Populationsolver.csv (2.77 kB)

Time series data of a guanaco population in Southern Tierra del Fuego (1977-2012)

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posted on 2013-10-10, 10:55 authored by María Zubillaga, Oscar Skewes Ramm, Nicolás Soto Volkart, Jorge E Rabinovich

The first column identifies the year each sample was carried out; columns 2-5 are the elements of the population projection matrix and represent the parameters the fecundity (newborn females per adult female (a13), the survival of female newborns (a21), the survival of female juveniles (a32), and the survival of female adults (a33). “Fem newborns”, “Fem Juveniles” and “Fem Adult” are the number of guanacos of each age class (the population vector) as calculated by the matrix model for each year; “Fem Population” results from the addition of the previous three columns, that is, it represents the total female population resulting from the matrix model. “Total Population both sexes (model)” is the total guanaco population (both sexes) originated from “Fem Population” multiplied by 2 (the sex-ratio in the guanacos is 1:1). “Total field population” is the total field guanaco population obtained by sampling by the Distance method (see text). “SSQ” is the sum of squares function as the goodness of fit criterion used for fitting the differences between the “Total Population both sexes (model)” and “Total field population” by changing the values of the population matrix elements (“a13”, “a21”, “a32” and “a33”). “Lambda” is the population growth rate (lambda) as estimated for each year with the PopTools “add-in” of the Excel spreadsheet based on the corresponding transition matrix of that year.