Chapter 4: Estimating Vital Rates Flashcards
(39 cards)
non-invasive capture and mark methods: sources of error
- genotypic error
- shadow effect
genotypic error
two or more individuals that share the same genetic ID or physical markings are counted as same individuals
genotypic error example
increased number of loci
shadow effect
same individual counted as multiple individuals in analyses
shadow effect example
hair cells of two individuals are amplified together, creating a ‘new’ individual
SCR - Spatial Capture Recapture Methods
- new class of sophisticated closed CMR methods
- incorporates spatial information of captures to estimate location and number of animal home ranges
SCR example
- R packages
- Bayesian approaches
open population models
- some caught, other dead or gone
- additions or losses are of interest
additions
- birth
- immigration
losses
- death
- emigration
Jolly Seber Abundance
Ni = Mi* ni / mi
Mi
estimate of number of marked animals alive in the population right before occasion i
how is abundance estimated
with closed-population models within each primary period
how gains and losses are estimated across the primary period
using open-population models
open population models examples
- survival
- recruitment
- emigration
- immigration
factors of survival estimation
- known fate
- CMR
- band recovery/return
known fate
all animals can be relocated
CMR (Cormack-Jolly-Seber)
only survivors are recorded
band recovery/return
- only deaths are recorded
- marked alive, bands returned via harvest
known fate models
S = x/n
S
survival
x
number of surviving animals
n
total number of sampled animals
Kaplan Meier Methods
S(t) = pi [1- (# of deaths at time i=di/ # at risk at time i=ri)]
