Data for: Perishing rich, expanding poor: Demography and population genetic patterns in two congeneric butterflies

In human-altered landscapes, specialist butterflies typically form
spatially restricted populations, genetically differentiated due to
dispersal restrictions. Generalists, in contrast, display minimum
differentiation but high genetic diversity. While local-level actions
suffice to conserve specialists and landscape-level actions are necessary
for generalists, minimum information exists regarding conservation of
species with intermediate features. We targeted two congeneric
butterflies, the recently re-expanding Argynnis adippe and the strongly
declining A. niobe, co-occurring in the pastoral landscape of the
Carpathian Mountains, Czech Republic. We integrated species distribution
models, mark-recapture, and microsatellite analysis to compare their
habitat requirements, adult demography, dispersal, and genetic patterns,
and expanded the genetic analysis across the Carpathian Arc and beyond to
delimit spatial conservation units. In two mountain valleys, both species
formed interconnected populations numbering thousands of individuals.
Mobility patterns suggested the populations’ interconnection across the
Czech Carpathians. Genetic diversity was extremely poor in the
non-threatened A. adippe and moderate in the declining A. niobe. No
population differentiation was detected within the Czech Carpathians (ca
1500 km2). Low genetic diversity and no differentiation was preserved in
A. adippe across East Central Europe, whereas in A. niobe, populations
from Serbia were differentiated from the Carpathian Arc + Alps. The high
adult mobility linked to low differentiation probably reflect the
distribution of larval resources, historically widespread but sparse and
currently declining for A. niobe (grazing-disturbed grounds), while
currently increasing for A. adippe (abandonment scrub, disturbed
woodlands). Units as large as entire mountain systems define population
boundaries, and hence conservation management units, for both species.