Geographic variation in resource use by specialist versus generalist butterflyfishes
KAUST DepartmentRed Sea Research Center (RSRC)
Biological and Environmental Sciences and Engineering (BESE) Division
Marine Science Program
Reef Ecology Lab
Permanent link to this recordhttp://hdl.handle.net/10754/561921
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AbstractLocalised patterns of resource use can be constrained by multiple factors. Comparison of resource use at multiple locations with differing resource availability can allow fundamental specialists to be distinguished from species that simply feed predominantly on prey types that are locally abundant. This study investigates geographic variation in the feeding ecology of coral-feeding butterflyfishes to examine whether patterns of resource use and levels of dietary specialisation vary among distinct locations, corresponding with changes in resource availability. Our specific aims were to investigate whether the dietary niche breadth of four butterflyfishes varies among five geographically separated locations and assess whether each species utilises similar resources in each location. Resource availability and dietary composition of four butterflyfishes were quantified at three sites across each of five geographic locations throughout the Pacific. Niche breadth, niche overlap, and resource selection functions were calculated for each species at each site and compared among locations. Availability of dietary resources varied significantly among locations and sites. Chaetodon vagabundus, C. citrinellus and C. lunulatus had low levels of dietary specialisation and used different resources in each location. Chaetodon trifascialis had high levels of dietary specialisation and used the same few resources in each location. Our results indicate that relative levels of dietary specialisation among different butterflyfishes do hold at larger spatial scales, however, geographical variation in the dietary composition of all butterflyfishes indicates that prey availability has a fundamental influence on dietary composition. Highly specialised species such as C. trifascialis will be highly vulnerable to coral loss as they appear to be largely inflexible in their dietary composition. However, the increased feeding plasticity observed here for C. trifascialis suggests this species may have a greater capacity to respond to coral loss than previously assumed. © 2011 The Authors. Ecography © 2011 Nordic Society Oikos.
SponsorsWe thank D. McCowan, K. Chong-Seng, M. Trapon, V. Messmer and D. Coker for assistance with field work. We also thank the staff of Heron Island Research Station, Lizard Island Research Station, Mahonia na Dari and Richard B Gump Research Station for logistical support. This research was funded in part by a Queensland Government Smart State PhD Scholarship and grants from the Wildlife Preservation Society of Australia, Project Aware and the Australian Coral Reef Society to RJL; and Sir Keith Murdoch Fellowships from the American Australian Association and a John and Laurine Proud Fellowships from the Lizard Island Research Station (a facility of The Australian Museum) to MSP and MLB.