Tag: taiwan

Not All Lizards Attended That Lesson

The Lizard Keeper’s Handbook. p 101

In his book, The Lizard Keeper’s Handbook (1997. Advanced Vivarium Stystems, Inc.), Philippe de Vosjoli explains at length how to select prey items of appropriate sizes to feed to pet lizards. I agree 100% with what he wrote. However, I must say that not all lizards apply these rules under natural conditions (I guess they were absent from class on the day that lesson was taught). Here are some photographs I took of brown anoles and Swinhoe’s tree lizards in my study area that preyed on prey items that most certainly did not fall within the ideal prey size categories. 

 1. An Anolis sagrei male with a large caterpillar.

 2. An Anolis sagrei female with the remains of a grasshopper that she had had in her mouth when we captured her.

 3. A Japalura swinhonis female that rushed in to grab a beetle grub that was exposed when we accidentally knocked over a dead betelnut palm (Areca catecha) in our study area.

 4. A Japalura swinhonis male that captured an adult Clanis bilineata in the secondary forest in our study area.

 

And I believe that anyone who works with the brown anole (Anolis sagrei) would agree with me that these lizards can do some truly amazing things, as can be seen from the photos above. One of the most mind-boggling things I have found in the stomach contents of some of these lizards are centipedes. On one occasion I found a 43 mm long Chinese red-headed centipede (Scolopendra subspinipes mutilans) in the stomach of a brown anole male (SVL = 54 mm). Not only was the prey almost as long as the body length of the predator, but centipedes are venomous. It takes guts to take on such a meal!

 

 

 

Never Underestimate The Ability Of The Media To Make A Bad Situation Worse

The brown anole (Anolis sagrei) was discovered in Santzepu, Chiayi County, southwestern Taiwan, in mid 2000, and except for a few academics, most people didn’t seem to notice the existence of this exotic invasive species. That all changed when red fire ants (Solenopsis invicta) were discovered in northern parts of the island in 2003. Suddenly, invasive species became a very hot topic, and the authorities launched various projects to assess and study invasive species in Taiwan. Soon, as could be expected, A. sagrei was also in the news.

Nature’s Lunch Box

Little blue heron snacks on A. sagrei. Photo copyright bullfrog101, http://www.flickr.com/photos/43104350@N02/4463474718/sizes/l/in/photostream/

In the West Indies and southeastern U.S., the enormous population size of anole species makes them an important component of the ecosystem.  In the rainforest of Puerto Rico, for example, the three most common anole species consume an estimated 450,000 insects per hectare.  The flip side of this abundance is that anoles—small, not very fast, presumably tasty—may be an important food source for many other species.  Indeed, most West Indian snakes eat anoles and, collectively, anoles constitute more than 50% of the diet of West Indian snakes.  Similarly, many types of birds will eat anoles at least occasionally (e.g., 40% of the species at one study site in Grenada were observed eating anoles), and some species eat them in large numbers.  In addition to birds and snakes, anoles seem to be eaten by just about any flesh-eating animal (or plant) big enough to do so.  Other documented predators include many types of lizards (including many instances of cannibalism), dogs, cats, mongooses, frogs, katydids, tarantulas, spiders, whip scorpions, and centipedes (see Lizards in an Evolutionary Tree for citations and further discussion).

Despite the ecosystem importance of anoles, and particularly of predation on them, there is still a lot we don’t know about who eats anoles, when and how.  For this reason, field studies are needed, and everyone should be encouraged to document observations they make.  For example, a recent post on the “Anolis Lizard” page on Facebook provided a link to a video of a crab eating an unfortunate A. agassizi (itself a remarkable and little known species from Malpelo Island in the Pacific).  I am unaware of any previous evidence of crab predation on anoles, and scavenging can be ruled out because the poor lizard is still alive.  This situation may be atypical, though, because Malpelo is essentially one big rock, and thus the anoles are always on the ground.

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