Equation 8: Assigning breeding males to "drain" (aka "floater") status

Males that don't find a territory AND don't find a mate become "drain" males (floaters). W2.mg+W2.mp = total male population at the end of spring migration. From thid gets subtracted birds that ended up in source habitat (K.bc) and those that paired with female in sink habitat (B.fk)

eq08_Bmd(W2, K.bc, B.fk)

Arguments

W2	population vector
K.bc	source carrying capacity
B.fk	females available in sink

Value

Number of males in drain habitat.

Details

Note that it is possible for the equation W2.mg+W2.mp - K.b to return a negative value if the number of males is less than the source habitat size (K.bc). The use of max() corrects for this.

References

Runge, MC and PP Marra. 2004. Modeling seasonal interactions in the population dynamics of migratory birds. In Greenberg, R and PP Marra, eds. Birds of Two Worlds.

Examples

W2. <- c(10,10,10,10)
names(W2.) <- c("mg","fg","mp","fp")
eq08_Bmd(W2 = W2., K.bc = 0, B.fk =5)
#> [1] 15