lab quiz 2 Flashcards
Mark and recapture strength
- provides info about birth, death, and movement rates
- provides info on absolute abundance
why do we care about population size
- if we want to know how the population is changing over time
- if we want to compare 2 populations
- if you want to look at interactions between species
what is the problem with grizzly bears
- gap in scientific understanding in grizzly bear ecology
- don’t know how to quantify them
- lack of ethics
Mark and recapture assumptions
- marking method must not affect the animals
- mark must last entire sampling period
- marked animals must disperse completely in the population
- likelihood of recapture is not influenced by age of the animal
- no immigration, no emigration (closed population)
- not births or deaths during the study
Peterson mark and recapture method
- mark and recapture once
Schanble mark and recapture method
- mark and recapture multiple times
how is the schnable method advantageous?
- easier to determine the violations (6 things)
Jolly Seabird mark and recapture method
- mark animals, release and recapture, the ones that weren’t marked you mark again
When would you use the Jolly Seabird method?
when you have an open population
What makes a population closed?
- Dispersal barriers
- Large surveyed area
- Low birth/death rate
- ONE OTHER THING? low immigration emigration?
what does a low confidence interval mean
precise estimate
when would you want to know the population size
- before undertaking a biological study
- designing conservation strategies
- setting management goals
what was the first ecological use of mark-and-recapture
to look at population estimates and mortality rates in fish
shortcomings of mark and recapture
- require considerable time and effort to get enough data
- each technique has a set of strict assumptions that should be met for the estimate to be reliable
what mark and recapture technique was used in the grizzly bear study?
Genetic analysis
- used hair samples to identify individual bears
what were the sampling methods on the grizzly bear study
- baited, barbed-wire hair traps
2. unbaited bear rub trees
how were grizzly bear population estimates corrected for lack of geographic closure
- by using a new method that utilizes information from radiocollared bears and the distribution of bears captured with DNA sampling
What method was used to estimate the distribution and abundance of showshoe hares?
- fecal-pellet plot counts
- mark and recapture estimates
How and what samples were gathered for population analysis
- took fecal pellet counts at annually cleared and uncleared plots
4 methods used for estimating snow leopard abundance
- prey biomass ratios
- capture/recapture density estimation
- photo-capture rate
- individual identification through genetic analysis
what are the long-term effects of flipper bands on king penguin populations
- 16% lower survival rate
- produced fewer chicks
- arrived later at the breeding grounds
- caused drag when the penguins swim
what is the main assumption of mark and recapture that is violated using flipper bands
- marking method does not affect the animal
explain how food availability had an effect on banded birds
- when resources were plentiful the researchers didn’t observe much of a difference between banded and unbanded
- studies that last under a year may not how banding has any effect
what is the major advantage that flipper bands have when compared to RFID chips
they are visible
what are RFID chips
- electronic chips that are inserted under the penguins skin
- emit radio waves that the researchers can use to track the penguins’ movements
major species in the great bear rainforest
- otters
- trees: spruce
- whales
- wolves
- sea lions
- eagles
- salmon
- spirit and black bears
where are the grizzleys and where are the black bears
grizzleys on the mainland and black bears on the island , some grizzleys have migrated to the islands now
How would competition influence food choice
- different food choices
- bears will eat the gonads of the salmon, wolves will eat the brains
- even tho they eat the same resource, can still reduce the competition
- wolves have been known to target bears but this is much more dangerous than eating salmon
advantageous of eating salmon
- good food source (protein)
- less handling time
diet of wolves from the mainland vs. diet of wolves from the island
Mainland: 25% marine, 75% terrestrial
Inner Island: 50% marine, 50% terrestrial
Outer Island: 75% marine, 25% terrestrial
different between Ho and Ha… location studies
Ho: diet is independent of location
Ha: diet is not independent of location
What does a large chi squared mean
- more significant
- smaller p-value