Heron: the story on HearLore

Heron

The word shitepoke, a name once used for the small green heron of North America, originated in the United States and appears in a published example from 1853, yet it reveals a startling truth about the bird's behavior that has persisted for centuries. This name, derived from the bird's habit of defecating when flushed, was not merely a crude joke but a practical observation recorded by early naturalists and preserved in Webster's Third International Dictionary of the English Language. The term shitepoke, along with its variants shikepokes and shypokes, reflects a long-standing human fascination with the heron's unglamorous habits, which were documented as early as the 12th century in Old French as hairon or eron. The name shiterow, a corruption of shiteheron, was even used as a derogatory term for a thin, weakly person, appearing in a list of game birds in a royal decree of James VI of Scotland between 1566 and 1625. This linguistic history underscores how deeply the heron has been woven into human culture, not just as a majestic bird but as a creature of both beauty and absurdity. The name heron itself first appeared in English around 1300, evolving from Frankish haigiro or Proto-Germanic haigrô, hraigrô, and later became corrupted to handsaw in Shakespeare's Hamlet, a testament to the bird's enduring presence in literature and folklore. The Norfolk Broads, a region in England, still refers to the heron as a harnser, preserving a linguistic thread that stretches back over a millennium. These names, from shitepoke to harnser, reveal a complex relationship between humans and herons, one that balances reverence with ridicule, and observation with myth.

The S-Necked Hunter

The heron's most distinctive feature is its ability to retract its neck into a tight S-shape, a modification of its 20 or 21 cervical vertebrae that allows it to strike with precision while remaining hidden. This unique anatomical adaptation enables the heron to hunt with a stillness that belies its size, as it can fold its neck tightly against its body, making it nearly invisible to prey. The neck is longer in day herons than in night herons and bitterns, a difference that reflects their hunting strategies and the environments they inhabit. The legs of the heron are long and strong, unfeathered from the lower part of the tibia, except in the zigzag heron, and in flight, the legs and feet are held horizontally, pointing backwards. The toes are long and thin, with three pointing forwards and one backwards, a design that allows the heron to stand firmly in shallow water while waiting for prey. The bill is generally long and harpoon-like, varying from extremely narrow, as in the agami heron, to wider as in the grey heron. The most atypical heron bill is owned by the boat-billed heron, which has a broad, thick bill, a feature that sets it apart from its relatives. The wings are broad and long, exhibiting 10 or 11 primary feathers, 15, 20 secondaries, and 12 rectrices, with the bitterns having only 10 rectrices. The feathers of the herons are soft and the plumage is usually blue, black, brown, grey, or white, and can often be strikingly complex. Amongst the day herons, little sexual dimorphism in plumage is seen, except in the pond herons, whereas for the night herons and smaller bitterns, plumage differences between the sexes are the rule. Many species also have different color morphs, such as the Pacific reef heron, which has both dark and light color morphs, with the white morphs only occurring in areas with coral beaches. This diversity in appearance and anatomy reflects the heron's adaptability to a wide range of environments, from the Galápagos Islands to the wetlands of North America.

What is the origin of the name shitepoke for the small green heron of North America?

The name shitepoke originated in the United States and appears in a published example from 1853. It derives from the bird's habit of defecating when flushed and was recorded by early naturalists. The term appears in Webster's Third International Dictionary of the English Language alongside variants like shikepokes and shypokes.

How many cervical vertebrae does a heron have and what is their function?

A heron possesses 20 or 21 cervical vertebrae that allow it to retract its neck into a tight S-shape. This anatomical adaptation enables the bird to strike with precision while remaining hidden from prey. The neck is longer in day herons than in night herons and bitterns to reflect different hunting strategies.

What is canopy feeding and which heron species uses this technique?

Canopy feeding is a hunting technique where the black heron forms a full canopy with its wings over its body to shade the water below. This behavior reduces glare and improves the bird's ability to sight prey. The strategy has also been documented in other species such as the little egret and grey heron.

How many eggs do herons typically lay and what colors are they?

Most heron species lay between three and seven eggs, though larger clutches occur in smaller bitterns. The eggs are typically glossy blue or white, with large bitterns laying olive-brown eggs. Single-egg clutches are reported for some tiger herons and clutch size varies by latitude.

When was the heron family reclassified under the order Pelecaniformes?

A 2008 study suggested that the heron family belongs to the order Pelecaniformes. In response to these findings, the International Ornithological Congress reclassified Ardeidae and their sister taxa Threskiornithidae under this order. The classification remains provisional as of August 2024 with 75 heron species listed by the IOC.

The Umbrella of Death

The black heron, a species found in the Amazon, employs a hunting technique so unusual that it has been described as forming a full canopy with its wings over its body, creating an umbrella-like structure that shades the water below. This behavior, known as 'canopy feeding,' allows the black heron to reduce glare and improve its ability to sight prey, a strategy that has been documented in other species such as the little egret and grey heron. The black heron's wings are used to frighten prey or possibly attract it to shade, a tactic that has been observed in the wild and studied by ornithologists. The heron's hunting techniques are diverse, ranging from sitting motionless on the edge of water to walking slowly, around or less than 60 paces a minute, snatching prey when it is observed. Other active feeding behaviors include foot stirring and probing, where the feet are used to flush out hidden prey. The heron's bill is used to spear the prey, with the head moved from side to side to calculate the position of the prey in the water and compensate for refraction. Some species of heron, such as the little egret and grey heron, have been documented using bait to lure prey to within striking distance, using items already in place or actively adding items to the water to attract fish such as the banded killifish. Items used may be man-made, such as bread, or natural, such as seeds, insects, flowers, and leaves, as observed in striated herons in the Amazon. This ability to use tools and adapt their hunting strategies to the environment highlights the heron's intelligence and resourcefulness, making it one of the most successful predators in the wetlands. The heron's diet includes a wide variety of aquatic animals, including fish, reptiles, amphibians, crustaceans, molluscs, and aquatic insects, and even larger prey such as birds and bird eggs, rodents, and more rarely carrion. Even more rarely, herons eating acorns, peas, and grains have been reported, but most vegetable matter consumed is accidental. This dietary flexibility allows the heron to thrive in a wide range of habitats, from the intertidal and mangrove areas of the Galápagos Islands to the wetlands of North America.

The Colonial Nesters

The heron's breeding strategies are as diverse as its hunting techniques, with most day herons and night herons being colonial, or partly colonial depending on circumstances, whereas the bitterns and tiger herons are mostly solitary nesters. Colonies may contain several species, as well as other species of waterbirds, and in a study of little egrets and cattle egrets in India, the majority of the colonies surveyed contained both species. Nesting is seasonal in temperate species, and in tropical species, it may be seasonal, often coinciding with the rainy season, or year-round. Even in year-round breeders, nesting intensity varies throughout the year, with tropical herons typically having only one breeding season per year, unlike some other tropical birds which may raise up to three broods a year. Courtship usually takes place in the nest, with males arriving first and beginning the building of the nest, where they display to attract females. During courtship, the male employs a stretch display and uses erectile neck feathers, and the neck area may swell. The female risks an aggressive attack if she approaches too soon and may have to wait up to four days. In colonial species, displays involve visual cues, which can include adopting postures or ritual displays, whereas in solitary species, auditory cues, such as the deep booming of the bitterns, are important. The exception to this is the boat-billed heron, which pairs up away from the nesting site. Having paired, they continue to build the nest in almost all species, although in the little bittern and least bittern, only the male works on the nest. Some ornithologists have reported observing female herons attaching themselves to impotent mates, then seeking sexual gratification elsewhere, a behavior that challenges traditional notions of monogamy in the heron family. The nests of herons are usually found near or above water, and although the nests of a few species have been found on the ground where suitable trees or shrubs are unavailable, they are typically placed in vegetation. Trees are used by many species, and here they may be placed high up from the ground, whereas species living in reed beds may nest very close to the ground. Though the majority of nesting of herons is seen in or immediately around water, colonies commonly occur in several cities when human persecution is absent. This adaptability to human environments highlights the heron's resilience and ability to thrive in a changing world.

The Blue and White Eggs

The heron's eggs are a striking feature of its breeding cycle, with most species laying between three and seven eggs, and larger clutches reported in the smaller bitterns and more rarely some of the larger day herons. Single-egg clutches are reported for some of the tiger herons, and clutch size varies by latitude within species, with individuals in temperate climates laying more eggs than tropical ones. On the whole, the eggs are glossy blue or white, with the exception being the large bitterns, which lay olive-brown eggs. The color of the eggs may serve as a form of camouflage, protecting them from predators, or as a signal to the parents, indicating the health and viability of the clutch. The eggs are laid in nests that are typically placed in vegetation, either high up in trees or close to the ground in reed beds, depending on the species and the availability of suitable nesting sites. The heron's breeding success is influenced by a variety of factors, including the availability of food, the presence of predators, and the stability of the environment. In some species, such as the little egret and cattle egret, the success rate of prey capture increases 3.6 times over solitary foraging when they follow large grazing animals, a behavior that has been documented in India. This ability to adapt their foraging strategies to the environment highlights the heron's intelligence and resourcefulness, making it one of the most successful predators in the wetlands. The heron's eggs are a symbol of renewal and rebirth, as they represent the continuation of the species and the cycle of life and death. In some Native American cultures, the heron symbolizes renewal, rejuvenation, and rebirth, an ever-present reminder that we are all a part of a larger cycle of life and death. The heron's eggs are also a symbol of purity and transformation in Buddhism, as they represent the potential for growth and change. The heron's eggs are a testament to the bird's ability to adapt to a wide range of environments, from the Galápagos Islands to the wetlands of North America, and to thrive in a changing world.

The Taxonomic Puzzle

The classification of the heron family, Ardeidae, is a complex and evolving field, with no clear consensus about the correct placement of many species into either of the two major genera, Ardea and Egretta. The relationships of the genera in the family are not completely resolved, and the classification of the individual heron/egret species is fraught with difficulty. A 2008 study suggests that this family belongs to the Pelecaniformes, and in response to these findings, the International Ornithological Congress reclassified Ardeidae and their sister taxa Threskiornithidae under the order Pelecaniformes instead of the previous order of Ciconiiformes. The cladogram shown below is based on a molecular phylogenetic study of the Ardeidae by Jack Hruska and collaborators published in 2023, which conflicts with the taxonomy published online in July 2023 by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC). The least bittern and the stripe-backed bittern were nested with members of the genus Botaurus, and Hruska and collaborators resurrected the genus Calherodius Peters, 1931 to contain two night herons that were previously placed in Gorsachius. The western cattle egret was embedded in the genus Ardea, and the eastern cattle egret was not sampled. The placement of the forest bittern was ambiguous, but the results suggest that it is probably closely related to members of the genus Ardeola rather than to the subfamily Tigriornithinae. As of August 2024 the IOC lists 75 heron species, divided into 18 genera, including fossil species such as Taphophoyx, Tigrisoma, and Tigriornis, and extinct species such as the Easter Island heron. The arrangement presented here should be considered provisional, and the relationships within the subfamily Ardeinae are very inadequately resolved. This taxonomic uncertainty reflects the complexity of the heron family and the challenges of classifying a group of birds that have evolved to occupy a wide range of ecological niches. The heron's classification is a testament to the ongoing efforts of scientists to understand the diversity and evolution of this family, and to the importance of preserving the heron's habitats and populations for future generations.