Differences in phenotypic variance between old and young congeneric species on a small island

Aim: Insular environments theoretically promote within-species phenotypic variance, in part but not only because insular species enjoy a lower number of trophic interactions than their mainland counterparts. However, environmental factors apparently confound empirical comparisons between insular and mainland systems. To address this issue, we studied sympatric, congeneric species from the same small island, but that stemmed from separate colonization events. We predicted that the time since the species had colonized the island would correlate positively with the within-species variance in morphometrics.
Location: Lifu Island, New Caledonia, South Pacific.
Taxa: Zosterops inornatus, Z. minutus, Z. lateralis (Passeriformes). 
Methods: We measured 7 morphological traits and used principal component analysis to compute axes of variation.
Results: The within-species variance in bill size and in feet/tail ratio corrected for body size increased with the estimated time since the species had ..., , , # Differences in phenotypic variance between old and young congeneric species on a small island

Raw morphometric data in millimeters from the three endemic species of Zosterops birds on Lifu island, New Caledonia, taken in Nov. 2022

SPECIES : 6 letter species code
EB : bill width
BN : bill length
BH : bill height
LT : tarsus length
ET : tarsus width
LP : wing length
LR : tail length