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Eagles abandoning egg
Beauty sits on top of a branch as Mathata sits in the background and guards the egg at Miller Park Zoo in Bloomington, Illinois, Tuesday afternoon (May 29, 2007). (Pantagraph/B Mosher)

BLOOMINGTON - The bald eagles at Miller Park Zoo have lost interest in tending to their remaining egg, a sign it will not hatch. | Eagle Watch

Although Beauty and Mathata were sitting on the egg less and less Friday, by Saturday it became apparent to zookeepers the pair abandoned the egg. Zookeeper Erik Heinonen said he visited the eagles a few times Saturday and the egg was untended.

Beauty, the zoo's female eagle, laid two eggs at the end of April about four days apart. One of the eggs disappeared in mid-May.

The average incubation period is about 34 to 38 days. Saturday was day 54 since the first egg was laid.

Zoo Superintendent John Tobias said the behavior proves the egg was not fertilized.

"We passed the hatch date, so it was a matter of time before they lost interest," Tobias said. "What I was told is they were sitting on it less and less."

Local eagle expert Given Harper said the two weeks the eagles tended the egg after the average incubation period ended was normal.

"This eventually would occur," said Harper, who is also the chairman of the biology department at Illinois Wesleyan University. "Some of this is mediated by hormones."

The eagle watch drew the attention of thousands, especially children. In addressing the disappointment of the outcome, Harper said, "Sometimes eggs don't hatch and this is the way nature sometimes takes its course."

Tobias said he will be at the zoo today and zookeepers likely will collect the egg from the nest then. What will happen to the egg has not been determined. Tobias said it will probably be destroyed but he needs to check with the U.S. Fish & Wildlife Service to see what the agency wants done with the egg.

"I don't know what they are going to want," Tobias said. He added that he would like to study the egg and its contents to see if it had been fertilized. "We may have to send it off to them like we do for feathers."

A disappointing result

The two eggs were the first Beauty laid since arriving at the zoo 13 years ago.

Both bald eagles came to the zoo because of injuries that prevent them from flying. Previously, Tobias said it was doubtful Mathata could have fertilized the egg because of his injuries.

However, around the time Beauty laid her eggs, a wild male eagle had been spotted near the enclosure.

In mid-May, one of the eggs disappeared. What happened remains unclear. It could have been taken by another animal or Beauty may have sensed something was wrong with the egg and ate it.

Harper said had the remaining egg hatched, it would have added an interesting twist to the story. "There would always be that speculation on who is the father," Harper added.

No matter the outcome, Harper said the eagle watch generated a lot of interest in eagles and birds of prey.

"There is a lot of bad things going on out there and this was a nice diversion for people looking for some good news, some fun news," Harper said.

The zoo attendance has been up because of the eagle watch. Tobias said the end result is disappointing.

"It really would have been neat to watch a chick grow and give people a chance to see something they otherwise wouldn't," Tobias said. "It would have been a great educational opportunity, but it still sparked a lot of interest."


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