Back to Nature (Published on TBNWeekly.com - Sept. 11, 2008)
Are green anoles disappearing from Florida?
How beautiful it is to watch the dazzling, emerald green anole bask in the morning
sun upon the back gate.
|A brown anole lizard.
A couple of weeks ago I was by mere chance afforded the opportunity to shoot
firsthand snapshots of the mating of two green anoles in my garden.
Fortunately I had a long lens close by which provided me some comfortable distance
from the amorous pair. They seemed to pay me no mind as I snapped away, eager to
capture the ardent moment on film.
The green anole, Anolis carolinensis, is the only official native member to the
vertebrate genera in Florida. Expressing concern, TBN readers have written Back to
Nature inquiring about the scarcity of green anoles at play in their gardens.
In the past when I worked in my garden I would always see the little green
lizards upon the garden wall playing and sunning themselves. Now all I see are
those ugly brown things," one reader wrote.
While researching I found several reports pointing to the dominance of the
nonnative brown anole, Anolis sagrei over the green Anolis carolinensis. Although
there does seem to be evidence that there are less green anoles today than in the
past some research indicates that brown anoles may not actually be the main culprit
for the decline in their populations. In fact, there are areas where green anoles
are dominant over brown anoles.
How can someone distinguish between a green and a brown anole?
For identification purposes: Green anoles can turn brown, but brown anoles are
unable to turn green. Brown anoles can turn darker brown and even black. Brown
anoles have strong markings down their backs. Green anoles have a bright blue eye
ring while in their green color change and their dewlaps are a quieter shade of
Brown anoles naturally display near ground level, moving back and forth, up and
down while showing off their bright orange dewlaps to impress other males. Green
anoles prefer higher and more secretive perches out of the way so, in fact, they
may not actually be as visible.
One aspect that may play in the decline of the green anole is competition for
food. In a report by J. Masterson of the Smithsonian Marine Station: In areas
where this exotic species (brown anole) has become established, it is very often
the most abundant reptile species present. Anolis sagrei is among the most abundant
lizards throughout Florida
The first anecdotal suggestions implicating the exotic brown anole in the decline
of native green anole populations in Florida were published in the 1960s (Collette
1961, King and Krakauer 1966). Direct studies of interspecific associations between
the two congeners appear much less significant than interspecific (within-species)
competitive interactions within these aggressive, territorial animals (Brown and
Field observations and experimental manipulations have demonstrated that brown
anoles in Florida prey directly on other small vertebrates including hatchlings of
the native green anole.
Another factor noted: brown anoles simply multiply more prolifically than green
anoles. Green anoles typically reproduce during the months of April through July
when levels of sex steroids and behavior are maximal.
And yet one more intriguing explanation attributed for the brown anoles high
profile in the garden as opposed to the secretive green anole: The brown anole
prefers to display conspicuously low to the ground, under foot, to be exact. They
seem to run from every corner as we walk along a path. They posture from lamp
posts, leafy plants, picnic tables, the handle of a shovel or atop a garden
Brown anoles are quite visible. As a result this also renders them easy targets
for roaming predators such as large birds and cats. House cats are one of the
lizards most formidable foes. House cats (a nonnative species to North
America and unnatural predator) are frequently left to roam backyard gardens at
their leisure to hunt down prey such as native birds and lizards. Once a cat
becomes adept at capturing the conspicuous brown anole the cat may turn predatory
interest to capturing the more secretive green anoles. Since the green anoles do
not breed as prolifically as the brown anoles, the green anoles are killed off and
the more heavily populating brown anole survives to be seen.
Reptiles have been evolving on our planet for more than 300 million years so the
causes of a species decline are often more complicated than the apparent
obvious theory. However, we have discovered with a wide variety of plants provided
in the garden, the lack of pesticides, in conjunction with the scarcity of
nonnative predators roaming freely in the garden, the green anole seems to be
living and reproducing naturally here, perhaps even making somewhat of a comeback.
For now were waiting in anticipation for the prodigies of these two lovely,
charismatic gems to beautify the garden in jeweled sunbeams on another
back to nature.
Karen can be reached at MyMuddyPawsStudio@gmail.com.