I read this news story about a female tiger being killed by her mating partner (or potential mating partner)

 

http://www.msn.com/en-us/news/us/female-tiger-killed-by-mating-partner-at-sacramento-zoo/ar-BBpmMxB?li=BBnbfcL&ocid=mailsignout

 

and I was wondering whether this is something that happens with any frequency and why.

At lest part of the reason might be that a zoo is a very unnatural environment.

I agree with John.

 

Putting two tigers who do not know each other together might trigger aggressive behaviour. You can never be sure what animal thinks, so basing any action on its behaviour is risky.

As mentioned, their environment is wholly unnatural. I do not know much about tigers, but I suspect that Carbonerd is correct. Parrots are well known for this behaviour (as another example) and you can easily find examples of captive / pet birds killing each other if they are not friends or bonded and wind up caged together. In the wild, they can just fly away. I myself have a lovebird, which is a somewhat ironic name for the species as they are extremely fearless and aggressive around other birds they don't like, small size be damned.

At least one species of great ape is guilty of killing members of the opposite sex.