Male and female Great Blue Herons look alike. Adult females are generally smaller than adult males and the ornamental plumage in males has been found to be longer on average, but these differences can be hard to discern. Because you can get a close-up view through the cams, you may be able to notice differences between individual birds. Some researchers believe that the length of the exposed culmen (upper ridge of a bird’s bill) can accurately sex herons (about 5.5” in males; 4.8” in females). The only way to tell for sure is by DNA testing or by observing behaviors (for example, witnessing the female lay an egg, or observing the male perching on the back of the female during mating).

Great Blue Herons usually start breeding during their third spring (at about 22 months old), though some have been observed attempting to breed during their first year.

We can’t tell which young herons are male or female just by looking. In general, the biggest nestling is the first one that hatched and smallest is the last one that hatched.

The parents don’t sit down on the chicks hard enough to smother them. The chicks can breathe even when their parents are brooding them.

By the time Great Blue Herons are two years old they will have most of their adult plumage, though it may not be 100% complete until their fourth spring.

Cam viewers refer to the chicks based on the order in which they hatch (#1, #2, #3, #4).

Banding birds with an individually numbered ring on their leg is a common practice in ornithology to mark and study individual birds. Special permits are required to band birds for scientific study. If the herons were needed in a study, then we would consider banding them, but presently the birds are not part of a study and we do not plan to band them. In order to avoid unnecessary disturbance at the nest, banding nestlings is done only when scientifically warranted.

Keep watching. You’ll probably see the parent come in with food before long. As the young grow, the parents may stay away from the nest for longer periods of time. In cases of severe food shortages, it’s possible that some young may starve.

Eyes open when the young hatch, but it is unknown what their vision is like upon hatching and how long it may take to develop.

Great Blue Heron fledglings leave the nest between 49-81 days.

A newly hatched chick weighs about 50 g (1 ¾ ounces). At 1-2 weeks they are about 6 inches; 2-4 weeks almost 12 inches; 4 to 6 weeks almost 4 feet!

It is very rare that a nestling will fall out of a nest except in extreme circumstances, such as a predator attack. Nestlings seem to know that they shouldn’t stray far!

This is a natural, well-documented behavior for nestlings of some bird species, including Great Blue Herons. Sibling rivalry often develops among young herons, so it’s normal to see this. The older siblings are usually bigger and have an advantage when jabbing at the younger siblings. During food shortages, the older chicks may be the only ones to survive.

In some cases, the aggression may be a way for the birds to tussle and hone their skills, such as when kittens or puppies in a litter tumble about and fight. Aggression can also result from competition for food. Studies indicate that the young herons are more likely to compete aggressively if the food items are small and are delivered to them directly, beak to beak, from the parents. The hypothesis is that when small prey are delivered in this way, there is an advantage for the young to jockey with one another for the best position.

Sometimes behaviors that look alarming, such as repeated jabbing, do not result in serious injury. In other cases, especially during food shortages, intense aggression may result in one sibling killing the other. This is called siblicide. In 2014 one chick was killed by the others.

We understand that people often feel upset when they witness events in nature such as predation, fighting, injury, or death. This is a live cam broadcasting in real time, so it is possible that viewers will see upsetting events. Viewers must decide for themselves whether they are comfortable enough with this possibility. If not, they may wish to stop visiting the cam page.

The heron cam is an opportunity to see an intimate, 24/7 view of nature as it is. The lives of these birds have touched and inspired hundreds of thousands of people. As in real life, however, nature shows us beautiful and profound moments, as well as moments that seem tragic or difficult to comprehend at times. At Millbrook’s Trevor Zoo we try very hard to help people understand all aspects of nature including the tough moments. We hope that you, like us, will choose to watch, question, and learn from what we see.

In this instance after the youngest chick died both parents attempted to throw it out of the nest with Hudson eventually being successful.

In all previous years all fledglings have headed toward the pond at the zoo located about 100 feet from the base of the nest tree. Whether the fledglings have done this on purpose is not known.

It would depend on the circumstances. We would need to consider factors such as whether the young heron can be safely captured and put back (considering dangers to both herons and humans: remember this nest is about 90’ up in the tree); whether it is old enough to survive on its own with its parents looking after it; whether it is injured and can be rehabilitated; and if so, what its quality of life would be.

After the herons fledge, they may come back to the nest for about three weeks.

We don’t know, since we won’t be able to recognize them. Very little is known about where the young herons go during the winter and where they return in spring. Studies of individually marked herons show that the young disperse in all directions two to three months after the breeding season ends. One juvenile Great Blue Heron that was banded in the United States was later found in Belize! A study of more than 3,000 juveniles showed that they disperse an average of 471 miles during their first winter.

Great Blue Herons usually weigh 4.6-5.5 pounds. They can be up to 4.5 feet tall and have a wingspan of 5 ½ to 6 ½ feet.

Yes. When asleep they will close their eyes.

Birds have what is known as a nictitating membrane or “third eyelid.” This is a clear eyelid, closest to the eyeball. It is transparent and can close and protect the eye when hunting.

No.

Bird poop is actually brown; the white pasty excrement is uric acid, the equivalent to a mammal’s urine. Mammals excrete waste as urea dissolved in urine. Birds excrete it as uric acid, which has a low solubility in water, so it comes out as a white paste.

We’ve always assumed that most birds have a poor sense of smell because the area of a bird brain involved in smell is relatively small compared to the area found in mammals. However, recent research reveals that birds have a high number of active genes that are associated with smell. Scientists have also discovered that some species of birds can tell each other apart by smell. So, though we don’t have all the details, herons probably do have some ability to smell.

Great Blue Herons can tolerate very cold winter temperatures. Under normal circumstances, it is unlikely that a healthy heron will freeze to death. It’s important for them to keep their feathers in good condition for insulation, and to be able to find enough food to maintain their body temperature.

Though this may happen due to injury, there are other reasons why birds sometimes stand on one leg. They may do this as a heat-saving measure, keeping the raised leg warm against their stomachs, or as a way to reduce fatigue in the raised leg. Birds may also stand on one leg to look more camouflaged when hunting prey as two legs may look suspicious to ground level or aquatic prey. Birds may also shift legs just to be more comfortable; in the same way a human will re-adjust their position!

These current cameras were installed in the trees on March 24, 2017.

Our first year of streaming the heron nests was 2014, and we have done it every year since.

The cam weighs 7 pounds and is installed 90 feet up a neighboring spruce tree. It is attached to a 20-foot 40-pound camera mount. The mount is constructed from 2” PVC pipe housing conduit inside for the cables used to power the cam and transmit the picture. The mount secures the cam to the tree and helps stabilize the picture and provides support to the tree so that the weight of the camera does not snap the top of the tree.

Mike Hearn of Mike Hearn Tree and Landscape, helped install the cameras this year with his climbing expertise. He got both cameras up in the trees in a matter of hours.

The microphone is positioned on the mount about 15 feet away from the nest. No climbers disturbed the birds.

No, the herons usually ignore the camera. Occasionally they peer at it, perhaps because they see their reflection.

The cam will stream during the entire nesting season.

The camera on the South Nest is an Axis P5636-E Mk II pan-tilt-zom camera(https://www.axis.com/us/en/products/axis-p5635-e/)

On the Infirmary Nest we have an Axis P5414-E pan-tilt-zoom camera (http://www.axis.com/products/cam_p5414e/)

In 2014, Millbrook School senior John Norfleet '14, decided to focus his CES (Culminating Experience for Seniors) project on setting up a bird camera on campus. His hard work resulted in our heron cameras! It was a learning experience for the whole team that allowed us to streamline the process year after year.