HONOLULU -- A newborn baby monk seal abandoned by its mother on Kauai is in critical but stable condition with a 50-50 chance of surviving, according to officials.

National Oceanic Atmosphere Administration crews recovered the seal from a beach on Kauai's northeast shore Friday after his mother neglected the newborn, and even started biting him on the head.

The seal was only a day or two old and part of its umbilical cord was still attached.

Hawaii federal scientists said they have never recovered such a young seal before.

They said it is a mystery why his mother rejected him.

"We really don't know. There's no way of reaching into her head and figuring out what's going on, but maybe she's a young mom that just hasn't quite figured it out yet," NOAA Marine Mammal Coordinator David Schofield said.

Veterinarians and scientists at NOAA's Kewalo Basin research facility are caring him for.

"Taking an animal this young, if we're successful, is going to teach us an incredible amount about how to care and nurture for these animals and make sure that they are able to survive," veterinarian Charles Littnan said.

They are slowly introducing him to shallow water and he is gaining weight, which is a good sign. As he gains more strength, NOAA will slowly increase the depth of the water he is swimming in.

He is extremely susceptible to disease and infection.

"He is on broad spectrum antibiotics, and that is to fight things like umbilical infection because he doesn't have the immunity to fight those things that a pup suckling from their mom would," veterinarian Gregg Levine said.