• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Feel the intensity, not your equipment. Maximum image quality. Minimum weight. The new ZEISS SFL, up to 30% less weight than comparable competitors.

Avon Avians

Well-known member
United States
Hello, folks!

As an owner of a red-eared slider turtle for over 12 years, I've been researching them and their behavior for quite some time now.

Generally, most sources say that red-eared sliders are more predatory when they are growing juveniles, and tend to lean towards herbivorous behavior when they are mature.
Red-eared sliders are often claimed to be herbivorous animals with little to no interest in attacking active prey.

One rather recent study showed that red-eared sliders in urban habitats are almost entirely herbivorous, not consuming much of any animal-based dietary components.
(J. D. Stephens and T. J. Ryan, 2019)

However, I've found a few other bizarre reports suggesting that they may have predatory tendencies at times.

One of the most interesting was an observation made back in 2007 by Day B. Ligon.

According to him...
"An agonistic encounter was observed between two red-winged blackbirds on the surface of a small pond..."
"Three adult red-eared sliders were observed swimming toward the two birds..."
"One of the birds flew away..."
"A third male blackbird attacked the water-bound male, but retreated almost immediately, perhaps after noticing the turtles nearby..."
"All three turtles disappeared beneath the water, and seconds later the remaining blackbird disappeared as well. An incomplete bird carcass floated back to the surface less than a minute after being pulled underwater, and the turtles were not observed again."

He goes on to say that the presence of three turtles in the incident probably did not imply cooperation, but rather high densities of the species within the pond.
However, there is a YouTube video of three red-eared sliders hunting an injured American bullfrog in an apparently cooperative(?) fashion.

The frog can be seen being grasped on the leg by one of the turtles while the other two attack it. It is possible, however, that the frog was already injured, and that red-eared sliders only attack vulnerable prey. While it is large, an American bullfrog has little in terms of defensive arsenal other than their alertness and ability to escape predators.
The person who posted the video said that the turtles were likely starving since there was no obvious aquatic vegetation in the pond (they were released there by humans).
Perhaps the same was true of the pond that the red-winged blackbirds inhabited? He never specified whether a lack of available food was responsible or not.

Whether or not red-eared sliders are predators have been disputed for a long time, mostly regarding their role as an invasive species.
According to the Tortoise Trust Website,

"The Tortoise Trust is happy to produce numerous detailed scientific citations detailing the diet and behaviour of this species that prove conclusively, beyond any doubt at all, that Red-eared sliders do not attack live water birds and that any such allegations are totally without scientific foundation."

Evidently, this website has never heard of the red-winged blackbird incident mentioned above.
It could be argued that red-winged blackbirds are not "water" birds and that the turtles only attack them because they are vulnerable and cannot swim well when they fall into a pond or other water body.

However, the first known case of a mallard duckling being preyed on by a red-eared slider was reported in 2021.
Andrés Pérez Salerno and Matthijs P. van den Burg reported...

"While observing the birds that inhabited the lake, he noticed an unusual movement in the water. Approaching rapidly, he observed an adult female Trachemys scripta (>25 cm carapace length) come up through the water column, grab a duckling (Anas platyrhynchos) from the water surface and submerge with its prey in its mouth. The attack lasted just seconds, and so the only photograph that could be taken showed only the shape of the turtle disappearing in the cloudy water. Thereafter, APS spent >15 minutes in the area, but did not see the turtle nor its duckling prey."

However, the claim that red-eared sliders can injure children is likely a dramatization of their tendencies. Even snapping turtles tend to avoid swimmers, and the concern that turtles will take off fingers or toes is likely just a rumor, at least for now. If such a case occurred, however, this would most likely be the result of a captive-bred red-eared slider being released into the wild after being hand fed. I can certainly confirm that our red-eared slider, whom we've acclimated to hand-feeding, would bite my finger without hesitation, but a wild-born red-eared slider that was never hand fed would probably never even approach a child.
This would really be more of an issue of feeding wild animals rather than an issue of an invasive species causing havoc.

As a red-eared slider owner and a reptile enthusiast, I do not support violent eradication of the species without concern for their welfare.
However, I'm hoping that this compilation of reports will shed some light on the predatory tendencies or Trachemys scripta elegans.
It is possible that the carnivorous tendencies of adult red-eared sliders depends on their digestive bacteria.
Apparently, one of the reasons that immature or juvenile red-eared sliders are predatory omnivores is because they don't have the gut microflora needed to digest plants and algae (although it is also because they need more protein to grow muscle mass.)
Perhaps some turtles simply cannot cultivate the necessary microbes to thrive solely on plant matter.
And perhaps turtles that feed mainly on vegetation will start to avoid or ignore animals since consuming them could cause digestive discomfort.
Since we actually own a red-eared slider, perhaps we could do a test to see if she can be "conditioned" to be herbivorous, or if her predatory behavior is too deeply rooted in her species.

There are several YouTube videos of violent red-eared sliders tearing apart large animals such as rodents and birds.
Often these are turtles in artificial environments and confined spaces, almost reminiscent of blood sports.
The turtles are clearly conditioned to be aggressive, and I do not consider this natural behavior.
(The turtles that display these behaviors are often fed almost entirely meat, and as a result probably wouldn't process plant matter very well.)

Users who are viewing this thread