Germination percent and rate for seeds ingested by Cuora amboinensis

To determine if seed germination was enhanced following
ingestion by a turtle, we conducted germination trials of ingested seeds from
fecal samples compared with control seeds collected from the forest. Control
seeds were collected by finding mature fruit on the forest floor and removing
the seeds from the pulp. Seeds of both types were rinsed with well water. Seeds
were placed in germination bags which consisted of a paper towel measuring 22 x
11 cm with an 11 x 11 cm sheet of clear plastic beneath it and a clip holding
the edge of the paper towel onto the plastic. Ten control or ingested seeds of
a given genus or species were placed on the half of the paper towel seated on
the plastic. The other half of the paper towel was saturated with well water and
then folded over on top of the seeds on the plastic sheet. The plastic sheet
with saturated paper towel containing the seeds was slid into a clear zip-top
plastic bag (17 x 15 cm). We inflated germination bags by blowing into them so
that the upper surface of the plastic bag was not resting on the top of the
paper towel. Germination bags were randomly positioned in a box measuring 195 x
189 x 12 cm and placed on a table beneath a roof outside. The bags received
ambient light but none received direct sunlight at any time of the day. Each
morning we inspected seeds in germination bags. Germination of seeds of A. teijsmannii, C. trifolia, D. serrata,
and V. cofassus could be seen unaided,
but we examined seeds of Ficus spp. and
N. cadamba using a microscope at 20x
magnification, because of their small size. About 4 ml of well water was added
to the upper surface of the paper towel every three days or as needed to keep
seeds moist.

For each of six plant species, we conducted germination
trials on seven replicates of seeds collected from the forest (controls) and seven
to 11 replicates of seeds that had been ingested by turtles. We documented date
of germination for each seed and removed germinated seeds from the bag to
prevent damage to the paper towel by the cotyledon. Trials were terminated
after 30 days for each germination bag because pilot trials indicated that all
of our target species were capable of germination within one to two weeks,
fruiting periods varied between species necessitating seed collection when
available, and because of limited space in the germination box. We compared germinability
(final percent germinated) between ingested and control seeds for each plant
species using a general linear model with a binomial distribution and a
logit-link function. We compared germination rate (days to germination) for
seeds ingested by turtles and control seeds for each plant species using a
general linear model with a Poisson distribution. Statistical analyses were
conducted in SAS (SAS Institute, version 9.4).