Alpacas are the only mammals known to directly inseminate the uterus

When alpacas mate, males deposit sperm directly into the uterus, a reproductive strategy not confirmed in any other mammals

By Sofia Quaglia

The alpaca (Vicugna pacos) uses a reproductive technique never confirmed in any other mammal

Zoonar GmbH / Alamy

Alpacas are the only mammals known to science in which males deposit sperm directly into the uterus. This unusual reproductive method inflicts small internal injuries that may help improve the chances of pregnancy.

Patricia Brennan at Mount Holyoke College in Massachusetts and her team examined and dissected the reproductive systems of 10 female alpacas that were euthanised within 24 hours of mating. They found bloody abrasions throughout the whole reproductive tract, suggesting that the male alpaca's…

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