| Abstract: | Comparative studies of co-occurring species using overlapping resources may help
in understanding the mechanisms supporting biotic diversity in species-rich
regions, such as the Mediterranean region of Europe. Three Papilionidae butterflies,
Archon apollinus, Zerynthia cerisy and Zerynthia polyxena, develop on
Aristolochia plants and co-occur in Greek Thrace. We used mark–recapture to
describe adult demography and dispersal, and searched for eggs and larvae to
assess host plants and microhabitat preferences. Adult flight timing followed a
sequence from earliest A. apollinus, through Z. polyxena to late Z. cerisy; this was
more prominent in 2010 (warm early spring) than in 2011 (cold delayed spring).
Population densities were highest for A. apollinus and lowest for Z. cerisy, whereas
dispersal ability followed a reverse pattern. Adults of all three species crossed
distances > 3 km and used all habitat types present. Four Aristolochia host plants
were used at the study locality: small Aristolochia pallida, intermediate
Aristolochia rotunda and Aristolochia hirta, and bulky, late-sprouting
Aristolochia clematitis. Both A. apollinus and Z. polyxena used all four
Aristolochia species, the former preferring Aristolochia rotunda and Aristolochia
hirta, the latter Aristolochia rotunda and Aristolochia pallida. Zerynthia cerisy did
not use the early-growing Aristolochia pallida while frequently using the lategrowing
Aristolochia clematitis. Further parameters affecting oviposition were
biotope and canopy closure: early A. apollinus tolerated shady sites but late
Z. cerisy avoided them. The simultaneous use of several host plants differing in
phenology and habitat requirements, combined with rather high dispersal ability,
arguably buffers the butterflies’ population dynamics against yearly variation in
weather, while allowing efficient occupation of the diverse Mediterranean landscapes.
The regional habitat diversity, created during millennia of human activity,
is currently threatened by land abandonment, which may diminish the resource
base for the studied butterflies.
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