Optics Mag is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Read more.

How Long Do Great Blue Herons Live? How Old Was the Oldest Recorded?

Last Updated on

Great Blue Heron in the water

Herons belong to the Ardeidae family. And in that family, we have a total of 64 members, all representing various species. In North America, there are 10 different Heron species—the Great Blue Heron happens to be the largest, standing at 4 feet tall.

Ironically, they are not as heavy as the other species that come in the same size. They only weigh 5 to 6 pounds, courtesy of the light, hollow bones. Those bones were designed to be hollow, to facilitate the flow of gasses around their bodies—a trait that’s shared by almost all birds.

eagle divider

What’s The Average Lifespan of a Great Blue Heron?

The oldest Great Blue Heron was 24.5 years at the time of its passing. And that’s quite impressive considering this species doesn’t really have a long lifespan compared to other birds. What we’ve learned from the current statistics is that their mortality rate is shockingly high during the first 2 years of their lives.

There’s a team of researchers that worked on a study between 1916 and 1958. They were curious as to why the Great Blue Heron’s population wasn’t exponentially increasing, although they weren’t being hunted down by humans. They even checked their preferred habitats, only to be disappointed when they found out that there was nothing significant to be reported.

To get to the bottom of the issue, they started observing them right from birth. And of the 349 birds that were sampled, 71% of them died in the first year after hatching. A decade or so later, another group of researchers did a similar study and found out that the mortality rate had reduced by only 2% in the first year.

But the good news was, if the bird could find a way to weather the storm during that first year, its life expectancy would dramatically increase in the second year. And those who survive the first 2 years have an average lifespan of 15 years.

a great blue heron in the water
Image Credit: chesser1023, Shutterstock

Why Do Some Great Blue Herons Live Longer Than Others?

1. Avian Dietary Needs

While the wild is not a safe place for a bird that’s not considered an apex predator, it has its perks. For example, the availability of a vast variety of foods. While they are out there having fun, it’s easy for them to come across nutritious rodents, frogs, fish, small birds, insects, snakes, salamanders, etc.

And the thing about the avian diet is that it’s more than just food, as it’s vital to the bird’s health. Great Blue Herons that live in areas that have depleted food sources always struggle to survive. They don’t usually have a variety to choose from, and as a result, only gain access to a poor diet. This normally leads to a shorter lifespan, as most of them eventually succumb to fungal, bacterial, and viral infections.

2. Base Diet

Every species has what we call a “base” diet. And the base diet must have more of the primary item that distinguishes a species as carnivore, herbivore, omnivore, granivore, or insectivore.

The Great Blue Heron falls under the piscivore category. Piscivores are animals or birds that solely rely on fish. So, if we have Herons in regions affected by winter, their lifespan will be relatively shorter than those that live in warmer regions.

This is because once those waters freeze, fishing will be virtually impossible. They’ll obviously look for alternatives but at the end of the day, whatever they get won’t be good enough to boost their immune systems. Consequently, making it difficult for them to ward off illnesses.

blue heron eating fish
Image Credit: Kathy Kay, Shutterstock

3. Environment & Conditions

Several studies have revealed that climate change is a menace to not just humans, but birds as well. They are being affected both directly and indirectly, as their distribution is closely affiliated with seasonal changes and temperature.

If the temperatures go up, they’ll end up consuming more energy for thermoregulation. And that will in turn negatively affect their basal levels of activity, breeding practices, migration behavior, and even overall body fitness.

The Great Blue Herons are partial migrants. And what that means is that they only migrate if they really have to. Changes in the environment and living conditions of a particular region are good enough reasons to make them want to move. But it comes at a cost, as they are more likely to lose their lives in the process.

During migration, these birds are vulnerable to a number of risk factors. Because they won’t be familiar with the territories that they’ll be flying over, they won’t anticipate attacks from predators looking for an easy kill. Chances are, they might also starve or die of dehydration if they can’t find refueling stations in time.

4. Sex

In mammals, females tend to live longer than their male counterparts. But the situation is different in birds, as the males have a longer lifespan. We used to think that male risky behavior is the reason why our men have a shorter lifespan, but recently, a group of experts came up with a different hypothesis.

They believe it has something to do with our sex chromosome pairings, and the same applies to our feathered friends. In humans, the males have XY chromosomes while the females are represented by the XX. Birds also have sex chromosomes, but they are way different from ours.

The male’s gene-rich sex chromosome is denoted by ZZ, and the female’s a ZW. So, as you can see, the females have two dissimilar chromosomes, just like male mammals do.

Experts are of the opinion that having same-sex chromosomes could be the reason why the average lifespan of genders of the same species keeps on varying across the divide. Hence, the reason why the male Great Blue Herons live longer than their mates.

Great Blue Heron spread its wings
Image Credit: VDV, Shutterstock

owl divider 2

The 5 Life Stages of a Great Blue Heron

Simply put, the life cycle of an animal is essentially the developmental stages that it goes through before getting to adulthood. Every living organism has a unique way of reproducing life, and the Great Blue Heron is no different.

  • Egg: The female Heron will be done laying her clutch by mid-March. They usually lay 3 to 5 eggs, depending on the conditions. She’ll kick off the incubation process the minute she’s done laying the first egg.
  • Hatchlings: After 4 weeks, the hatchlings will break the egg using their bills (from the inside) and ask for food. Both parents will work hard to ensure they are well fed and always warm.
  • Chicks: They’ll have a complete plumage 7 weeks from the time they hatched. It will take close to a week for them to learn how to fly and to take their first flight.
  • Juvenile: At this point (9 weeks old) they are being taught how to hunt and protect themselves against predators.
  • Adult: When they get to their 12th week, their parents will leave the nest. They’ll then be all alone, exploring the world, until they are sexually mature enough to look for a mate.

Final Thoughts

What’s the average lifespan of the Great Blue Heron? 15 years. But we now know if the conditions are suitable for their survival, they can clock more than 24 years. You have to understand that surviving out there in the wild for that long is no mean feat. There are so many forces working against them, including nature.

Featured Image Credit: Brian Lasenby, Shutterstock

About the Author Robert Sparks

Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.