Gila monster nest guarding

Over the past few years successfully breeding Gila monsters I have seen an interesting behavior that is fascinating; nest box guarding! Each year after laying eggs my females back fill the nest boxes and then vigorously defend the nest. I cannot re-connect the cages with the males for at least a month after oviposition! The moms get extremely aggressive and if I put my hand in to grab or move something they run over to attack.

I am curious how this works in the wild as it’s obviously an innate behavior, but with wild Gila monsters breeding habits virtually unknown to us it may be some time before we know the answer.

Once the female Gila monster backfills the nest I know viable egg laying is over (I also check on ultrasound to be sure). Some slugs can still be laid after the nest is filled, but they are most certainly bad.

I how in the future we can piece the puzzle together between wild and captive behaviors and shed more light into the secret lives of Gila monsters!

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