Format: ORAL

Santiago Martn-Bravo1, Mnica Mguez1, Diego Herrero1, Kerry Ford2, Pedro Jimnez-Mejas1, Miquel Cap3

1Botany Area, Universidad Pablo de Olavide, ctra. de Utrera km 1, 41013, Seville, Spain 2Landcare Research-Manaaki Whenua, Lincoln, New Zealand 3Plant & Animal Ecology Lab. Centro para la Conservación de la Biodiversidad y el Desarrollo Sostenible. Departamento de Sistemas y Recursos Naturales. Universidad Politécnica de Madrid, 28040 Madrid, Spain

The moas were giant flightless birds (ratites) endemic to New Zealand, where they were the largest herbivores before their rapid extinction after colonization by maori people (c. 1440 AD). Moas herbivory is considered a major force in the evolution of native vegetation, and their evolutionary legacy can still be seen in traits of different plant species. Colour-based plant defence has been proposed as a strategy to avoid herbivory. Genus Carex, which has a hotspot of diversity and endemicity in New Zealand, has red-leaved species in four different lineages. Despite this is a unique feature not found elsewhere in this megadiverse cosmopolitan genus, its evolution has not been investigated yet. In order to evaluate if red foliage could have helped Carex to escape from herbivores, a cafeteria-type experiment was conducted in a zoo using the moas closely related extant species Dromaius novaehollandiae (emu) as a proxy. We exhibited green-leaved and red-leaved morphotypes of two Carex species (subgen. Carex, sect. Echinochlaenae) to evaluate emus diet preference on the different colour morphotypes. We studied different growth parameters in control and bird-exposed plants (e.g., dry biomass, specific leaf area, root-shoot ratio, etc), and the interaction of birds with plants (time, peck number) through phototrapping, during three two-week cafeteria presentations. Our results show that emus clearly interacted and consumed the green plants over the red ones, which was also evident from several significant measured plant variables. This suggests that red-leaved plants could be less visually attractive and/or palatable to ratite birds. Our study supports the hypothesis that red-leaved Carex foliage could have adaptively evolved to avoid herbivory by moas in New Zealand.