Mating alpacas can be done at any time as they are 'induced ovulators' i.e. they only ovulate when a male is introduced. If females are ready for mating they will sit with the male sitting over them. After mating has taken place it is usual to introduce the female to the male again the following week. If she spits at the male that is a good indication that mating was succesful, although it is usual to confirm success with an ultrasound scan. Gestation takes 11 months and it is best to plan for cria (as alpaca babies are called) to be born during the warmer, lighter months as they do tend to do better.
Birthing is a lot more straightforward than for many livestock. A normal birth will almost invariably take place during the day time as alpacas have adapted to the high altitude climate where it gets very cold at night. Help is rarely needed. Most cria are up and suckling within a few hours. If they are not this is an indication of a problem. Special alpaca colostrum can now be bought and alpacas can be bottle fed, although care must be taken with males as if they become too familiar they can become too difficult to handle later.
If cria are born during cold or wet weather, it is possible to buy waterproof jackets for them and they are vulnerable to the cold and wet for the first few months.
The young are usually weened at around 6 months to allow the mother to regain weight and if pregnant to develop the new cria foetus. Females can be mated soon after birth and the optimum time for mating is 3 weeks after the birth. This means that it is possible to have a cria every year from a female.