Live birth vs. Eggs: A look at Northern Alligator Lizards

Did you know that Northern Alligator lizards are viviparous and will give live birth? This is quite rare for reptiles, and more so for lizards. There are a few snakes and lizards species that give live birth, but it is more common for reptiles to lay eggs. Viviparous is when the embryo is developed in the female and there is live birth. Also nutrients are given directly to the embryo from the mother. Oviparous is when the organism lays eggs, and the embryo develops outside the female, in the egg.

There are strengths and weakness to each strategy. Viviparous organisms are usually more developed and given more parental care, giving them a better chance of survival. However, it takes a lot more energy for the female. Oviparous organisms can usually have a lot more young and it's less energetically draining. However, there is generally less protection of the young and there can be higher mortality rates.

Northern Alligator lizards are seen having around 2-8 young, but only every other year since they need a year between giving birth to recover. However the young are given quite a bit of parental care, so they have the best chance of survival. With less young, they want to make sure the ones they have, have a good chance of making it.