Seduced by
FL
WER P WER!
Lizards as pollinators and seed dispersers.
Zoologist and conservation biologist Kit
Prendergast looks at an unlikely group
of lizards.
I
n terms of pollinators, we typically think of bees, as
well as various other insects, birds, and sometimes
bats. And the typical agents of seed dispersal tend to be
birds and mammals. Yet there has been an increasing
recognition that lizards can in fact play these roles. Most
reptiles, especially lizards, are insectivorous. In fact, only
about 1% of the world’s roughly 4,000 species of lizards
are known to consume plant material, and thus have
even the potential to be pollinators or seed dispersers. In
this article, I will introduce you to the extraordinary
mutualisms that have evolved between lizards and
plants, with the lizards mediating pollination (known as
saurophily) and/or seed dispersal (saurochory).
A total of 46 lizard species belonging to six families have
been documented to consume nectar: this includes 21
geckos (family Diplodactylidae), 14 anoles (family
Dactyloidae), five lacertids (family Lacertidae), and three
skinks (family Scincidae). Whilst over 200 species of
lizards have been observed to eat fruit, my preliminary
review of frugivorous lizards included 64 species from 10
families: amongst these were 17 skinks, 11 geckos, 10
iguanids (family Iguanidae), 6 anoles, six species from
the family Tropiduridae, 5 lacertids, one varanid (family
Varanidae), and a single agamid (our own Intellagama
lesueurii, the Australian Water Dragon). Thus, there is a
greater taxonomic diversity and range of species that are
frugivorous compared to those that are nectivorous. Just
12 species of lizards have been recorded to consume
both nectar and fruit, and therefore be both potential
pollinators and seed dispersers (however the majority
consumed nectar and fruit from different plant species).
Of potential concern is that some species which may be of
importance in plant reproduction (especially pollinators)
have not had their conservation status assessed. Of those
that have, roughly half are considered to be threatened
with extinction: two endemic species from Rodrigues
Island are already extinct.
Although it is unsurprising that lizards are rarely
herbivorous (plant parts contain high volumes of
cellulose which requires considerable mechanical and
chemical breakdown, necessitating strong jaws, grinding
molars and a large gut containing symbiotic microbes),
Composite photo by Rachael Hammond.