Even though they are in the same family, Camelidae, alpacas and llamas are used for different purposes by humans.
Alpacas are used for their fiber while llamas are used as pack animals or in meat production. The average llama is roughly twice the size of the average alpaca. An average alpaca stands 34″- 36″ at the withers (shoulders), whereas a llama stands 42″- 48″ at the withers. Most alpacas weigh between 100 and 175 pounds when fully grown. Llamas on the other hand weigh in the neighborhood of 200 to 350 pounds with some as heavy as 400 pounds. There are differences in the body and head, especially the shape of the ears.
The llama is easily distinguished by its long banana-shaped ears. The alpaca has shorter spear-shaped ears. From the side, llamas generally have a longer face; alpacas have a shorter, more compact appearance. A llama’s back is straighter, which makes them good for packing.
The llama has a very coarse outer coat over a softer inner coat – as opposed to the alpaca, which has a very fine, single coat. The llama has coarse guard hair which protects its fine, inner coat of fleece from the chafing of the pack on its back. Alpacas do not have guard hair in the prime fleece of this “blanket” area. In addition, the llama produces far less fiber per animal than the alpaca, despite its much larger size. This is because the alpaca has been domesticated and carefully bred for over 6000 years as a luxury fiber-producing animal. The llama has been bred for the same amount of time as a pack-carrying animal. Its purpose has traditionally been to carry packs in mountainous terrain.
In addition to its packing use, the llama makes a very good guard animal for alpacas, sheep and other small livestock. They are also used for pulling carts.
Normally, alpacas command a higher price than llamas due to their luxury fiber.