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Why the eggs from Big Bear's internet-famous eagles may never hatch

There are a number of factors that could explain why an eagle’s eggs may never hatch, including weather, lack of food and the age of the parents.
Jackie and Shadow care for the eggs in their nest.
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The world is watching bald eagle parents, Jackie and Shadow, in California’s Big Bear Valley as the pair take turns caring for their eggs, waiting for them to hatch. But the eaglets everyone is hoping to see may never come.

According to Friends of Big Bear Valley, the organization hosting the popular live cam of the eagles, the eggs were laid on Jan. 25, 28 and 31 in a nest tucked into the San Bernardino Mountains overlooking Big Bear Lake.

“At this point, they are past the time frame that her eggs usually hatch, which is 38 to 39, into 40 days. Some eagle eggs have taken longer than that to hatch, like up to 44 days. But we’re basically right at the end of the cycle for all three eggs,” Sandy Steers, the executive director of Friends of Big Bear Valley, told Scripps News Thursday.

@scrippsnews Have you been watching Jackie and Shadow? 🦅 The bald eagle couple lives in a nest in #California’s Big Bear Valley. A local nonprofit operates a 24/7 live stream camera sharing their eagle lives to the world. However, Jackie’s eggs laid at the end of January may not hatch. Here’s why. #eaglecam #bigbearvalley #jackieandshadow ♬ original sound - Scripps News

All of Jackie and Shadow’s eggs are now over 40 days incubated based on the dates provided by the organization, as March 11 marks day 40 for the last egg laid. 

In a recent Facebook post, the Friends of Big Bear Valley said there were still no changes in the pip watch — or monitoring the eggs for cracks — as of Sunday night. 

A retired professor who goes by the online name of “elfruler” maintains a blog dedicated to observing and researching bald eagle nest cams across the country. Data curated from bald eagle cams between 2006 to 2016 shows one of the longest incubation periods for a clutch of eggs was a little over 40 days, with the average time being 36.5 days. 

The data on elfruler’s blog also shows that the first egg in an eagle’s clutch of multiple eggs almost always takes longer to hatch than the ones laid after it. This is usually due to the fact that later eggs are incubated more consistently than earlier eggs, therefore developing more quickly and hatching in less time, according to elfruler.

Sadly, this research doesn’t bring a feeling of hopefulness for Jackie and Shadow’s beloved chicks. 

Must watch live cam: Bald eagles Jackie and Shadow await hatchlings
A pair of bald eagles named Jackie and Shadow watch over their eggs in a nest high atop a tree.

Must watch live cam: Bald eagles Jackie and Shadow await hatchlings

Jackie got national attention after that big California winter storm for sitting on her eggs, protecting them from wind and snow for 62 hours.

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There are a number of factors that could explain why an eagle’s eggs may never hatch, including weather, the age of the parents, and disruption from human activity — or the egg may have never been properly fertilized to begin with. 

Even the altitude or humidity could play a role, Steers said.

Another issue could be hatching failure, in which a chick begins the hatching process but dies before it can fully emerge, elfruler wrote, but it’s hard to determine if that is the cause from the limited view of a webcam. 

“It is often impossible to know whether a broken or unhatched egg was infertile or nonviable,” elfruler said. 

And if the egg does not break apart from the natural progression of deterioration after it doesn’t hatch, “the parents do not know whether it is infertile or nonviable, and they may continue to incubate it for days or even weeks beyond the time it should have hatched,” elfruler continued. 

The Friends of Big Bear Valley said this is the second year in a row that Jackie and Shadow hoped to welcome offspring. Jackie reportedly laid eggs last year that didn't develop into chicks.

“In eagle nests across the country, there are actually a lot of times they don't hatch. I think it's about 50% that don't hatch," Steers said.

“Once the chicks hatch, then it's only about a 50% chance of them getting to their first year," she said.

The nonprofit installed its livestream eagle camera in 2016, with the support of the U.S. Forest Service. It has since detailed the love stories and journeys of eagles attempting to start a family on its website and social media. Jackie and Shadow have been together since the fall of 2018.

So what happens next? If the eggs happen to hatch, the parents will immediately start feeding them fish and keeping them warm. If the eggs don't hatch, the parents will slowly start leaving the eggs a little bit at a time.

"Sometimes the eggs kind of get buried in the nest with other sticks, sometimes predators like ravens or other animals will come and have the eggs," Steers explained.

Regardless of the outcome, Jackie and Shadow will continue to hang around the area all year.

“They do come and check the nest every week, sometimes two, just to see that everything is there. Sometimes they meet up in the nest," Steers said.

“Whether you are a new or long time viewer of Jackie and Shadow, we can all clearly see the genuine love and care this pair has for one another. Perhaps we can all take a page out of their love story and use it to draw us all together,” the organization wrote Sunday. “No matter what the outcome of this chapter may be, we know from past years they will take it in stride, remain strong and resilient and move forward. Hopefully, we can accept this as a wonderful gift from Jackie and Shadow and view it as a teachable moment for all of us to do the same.”