at female offspring) • Table 53.2

11. Population Growth • Measuring growth rate using birth rate and death rate (ignore immigration/emigration) • Growth rate=birth rate-death rate • r=b-d • zero population growth (ZPG) is where birth rate=death rate • ΔN/ΔT=bN-dN • N=population size • ΔN/ΔT=rN • Also abbreviated dN/dT=rN (differential calculus) • These will lead to an exponential growth pattern (J shaped) • Intrinsic rate of increase is the maximum rate a population can increase in an ideal unlimited environment • dN/dt=rmaxN • See fig 53.7 • Know how to analyze these graphs

12. Logistic model of population growth • Incorporates carrying capacity into the equation (K). • dN/dt= rmaxN((K-N)/K) • states that as the population nears carrying capacity, the growth rate slows down, When carrying capacity is reached, growth rate is 0. • See fig 53.9 • S shaped curve • Logistics model still does not accurately reflect growth patterns • K (carrying capacity)is rarely a stable figure • Assumes that at low numbers, all offspring survive • Some overshoot K

13. Life History traits • Schedule of reproduction • Big Bang reproduction (semelparity) • Lay thousands of eggs at once • Used when there is an erratic climate (parent won’t survive) • Repeated reproduction (iteroparity) • Produce some eggs each year • Used when chance of survival for offspring is poor • Battle for time and energy in reproduction vs. survival (fig 53.13) • Don’t forget paternity time • K-selection • Density-dependent • Sensitive to population density • Population that number are close to K • r-selection • density-independent • maximize reproductive success in uncrowded environment (population is growing=r)

14. Limiting factors (affect birth and death rate) • Resource limitations (food or space) • Health • Predation • Many cause fluctuations in carrying capacity • Human Population Growth • Has grown exponentially for 300 years. • ZPG=fertility rate of 2 • What is carrying capacity of humans? • Age structure graphs • Relative number of individuals at each age • See fig 53.24 • Ecological footprint • Uses available resources to calculate carrying capacity of countries • Measured in land area/person • See fig 53.26