The gorilla born at the Como Zoo to first-time mother Alice on Wednesday has died, the zoo announced Monday.
The "preliminary hypothesis" is there was difficulty with the newborn's feeding that led to the death Sunday, the zoo said in a statement.
The statement added that zoo leadership was making the announcement "with a very heavy heart." This was the first gorilla birth in the 55 years that Como has housed the large primates.
A zoo spokesman said the baby's death will be taken into account by zoo staff as another gorilla, Dara, is anticipated to give birth late this year or early in 2015.
"Each pregnant animal at the zoo has its own individual birth plan," said Como spokesman Matt Reinartz. "This will play a factor in Dara's plan as well."
Since the birth, the baby and Alice were under zookeeper watch and care around the clock, the zoo statement noted. The baby appeared to be doing well through Saturday evening, strong in grip and voice, and Alice had been taking well to motherhood.
But then, the statement read, staff started having difficulty keeping tabs on the baby's feeding regimen because Alice would cradle the newborn to her chest with her back toward zookeepers.
The statement then went on to describe the baby's final hours:
"On Sunday morning it was apparent that the baby was weak and his health failing. While the [staff's] intervention process was happening, the baby was set down by Alice, and the zookeepers were able to retrieve him without the need to immobilize Alice.
"Resuscitation efforts on the infant were quickly performed but were unsuccessful."
A necropsy will be performed in an attempt to determine the cause of death.
The baby was born at roughly 4 pounds, and the zoo's birth announcement noted that he was apparently "healthy, strong and bonding with Alice."
Patrons never got an in-person look at the baby. Zoo officials were intending to keep Alice and her son off-exhibit for several weeks to avoid interfering with bonding.
Dr. Kristen Lukas, director of conservation and science at Cleveland Metroparks Zoo and the chair of the Gorilla Species Survival Plan, said: "The entire Gorilla SSP shares the Como Zoo's heartbreak over this sad event. It is always difficult to lose a young one, but we fully understand the significance of this particular birth for Como Zoo and are very sorry for your loss."
Out of 437 gorilla births at Association of Zoos and Aquariums institutions since 1980, 26 percent of males and 20 percent of females did not make it to their first birthday.
In western lowland gorilla populations in the wild, mortality rates in the first year have been reported up to 42 percent and in mountain gorillas, first-time mothers have 50 percent higher infant-mortality rates than second-time mothers.
Alice's housemate, Dara, is expecting and likely to give birth in December or January. In both cases, the father is Schroeder, 29, who has lived at Como since he was 5. Alice is 12, and Dara is 11.
Alice and Dara were among six gorillas moved to Como last year to live in the zoo's new $11 million Gorilla Forest exhibit, the largest all-mesh gorilla enclosure in North America.
Como's gorillas, while born in the United States, are descended from gorillas that inhabit the forests of Central and West Africa. These western lowland gorillas are critically endangered.
Gorilla gestation takes about eight months.