Unusual damage to wild turtle shell - What could cause this??

[Raymonde]

Hi, I have been doing research on wild turtles in urban lakes around Brisbane.
At one of my sites, Minnippi Parklands (Tingalpa) Brisbane, I caught a female brisbane river turtle (Emydura macquarii signata)(carapace length was 24.1cm) that had some very unusual damage to its shell that looked a lot like bite marks. The only thing i have seen that was similar was a photo of a turtle that had been bitten by a crocodile. The turtle i caught also had its back right leg missing, half of the front right foot and had a damaged left eye (possibly blind). All the injuries were old and completely healed and the turtle seemed in good condition.

Does anyone have any ideas on what could have caused this kind of damage???

Although crocodiles have been known to come as far south as brisbane, it is very rare. So it is unlikely that the turtle encountered the crocodile here... I guess it is possible that someone transported the turtle from further north and released it at Minnippi Parklands, but i find this equally unlikely.
My only other idea is that the damage was done when the turtle was a lot younger/smaller, and therefore could have been a large fish or eel or bird.

So, what are other people's thoughts??

thanks Raymonde

 

[Ramsayi]

My guess would be at some stage of its life it was attacked by a car.

 

[Snake Catcher Victoria]

Could it be rats?

 

[PythonLegs]

Looks like an outboard motor- have seen a few greens and loggerheads with pretty similar shell damage

 

[Cockney_Red]

Bull shark

 

[raycam01_au]

agreed wiff Cockney_Red

they dun mind alittle fresh water, n have good chompers

 

[Raymonde]

rats is a possibility, and foxes are another, particularly if it was when it was younger.

i find that outboard motor or a car would be unlikely (though not impossible). The lake in which it was caught is approx 4 hectares and does allow canoes but doesn't have vehicle access. The nearest roads are 400m but it doesn't really look like car damage to me.

I hadn't thought of a bullshark.... The lake IS within 100m of Bulimba creek, which at that point is tidal, though brackish, and about 10m wide. There are also freshwater mullet in the lake, so i guess a bullshark could have got into the lake, although i don't like to think about it.... as i was wading into the lake a lot and quite deep and not really aware of where my hands were.....

the lake also has other large fish including tilapia, carp, longfinned eels and eel-tailed catfish. I was thinking an eel could cause that sort of damage to a hatchling or juvenile...

Bull shark

agreed wiff Cockney_Red

they dun mind alittle fresh water, n have good chompers

yes, i am beginning think a bullshark is a strong possiblility... which is creeping me out no end... i was in that lake all the time, for the last 3 years :shock:... i really hope there wasn't a bullshark, i have a very healthy respect for them and really don't want to be in the same water as them...

my hope is that the turtle got attacked while it was in bulimba creek and at some point found its way into the lake and that all the bullsharks are in the creek and not the lake... this may be wishful thinking but i'm sticking to it, as it gives me piece of mind...

although if i think about it, it is also possible that the lake has been connected to Bulimba creek during a flood...:|

 

[004dam]

rats is a possibility, and foxes are another, particularly if it was when it was younger.

i find that outboard motor or a car would be unlikely (though not impossible). The lake in which it was caught is approx 4 hectares and does allow canoes but doesn't have vehicle access. The nearest roads are 400m but it doesn't really look like car damage to me.

I hadn't thought of a bullshark.... The lake IS within 100m of Bulimba creek, which at that point is tidal, though brackish, and about 10m wide. There are also freshwater mullet in the lake, so i guess a bullshark could have got into the lake, although i don't like to think about it.... as i was wading into the lake a lot and quite deep and not really aware of where my hands were.....

the lake also has other large fish including tilapia, carp, longfinned eels and eel-tailed catfish. I was thinking an eel could cause that sort of damage to a hatchling or juvenile...






yes, i am beginning think a bullshark is a strong possiblility... which is creeping me out no end... i was in that lake all the time, for the last 3 years :shock:... i really hope there wasn't a bullshark, i have a very healthy respect for them and really don't want to be in the same water as them...

my hope is that the turtle got attacked while it was in bulimba creek and at some point found its way into the lake and that all the bullsharks are in the creek and not the lake... this may be wishful thinking but i'm sticking to it, as it gives me piece of mind...

although if i think about it, it is also possible that the lake has been connected to Bulimba creek during a flood...:|

I have seen sharks way up in the fresh where we catch wild bass though these are connected to estuary systems but they are pretty far up river . I wouldn't rule out a possibility of a shark.

 

[DanN]

???? It seem unlikely that marks such of those were made by another animal without causing damage to the fleshy parts of the turtle (e.g., tail).

Given your proximity to Brisbane, and the consistency of the markings, I would assume that humans have made the marks. Either by folk who enjoying marking turtles for no reason or by researchers. Do you know of any mark-recapture studies carried out in the area?

I suggest you look up ways with which researchers mark turtles – very similar. The marks look as though they were created early in life and may have subsequently enlarged as the animal grew

My 2 cents.

 

[Raymonde]

I have seen sharks way up in the fresh where we catch wild bass though these are connected to estuary systems but they are pretty far up river . I wouldn't rule out a possibility of a shark.

oh i believe its more than possible... i just am trying not to think about me and bull sharks in the same lake.... Like i said, the creek IS brackish and there ARE mullet in the lake, which suggests, sharks could also have made it into the lake too which is a scary thought... so glad i don't have to go in there anymore....

 

[SteveNT]

Bull shark

+1

 

[Raymonde]

???? It seem unlikely that marks such of those were made by another animal without causing damage to the fleshy parts of the turtle (e.g., tail).

Given your proximity to Brisbane, and the consistency of the markings, I would assume that humans have made the marks. Either by folk who enjoying marking turtles for no reason or by researchers. Do you know of any mark-recapture studies carried out in the area?

I suggest you look up ways with which researchers mark turtles – very similar. The marks look as though they were created early in life and may have subsequently enlarged as the animal grew

My 2 cents.

i am the mark recapture researcher in the area, there are a few others but they mostly work at University of Queensland. I don't think researchers would make these kinds of marks... at least i would never do that. And the turtle was missing its whole back leg and part of the foot at the front which to me suggests a predator of some kind.... unless it had 2 run ins with something...

i guess there could be really cruel people out there that torture turtles but it doesn't seem likely, other animals would be easier to get hold of if someone was evil enough to like harming animals

 

[DanN]

And the turtle was missing its whole back leg and part of the foot at the front which to me suggests a predator of some kind.... unless it had 2 run ins with something...

Missed that in the photo.

My bad - you can disregard everything I said

 

[dylan-rocks]

Could it be a turtle that was injured , healed up and released???? Just putting out there

 

[Khagan]

It's growing another head.

 

[JasonL]

Female turtle, attacked out of the water when egg laying = fox or similar land animal, rear of carapace looks chewed on.

 

[-Peter]

Crocodile, check out John Cann's book. Obviously another range extension,

 

[Adsell]

My suggestion would be a dog. A basking turtle could easily be attacked by a dog.
Ads

 

[cadwallader]

Female turtle, attacked out of the water when egg laying = fox or similar land animal, rear of carapace looks chewed on.

that sounds like a winner to me...

 

[Luvbuz]

Bulimba Creek would connect to the wetlands during flood periods. We fished the Bulimba Creek/Brisbane River estuaries several years ago and were bitten off by numerous small bull sharks and small whaler sharks. My best guess agrees with others that perhaps a small bull shark had a chomp when the turtle was a little younger and managed to escape being landlocked by swimming back into the creek before the floodwaters receded. The bite diameter and shape doesn't (to me anyway) resemble a canine or feline bite and scarring from a bite wouldn't grow bigger as the animal grows! That's my two bob's worth anyhow!