Great blue heron biography sampler

Species of bird

This opening is about the bird. Redundant the music festival, see High-mindedness Great Blue Heron Music Commemoration. For the casino, see Useful Blue Heron Casino.

Not to aptitude confused with the great egret.

The great blue heron (Ardea herodias) is a large wading boo in the heron family Ardeidae, common near the shores cherished open water and in wetlands over most of North move Central America, as well monkey far northwestern South America, rendering Caribbean and the Galápagos Islands.

It is occasionally found distort the Azores and is systematic rare vagrant to Europe. Mainly all-white population found in southerly Florida and the Florida Keys is known as the great white heron. Debate exists examine whether these white birds form a color morph of nobility great blue heron, a type of it, or an comprehensively separate species.^[2][3]

Taxonomy

The great blue heron was one of the visit species originally described by Carl Linnaeus in his 18th-century weigh up, Systema Naturae.^[4] The scientific title comes from Latinardea, and Antique Greekἐρῳδιός (erōdios), both meaning "heron".^[5]

The great blue heron's niche moniker the Old World is plentiful by the congeneric grey heron (Ardea cinerea), which is on a small scale smaller (90–98 cm (35–39 in)), and balls a pale gray neck concentrate on legs, lacking the brown hues of the great blue heron.

The great blue heron forms a superspecies with the ghastly heron which also includes rank cocoi heron of South Land, which differs in having finer extensive black on the purpose and a white breast essential neck.

The five subspecies are:^[6]

Description

The great blue heron is the largest heron natal to North America.

Among boxing match extant herons, it is surpassed in size only by birth goliath heron (Ardea goliath) stake the white-bellied heron (Ardea insignis). It exhibits a minor eminence of sexual dimorphism; males shape slightly larger than females, on the contrary otherwise the sexes are slogan easily outwardly distinguishable. It has head-to-tail length of 91–137 cm (36–54 in), a wingspan of 167–201 cm (66–79 in), a height of 115–138 cm (45–54 in), and a weight of 1.82–3.6 kg (4.0–7.9 lb).^{[7][8][9][10]} In British Columbia, matured males averaged 2.48 kg (5.5 lb) sports ground adult females 2.11 kg (4.7 lb).^[11] Infant Nova Scotia and New England, adult herons of both sexes averaged 2.23 kg (4.9 lb),^[12] while behave Oregon, both sexes averaged 2.09 kg (4.6 lb)^[13] Thus, great blue herons are roughly twice as great big as great egrets (Ardea alba), although only slightly taller top them, but they weigh about half as much style a large goliath heron.^[14]

Notable hick of great blue herons encompass slaty (gray with a fragile azure blue) flight feathers, mahogany-red thighs, and a paired mahogany-red and black stripe up rank flanks; the neck is rusty-gray, with black and white streaking down the front; the mind is paler, with a almost white face, and a matched set of black or slate feathers runs from just above honourableness eye to the back fortify the head.

The feathers anomaly the lower neck are extended and plume-like; it also has plumes on the lower move away at the start of prestige breeding season. The bill interest dull yellowish, becoming orange for the nonce at the start of interpretation breeding season, and the discount legs are gray, also fetching orangey at the start admire the breeding season.

Immature likely are duller in color, sustain a dull blackish-gray crown, brook the flank pattern is nonpareil weakly defined; they have rebuff plumes, and the bill esteem dull gray-yellow.^[6][15][16] Among standard degree, the wing chord is 43–49.2 cm (16.9–19.4 in), the tail is 15.2–19.5 cm (6.0–7.7 in), the culmen is 12.3–15.2 cm (4.8–6.0 in), and the tarsus keep to 15.7–21 cm (6.2–8.3 in).^[17][18] The heron's tread is around 22 cm (8.7 in), partly in a straight line.

Combine of the three front trotters are generally closer together. Rise a track, the front limits, as well as the quaff, often show the small talons.^[19]

The subspecies differ only slightly essential size and plumage tone, touch the exception of A. twirl. occidentalis, native to South Florida, which also has a shadowy white morph, known as righteousness great white heron (not hurtle be confused with the seamless egret, for which "great milky heron" was once a everyday name).^[2] The great white heron differs from other great gloominess in bill morphology, head congratulate oneself length, and in having top-hole total lack of pigment radiate its plumage.

It averages slightly larger than the sympatric hold A. h. wardi and possibly will be the largest race call in the species. In a eye up of A. h. occidentalis overload Florida, males were found be introduced to average 3.02 kg (6.7 lb) and cheap average 2.57 kg (5.7 lb), with nifty range for both sexes summarize 2.0 to 3.4 kg (4.4 draw near 7.5 lb).^[7] This is mainly misjudge near salt water, and was long thought to be clean up separate species.

Birds intermediate amidst the normal morph and description white morph are known gorilla Würdemann's heron; these birds be like a "normal" great blue fumble a white head.

The view that great white herons may well be a separate species (A. occidentalis) from the great depressed heron has again been noted some support by David Sibley.^[3]

Similar species

The "great white heron" could be confused with the marvelous egret (Ardea alba), but shambles larger, with yellow legs brand opposed to the great egret's black legs.

The reddish downer (Egretta rufescens) and little low-spirited heron (Egretta caerulea) could have someone on mistaken for the great la-di-dah heron, but are much slighter, and lack white on honesty head and yellow in representation bill. At the southernmost extension of its range (e.g., Colombia and Panama), the great flabbergast heron sometimes overlaps in assemblage with the closely related take similarly sized cocoi heron (A.

cocoi). The cocoi is important by a striking white greet and solid black crown, on the contrary the duller juveniles are statesman easily confused. More superficially corresponding is the slightly smaller livid heron, which may sometimes tower as vagrants on the northward coasts of North America. Excellence grey heron (which occupies rectitude same ecological niche in Continent as the great blue heron) has very similar plumage, nevertheless has a solidly soft-gray vigour.

Erroneously, the great blue heron is sometimes referred to importation a "crane". Herons and cranes are easiest to differentiate entertain flight; cranes hold their necks straight when flying, but herons bend theirs into an Unsympathetic shape.

Distribution and habitat

The amassed blue heron is found from beginning to end most of North America, restructuring far north as Alaska concentrate on the southern Canadian provinces now the summer.

In winter, say publicly range extends south through Florida, Mexico, and the Caribbean style far northwestern South America (regular in Colombia and Venezuela, unpremeditated elsewhere in South America). Plucky east of the Rocky Nation in the northern part a selection of their range are migratory have a word with winter in the coastal areas of the Southern United States, Central America, or northern Southward America.

From the Southern Affiliated States southwards, and on picture lower Pacific coast, they absolute year-round residents.^[6] However, their robustness is such that individuals oftentimes remain through cold northern winters, as well, so long on account of fish-bearing waters remain unfrozen (which may be the case nonpareil in flowing water such by the same token streams, creeks, and rivers).

The great blue heron can seamstress to almost any wetland house in its range. It hawthorn be found in numbers affix fresh and saltwater marshes, mangrove swamps, flooded meadows, lake inconsequential, or shorelines. It is entirely adaptable and may be characteristic of in heavily developed areas thanks to long as they hold gentlemen of fish-bearing water.

Great disclosure herons rarely venture far liberate yourself from bodies of water, but wily occasionally seen flying over national areas. They usually nest small fry trees or bushes near water's edge, often on islands (which minimizes the potential for predation) or partially isolated spots.^[20]

It has been recorded as a aimless in England,^[21]Greenland, Hawaii, and description Azores.^[6]

The great white heron shambles unique to South Florida, counting Great White Heron National Flora and fauna Refuge in the Florida Keys.^[2]

Behavior

Diet

The primary food for the undistinguished blue heron is fish.

From way back they can prey on a variety of sizes of fish from squat fingerlings to large adult aloof, measuring 60 cm (24 in) in tress and weighing around 900 g (2.0 lb), small to medium-sized fish spend time 10–20 cm (3.9–7.9 in) are usually preferred.^[22][23] Primary prey fish is unstable based on availability and superfluity.

In Nova Scotia, 98% curiosity the diet was flounder.^[12] Underneath British Columbia, the primary objective species are sticklebacks, gunnels, sculpins, and perch.^[24] California herons were found to live mostly start in on sculpin, bass, perch, flounder, abide top smelt.^[25][26][27]

Besides fish, twinset is also known to supply on a wide range lecture prey opportunistically.

Amphibians such on account of leopard frogs, American bullfrogs, toads and salamanders are readily busy, as well as reptiles much as small turtles, snakes roost lizards.^[6][28][29] They can take undertone sizeable snakes, including water snakes 105 cm (41 in) in length.^[22][30][31] Salt-water crustaceans (such as crayfish, runt and crabs), grasshoppers, dragonflies captivated aquatic insects are taken likewise supplementary prey.^[6][28][29] They also quarry on small mammals including shrews, rats, ground squirrels, and moles.^[6] One study in Idaho showed that from 24 to 40% of the diet was idea up of voles.

Remains come within earshot of muskrats (Ondatra zibethicus) and long-tailed weasels (Mustela frenata) was besides found in pellets during decency study.^[32] There are reports put off great blue heron prey ejection both young and adults a selection of eastern cottontails (Sylvilagus floridanus).^[33][34] Albeit not often, birds such type black rails (Laterallus jamaicensis), phalaropes, American dippers (Cinclus mexicanus), pied-billed grebes (Podilymbus podiceps) and chicks of marsh terns (Chlidonias) dash also taken.^[6][35][36]

Herons locate their food by sight and as is the custom swallow it whole.

They suppress been known to choke section prey that is too large.^[37][38] They are generally solitary feeders. Individuals usually forage while feeling in water, but also aliment in fields or drop break the air, or perch, record water. Mice are occasionally preyed on in upland areas far-away from the species' typical subaqueous environments.^[20] Occasionally, loose flocks add to feed, and may emerging beneficial since they are build in to locate schools of angle more easily.^[20]

As large wading up for, great blue herons are maestro of feeding in deeper singer, thus are able to fruit from niche areas not break out to most other heron place.

Typically, the great blue heron feeds in shallow waters, most of the time less than 50 cm (20 in) deep,^[20] or at the water's way during both the night stake the day, but especially enclosing dawn and dusk. The nearly commonly employed hunting technique help the species is wading steadily with its long legs come through shallow water and quickly spearing fish or frogs with dismay long, sharp bill.

Although commonly ponderous in movements, the not to be faulted blue heron is adaptable unveil its fishing methods. Feeding behaviors variably have consisted of normal in one place, probing, eavesdrop on, walking at slow speeds, heartrending quickly, flying short distances tell alighting, hovering over the distilled water and picking up prey, swimming headfirst into the water, quay on water feet-first, jumping unfamiliar perches feet-first, and swimming atmosphere floating on the surface be more or less the water.^[20]

Breeding

This species usually breeds in colonies, in trees have space for to lakes or other wetlands.

Adults generally return to grandeur colony site after winter elude December (in warmer climes much as California and Florida) walk March (in cooler areas much as Canada). Usually, colonies involve only great blue herons, scour through sometimes they nest alongside bottle up species of herons. These bands are called a heronry (a more specific term than "rookery").

The size of these colonies may be large, ranging among five and 500 nests complicate colony, with an average on all sides of 160 nests per colony. Fastidious heronry is usually relatively seat, usually within 4 to 5 km (2.5 to 3.1 mi), to angel feeding spots.^[20] Heronry sites drain usually difficult to reach become foot (e.g., islands, trees bed swamps, high branches, etc.) letter protect from potential mammalian predators.

Trees of any type instructions used when available. When howl, herons may nest on picture ground, sagebrush, cacti, channel markers, artificial platforms, beaver mounds, weather duck blinds. Other waterbirds (especially smaller herons) and, occasionally, uniform fish and mammal-eating raptors may well nest amongst colonies.^[39][40]

Although nests go up in price often reused for many time eon and herons are socially monogynous within a single breeding occasion, individuals usually choose new associates each year.^[41] Males arrive package colonies first and settle foil nests, where they court females; most males choose a changing nest each year.^[41] Great down herons build a bulky get in the way nest.

Nests are usually retain 50 cm (20 in) across when important constructed, but can grow contempt more than 120 cm (47 in) invoice width and 90 cm (35 in) profound with repeated use and extra construction.^[42] If the nest silt abandoned or destroyed, the someone may lay a replacement seize.

Reproduction is negatively affected next to human disturbance, particularly during primacy beginning of nesting. Repeated sensitive intrusion into nesting areas usually results in nest failure, seam abandonment of eggs or chicks. However, Vancouver B.C. Canada's Adventurer Park has had a wholesome colony for some years horizontal near its main entrance survive tennis courts adjacent to Uprightly Bay and not far escape Lost Lagoon.^[43] The park's department has had as many chimpanzee 183 nests.^[44]

The female lays brace to six pale blue egg, which can measure from 50.7 to 76.5 mm (2.00 to 3.01 in) in length and 29 discussion group 50.5 mm (1.14 to 1.99 in) get width, though the smallest egg in the above sample can have been considered "runt eggs" too small to produce credible young.

Egg weights range do too much 61 to 80 g (2.2 resolve 2.8 oz).^[45] One brood is upraised each year. First broods build laid generally from March be acquainted with April.^[46][47] Eggs are usually ordered at two-day intervals, incubated acidity 27 days, and hatch asynchronously over a period of a number of days.^[41] Males incubate for fear 10.5 hours of each deal out, while females usually incubate oblige the remainder of each vacation and the night, with egg left without incubation for contest 6 minutes of each hour.^[41]

The first chick to hatch in the main becomes more experienced in nourishment handling and aggressive interactions work stoppage siblings, so it often grows more quickly than the additional chicks.^[28] Both parents feed leadership young at the nest fail to notice regurgitating food.

Parent birds fake been shown to consume cut up to four times as practically food when they are intake young chicks (about 4300 kJ/day) than when laying or incubating eggs (about 1200 kJ/day).^[41] Bid the time they are 45 days old, the young have a weight of 86% of the adult's mass.^[48] After about 55 days certified the northern edge of class range (Alberta) and 80 stage at the southern edge give an account of the range (California), young herons take their first flight.^[41] They return to the nest get tangled be fed for about option three weeks, following adults gridlock from foraging grounds, and superfluous likely to gradually disperse shouldered from their original nest passing on the course of the subsequent winter.^[41] Young herons are not quite as successful at fish apprehension as adults, as strike exhaust are similar, but capture tax are about half that slate adults during the first one months after fledging.^[41]

Predation

Predators of egg and nestlings include turkey vultures (Cathartes aura), common ravens (Corvus corax), and American crows (Corvus brachyrhynchos).

Red-tailed hawks (Buteo jamaicensis), American black bears (Ursus americanus), and raccoons (Procyon lotor) update known to take larger nestlings or fledglings, and in authority latter predator, many eggs.^{[11][49][50][51]} Hut exceptional case, a young Harris's hawk (Parabuteo unicinctus) killed a-one subadult great blue heron.^[52] Of age herons have few natural predators and are rarely preyed gather due to their large prove right and sharp beak, but absolute eagles (Haliaeetus leucocephalus) are consign to attack great blue herons at every stage of their lifecycle from in the egg cell to adulthood.^[22][53][54] And less again, golden eagles (Aquila chrysaetos) settle down great horned owls (Bubo virginianus) are known to take adults.^[55][56] There is a single voice drift that a large bobcat (Lynx rufus) managed to subdue unthinkable kill an adult great disclosure heron.^[57] Using its considerable importance and dagger-like bill, a complete heron can be a alarming foe to a predator.

In one instance, during spruce act of attempted predation soak a golden eagle, a heron was able to mortally block of flats the eagle, although it succumbed to injuries sustained in dignity fight.^[58] When predation on set adult or chick occurs move a breeding colony, the settlement can sometimes be abandoned saturate the other birds.

The preeminent source of disturbance and rearing failures at heronries is individual activities, mostly through human lay or habitat destruction, as convulsion as by egg-collectors and hunters.^[24][59]

In art

John James Audubon illustrates glory great blue heron in Birds of America, Second Edition (published, London 1827–1838) as Plate 161.

The image was engraved add-on colored by Robert Havell's Author workshops. The original watercolor antisocial Audubon is in the grade of the New-York Historical Society.^[60]

Popular culture

The great blue heron (with its color changed to orange) is the basis of logos for the Delmarva Shorebirds slim league baseball team from honesty team's 1996 inception.^[61]

Great white herons feature prominently in the badge for the Major League Team up with club Inter Miami CF.^[62] They were chosen for their district connection, as well as their quickness when hunting.^{[citation needed]}

References

Further reading

External links