Banca de QUALIFICAÇÃO: VIRGINIA HELEN FIGUEIREDO PAIXAO
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE : VIRGINIA HELEN FIGUEIREDO PAIXAO
DATA : 10/10/2019
HORA: 13:00
LOCAL: Sala de Reuniões da administração CB
TÍTULO:
Cacti-vertebrates interactions network in a Brazilian dry forest
PALAVRAS-CHAVES:
Plant-animal interactions;Frugivory;Cactaceae;Caatinga;Seed dispersal;Florivory
PÁGINAS: 32
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:
Cactaceae is one of the most diverse plant families in the Neotropics. Cacti species produce fruits rich in water and sugar content in arid zones over the world, where they maintain frugivore communities that disperse its seeds. In our first chapter, we investigated network structure and species roles of a cacti-frugivores interactions network in an area of Caatinga domain dominated by cacti in northeastern Brazil.We used camera trapping to record the interactions of vertebrate frugivores with six cacti species. We analysed network modularity (Q), specialization (d’ and H2’) and species roles (zc values) with quantitative metrics with four of the cacti species that had enough data. We found a different use of cacti species by animal class, where birds consumed more frequently fruits of columnar cacti that are taller in comparison to globular cactus, which was in turn more eaten by lizards. Our network was structured in four modules, which one composed by a single cactus species, and marked by a high network specialization. Evidences suggest the importance of trait match between frugivores and cacti in network structure, with the extreme example of globular cactus and lizards that are highly mutually specialized. Most of our species were classified as peripherals, probably due to the exclusiveness of interactions, with only one Passerine bird classified as connector, that due to its dispersal capacities it’s important to module and network coherence. Our findings illustrate that our modular and specialized network might be a reflection of a coevolutionary history between animal taxa and cacti species, with a structural importance of trait matching. During our camera trapping surveillance of frugivory events, we found an unexpected behaviour performed by the Tropiduridae Tropidurus hispidus of eating the Tacinga inamoena cactus flowers. Our second chapter is then a description of this behaviour not previously described in literature. Florivory is an event of consumption of flower structures that tends to be entirely eaten when performed by vertebrates. We detected four florivory events by lizards, three of them in the dry season. It is known that this species feed on flowers mostly in the drier periods at Caatinga sitesas an adaptation to water/food scarcity and that the search for flower food is due to not only the need of water but the high nutrient content.
MEMBROS DA BANCA:
Interno - 1678202 - CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
Presidente - 1718346 - EDUARDO MARTINS VENTICINQUE
Interna - 3058386 - VANESSA GRAZIELE STAGGEMEIER