The tweet racked up more than 4.5 million views and nearly 140,000 likes. On March 26, the sanctuary posted an update on Facebook about Murphy and the stone, which they later dubbed “RockBaby.”

“Although it might make you feel sad that Murphy has built a nest and is nurturing a rock as an egg, it’s just his hormonal response to spring. Murphy is not sad, so you don’t need to be,” the post read.

In a subsequent update on April 4, the group said Murphy had grown so protective of RockBaby that he took over a third of the 90,000 cubic-square-foot enclosure he shared with four other eagles.

Due to Murphy’s aggression, he and the rock were moved into their own space not accessible to the public.

Still, good news was on the way for Murphy. On April 2, the sanctuary shared photos of an injured bald eagle chick they received after a storm blew its nest down. The organization said the baby would be placed with an adult eagle because it was at high risk of imprinting on a human.

Although Murphy wasn’t a contender for the job at first, the sanctuary wrote on April 12 that he turned out to be the chick’s best option.

“It was then decided that we would give Murphy a chance at fostering the eaglet. Murphy’s dad instincts were already in high gear, but at 31 years old, he had never raised a chick before,” the sanctuary wrote. “It’s definitely a gamble, but also the chick’s best chance.”

The baby was introduced to Murphy in a small wood and wire box the group jokingly refers to as “Baby Jail.” Once the box was placed in Murphy’s enclosure, staff monitored their interactions as Murphy learned to accept the chick. The chick was then removed from the box and allowed to interact with Murphy, who began to feed and protect it.