Frugivory in lizards is often assumed to be constrained by body size;only large individuals are considered capable of consuming fruits, with the potential of acting as seed dispersers. However, only one previous study...Frugivory in lizards is often assumed to be constrained by body size;only large individuals are considered capable of consuming fruits, with the potential of acting as seed dispersers. However, only one previous study has tested the correlation of frugivory with body and head size at an archipelago scale across closely related species. All nine lava lizards (Microlophus spp.) were studied on the eleven largest Galapagos islands from 2010 to 2016 to investigate whether frugivory is related to body and head size. We also tested whether fruit abunda nee in flue nces fruit con sumption and explored the effect of seed ingestion on seedling emergence time and percentage. Our results showed that across islands, lava lizards varied considerably in size (64-102 mm in mean snoutvent length) and level of frugivory (1-23%, i.e., percentage of droppings with seeds). However, level of frugivory was only weakly affected by size as fruit consumption was also common among small lizards. Lava lizards consumed fruits throughout the year and factors other than fruit abundance may be more importa nt drivers of fruit selecti on (e.g., fruit size, energy con tent of pulp). From 2,530 droppings, 1,714 seeds of at least 61 plant species were identified, 76% of the species being native to the Galapagos. Most seeds (91%) showed no external structural damage. Seedling emergence time (44 versus 118 days) and percentage (20% versus 12%) were enhanced for lizardingested seeds compared to control (uningested) fruits. De-pulping by lizards (i.e., removal of pulp with potential germi nation inhibitors) might in crease the chances that at least some seeds find suitable recruitment conditi ons. We con eluded that lizards are importa nt seed dispersers throughout the year and across the whole archipelago, regardless of body size.展开更多
文摘Frugivory in lizards is often assumed to be constrained by body size;only large individuals are considered capable of consuming fruits, with the potential of acting as seed dispersers. However, only one previous study has tested the correlation of frugivory with body and head size at an archipelago scale across closely related species. All nine lava lizards (Microlophus spp.) were studied on the eleven largest Galapagos islands from 2010 to 2016 to investigate whether frugivory is related to body and head size. We also tested whether fruit abunda nee in flue nces fruit con sumption and explored the effect of seed ingestion on seedling emergence time and percentage. Our results showed that across islands, lava lizards varied considerably in size (64-102 mm in mean snoutvent length) and level of frugivory (1-23%, i.e., percentage of droppings with seeds). However, level of frugivory was only weakly affected by size as fruit consumption was also common among small lizards. Lava lizards consumed fruits throughout the year and factors other than fruit abundance may be more importa nt drivers of fruit selecti on (e.g., fruit size, energy con tent of pulp). From 2,530 droppings, 1,714 seeds of at least 61 plant species were identified, 76% of the species being native to the Galapagos. Most seeds (91%) showed no external structural damage. Seedling emergence time (44 versus 118 days) and percentage (20% versus 12%) were enhanced for lizardingested seeds compared to control (uningested) fruits. De-pulping by lizards (i.e., removal of pulp with potential germi nation inhibitors) might in crease the chances that at least some seeds find suitable recruitment conditi ons. We con eluded that lizards are importa nt seed dispersers throughout the year and across the whole archipelago, regardless of body size.
