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. 2019 Oct 31;14(10):e0222366. doi: 10.1371/journal.pone.0222366

Table 1. Parameters used in the zebra population dynamic model and their default values.

Symbol time scale Definitions Value Source
Ry Year Total rainfall of given year y (in mm) -
K Year Annual carrying capacity Ky=hRyi [16]
h Year Constant variable affecting carrying capacity (e.g. related to habitat) 1.79 [16]
i Year Modulating factor affecting how carrying capacity increases with rainfall 1.6 [16]
b(t) Month Proportion of total birth in given month t, see Fig 2A - [17]
ρ - Proportion of females 0.5
σY Month Transition rate from foal to juvenile 1/12
1/σJf(K) Month The mean time taken till first conception 12((α + cmat/Ky−1) − 1) [16]
1/σJm(K) Month The mean time taken to mature to adult male 12((α + cmat/Ky−1) − 1) [16]
μY(K) Month Monthly mortality rate of foals (sY + cY/Ky−1)/12 [16]
μJ(K) Month Monthly mortality rate of juveniles (sJ + cJ/Ky−1)/12 [16]
μF(K) Month Monthly mortality rate of foals (sF + cA/Ky−1)/12 [16]
μM(K) Month Monthly mortality rate of foals (sM + cA/Ky−1)/12 [16]
sY Year Density independent annual mortality rate—Foals 0.19 [16]
sF Year Density independent annual mortality rate—Adult females 0.03 [16]
sM Year Density independent annual mortality rate‑Adult males 0.03 [16]
α Year Density independent age at first conception (in year) 3.4 [16]
cY Year Constant defining sensitivities to rainfall on annual mortality rate—Foals 0.164 [16]
cY Year Constant defining sensitivities to rainfall on annual mortality rate—Juveniles 0.173 [16]
cA Year Constant defining sensitivities to rainfall on annual mortality rate—Adults 0.083 [16]
cmat Year Constant defining sensitivities to rainfall on age at first conception 0.625 [16]