A major challenge in evolutionary ecology is to understand how co-evolutionary processes shape patterns of interactions between species at community level. Pollination of flowers with long corolla tubes by long-tongued hawkmoths has been invoked as a showcase model of co-evolution. Recently, optimal foraging models have predicted that there might be a close association between mouthparts' length and the corolla depth of the visited flowers, thus favouring trait convergence and specialization at community level.
Here, we assessed whether hawkmoths more frequently pollinate plants with floral tube lengths similar to their proboscis lengths (morphological match hypothesis) against abundance-based processes (neutral hypothesis) and ecological trait mismatches constraints (forbidden links hypothesis), and how these processes structure hawkmoth–plant mutualistic networks from five communities in four biogeographical regions of South America.
We found convergence in morphological traits across the five communities and that the distribution of morphological differences between hawkmoths and plants is consistent with expectations under the morphological match hypothesis in three of the five communities. In the two remaining communities, which are ecotones between two distinct biogeographical areas, interactions are better predicted by the neutral hypothesis.
Our findings are consistent with the idea that diffuse co-evolution drives the evolution of extremely long proboscises and flower tubes, and highlight the importance of morphological traits, beyond the forbidden links hypothesis, in structuring interactions between mutualistic partners, revealing that the role of niche-based processes can be much more complex than previously known.
Hawkmoth-plant pollination network (CY2 community)
Cuantitative hawkmoth-plant pollination network from CY2 community (Chaco-Yungas transition 2, El Fuerte locality, Argentina). Column names correspond to hawkmoth species and row names correspond to plant species. The number in each cell correspond to the number of hawkmoth individuals carrying pollen for a given plant species.
network_CY2.txt
Hawkmoth-plant pollination network (CY1 community)
Cuantitative hawkmoth-plant pollination network from CY1 community (Chaco-Yungas transition 1, Terma de Reyes locality, Argentina). Column names correspond to hawkmoth species and row names correspond to plant species. The number in each cell correspond to the number of hawkmoth individuals carrying pollen for a given plant species.
network_CY1.txt
Hawkmoth-plant pollination network (CM community)
Cuantitative hawkmoth-plant pollination network from CM community (Chaco Montane Dry Woodland, Argentina). Column names correspond to hawkmoth species and row names correspond to plant species. The number in each cell correspond to the number of hawkmoth individuals carrying pollen for a given plant species.
network_CM.txt
Hawkmoth-plant pollination network (AF community)
Cuantitative hawkmoth-plant pollination network from AF community (Atlantic Forest, Brasil). Column names correspond to hawkmoth species and row names correspond to plant species. The number in each cell correspond to the number of hawkmoth individuals carrying pollen for a given plant species.
network_AF.txt
Hawkmoth-plant pollination network (CE community)
Cuantitative hawkmoth-plant pollination network from CY2 community (Cerrado, Brasil). Column names correspond to hawkmoth species and row names correspond to plant species. The number in each cell correspond to the number of hawkmoth individuals carrying pollen for a given plant species.
network_CE.txt
Hawkmoth proboscis length (AF community)
Hawkmoths species from AF community (Atlantic Forest, Brasil) with values of mean proboscis lenght
HPL_AF.txt
Hawkmoth proboscis length (CE community)
Hawkmoths species from CE community (El Cerrado, Brasil) with values of mean proboscis lenght
HPL_CE.txt
Hawkmoth proboscis length (CM community)
Hawkmoths species from CM community (Chaco Montane Dry Woodland, Argentina) with values of mean proboscis lenght
HPL_CM.txt
Hawkmoth proboscis length (CY1 community)
Hawkmoths species from CY1 community (Chaco-Yungas Transition, Terma de Reyes locality, Argentina) with values of mean proboscis lenght
HPL_CY1.txt
Hawkmoth proboscis length (CY2 community)
Hawkmoths species from CY2 community (Chaco-Yungas Transition, El Fuerte locality, Argentina) with values of mean proboscis lenght
HPL_CY2.txt
Effective flower lengths (AF community)
Plant species pollinated by hakwmoths from AF community (Atlantic forest, Brasil) with mean values of effective flower length
EFL_AF.txt
Effective flower lengths (CE community)
Plant species pollinated by hakwmoths from CE community (El Cerrado, Brasil) with mean values of effective flower length
EFL_CE.txt
Effective flower lengths (CM community)
Plant species pollinated by hakwmoths from CM community (Chaco Montane Dry Woodland, Argentina) with mean values of effective flower length
EFL_CM.txt
Effective flower lengths (CY1 community)
Plant species pollinated by hakwmoths from CY1 community (Chaco-Yungas transition, Terma de Reyes locality, Argentina) with mean values of effective flower length
EFL_CY1.txt
Effective flower lengths (CY2 community)
Plant species pollinated by hakwmoths from CY2 community (Chaco-Yungas transition, El Fuerte locality, Argentina) with mean values of effective flower length
EFL_CY2.txt