[R] Exponential population model

Msindai, Nadejda
Fri, 26 Aug 2016 12:49:48 -0000

Dear admin

I am writing to ask for help with writing an R script to model the current
population size using life history data (I do not know the intrinsic rate of
increase (r)).

My study population are a group of introduced chimpanzees, that were released by
the Frankfurt Zoological Society in 1966-1969 onto an island in Lake Victoria.

Thus I want to run a density independent population model using life history
data, with 0 net migration/immigration (so this is a closed system).


These are the individuals entering the system (in my case arriving on the
island), after 1969 no new animals arrive.

Year    1966    1966    1966    1966    1966    1966    1966    1968    1969
1966    1966    1966    1966    1968    1969
Animal ID       F1      F2      F3      F4      F5      F6      F7      F8
F9      M1      M2      M3      M4      M5      M6
DOB     1955    1955    1956    1957    1958    1959    1955    1960    1960
1958    1959    1959    1962    1960    1960

Notes:  Year is the year animal was released into the population
        F=female
        M=male
        DOB=date of birth


Using the following life history data I want to estimate the population size for
the year 1979, 1989, 1999, and 2014, as well as future projection for 2019, 2029
etc.

Age at first birth for females: 11 years
Birth interval: 55.2 months
Age at last birth: 50 years (in 40-50 years only 47% of females have offspring)
Survival to 8 years = 67.7%(Female) 51.4%(Male)
Survival to 15 years 41%(Female) 27%(Male)
Survival 15-40 years 18%(Female) 11%(Male)
Survival 40+ years 7%(M/F)



Birth ratio set as ___M = Male, F = Female (set as 50:50)






I hope you can be of help

Kind regards

Josephine




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