Female crocodiles have long been known as attentive parents, carrying their newly hatched offspring in their mouths from sandy nests on land to the water and even manipulating intact leathery eggs in their mouths to liberate slow-hatching babies.
Now biologists working in India report the first documentation that father crocs, once thought to play only a minor role in caring for offspring, will do the same things without the mother's assistance.
Parental care of any sort is rare among reptiles, except crocodiles. The new report, published in the autumn issue of National Geographic Research, was based on observations at a crocodile farm in India.
One day a male was seen digging into a nest on a sandbank near water's edge. After uncovering several newly hatched babies, he picked them up in his mouth and, one by one, carried them toward the water. A female, thought to be the mother, was floating offshore, occasionally chasing away other females.
Over a period of hours the male excavated 26 hatchlings and ferried them to the water where the female guarded them. When the male encountered unhatched eggs, he took them into his mouth, opened and closed his jaws several times and a baby croc crawled out.
Among alligators and a different species of crocodile, males do not help care for the young. Jeffrey W. Lang, the University of North Dakota biologist who made the observations, says that males of the mugger-crocodile species he observed may be different because this species produces two nests of eggs, about 40 days apart, in each breeding season.
If the mother is occupied with the first batch of young, she may not be able to care for the second. Lang speculates that the father's involvement makes the two-nest pattern work.