Abstract
Birds are known to act as potential vectors for the exogenous dispersal
of bryophyte diaspores. Given the totipotency of vegetative tissue of
many bryophytes, birds could also contribute to endozoochorous bryophyte
dispersal. Research has shown that fecal samples of the upland goose
(Chloephaga picta) and white-bellied seedsnipe (Attagis
malouinus) contain bryophyte fragments. Although few fragments from
bird feces have been known to regenerate, the evidence for the viability
of diaspores following passage through the bird intestinal tract remains
ambiguous. We evaluated the role of endozoochory in these same
herbivorous and sympatric bird species in sub-Antarctic Chile. We
hypothesized that fragments of bryophyte gametophytes retrieved from
their feces are viable and capable of regenerating new plant tissue.
Eleven feces disc samples containing undetermined moss fragments from
C. picta (N=6) and A. malouinus (N=5) and
six moss fragment samples from wild collected mosses (Conostomum
tetragonum, Syntrichia robusta, and Polytrichum strictum)
were grown ex situ in peat soil and in vitro using a
agar-Gamborg medium. After 91 days, 20% of fragments from A.
malouinus feces, 50% of fragments from C. picta feces, and 67%
of propagules from wild mosses produced new growth. The fact that moss
diaspores remained viable and can regenerate under experimental
conditions following the passage through the intestinal tracts of these
robust fliers and altitudinal and latitudinal migrants, suggests that
sub-Antarctic birds may play a critical role in bryophyte dispersal.
This relationship may have important implications in the way bryophytes
disperse and colonize habitats facing climate change. Keywords: birds,
bryophyte dispersal, endozoochory, mosses, sub-Antarctic