Identifying the African wintering grounds of hybrid flycatchers using a multi-isotope (δ2H, δ13C, δ15N) assignment approach.
Migratory routes and wintering grounds can have important fitness consequences, which can lead to divergent selection on populations or taxa differing in their migratory itinerary. Collared (Ficedula albicollis) and pied (F. hypoleuca) flycatchers breeding in Europe and wintering in different sub-Saharan regions have distinct migratory routes on the eastern and western sides of the Sahara desert, respectively. In an earlier paper, we showed that hybrids of the two species did not incur reduced winter survival, which would be expected if their migration strategy had been a mix of the parent species' strategies potentially resulting in an intermediate route crossing the Sahara desert to different wintering grounds. Previously, we compared isotope ratios and found no significant difference in stable-nitrogen isotope ratios (δ15N) in winter-grown feathers between the parental species and hybrids, but stable-carbon isotope ratios (δ13C) in hybrids significantly clustered only with those of pied flycatchers. We followed up on these findings and additionally analyzed the same feathers for stable-hydrogen isotope ratios (δ2H) and conducted spatially explicit multi-isotope assignment analyses. The assignment results overlapped with presumed wintering ranges of the two species, highlighting the efficacy of the method. In contrast to earlier findings, hybrids clustered with both parental species, though most strongly with pied flycatcher.
Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada; Theoretical Biology Group, University of Groningen, Groningen, Groningen, The Netherlands.
Thor
T
Veen
Animal Ecology, Uppsala University, Uppsala, Uppland, Sweden.
Mårten B
MB
Hjernquist
Environment Canada, Saskatoon, Saskatchewan, Canada.
Steven L
SL
Van Wilgenburg
Environment Canada, Saskatoon, Saskatchewan, Canada.
Keith A
KA
Hobson
Department of Marine Ecology, Royal Netherlands Institute for Sea Research, Den Burg, Noord-Holland, The Netherlands.
Eelke
E
Folmer
Deep Earth Cluster, Vrije Universiteit Amsterdam, Amsterdam, Noord-Holland, The Netherlands.
Laura
L
Font
Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, Gelderland, The Netherlands; Centre for Integrative Ecology, Deakin University, Geelong, Victoria, Australia.
Marcel
M
Klaassen
D017954:Africa South of the Sahara; D025041:Animal Migration; D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D003903:Deuterium / Q000032:analysis; D005241:Feathers / Q000737:chemistry; D009587:Nitrogen Isotopes / Q000032:analysis; D012621:Seasons; D020308:Songbirds
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D003903:Deuterium