The great blue heron is the largest in North America. These extremely adaptable birds are widespread throughout Canada, the United States, and Mexico.
Mated pairs flock to breeding territories in swamps, wetlands, prairies, shorelines, and even agricultural areas and man-made water sources across the continent.
Differentiating between males and females Great Blue Herons can be pretty tricky. Female great blue herons have almost identical plumage to the males. The most significant difference between the two is their size.
Females also exhibit slight behavioral differences from males when it comes to nesting, feeding, and incubation. This article will discuss the characteristics that set the female great blue heron apart. Read on to discover more!
Size is the best way to tell male and female Great Blue Herons apart - female foreground, male in the background
The size difference is the best way to tell if a great blue heron is male or female. Adult females are typically smaller than adult males. They also have smaller beaks.
Male and female great blue herons have nearly identical plumage, except that a male heron’s ornamental feathers are, on average, longer than a female’s. However, this difference can be difficult to discern when looking at an individual rather than a pair.
Male (back) and female (front) - note the size difference
The adult female great blue heron boasts beautiful gray-blue plumage on her upper body and neck. The fore-neck is gray, streaked with black, white, and rusty brown. The female’s head is primarily white, with dark blue stripes running from above the eyes to the back of the head.
The same blue plumage also covers the flanks, while the underbelly is white, streaked with black.
Juvenile female great blue herons are distinguishable from adults by their plumage. Juveniles are almost entirely gray. It isn’t until the young herons' second fall that their gray crowns become streaked with white. By their third year, juveniles begin to grow out their adult plumage.
Close up of a Great Blue Heron
Female great blue herons are not bigger than males. On average, females are slightly smaller, measuring roughly 38 inches in body length. Males, on the other hand, typically measure closer to 54 inches long. The size difference is apparent when a great blue heron pair are together.
Male and female blue herons share many of the same responsibilities and exhibit very similar behaviors.
Unlike other bird species, where one parent primarily takes care of the nest and nestlings while the other provides food, great blue herons share these responsibilities almost equally.
However, there are a few differences worth discussing. We will dive into those below.
Great Blue Heron foraging along a muddy shoreline
Great blue herons have a relatively small repertoire of calls - their vocalizations are separated into seven different sounds. The Frawnk call is the most widely known. It is a loud, almost prehistoric-sounding alarm call given when threatened or when being aggressive toward other birds.
On average, male and female great blue herons are quiet birds. Vocalizations are primarily reserved for alarms and communication during foraging and feeding young. Unlike many other bird species where the male is generally more vocal than the female, both male and female herons use the same seven vocalizations.
Great Blue Herons are generally quiet silent birds
During nesting season, male great blue herons arrive at nest sites first, then begin courting females. Once a pair has formed, the male gathers materials and brings them to the female, while she does most of the placing or nest construction.
As with nest building, both parents also share responsibilities for brooding and feeding their young. The brooding period occurs during the first 3 to 4 weeks after hatching. During this time, one parent is with the nestling constantly. The female great blue heron typically broods at night, while the male stays with the nest throughout the day.
Once the brooding period is over, both parents begin leaving the nest to forage and bring food back for their young. Females spend most of the daytime foraging, while males primarily remain at the nest. Then, the pair switches responsibilities come nightfall - the female stays with her young while the male forages.
Breeding pair of Great Blue Herons, with their young chicks in the nest
Similar to nesting and feeding, both male and female great blue herons share incubation responsibilities. One parent will remain on the nest for long periods, while the other hunts and brings back food. The male generally incubates during the day, while the female takes over at night.
Based on female and male behavior regarding nesting and caring for young, it would be nearly impossible for a female great blue heron to raise nestlings on her own. Her mate shares the responsibilities of incubation, brooding, and feeding nearly equally.
For a female heron to take it all on by herself, would mean leaving the nestling alone and vulnerable for long periods. Otherwise, she would not be able to take care of herself or provide her young with food.
Great Blue Heron taking off from the water
Female great blue herons are a pale gray-blue, with black and white streaking on their necks, chest, and belly. Their heads are white except for wide, dark blue stripes above each eye. They also have dark blue patches along their flanks.
Female great blue herons have a repertoire of calls. However, they are predominantly quiet birds. Their most common vocalization, at least that humans hear, is the Frawnk call. It is a loud and robust alarm sound used when threatened.
The go-go-go call generally precedes the Frawnk. It is given when a mild disturbance occurs.
They also have a second alarm call, or scream, given when a disturbance is more serious. Besides alarm vocalizations, there are four other calls utilized by the female great blue heron that primarily serve as communication between mates and young, or amongst a flock while foraging.
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