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Welcome to the John Bunker Sands Eagle Tower Cam

Frequently Asked Questions

Updated: November 6, 2023
 Questions Answered: 55
  
 
The questions and answers below apply to the bald eagles, their nest, and other topics related to the eagle camera system installed in the "eagle tower" near the John Bunker Sands Wetland Center.
 
Answers are correct to the best of our knowledge, and current as of their date of posting to this site, but are subject to change as needed for accuracy.
 
Keywords are placed at the beginning of each question to help you identify the nature of the question and its related answer.
 
Questions with an "MP3" icon have a link to examples of audio. For details, hover your cursor over the icon. To listen, click the icon. A new tab will open and play the audio. To return to this FAQ page, simply close the newly created "audio" tab.
 


Click the Section, then click the question of interest within that section. (Click again to close.)
Location - Where is this nest located?
The nest is part of the John Bunker Sands Wetlands Center 25 miles (45 km) southeast of Dallas, Texas (USA). The nest itself is on private land near the Wetlands Center in an "arm" of a custom high-voltage transmission tower constructed specifically for the eagles, where it was moved from the original nest site. The new tower has no electrical wires on it, so there's no danger of electrocution to the eagles.
Location - Why was the nest moved from its original location?
It was moved out of concern for the eagle's safety. When the bald eagles built their first nest in this area, they chose a cross arm in an active high voltage transmission tower. John DeFillipo, Director for the John Bunker Sands Wetland Center, as well as other people, felt the birds were in danger from the wires, and a decision was made to relocate the nest (and the arm on which it was built) to a safe location.
Location - When was the nest moved from the active high voltage tower?
The nest was moved to its present location July 12, 2014. Plans were in place to move it in 2013, but the eagles returned earlier than usual that summer and the relocation effort hadn't yet started. Consequently the project was postponed one year until the birds flew north for the summer. (Federal law prohibits the disturbing the eagles.)
Location - How far is the new tower from the orignal tower?
Approximately 1/4 mile (0.4 km).
Location - How high is the nest above the ground?
The nest is approximately 85 feet (26 meters) above the ground.
Nest - What is the long strip of metal under the nest?
During relocation of the nest to the new tower in 2014, ONCOR replaced a long flat piece of PVC plastic that had been in place under the nest to protect the insulators, and installed a metal sheet. They were able to do so without damaging the nest. The eagles found this original protective surface very suitable for building their nest. The rectangular metal sheet is visible behind the nest in the video. When wet, it resembles a mirror.
Nest - How much does the nest weigh?
Estimated weight is 600 pounds (272 kg). This is based on the 200 pound (91 kg) weight in 2014 when the tower arm with the nest was moved to its present location, and the amount of material added by the eagles in the intervening years.
Nest - What is the nest diameter?
Nest diameter is estimated to be approximately 8 to 9 feet (2.4 to 2.7 meters) based on the width of the tower arm.
 
 
What are the bird's names?
The birds are named "Mom" and "Dad". Eaglets are named JBS1, JBS2, JBS3 (etc.), with "JBS" after the late John Bunker Sands, primary Wetland Center benefactor. The number in the name after "JBS" indicates their sequence in hatching. JBS1 was first, JBS2 was second, and so forth.
Is this the same pair of eagles that's been here since 2014?
John Bunker Sands Wetland Center eagle cam veterans have mixed opinions. Many believe it's the same pair. Others feel this may be a new male compared to 2014 due to behavorial changes they've observed, but they aren't certain if or when a change of partner may have occurred. No conclusive evidence exists one way or the other.
How can we tell the male from female eagle?
Female eagles tend to be larger than males by approximately 25%. If the eagles don't have distinctive markings, and they're not together, it's difficult to know which one you're seeing. The Wetland Center eagles have subtle differences veteran eagle watchers can see, but it's difficult for newcomers.
How much do the eagles weigh?
Female eagles typically weigh 12-14 lbs (5.5-6.3 kg). Males are lighter at a typical weight of 8-10 lbs (3.6-4.5 kg).
How many eggs has this pair laid?
15 eaglets have hatched in this nest since 2011. The eaglet in 2021 didn't survive, with its death believed due to humans illegally intruding at the tower and frightening the eagles off the nest for several days. Two other eaglets were hatched in a nearby nest in 2022. The first 2 eaglets were hatched while the nest was on the live high voltage tower, before it was moved to the present location in 2014. Eaglets are named "JBS" with a number, such as "JBS-1", "JBS-2", "JBS-3" and so forth, after John Bunker Sands. In 2022, JBS-16 and JBS-17 were hatched, and fledged that summer. In 2015, 2018 and 2020, there was only one egg each of those years. Total as of 2022: 17 eggs.
At what age do young begin to fly?
At approximately 8 weeks of age, eaglets are strong enough to flap their wings, lift their feet off the nest, and rise up in the air. The young "fledge" (leave the nest) between 8 and 14 weeks of age. They remain close to the nest and tended by their parents for approximately 6 more weeks. Juvenile eagles start dispersing away from their parents about 8 weeks after they fledge.
At what age to eagles reach maturity and begin families?
Maturity is typically around five years of age for both males and females, but instances as early of four years have been recorded.
Why do the eagles "pant"? (Breathe through their mouth.)
You may have observed the eagles panting (breathing through their mouth). They pant for several reasons, but most commonly because they're hot. Birds don't sweat. In this case, panting is the eagle's way of cooling off. Due to their dark feathers, and the fact they have additional layers of feathers to keep them warm in cold weather, bald eagles can get hot in direct sunlight, even on a cool day.
How far around can eagles rotate their head?
Eagles can rotate their head almost 180 degrees in each direction! Eagles have 14 cervical vertebrae. Humans have 7 cervical vertebrae and can typically rotate just 70-90 degrees in either direction.
In February 2021, Texas experienced record cold and snow. How do the eagles handle this?
Eagles are uniquely suited for cold weather. They have a layer special of "down" feathers that retain heat their bodies generate. The down feathers are covered by thousands of waterproof feathers that repel water, while at the same time adding several more layers of insulation. Eagles are often seen panting to cool themselves on days that feel cold to humans.
Where do the eagles sleep at night?
During the nesting season, if "Mom" is incubating the egg(s), "Dad" typically sleeps on the tower above the nest where he can provide immediate protection if needed. If "Dad" is incubating the egg(s), the roles reverse. When the eagles aren't incubating, they sleep at the nest or in nearby trees.
Does the light at the nest bother the eagles at night?
No. It's infrared light. Neither the eagles nor humans can see infrared light. The camera is sensitive to infrared light, and converts it into a gray-scale image.
 
 
How many eggs does a female bald eagle usually lay?
Typically two. One egg is less common, but not unusual. Three eggs also occur, but even less frequently than one.
How many days are typical between eggs when more than one is laid?
Typically three days between eggs, but can be four or five.
How long does it take for an egg to hatch?
Eggs usually hatch around 35 days after laying. However, it can be as little as 33 days, and as long as 40 days. Eagles often employ "delayed incubation" for the first egg so it and the second egg hatch around the same time. They delay incubation by not sitting on the egg for periods of time up to two to three hours. This slows development of the chick, but isn't harmful. At earlier stages of embryo development, it's not uncommon for adults to leave an egg uncovered for long periods of time, often for hours.
Once a chick has begun pipping (hatching), how long does it take for fully emerge from the shell?
Pipping can easily take 2 days, and is exhausting for the chick. They often take an extended nap after they finally crack the shell with their egg tooth. The egg tooth falls off within a few days of hatching.
Why does it take so much time for a chick to emerge from the shell?
Before hatching, chicks absorb oxygen thru a mat of membranes under the shell. During hatching, they cut the blood supply to the membranes and trap the blood in their body. The chick absorbs the yolk sack into its body and inflates its lungs for breathing outside of the shell. That's a lot of work, and chicks have to do it by themselves. It is a lot to do, and it takes time and energy!
Why do the eagles roll the egg(s)?
Eagles roll the egg(s) every 1- 2 hours to prevent the yolk from sticking to the interior surface of the shell. If this were to happen, blood vessels covering the yolk could touch and stick to the shell surface, killing the chick.
What temperature must the eggs be for hatching?
Eggs must be maintained at a temperature close to 105° F (40.5° C).
What happens to the shell fragments after a chick hatches??
Once the chicks hatch, the parents typically don't get rid of the shells. Broken shell fragments sit at the bottom of the nest, sometimes for a long time, before getting crushed into tiny pieces. Some bald eagles reportedly discard shell pieces, or consume the shells, perhaps to avoid attracting predators. Eagle nesting behavior may vary by region.
 
 
Camera - How many cameras are installed at this nest?
One camera. This is a replacement for the previous cameras.
Camera - Why was the old camera system replaced?
The previous eagle cam and its associated electronics were destroyed by a storm in 2018. Steps were underway to replace the entire system in 2019 when the eagles returned early, and work had to be postponed until the eagles left the nest in the summer of 2020. The new system was completed in late September, 2020.
Camera - How was the new camera system installed?
Installation was a team effort involving John Bunker Sands Wetland Center staff, a Texas Licensed Professional Engineer specializing in solar energy who designed the new system, a solar installation contractor, Oncor (local utility company), and a crew from a crane company. The entire system including the solar panels, batteries, digital electronics, communications, camera and microphone took 20 hours over a very long a weekend of work to install.
Camera - What type of camera is in use at this site?
It's a high-definition 1080p color camera.
Camera - Is the nest cam equipped with infrared lighting for night viewing?
Yes. The system has an infrared illumination system that turns on at dusk and off at sunrise. The camera can "see" the infrared light and change it to a viewable image. Being infrared, the light is invisible to the eagles, but not to the camera. Infrared light lacks color, so the video from the camera in the infrared mode is various shades of gray.
Camera - What causes the shadow on the nest at night when the infrared light source is in use?
A tower arm support bracket between the infrared light source and the nest causes the shadow. Some visitors to the JBS Eagle Cam site describe the shape as resembling an alligator.
Camera - Can the camera be moved to give an overhead view directly into the nest?
No. The camera is mounted to the tower in a location that doesn't interfere with the eagles, and gives the best available view of the nest considering the mechanical constraints imposed by the tower and arm. A diagonal support arm in the tower arm does block the view of the center of the nest. It can't be moved or removed because this would disturb the nest, which is prohibited by Federal law.
Camera - Does the camera pan, tilt, and zoom?
Yes. The camera can rotate a continuous 360° without needing to rotate back. It also tilts up and down approximately 90°, and has a 30X optical zoom for close-ups of the nest and the eagles.
Camera - How is the camera controlled?
The camera is remotely controlled by staff members at the John Bunker Sands Wetland Center.
Camera - Why does the camera shake when it's windy?
The camera bracket was fabricated on site the day of installation. Sheet metal used for the bracket was thinner than planned, but was all that was available at the site at that time. When a strong wind blows, the camera shakes. This motion is exaggerated when the camera is zoomed in on the nest. Despite appearances, the tower itself doesn't move.
Camera Power - Do the solar panels make electricity in cloudy and rainy weather?
Yes. However, it's less energy than on clear days. Sometimes much less. During periods of very heavy overcast, the solar panels may not generate any power at all, in which case batteries provide the electrical energy required to keep the system operating for up to 10 days without charging.
Camera Power - Where does the camera get its power on cloudy days and at night?
Batteries provide all the power needed by the camera system. They have sufficient energy storage for approximately 10 days without sun.
Microphone - Why is there so much wind noise in the audio?

The microphone is extremely sensitive. The "volume" control is set to maximum to help ensure chicks can be heard. Wind blowing past the microphone makes it sound like a hurricane at certain times. It's all in the microphone. The eagles hear ordinary wind noise. Extremely loud noises may create a "popping" sound in the microphone audio due to the way the sound is converted to a digital signal for sending it to the Internet.
 
 
How tall is the eagle tower?
The tower is approximately 100 feet tall at the top. The arm where the nest is located is approximately 15 feet below the top. Eagles often perch on the tower above the arm and guard against intruders. The camera can't point upward, so we aren't able to see the eagles when they're on the tower above the nest.
How far is the new tower from the tower where the nest was originally located?
The new tower is approximately 1/4 mile (0.4 km) from the original site.
Is the tower made entirely of steel?
Yes.
Does the new eagle tower have high voltage wires?
No. In fact, it has no wires at all. It was custom manufactured and donated by Falcon Steel specifically for the purpose of providing a safe location for the eagle nest.
A support arm blocks a clear view of the nest. Can it be removed to improve what we can see?
No, for two reasons. #1: Disturbing a bald eagle nest is a violation of federal law. #2: Even if it was legal, removing the strut would weaken the arm.
What direction is the "nest arm" oriented on the eagle tower?
The arm holding the eagle nest points west-northwest (288° on the compass) from the tower. Distant lights visible on the horizon at night are from the Dallas area.
What is the "clanging" noise on the tower? (Click the MP3 icon to listen):    

Most noises occur when eagles perch and move on the tower. Their talons sound like metal on metal. Large raindrops falling on the tower make a "clang" on impact. Metal conduit with camera wiring may bump the tower when it's very windy. (Eagles ignore it.) It could also be the eagles "feaking" (cleaning their beak). This recording includes talons on the tower, eagle "chortles" (0:18 to 0:28), wild pigs (1:01), and wind (1:08) Total recording time: 1:40.
 
 
How many solar panels provide power for the Eagle Tower Cam?
Six 280 watt solar panels provide the power for charging the batteries and operating the equipment. 1,680 watts is more than needed at present, and was done to ensure ample margin for recharging the batteries in cloudy weather.
Will the eagle droppings soil the solar panels?
No. If you watch the installation video carefully, you'll see the solar panel rack is separated from the tower by more than six feet. In addition, the rack is on the side of the tower opposite from the nest.
How long will the system operate only on battery power during extended periods of cloudy weather?

Batteries in this system provide up to 10 days of reserve power if there's little sunlight due to heavy overcast. These are "lead-carbon" batteries (different from car batteries), and may be discharged very deeply without affecting their life expectancy. This reserve was put to the test in February 2021 when a record winter storm covered the solar panels with ice and snow that lasted a week. The batteries provided power the entire time without being recharged. The ice and snow melted off in the afternoon of the sixth day. The system operated perfectly the entire time.

What is the life expectancy of the batteries in this system?
Batteries are predicted to last 12 to 15 years. The batteries require no maintenance.
 
 
Weather - Does it ever snow at the JBS nest site?
Yes, but only rarely. Snow occurs approximately every five years or so, with depths of one to two inches at most. An exception to this occurred in February 2021 when a record snow and ice storm struck the area, and a historic low temperature of -2° was recorded. More than six inches of ice and snow accumulated on the solar panels and lasted for almost a week before melting off.
What is the rectangular gray box visible on the tower leg in the upper right side of the video image?
The microphone enclosure. The round protrusion barely visible on the backside of the box is the opening to the microphone itself. The microphone is protected by an internal weatherproof membrane that prevents entry of water and insects, yet allows sound to pass through. The box and its associated conduit are held to the tower leg with several stainless steel straps, two of which are visible in the video image.
As we watch the live video, a spinning circle often appears. What is this circle, and what causes it?
The spinning circle indicates "buffering", where the video signal isn't arriving fast enough to play steadily. Possible causes are too extensive to cover here. Visit WikiHow Youtube Buffering for more information and possible steps to take. Also type "Youtube buffering" into your favorite search program for other suggestions.
 
 
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