Data from: Paternity assignment and demographic closure in the New Zealand southern right whale

The identification and characterisation of reproductively isolated
subpopulations or ‘stocks’ is essential for effective conservation and
management decisions. This can be difficult in vagile marine species like
marine mammals. We used paternity assignment and ‘gametic recapture’ to
examine the reproductive autonomy of southern right whales (Eubalaena
australis) on their New Zealand (NZ) calving grounds. We derived DNA
profiles for 34 mother-calf pairs from skin biopsy samples, using
sex-specific markers, 13 microsatellite loci and mtDNA haplotypes. We
constructed DNA profiles for 314 adult males, representing 30% of the
census male abundance of the NZ stock, previously estimated from genotypic
mark-recapture modelling to be 1085 (95% CL 855, 1416). Under the
hypothesis of demographic closure and the assumption of equal reproductive
success among males, we predict: (1) the proportion of paternities
assigned will reflect the proportion of the male population sampled and
(2) the gametic mark-recapture (GMR) estimate of male abundance will be
equivalent to the census male estimate for the NZ stock. Consistent with
these predictions, we found that the proportion of assigned paternities
equalled the proportion of the census male population size sampled. Using
the sample of males as the initial capture, and paternity assignment as
the recapture, the GMR estimate of male abundance was 1001 (95% CL 542,
1469), similar to the male census estimate. These findings suggest that
right whales returning to the NZ calving ground are reproductively
autonomous on a generational timescale, as well as isolated by maternal
fidelity on an evolutionary timescale, from others in the Indo-Pacific
region.