Is homosexual behaviour to be put on a par with heterosexual behaviour?

In addition to heterosexual behavior, homosexual behavior has been observed in wolves.

Daken has also been shown on numerous occasions engaging in heterosexual behavior and sleeping with female characters.

Also, heterosexual behavior can have reproductive effect, but has no social adaptive value in monks or nuns.

Septal stimulation for the initiation of heterosexual behavior in a homosexual male.

The penguin's heterosexual behavior was widely reported in national news, including the Chicago Tribune.

One possibility is bisexuality, the combination of homosexual and heterosexual behaviour in the same individual.