Eagle cams such as the Pennsylvania Game Commission's cam in Hanover and the one at U.S. National Arboretum, which is operated by the United States Department of Agriculture, give people a firsthand look at nature from home, work or the classroom.

And that means even the parts of nature that are hard to watch. That was the case this year when the bald eagle pair in Hanover featured on the video feed did not have any young survive past the fledging stage. The first eaglet hatched and died two days later.This week, the father was still sitting on the nest, trying to hatch an egg that does not appear to be viable.Two eaglets are thriving in the nest at the arboretum.Nature prevails and now other birds are pulling twigs from the nest to make their own.Despite that setback, the eagle cam is just one example of how the population of bald eagles is coming back strong in Pennsylvania, and providing a great educational tool for agencies like the game commission."Bald eagles are a great conservation success story of how we can implement our mission for a particular species. In only 30 years we've gone from a species that was almost extricated from the state, to a healthy population of over 300 nesting pairs," said Patricia Barber, endangered bird biologist for the game commission.Barber held a webinar for fans of the eagle cam recently, and answered many of the questions about the birds.Regardless of how large the population gets, it's always difficult to be a young eagle, Barber said.Out of the gray fur-covered young known as fledglings, only 50 percent will make it to the fledging stage, where they leave the nest for the first time.Once they get out of the nest and begin to fly, things aren't much easier. They have to learn to forage, not to mention how to land back at the nest. Out of those, another 50 percent die before they make it to a year old.If the fledglings make it past a year old, many eagles can live into their 20s. The oldest bald eagle recorded in Pennsylvania was 38 years old."It's really difficult to be a raptor. It's difficult to learn how to hunt, how to survive, especially when it's harsh, to avoid highways, just all the pieces that a bird needs to learn in order to survive a long time," Barber said.Losing young can be hard on eagles as well, just like on humans.Eagles will typically mate year after year. If a partner dies, they are usually quickly replaced by another one, and they'll continue to mate.But if a couple is unable to produce fledging young, they will usually go their separate ways. That's especially true of first-time couples.That sensitivity makes it even more important that residents show respect to eagle nests if they do happen to come across one."There's a lot of variation from one pair to another - you may have a pair in an urban area that tolerates a lot of activity, but you can't be sure that a bird in a more wild area will tolerate those same activities," Barber said.The game commission has several tips for eagle watchers to help protect eagle nests.Stay back from an active nest - 1,000 feet is the recommended distance. If talking is necessary, whispering is best. Eagles are most alarmed by pedestrians, so some sort of blind to cover you helps.If the eagle reacts in any way, it means someone is too close. Flushing an eagle off the nest can expose an egg to harsh temperatures and even predators."We're really excited about the success of bald eagles, and while we know there will be challenges in the future, the healthy population we have now will allows people to learn about eagles in particular, and wildlife in general," Barber said.People are often curious when watching the eagle cam about what the adults are doing when they're not on the nest.It's important to remember that during nesting season, all the adults' attention is focused on the nest. So if you don't see them on the camera, they're off foraging, protecting the nest or the breeding territory, or most likely perched nearby watching the nest making sure it doesn't have to intervene in any way.When fledglings disappear from the nest, often it means they've matured enough to fly away.Eagle pair bonds are long-term in general. Successful birds, those who raise young to fledging age, tend to continue to remain a pair year after year, as long as both members survive.But if a pair member dies, that breeder is usually replaced by another adult in that population, we call them a floater, who hasn't obtained breeding territory. Oftentimes we miss those replacements they happen so quickly.It's important to note that new pairs, if their nest is disturbed, are much more likely to separate.