random
what are cohort life tables?
- follow over time, recording deaths
- difficult to collect in nature
what is type 1 survivorship?
juveniles survival is high and most mortality occurs among older individuals.
why is it important to understand patterns of survivorship?
if we know when mortality is highest, we can target
- raise until can be released
what are static life tables?
- stationary, time specific.
- uses age at death to build a life table.
- can calculate/measure age at death for many species. ex) using tree rings. horns on sheep, growth rings in ears of fish.
what is type 2 survivorship?
individuals die at equal rates regardless of age.
what are dall sheep in alaska?
lots of wold predation on young and old dalls. few 2-5 yr olds preyed on.
- through the survivorship curves, it was shown that wolf predation was not a big cause of mortality until the sheep aged and were targeted when they were older.
what is k selected?
some species have high survival when young.
- more energy invested in their offspring to help them survive (spend more time in parental care)
- have less offspring at a time.
ex) humans, elephants, dall sheep.
what is type 3 survivorship?
individuals die at a high rate as juveniles and then at much lower rates later in life
what is age distribution?
- % of population in each age class
- population structure and age distribution quantify the number of individual ages/different sexes. population can increase, decrease or remain stable.
- humans: budget planning. Non-humans: conservation.
what is r selected?
some species have low survival when young.
- invest less in in their individual offspring (spend less time/energy in parental care)
- many offspring at a time
ex) sea turtles and bait fish.
What is the order on a graph.
right to left, 1, 2, 3.