A tale of two mistletoes: phenology and fauna associated with two sympatric species

Abstract

Mistletoes are parasitic plants that largely rely on animals for pollination and seed dispersal but establish complex interactions with their host plants. Mistletoes are considered keystone species in forest ecosystems as they facilitate several interactions. We studied the fauna associated with two sympatric mistletoe species (Tristerix corymbosus and Desmaria mutabilis) from the temperate rainforests of southern Chile. We set 40 camera traps from November 2021 to May 2022 to monitor the main pollinator (the hummingbird Sephanoides sephaniodes), the main seed disperser (the arboreal marsupial Dromiciops bozinovici), and other animals (birds, mammals, reptiles, and insects). We compared fauna associated with T. corymbosus between spring and summer-fall periods and between T. corymbosus and D. mutabilis during summer-fall. Species composition associated with T. corymbosus showed a significant temporal variation, mainly explained by S. sephaniodes and D. bozinovici, which are more abundant in the summer-fall period. We found that animal species composition differences between mistletoe species were mainly explained by S. sephaniodes, D. bozinovici, and insects. While T. corymbosus was mainly pollinated by hummingbirds, insects frequently visited D. mutabilis flowers. Although both mistletoes have many similarities, they also have some phenology differences that affect their associations with animals, potentially influencing ecological processes.