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EagleCam | Freezing temps may have killed eggs

by wcnc


Posted on November 2, 2009 at 6:12 PM

Updated Sunday, Nov 1 at 6:12 PM

NewsChannel 36 has partnered with Carolina Raptor Center to bring you pictures as Savannah, a bald eagle in captivity due to injuries, takes care of her nest. Her mate is Derek

Click here for a web cam of Savannah's nest.

3/19 Savannah left the nest after 51 days of incubating her egg. The egg was cold when Julia Raddatz, rehabilitation coordinator at Carolina Raptor Center, gathered it for examination in the lab. After evaluation, it was determined that the egg developed for approximately two weeks. It's very likely that the egg froze during the first snowfall of the year when temperatures dipped to the low teens in early February. To keep herself occupied, Savannah has been moving nesting material in the aviary and built another nest near her old one. The aviary is open again for public viewing and Savannah enjoys visitors coming to see her at Carolina Raptor Center.

3/10 At 11 a.m. today Julia Raddatz, rehabilitation coordinator at Carolina Raptor Center, removed Savannah's egg from her nest and brought it into a dark room to candle it. Candling an egg is the process of holding an egg up to a bright light in order to visualize the density of its contents.

Upon candling, Julia saw that the contents of Savannah's egg were too dense to allow light to pass through. This could mean two things: It could mean that an embryo has developed to the point that it has taken up the entire egg or, the far more likely possibility, the egg was fertilized but development stopped at an early state. Julia also noted that there was no movement within the egg. She did not hear any sounds coming from the egg, or any other outward signs of hatching.

When an embryo begins to develop within an egg, it causes the chemistry of the egg to change. Then, when development stops, the contents will decompose faster than if it were never fertilized, causing the contents to become more dense, which likely explains what Julia saw when she candled it.

The egg was placed back in the nest so Savannah can make the choice of when she is done incubating her egg. Savannah returned to the nest almost immediately after the egg was returned to her.

CRC staff will be removing the visual barrier around the eagle aviary tomorrow afternoon so the public can come out and see where Savannah's nest is located and all five bald eagles in the enclosure.

3/9 Due to the length of time that Savannah has been laying on her egg, CRC staff will be removing Savannah's remaining egg at 11 a.m. on Tuesday to inspect the viability of the remaining egg. If the egg is fertile, it will be returned to the nest and if not, we will gain what knowledge we can from the egg. Normal length of incubation for bald eagle eggs is 34-37 days. As of tomorrow, 44 days will have passed since the first egg was laid and it is very unlikely that hatching could still occur. Savannah's change in behavior last week may have been due to her expecting the eggs to hatch as the incubation period was nearing its end. Expect more information by late afternoon on Tuesday.

3/6 Last night Savannah removed one of her eggs from the nest. The egg was infertile. Carolina Raptor Center staff candled the second egg around 11 a.m. and there's hope it will hatch. The egg was placed back in the nest and Savannah returned to sitting on it. There's hope it will hatch by Monday. PHOTOS of CRC staff inspecting the egg

3/5 Over the past 48 hours, Savannah is still behaving differently. She has been moving the eggs around much more and standing up to check on them often. This may be because she is hearing noises within the eggs or feeling them start to move around. At approximately 10am, staff confirmed that 2 eggs are still present, although it is difficult to see them clearly enough to know if they are starting to crack/hatch.
If there's no visual confirmation that the eggs have begun to hatch by 1:00pm tomorrow (Friday), CRC staff will candle the eggs to see if they are indeed fertile.

3/3 After our snow storm, with temperatures dropping to the low teens, Savannah is exhibiting abnormal behavior. She will sit on the nest and quickly stand up, looking quite agitated and nervous. It's quite possible that the eggs have started to wiggle.

2/26 Everything has been going very well for Derek and Savannah. CRC staff closed off the remainder of their enclosure from the public this week in preparation for the eaglets hatching this Saturday the 28th through Tuesday the 3rd.

It is important that we prevent the eaglets from seeing our staff and visitors to protect them from imprinting on humans. Imprinting is a natural process that causes the newly hatched eaglets to become strongly attached to their parents. In the simplest terms: imprinting is how and when an eaglet learns that it is an eagle, and how to behave like an eagle.

Keep your eyes on EagleCam , and you might be the first one to see the eggs start to hatch!

2/15 Derek and Savannah are still doing a wonderful job caring for their eggs, but they aren't the only "love birds" at Carolina Raptor Center. Our Golden Eagles, Pioneer and Orion have also made a nest! Pioneer (the female) has laid eggs a few times before, and although they have never hatched, there is always a first time for everything.

The staff at CRC is keeping a close eye on our Golden Eagles and we're providing everything they need for nesting. Visitors to CRC can come and watch Pioneer and Orion continue to build their nest.

2/10 - Derek and Savannah have probably been enjoying the warm weather these last few days. They are now well into their second week of incubating their eggs and everything appears to be going very well. The staff at CRC has every hope that they will hatch two healthy eaglets this year.

2/4 - Derek and Savannah have been very dedicated parents through last night's snow and below freezing temperatures. Savannah has been on the nest almost all day today, with Derek taking over incubation duties for short relief shifts.

Bald eagles are known to spend more time on their eggs in cold weather in order to maintain their eggs at a constant temperature. If the eggs cool below a critical temperature, the eaglets would not survive.

2/2 - Savannah and Derek have been incubating their eggs for one week now. Bald eagle eggs generally require 34 to 37 days of incubation, so we hope to see their eggs hatch between February 28th and March 3rd.

1/28 - Savannah laid her second egg sometime between 6 p.m. Tuesday and 7 a.m. Wednesday! Bald eagles usually lay two eggs an average of three days apart; so Savannah is right on time. It's also a great sign that Derek and Savannah stayed on the nest during the rainstorm today.

1/27 - Derek and Savannah have been taking turns lying on their egg. CRC staff is keeping a close eye on the pair via EagleCam, hoping to see a second egg laid in the next 24 to 48 hours.

1/25 - SAVANNAH LAID AN EGG IN THE NEST! She has been lying on her egg when no one is around and meticulously tending to the nest, but is easily scared off the when people approach the aviary.

1/23 - WCNC EagleCam is up and running internally!

1/22 - CRC staff added more large sticks near the nest. Savannah and Derek's behavior is unchanged.

1/18 - Savannah has been seen near the nest regularly, adding nest materials, and has dug a 6" deep hole in the middle of the nest.

1/15 - Savannah was again observed on nest at 11:00 am. Nesting materials appeared to have been moved around. CRC staff added more nesting materials (sticks and small pine bows) near nest. Savannah and Derek were acting "protective" of nest.

1/14 - Savannah was seen sitting on the nest in the morning.

1/12 - CRC staff inspected the nest box to ensure that it was structurally sound. Mulch and nesting materials were added to the nest. A small shade was added above the nest and the EagleCam housing unit and photo blind were added to the right side of the nest.

Keepers started observing Savannah and Derek sitting closer together than usual (on the same branch) frequently since at least January 1.