Aggression between Emys Emys?

mikeh

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Today I witnessed one of my juvenile emys making a move and biting the other one on the neck. It seemed to be a clearly intentional bite, holding onto the skin until the other one was able to slip away. Over past few months I've seen the aggressor flip the other one on occasion when they cross each others path and display head bobbing after flipping took place. But the bite is of a concern. They have been raised together since hatchlings and from everything I've read, Emys should be getting along. I guess so much for that. Looks like I'll have to start thinking of rehoming one.

Has anyone experienced this aggression between Emys that have been raised together since hatchlings and is this aggression any indication of sexing the aggressor?
 

Yvonne G

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I'm thinking that both of yours must be males. I used to have 4 intergrade males in with my Mep, and there was one dominant male Mep in that group. I NEVER saw aggression between the males, however, the dominant 65lb female occasionally was very aggressive. When she took it in her mind to be a bully, I was going out several times throughout the day to make sure one of the other tortoises hadn't been tipped over. This aggression was very occasional. Most of the time they get along famously. I'm sure it has something to do with "her time of the month," but she's being aggressive today, and this is nowhere near their breeding season.

Can you put up a partial fence in their habitat so they can't see across the whole area? this helps them to get out of sight of each other. Also, put in two feeding stations and feed them separately. Do all you can to help them stay out of each others' way before you think about selling one of them.
 

tortadise

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Sounds pretty typical to me. The thin I would think of Manouria is the issue that they're all the same age. Too many males same size(within very close proximity I imagine) and age. One must be the victor and established alpha. Among my emys are 3 males. Never have I seen any aggression from the male or female. However they are the known alphas within either indoor or outdoor enclosure. So they all know each other's place within the group. One male is 25-30 female is 30-40, another male is 6 and the other came from another members group so 7-8 now? Hope that makes sense. They can be quite aggressive. I agree with Yvonne and maybe separate for a while. Leaving together may end in some bad wounds.
 
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Millerlite

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I have mine all togeter and never seen aggression. I don't know if I have males or females tho. I feel like I have females.

Kyle
 

mikeh

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Thanks for the feedback. I'll do closer monitoring of the two. The enclosure is well planted with sight barriers. It is on the small size of 6'x3', perhaps this has something to do with it as the they are growing bigger, now at over 7"? The aggressor has also started to eye and look up the walls which is new as well.
 

HermanniChris

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Figured I would throw this little experience in real quick because it could potentially save someone's tortoise. I temporarily had to keep my male MEE together with my male MEP last summer while I repaired the MEE's pen. Well, HUGE mistake on my part. My male MEP immediately went after him and within minutes, he managed to clamp down on the MEE's neck and completely rip the skin back. It was gruesome to say the least. I healed him up myself and he is alive and well today, breeding like a machine but he was lucky that I was there to get him out before more damage was done. Just some food for thought!
 

emysbreeder

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Every combination of Manouria will fight. In your case I would guess that you have two males. Sometimes even with a pair the male will put the female in a male's role. Fighting can cause very bad injuries and often in the eyes. You will have to separate them. What I do when this is the case is let the aggressor sparDSCF1516.JPG DSCF1524.JPG DSCF1519.JPG with another male. I stand by ready to put my boot between them if it looks like a bite is about to take place. Once the male starts ramming the other I quickly turn the one being rammed over. I let the aggressor see the other upside down for a half minute then take it out. This will calm him down for a wile. "Nature is cruel and inefficient."*vm in press. In Nature most eggs are eaten by predators. The few that make it if males have to dodge the bullet for another 10-15 years, then fight it own kind to the death. In captivity here the hatch rate is thousands of times better and no one dies. Vic Morgan
 
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Kapidolo Farms

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Today I witnessed one of my juvenile emys making a move and biting the other one on the neck. It seemed to be a clearly intentional bite, holding onto the skin until the other one was able to slip away. Over past few months I've seen the aggressor flip the other one on occasion when they cross each others path and display head bobbing after flipping took place. But the bite is of a concern. They have been raised together since hatchlings and from everything I've read, Emys should be getting along. I guess so much for that. Looks like I'll have to start thinking of rehoming one.

Has anyone experienced this aggression between Emys that have been raised together since hatchlings and is this aggression any indication of sexing the aggressor?
I don't know if this is in another post of yours or otherwise said anywhere - how many are housed together? Two of any species (tortoise), and two alone, tend to have an unsettled subordinate/superior thing going on. When I housed several neonates togther, there was no aggression going on, but as I sold them and fewer were togther they tended to be more fussy with each other. Tom has some great narratives about this 'just two' issue. I find three can also have an unresolved subordination thing going on. Once you have four five or more it seems to overwhelm their interest to establish an order and it's a different dynamic, much less hassle and tussel, at least with neonates to subadults.
 

emysbreeder

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All of my emys are kept in pairs, except for one trio. They are all stable and rarely fight except when I change males every six months. There is always some degree of fighting at that point and they have to be watched all day for several days. There are a few that will fight brutally every year. The mock dueling where I introduce a smaller male for a short duration is used when the male gets board and is not mounting when he should be. It is peaceful for the most part all year. Three, four or more will end up in mass chaos at nesting resulting in broken eggs and turnovers. Another reason mine dont fight much is that each enclosure is huge between 3k and 9000 s.f. Males mature much faster and will start pushing others around at 6 to7" in both ssp. This varies from tort. to tort. When a female has a territory battle with another of ether sex she will mount like a male and to my total surprise vocalize just like a copulating male with load groan. Truth stranger than fiction, sex there every night. Vic DSCF1009.JPG
 

ascott

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They are the closest living relative (sister group) to members of the Genus Gopherus....so not surprising that they can turn gladiator quickly....
 

Berkeley

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Sorry to hijack the thread, Mike!

Vic-
From a quick search, I found this on Wikipedia:
Gopherus is a genus of tortoises commonly referred to as gopher tortoises. The gopher tortoise is grouped with land tortoises that originated 60 million years ago, in North America. A genetic study has shown that their closest relatives are in the Asian genus Manouria.[1]

And the reference cited:
Le, M.; Raxworthy, C. J.; McCord, W. P.; Mertz, L. (2006-05-05). "A molecular phylogeny of tortoises (Testudines: Testudinidae) based on mitochondrial and nuclear genes".Molecular Phylogenetics and Evolution 40 (2): 517–531.
Abstract
Although tortoises of the family Testudinidae represent a familiar and widely distributed group of turtles, their phylogenetic relationships have remained contentious. In this study, we included 32 testudinid species (all genera and subgenera, and all species of Geochelone, representing 65% of the total familial species diversity), and both mitochondrial (12S rRNA, 16S rRNA, and cytb) and nuclear (Cmos and Rag2) DNA data with a total of 3387 aligned characters. Using diverse phylogenetic methods (Maximum Parsimony, Maximum Likelihood, and Bayesian Analysis) congruent support is found for a well-resolved phylogeny. The most basal testudinid lineage includes a novel sister relationship between Asian Manouria and North American Gopherus. In addition, this phylogeny supports two other major testudinid clades: Indotestudo+Malacochersus+Testudo; and a diverse clade including Pyxis, Aldabrachelys, Homopus, Chersina, Psammobates, Kinixys, and Geochelone. However, we find Geochelone rampantly polyphyletic, with species distributed in at least four independent clades. Biogeographic analysis based on this phylogeny is consistent with an Asian origin for the family (as supported by the fossil record), but rejects the long-standing hypothesis of South American tortoises originating in North America. By contrast, and of special significance, our results support Africa as the ancestral continental area for all testudinids except Manouria and Gopherus. Based on our systematic findings, we also propose modifications concerning Testudinidae taxonomy.


I haven't read this one yet myself, so I can't offer commentary. But perhaps it will explain in greater detail in the article.
Hope that helps!
--Berkeley
 

emysbreeder

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Sorry to hijack the thread, Mike!

Vic-
From a quick search, I found this on Wikipedia:
Gopherus is a genus of tortoises commonly referred to as gopher tortoises. The gopher tortoise is grouped with land tortoises that originated 60 million years ago, in North America. A genetic study has shown that their closest relatives are in the Asian genus Manouria.[1]

And the reference cited:
Le, M.; Raxworthy, C. J.; McCord, W. P.; Mertz, L. (2006-05-05). "A molecular phylogeny of tortoises (Testudines: Testudinidae) based on mitochondrial and nuclear genes".Molecular Phylogenetics and Evolution 40 (2): 517–531.
Abstract
Although tortoises of the family Testudinidae represent a familiar and widely distributed group of turtles, their phylogenetic relationships have remained contentious. In this study, we included 32 testudinid species (all genera and subgenera, and all species of Geochelone, representing 65% of the total familial species diversity), and both mitochondrial (12S rRNA, 16S rRNA, and cytb) and nuclear (Cmos and Rag2) DNA data with a total of 3387 aligned characters. Using diverse phylogenetic methods (Maximum Parsimony, Maximum Likelihood, and Bayesian Analysis) congruent support is found for a well-resolved phylogeny. The most basal testudinid lineage includes a novel sister relationship between Asian Manouria and North American Gopherus. In addition, this phylogeny supports two other major testudinid clades: Indotestudo+Malacochersus+Testudo; and a diverse clade including Pyxis, Aldabrachelys, Homopus, Chersina, Psammobates, Kinixys, and Geochelone. However, we find Geochelone rampantly polyphyletic, with species distributed in at least four independent clades. Biogeographic analysis based on this phylogeny is consistent with an Asian origin for the family (as supported by the fossil record), but rejects the long-standing hypothesis of South American tortoises originating in North America. By contrast, and of special significance, our results support Africa as the ancestral continental area for all testudinids except Manouria and Gopherus. Based on our systematic findings, we also propose modifications concerning Testudinidae taxonomy.


I haven't read this one yet myself, so I can't offer commentary. But perhaps it will explain in greater detail in the article.
Hope that helps!
--Berkeley
 

emysbreeder

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Sorry you went to so much trouble, I new that part as Auffenberg suggest this in Copeia 1971 and mentioned again in Pritchards book Ency of turtles p311. . Mccord and his 2006 buddies proved it with Molecular phylogenetic s. I was curious about the male combat and wondered what might have been written about it. But never the less it was a very good and though out answer! Vic
 

ascott

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I was curious about the male combat and wondered what might have been written about it.

Male combat, that is the key phrase...especially with a tenacious species.....instant gladiators.
 

mikeh

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How does a juvenile male recognize he is facing another juvenile male? As they are not mature we can't tell visually. How do they know?
 

emysbreeder

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Pheromones. Manouria have these little wart looking nodules on their chin. Although, is it known when they become functional. Vic
 

emysbreeder

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Sorry to hijack the thread, Mike!

Vic-
From a quick search, I found this on Wikipedia:
Gopherus is a genus of tortoises commonly referred to as gopher tortoises. The gopher tortoise is grouped with land tortoises that originated 60 million years ago, in North America. A genetic study has shown that their closest relatives are in the Asian genus Manouria.[1]

And the reference cited:
Le, M.; Raxworthy, C. J.; McCord, W. P.; Mertz, L. (2006-05-05). "A molecular phylogeny of tortoises (Testudines: Testudinidae) based on mitochondrial and nuclear genes".Molecular Phylogenetics and Evolution 40 (2): 517–531.
Abstract
Although tortoises of the family Testudinidae represent a familiar and widely distributed group of turtles, their phylogenetic relationships have remained contentious. In this study, we included 32 testudinid species (all genera and subgenera, and all species of Geochelone, representing 65% of the total familial species diversity), and both mitochondrial (12S rRNA, 16S rRNA, and cytb) and nuclear (Cmos and Rag2) DNA data with a total of 3387 aligned characters. Using diverse phylogenetic methods (Maximum Parsimony, Maximum Likelihood, and Bayesian Analysis) congruent support is found for a well-resolved phylogeny. The most basal testudinid lineage includes a novel sister relationship between Asian Manouria and North American Gopherus. In addition, this phylogeny supports two other major testudinid clades: Indotestudo+Malacochersus+Testudo; and a diverse clade including Pyxis, Aldabrachelys, Homopus, Chersina, Psammobates, Kinixys, and Geochelone. However, we find Geochelone rampantly polyphyletic, with species distributed in at least four independent clades. Biogeographic analysis based on this phylogeny is consistent with an Asian origin for the family (as supported by the fossil record), but rejects the long-standing hypothesis of South American tortoises originating in North America. By contrast, and of special significance, our results support Africa as the ancestral continental area for all testudinids except Manouria and Gopherus. Based on our systematic findings, we also propose modifications concerning Testudinidae taxonomy.


I haven't read this one yet myself, so I can't offer commentary. But perhaps it will explain in greater detail in the article.
Hope that helps!
--Berkeley
 

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