You cannot. A female cockatiel needs a male cockatiel to mate with her before she will produce fertile eggs.
And incidentally, birds do not "fall pregnant".
A peacock is male and a peahen is the female. A peahen cannot get pregnant without mating. The process includes the birds mating and then the female laying eggs.
No, a dog cannot have pups without mating. Mating needs to happen so the female can get pregnant with the pups.
By mating with a male dog.
Yes
he is probably trying to attract her for mating reasons.
Most female birds regardless of species will lay eggs when they feel like it. Mating is not required.
No they can't, there needs to be a male and a female and there needs to be mating. However if you buy a female from a bad petshop then there is always a possibilty that she might be pregnant from being kept in with males while at the petshop.
yes they will fight
It's either that or an illness. Call your vet.
Yes! but once impregnated the female is fertilized rest of her life. This basically means that cockroaches do not need to keep mating to get pregnant.
Because they are not pregnant yet, but they will soon. I used a clenax box as a nest for them and I wrote "Nest" and my green and white budgie mating happend.
After mating, yes. After the female has given birth to the bunnies, no. If the female gets pregnant RIGHT after giving birth, her health will go down. Best to wait a day or two before mating again. Better yet, go and spay and neuter that couple.