117-405: The common loon or great northern diver ( Gavia immer ) is a large member of the loon , or diver, family of birds. Breeding adults have a plumage that includes a broad black head and neck with a greenish, purplish, or bluish sheen, blackish or blackish-grey upperparts , and pure white underparts except some black on the undertail coverts and vent. Non-breeding adults are brownish with
234-699: A wingspan of 136 cm (54 in). Its weight can vary anywhere from 2.2 to 7.6 kg (4.9 to 16.8 lb). Sizes vary regionally, especially by body mass, with the smallest bodied loons on average from lower-central Canada and the Great Lakes , while westerly birds are similar or mildly larger, and loons breeding further east can appear to be significantly larger. Furthermore, males average up to nearly 27% more massive than females in some populations. Breeding loons in Maine averaged 4.65 kg (10.3 lb) in females and 5.97 kg (13.2 lb) in males, essentially
351-404: A broad black head and neck with greenish, purplish, or bluish sheen. It has a black bill sometimes with a pale tip, and red eyes . The neck is encircled with a characteristic black ring and has two white necklaces of eight to ten short streaks on the upper foreneck, and a noticeable collar of white, parallel lines forming a large oval on the neck-side. The central lower foreneck is pure white, and
468-475: A dark culmen and tip, but in early spring the tip may turn whitish. The underparts, lower face, chin, and throat are also whitish. The foreneck is whitish, usually forming wedge-shaped notch in dark neck-sides, and may sometimes reveal a shadowy trace of the neck ring or a pale collar. It has dark brownish grey upperparts with an unclear pattern of squares on the shoulders and some wing coverts spotted with white, which are usually concealed while swimming. The male and
585-678: A dark neck and head marked with dark grey-brown. Their upperparts are dark brownish-grey with an unclear pattern of squares on the shoulders, and the underparts, lower face, chin, and throat are whitish. The sexes look alike, though males are significantly heavier than females. During the breeding season, loons live on lakes and other waterways in Canada, the northern United States (including Alaska ), and southern parts of Greenland and Iceland. Small numbers breed on Svalbard and sporadically elsewhere in Arctic Eurasia. Common loons winter on both coasts of
702-416: A dark, brownish-grey nape that may look darker than the pale-edged black feathers. It has a dark grey to black head, neck, and upperparts, with white throat, cheeks, and underparts. During the first winter, the bill shape of the young may not be as fully developed as that of the adult, and during the second winter, it much resembles the breeding adult, but with wing coverts lacking white spots. The common loon
819-664: A few days old, and they fly to their wintering areas before ice forms in the fall. The common loon is assessed as a species of least concern on the IUCN Red List of Endangered Species . It is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds applies. The United States Forest Service has designated the common loon a species of special status because of threats from habitat loss and toxic metal poisoning in its US range. The common loon
936-416: A few days to a few weeks during spring migration, settling on their lake once a portion of it becomes ice-free. Copulation takes place ashore, often on the nest site, repeated daily until the eggs are laid. The preceding courtship is very simple, with mutual bill-dipping and dives. The displays towards intruders, such as bow-jumping (an alternation of fencing and bill-dipping postures and rushing (running "along
1053-400: A group of aquatic birds found in much of North America and northern Eurasia . All living species of loons are members of the genus Gavia , family Gaviidae and order Gaviiformes . Loons, which are the size of large ducks or small geese , resemble these birds in shape when swimming. Like ducks and geese, but unlike coots (which are Rallidae ) and grebes ( Podicipedidae ),
1170-714: A key moment in the beginnings of modern racism . "Employing the English word "race" as a synonym for human variety, they interpret the multiplicity of Polynesian culture in terms of a linear hierarchy that naturally ascends towards the white European ideal." In November 1779 Forster was appointed Professor of Natural history and Mineralogy at the University of Halle , and director of the Botanische Garten der Martin-Luther-Universität Halle-Wittenberg , where he remained until his death. His Descriptiones animalium , completed within
1287-449: A mound along the vegetated coasts of lakes greater than 3.7 ha (9.1 acres). After a week of construction in late spring, one parent climbs on top to mold the interior of the nest to the shape of its body. Based on a number of studies, nesting success averages about 40%, and most newly hatched young survive due to parental care. Eggs from first clutches are typically laid in May or early June,
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#17330862391931404-406: A necropsy of a bald eagle found floating on a Maine lake (beside the floating body of a loon chick) found that the eagle had been stabbed through the heart by an adult loon's beak. Biologists , especially from Chapman University , have extensively studied the mating behaviour of the common loon ( G. immer ). Contrary to popular belief, pairs seldom mate for life . Indeed, a typical adult loon
1521-411: A pH at around 4.5 exhibited reproductive success below a calculated positive growth rate threshold. An association has also been observed between elevated blood methylmercury levels and aberrant incubation patterns. Adult common loons with high levels of methylmercury were found to spend less time incubating and in the nest, increasing the risks of predation and the eggs overheating/overcooling. Together,
1638-410: A particular tremolo that can be used to identify a flying loon. Its flying speed is as much as 120 km/h (75 mph) during migration. Particularly during the breeding season, common loons frequently engage in territorial disputes against other water birds, including ducks and geese, and will attack or drive off competitors and intruders to their territory. Fish account for about 80% of the diet of
1755-433: A spear-shaped bill. Males are larger on average, but relative size is only apparent when the male and female are together. In winter, plumage is dark grey above, with some indistinct lighter mottling on the wings, and a white chin, throat and underside. The specific species can then be distinguished by certain features, such as the size and colour of the head, neck, back and bill. But reliable identification of loons in winter
1872-627: A stable population trend that does not warrant a vulnerable rating. It also has a large population size of 612,000 to 640,000 individuals. The estimated breeding population ranges from 1,400 to 2,600 mature individuals in Europe. Over half of the breeding population in North America is found in Ontario with 97,000 territorial pairs, and in Quebec with 50,000 territorial pairs. About 2,400 individuals occur in each of
1989-499: A strong tendency to settle as breeders on a lake that resembles their natal one, a phenomenon termed natal habitat imprinting. This preference is based on two lake attributes: size and pH. The behaviour is puzzling, because it is as strong in loons hatched on small, acidic lakes as those from large lakes of neutral pH. Hence, the former group is exhibiting active preference for lakes that have been shown to result in higher chick mortality and lower breeding success. The common loon produces
2106-479: A territory and may breed together for a decade or more. Both members of a pair build a large nest out of dead marsh grasses and other plants formed into a mound along the vegetated shores of lakes. A single brood is raised each year from a clutch of one or two olive-brown oval eggs with dark brown spots which are incubated for about 28 days by both parents. Fed by both parents, the chicks fledge in 70 to 77 days. The chicks are capable of diving underwater when just
2223-401: A variety of vocalizations, the most common of which are the tremolo , the yodel, the wail, and the hoot. Each of these calls communicates a distinct message. The frequency at which it vocalizes has been shown to vary based on time of day, weather, and season. It is most vocally active between mid-May and mid-June. The wail, yodel, and tremolo calls are sounded more frequently at night than during
2340-407: A wide range of behavioral, reproductive, and survival effects on the common loon. Previous research has found a correlation between mercury levels and pH , with more acidic aquatic environments being at the highest risk for elevated methylmercury concentrations. Once mercury enters the water, it is taken up by fish and spread throughout the food chain. Resulting from this transmission of mercury, there
2457-458: Is 42 seconds, but the maximum duration spent underwater is about 1 min (60 s). The common loon's mating system is serially monogamous ; breeding pairs jointly defend a territory consisting of an entire small lake or a protected bay within a large lake. A given male and female remain together throughout a breeding attempt, rear their own biological offspring, reunite each spring, and may breed together for many consecutive years. However, in
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#17330862391932574-409: Is a long call consisting of up to three notes, and is often compared to a wolf 's howl . It uses this call to communicate its location to other loons. The call is given back and forth between breeding pairs or an adult and its chick, either to maintain contact or in an attempt to move closer together after being separated. It is a loud aaoo , weee-wea weee-wea weee-wea , or ooo-aaah-éééé . The hoot
2691-429: Is a short, soft call and is another form of contact call. It is a more intimate call than the wail and is used exclusively between small family groups or flocks. The common loon hoots to let other family or flock members know where it is. This call is often heard when the adult loon is summoning its chicks to feed. Considerable information on longevity and survival rates has been collected in the past two decades, owing to
2808-662: Is a significant positive correlation between mercury levels in fish and mercury levels in male, female, and chick blood of common loons; consequently, an increase in mercury concentration in the blood of common loons and fish was seen with a decrease in local aquatic pH. Although there have been reductions in recent years in acidifying emissions, there has been limited biological recovery in these lakes most likely due to climate change. Research has shown that warmer summer temperatures can inhibit reestablishment of cold-water fish species in acidified lakes and droughts brought on by increased summer temperatures can further acidify lakes. Although
2925-608: Is also found in tubenoses ( Procellariiformes ) and penguins (Sphenisciformes), both relatives of the loons. Loons are excellent swimmers, using their feet to propel themselves above and under water. However, since their feet are located far back on the body, loons have difficulty walking on land, though they can effectively run short distances to reach water when frightened. Thus, loons avoid coming to land, except for mating and nesting. Loons fly strongly, though they have high wing loading (mass to wing area ratio), which complicates takeoff. Indeed, most species must run upwind across
3042-424: Is best known as the naturalist on James Cook 's second Pacific voyage , where he was accompanied by his son Georg Forster . These expeditions promoted the career of Johann Reinhold Forster and the findings became the bedrock of colonial professionalism and helped set the stage for the future development of anthropology and ethnology. They also laid the framework for general concern about the impact that alteration of
3159-401: Is closely associated with the common loon to which it is attracted to chemicals in the uropygial gland secretions as well as by visual and tactile cues. This fly is detrimental to loons, their preferred hosts, transmitting blood-borne parasites and viruses, and causing nest abandonment when numbers are high. External parasites include ischnoceran feather lice , although these are not found on
3276-412: Is distinguished from the black-throated loon ( G. arctica ) and the red-throated loon ( G. stellata ) mainly by its larger size. It usually has a steeper forehead and a bulging forecrown, somewhat similar to the black-throated loon. Its bill is heavier and the back is paler than its hindneck. It is more difficult to separate from the yellow-billed loon, but its breeding plumage has more white markings on
3393-504: Is endangered by personal water-craft and powerboats that may drown newly born chicks, wash eggs away, or swamp nests. It is still considered an "injured" species in Alaska as a result of the Exxon Valdez oil spill . In a 2003 survey of New England dead loons, lead poisoning from fishing weights accounted for about half of the deaths, and other human factors directly caused the death of 52% of
3510-423: Is interpreted as terminal investment, a "go for broke" strategy seen in senescing animals that are attempting to eke out another year or two of breeding before they die. Adult common loons have few predators, although bald eagles will attack incubating birds. Attacks by sharks in winter have also been recorded. When a predator approaches (either the loon's nest or the loon itself), the common loon sometimes attacks
3627-481: Is likely to have several mates during its lifetime because of territorial takeover. Each breeding pair must frequently defend its territory against "floaters" (territory-less adults) trying to evict at least one owner and seize the breeding site. Territories that have produced chicks in the past year are especially prone to takeovers, because nonbreeding loons use chicks as cues to indicate high-quality territories. One-third of all territorial evictions among males result in
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3744-423: Is often difficult even for experts – particularly as the smaller immature birds look similar to winter-plumage adults, making size an unreliable means of identification. Gaviiformes are among the few groups of birds in which the young moult into a second coat of down feathers after shedding the first one, rather than growing juvenile feathers with downy tips that wear off, as is typical in many birds. This trait
3861-521: Is the provincial bird of Ontario , and it appears on Canadian currency, including the one-dollar "loonie" coin and a previous series of $ 20 bills . In 1961, it was designated the state bird of Minnesota , and appears on the Minnesota State Quarter . The common loon is also known as the great northern diver in Eurasia . (Another former name, great northern loon, was a compromise proposed by
3978-597: The Adirondack Mountains are particularly affected by methylmercury as the acidity of the lakes provides an environment conducive to converting environmental mercury to methylmercury. One study found that 21% of the male Adirondack common loon and 8% of the female Adirondacks common loon sampled were at high risk for detrimental impacts such as behavioral and reproductive abnormalities. In the Adirondacks, bioaccumulation factors for methylmercury were found to increase up
4095-566: The Adirondack Mountains found that elevated levels of methylmercury are associated with reduced diving frequency in adult common loons. One study found that brood productivity was reduced by half when female blood mercury levels exceeded 4.3 μg/g and productivity completely failed when female blood mercury levels exceeded 8.6 μg/g. These results are related to fish mercury levels of 0.21 μg/g and 0.41 μg/g, respectively. As mercury levels and pH are correlated, scientists have found that brood success decreases with decreasing pH such that environments with
4212-528: The Arctic coast. They are known to exhibit high breeding site fidelity. Some common loons remain in Iceland year-round, although most migrate. In North America, they winter mainly along north Atlantic and north-east Pacific coasts, many stopping off on the Great Lakes during their migration . They migrate in the day, starting about two hours after sunrise and flying at altitudes of 1500 to 2700 m above sea level, above
4329-704: The Crown of Poland . He studied languages and natural history at the Joachimsthal Gymnasium in Berlin, theology at the University of Halle , afterwards serving as a Protestant pastor in Mokry Dwór (Nassenhuben) Pomeranian Voivodship . He married his cousin Elisabeth Nikolai. They had several children including a son, Georg Forster and a daughter, Virginia Viktoria Foster. In 1765 he accepted an offer made to him by
4446-518: The International Ornithological Committee .) It is one of five loon species that make up the genus Gavia , the only genus of the family Gaviidae and order Gaviiformes . Its closest relative is another large black-headed species, the yellow-billed loon or white-billed diver ( Gavia adamsii ). There are no recognized subspecies of the common loon. Danish zoologist and mineralogist Morten Thrane Brünnich first described
4563-560: The Late Miocene . Study of the interrelationships of the extant species has found that the red-throated loons are the most basal of the five species. Gavia stellata G. arctica G. pacifica G. immer G. adamsii † Gavia egeriana † G. schultzi † G. howardae G. stellata † G. brodkorbi † G. paradoxa † G. moldavica † G. concinna G. arctica G. pacifica † G. fortis G. adamsii G. immer Nearly ten prehistoric species have been named to date in
4680-522: The Late Pliocene of Orciano Pisano , Italy , is known from a cervical vertebra that may or may not have been from a loon. If so, it was from a bird slightly smaller than the common loon . Older authors were quite sure the bone was indeed from a Gavia and even considered G. concinna a possibly junior synonym of it. This is now regarded as rather unlikely due to the quite distinct range and age. The Early Pliocene Gavia skull from Empoli (Italy)
4797-529: The Pliocene , and specimens from the Pleistocene of California and Florida appear to represent a paleosubspecies of the common loon. The adult common loon can range from 66 to 91 cm (26 to 36 in) in length with a 127 to 147 cm (4 ft 2 in to 4 ft 10 in) wingspan , slightly smaller than the similar yellow-billed loon. On average, it is about 81 cm (32 in) long and has
Common loon - Misplaced Pages Continue
4914-495: The smew ( Mergellus albellus ). This small sea-duck is quite unrelated to loons and just happens to be another black-and-white seabird which swims and dives for fish. It is not likely that the ancient Romans had much knowledge of loons, as these are limited to more northern latitudes and since the end of the last glacial period seem to have occurred only as rare winter migrants in the Mediterranean region. The term gavia
5031-626: The Adirondacks by performing research, engaging the public, and informing public policy. The common loon's breeding range has moved northward, the species breeding as far south as Iowa a century ago. It too is adversely affected by acid rain and pollution, as well as lead poisoning from fishing sinkers (especially those that are about the size of the grit stones they ingest) and mercury contamination from industrial waste. Heavy metals such as mercury may be partially removed through biological processes such as excretion or deposition in feathers, but their adverse effects are magnified through concentration of
5148-731: The Atlantic Coast, 423,000 to 446,000 adults and 72,000 to 76,000 juveniles are found. The common loon is listed under Appendix II of the Convention on the Conservation of Migratory Species , and in Article I under the European Union (EU) Birds Directive . It is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) is applied. In Europe it appears in 20 Important Bird Areas ( IBAs ), including Ireland, Svalbard, mainland Norway, Iceland, Spain, and
5265-830: The Atlantic seaboard from Massachusetts to Maine have some of the highest concentrations of common loons. Occasional vagrants are recorded inland in Mexico, in San Luis Potosí and Coahuila , as well as in Chiapas and Oaxaca in the south. They are accidental in northern Japan and the Commander Islands in northwestern Pacific, and Cuba in the West Indies . The common loon is an expert fisher, catching its prey underwater by diving as deep as 60 m (200 ft). With its large webbed feet,
5382-547: The Dissenting Warrington Academy , succeeding Joseph Priestley . Compelled by his violent temper to resign this appointment, Forster then moved with his son to London, where they earned a precarious living by doing translations. In 1771, he published A Catalogue of the Animals of North America , which listed the region's mammals, birds, reptiles, fish, insects, arachnids, and crustaceans, and led to his election to
5499-878: The Gavia lineage for maintaining homeostasis due to maybe having a role in maintaining ion and pH balance. Common loons are mainly Nearctic , and breed from 48° N to the Arctic Circle , locally south to 40° N and north to 78° N . During their breeding season in spring and summer, most common loons live on lakes and other waterways in the northern United States and Canada, as well as in southern parts of Greenland , in Iceland, in Svalbard , in Jan Mayen , and in Bear Island in Norway; and in Alaska , to
5616-761: The Royal Society of London in 1772. When Joseph Banks withdrew at the last moment as naturalist on Cook's second voyage, Forster and his son were appointed to fill the vacant position. In July 1772 they set sail on the Resolution , returning to England in July 1775. During a stop in Cape Town , Forster engaged the Swedish naturalist Anders Sparrman to act as his assistant. Both the Forsters kept detailed diaries of everything they saw on
5733-540: The Russian government to inspect and report upon the new colonies founded on the banks of the Volga , in the province of Saratov . His irritable temper soon involved him in difficulties with the Russian government, and in the following year he went with Georg (the eldest of eight children, seven of which survived childhood) to England and became teacher of natural history at Warrington , Lancashire. He spent three years teaching at
5850-1110: The South Baltic and directly over land to the Black Sea or Mediterranean. Loons can live as long as 30 years and can hold their breath for as long as 90 seconds while underwater. Loons are migratory birds, and in the winter months they move from their northern freshwater lake nesting habitats to southern marine coastlines. They are well-adapted to this change in salinity, however, because they have special salt glands located directly above their eyes. These glands filter out salts in their blood and flush this salty solution out through their nasal passages, which allows them to immediately consume fish from oceans and drink saltwater after their long migration. Loons find their prey by sight. They eat mainly fish , supplemented with amphibians , crustaceans and similar mid-sized aquatic fauna . Specifically, they have been noted to feed on crayfish , frogs , snails , salamanders and leeches . They prefer clear lakes because they can more easily see their prey through
5967-451: The US as far south as Mexico, and on the Atlantic coast of Europe. Common loons eat a variety of animal prey including fish, crustaceans , insect larvae, molluscs , and occasionally aquatic plant life. They swallow most of their prey underwater, where it is caught, but some larger items are first brought to the surface. Loons are monogamous ; that is, a single female and male often together defend
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#17330862391936084-626: The United Kingdom. It is also a listed species in 83 Special Protection Areas in the EU Natura 2000 network. The USDA National Forest Service has designated the common loon a species of special status, and in the upper Great Lake regions of the Huron-Manistee , Ottawa , and Hiawatha national forests as a regional forester sensitive species. The common loon is a key indicator of mercury deposition in aquatic environments due to its position at
6201-421: The behaviour; pairs composed of last year's female and a new male tend to select a new nest site, regardless of the success or failure of the previous year's attempt. Despite the lead role of males in nest site selection, both sexes contribute substantially to nest construction. The nest is about 56 cm (22 in) wide and is constructed out of dead marsh grasses and other indigenous plants, and formed into
6318-439: The bird's head. Botulism , acquired by eating infected fish, can lead to paralysis and drowning. Aspergillosis is another cause of emaciation and death. Outbreaks sometimes lead to thousands of deaths. Since 1998, the common loon has been rated as a species of least concern on the IUCN Red List of Endangered Species . This is because it has a large range – more than 20,000 km (7,700 sq mi) – and because it has
6435-468: The bird's practice of catching fish by diving. The North American name "loon" was first recorded in this sense in New Englands Prospect (1634) by William Wood (1580–1639); "The Loone is an ill shap'd thing like a Cormorant". It may be derived from Old Norse lómr , as are modern Swedish and Danish lom , in each case referring to the distinctive call. A number of fossil loon species are known from
6552-573: The bones of frogs and salamanders. The gastroliths may also be involved in stomach cleaning as an aid to regurgitation of indigestible food parts. Loons may inadvertently ingest small lead pellets, released by anglers and hunters, that will contribute to lead poisoning and the loon's eventual death. Jurisdictions that have banned the use of lead shot and sinkers include but are not limited to Maine , New Hampshire , Vermont , Michigan , some areas of Massachusetts , Yellowstone National Park , Canada , Great Britain , and Denmark . Loons nest during
6669-447: The book was insufficient to clear his debts, and the bulk of Georg's drawings from the voyage had to be sold to Joseph Banks. During the next few years Forster undertook a variety of writing work, including a German translation of Thomas Pennant 's Arctic Zoology . Johann Reinhold's "Observations Made During a Voyage Round the World" (1778) and Georg's "A Voyage Round the World" (1777), mark
6786-661: The breeding population in the United States. There are about 100 territorial pairs in the northwestern U.S. states of Washington, Idaho, Montana, and Wyoming. About 2,250 territorial pairs are found in New England and New York. In winter, 3,500 to 4,500 individuals are found in the United Kingdom, and even fewer individuals are found in the western European coastline and in Iceland. Along the Pacific Coast, about 184,000 to 189,000 adults and 31,000 to 32,000 juveniles are found, and along
6903-403: The chicks better from intruding loons and eagles, which are their main predators. Male parents defend broods consisting of two chicks more vigorously than singleton chicks, chiefly with the territorial yodel call. The chicks are capable of making shallow dives from their first day but make deeper dives as they grow. Fledging takes 70 to 77 days. Usually, only one brood is raised. Both parents feed
7020-445: The chicks can grasp them. If food is scarce, the larger chick may peck its small sibling incessantly; on small lakes with limited food, only one chick often survives. Juveniles leave the breeding ground before ice formation in the fall, weeks after their parents. A pair of loons raising two chicks have been estimated to feed on 423 kg of fish during the five and a half months that they spend in their breeding territory. Loons exhibit
7137-420: The chicks live prey from hatching to fledging. As they grow, chicks are able to catch an increasingly large proportion of their diet by themselves; they can feed and fend for themselves after about two months, although many juveniles continue to beg from adults well beyond this age. The parent birds capture small fish and hold them crosswise in their bill, call and approach the chicks with their head lowered so that
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#17330862391937254-405: The common loon are able to decrease their methylmercury levels by molting and laying eggs, continued consumption of fish with raised methylmercury levels prevents these mechanisms from effectively lowering methylmercury levels. Mercury concentrations have been shown to vary by the sex and age of common loons. Male common loons were found to contain the highest blood mercury concentration likely due to
7371-483: The common loon in 1764, as Colymbus immer in his Ornithologia Borealis . The now-defunct genus Colymbus contained grebes as well as loons, and remained in use until the International Commission on Zoological Nomenclature attempted to clarify the nomenclature in 1956 by declaring Colymbus a suppressed name unfit for further use and establishing Gavia , created by Johann Reinhold Forster in 1788, as
7488-694: The common loon is an efficient underwater pursuit predator and adroit diver. It needs a long run-up distance to gain momentum for flight take-off and is ungainly on land, sliding on its belly and pushing itself forward with its legs. Its clumsiness on land is due to the legs being positioned at the rear of its body; the pelvic muscles are well developed, ideal for swimming but not well-suited for walking. When it lands on water, it skims along on its belly to slow down, rather than braking with its feet, as they are set too far back. The common loon swims and dives well, and flies competently for hundreds of kilometres in migration. It flies with its neck outstretched, usually calling
7605-435: The common loon-chicken split 90 million years ago. It is theorized that these candidate genes are related to hemoglobin affinity for oxygen, solute exchange, immunoglobulin function related to immune defense, nervous system development and a number of molecular pathways related to DNA metabolic function, and G-receptor pathways potentially involved in low-light visual acuity. For example, SLC48A, and SLC20A1 are candidate genes in
7722-514: The common loon. It forages on fish of up to 26 cm (10 in) in length, including minnows , suckers , gizzard shad , rock bass , alewife , northern pike , whitefish , sauger , brown bullhead , pumpkinseed , burbot , walleye , bluegill , white crappie , black crappie , rainbow smelt , and killifish . The young typically eat small minnows, and sometimes insects and fragments of green vegetation. The freshwater diet primarily consists of pike , perch , sunfish , trout , and bass ;
7839-483: The convective and turbulent layer of air. In winter they can be seen on North America coasts as far south as Baja California , Sonora , northern Sinaloa , southern Texas , and rarely northern Tamaulipas . In the east, several thousand winter along western European coasts, probably originating from Iceland, Greenland, and Canada. Their range extends into northwestern Europe from Finland to Portugal and southern and northwestern Spain ( Galicia and Asturias ), as well as
7956-422: The day; calls have also been shown to occur more frequently in cold temperatures and when there is little to no rain. The tremolo call—sometimes called the "laughing" call—is characterized by its short, wavering quality. It often uses this call to signal distress or alarm caused by territorial disputes or perceived threats. It emits a tremulous series of up to 10 rather high notes (hu)-heheheheheheha . It also uses
8073-569: The death of the owner; in contrast, female loons usually survive. Birds that are displaced from a territory but survive usually try to re-mate and (re)claim a breeding territory later in life. In 2020, a loon hatched for the first time in over a century in Southeastern Massachusetts at Fall River, the Massachusetts Division of Fisheries and Wildlife and Biodiversity Research Institute. The chicks were relocated in 2015 with
8190-478: The effects of heightened methylmercury levels on parenting behaviors may contribute to lower chick survival rates. One study in Maine and New Hampshire found that high levels of methylmercury in parents are associated with a significant decrease in the number of fledged young, with common loons in the highest risk group producing 41% fewer fledged young than common loons with low levels of methylmercury. The common loons of
8307-464: The effects of some of these threats, namely terrestrial predation and water-level fluctuations, through the deployment of rafts in the loon's breeding territories. In addition, artificial floating nesting platforms have been provided for the common loon in some lakes to reduce the impact of changing water levels due to dams and other human activities. The common loon abandons lakes that fail to provide suitable nesting habitat due to shoreline development. It
8424-1160: The eggs are lost, the pair may re-nest, usually in a different location. Since the nest is very close to the water, rising water may induce the birds to slowly move the nest upwards, over a metre. Despite the roughly equal participation of the sexes in nest building and incubation, analysis has shown clearly that males alone select the location of the nest. This pattern has the important consequence that male loons, but not females, establish significant site-familiarity with their territories that allows them to produce more chicks there over time. Sex-biased site-familiarity might explain, in part, why resident males fight so hard to defend their territories. Most clutches consist of two eggs, which are laid in May or June, depending upon latitude. Loon chicks are precocial , able to swim and dive right away, but will often ride on their parents' back during their first two weeks to rest, conserve heat, and avoid predators. Chicks are fed mainly by their parents for about six weeks but gradually begin to feed themselves over time. By 11 or 12 weeks, chicks gather almost all of their own food and have begun to fly. In 2019,
8541-481: The event of death or territorial eviction of one pair member by an intruding loon of the same sex, the other pair member quickly establishes a pair bond with the evicting bird. (Hence, most adult loons have two or more different mates during their lives.) Evicting individuals tend to be young males and females (5 to 9 years old), while evicted adults are often those 15 years and older. Pairs do not remain together during winter; in addition, males usually precede females by
8658-815: The fact that they tend to consume bigger fish with higher mercury concentrations. Females contained the second highest blood mercury concentration with differences between the males likely being due to the fact that females can expel mercury into the eggs they lay. Juveniles had the lowest blood mercury concentration. Scientists found that the data from juveniles helped to best indicate the local mercury availability as they are fed exclusively from their natal territory. Elevated levels of mercury have been associated with changes in foraging and brooding behavior among adult common loons, especially in higher concentrations. Studies have found that elevated levels of methylmercury are associated with lethargy and decreased time spent foraging in adult common loons. A different study carried out in
8775-484: The female have similar appearances, although they exhibit sexual dimorphism in their physical dimensions with the male larger and significantly heavier than the female. The heavy dagger-like bill is evenly tapered and greyish, sometimes having a black tip. The bill colour and angle distinguish this species from the yellow-billed loon. The neck is short and thick. It swims very low in the water, with sometimes only its head held above and horizontal to water. It must run across
8892-486: The fish attempts to evade the common loon, the bird chases it down with excellent underwater manoeuvrability due to its tremendously strong legs. Most prey are swallowed underwater, where they are caught, but some larger prey are first brought to the surface. It is a visual predator, so it is essential to hunting success that the water is clear. It normally dives 4 to 10 m (13 to 33 ft), but has been recorded to dive up to 70 m (230 ft). The average diving time
9009-560: The food chain, leaving common loons at the highest risk for detrimental effects from methylmercury. Spatial analysis indicates that the highest aquatic mercury concentrations are found in the southwestern portion of the Adirondacks, an area with lakes heavily affected by acid rain. Organizations such as the Adirondack Loon Center and the Adirondack Cooperative Loon Program spearhead loon conservation efforts in
9126-404: The future nest site, and build their nests close to the water, preferring sites that are completely surrounded by water such as islands or emergent vegetation. Loons use a variety of materials to build their nests including aquatic vegetation, pine needles, leaves, grass, moss and mud. Sometimes, nest material is almost lacking. Both male and female build the nest and incubate jointly for 28 days. If
9243-524: The genus Gavia , and about as many undescribed ones await further study. The genus is known from the Early Miocene onwards, and the oldest members are rather small (some are smaller than the red-throated loon ). Throughout the late Neogene , the genus by and large follows Cope's Rule (that population lineages tend to increase in body size over evolutionary time). List of fossil Gavia species List of fossil Gavia specimens "Gavia" portisi from
9360-663: The genus Gavia . It has been suggested that the genus Gavia originated in Europe during the Paleogene . The earliest species, G. egeriana , was found in early Miocene deposits in Dolnice in the Czech Republic. During the remainder of the Miocene , Gavia managed to disperse into North America via the Atlantic coastlines, eventually making their way to the continent's Pacific coastlines by
9477-414: The genus name to refer to grebes, while Europeans used it for loons, following Nicholas Aylward Vigors and Richard Bowdler Sharpe . The International Commission on Zoological Nomenclature tried to settle this issue in 1956 by declaring Colymbus a suppressed name unfit for further use and establishing Gavia , created by Johann Reinhold Forster in 1788, as the valid genus name for the loons. However,
9594-494: The head droops more than in similar aquatic birds. Male and female loons have identical plumage , which is largely patterned black-and-white in summer, with grey on the head and neck in some species. All have a white belly. This resembles many sea-ducks (Merginae) – notably the smaller goldeneyes ( Bucephala ) – but is distinct from most cormorants, which rarely have white feathers, and if so, usually as large rounded patches rather than delicate patterns. All species of loons have
9711-522: The hopes of re-establishing breeding and nesting patterns. The European Anglophone name "diver" comes from the bird's habit of catching fish by swimming calmly along the surface and then abruptly plunging into the water. The North American name "loon" likely comes from either the Old English word lumme , meaning lummox or awkward person, or the Scandinavian word lum meaning lame or clumsy. Either way,
9828-662: The implementation of an efficient capture protocol that permits marking and monitoring of large study populations. A rough preliminary analysis showed that common loons of both sexes survive at an annual rate of over 90% until they reach their mid-20s, but show a survival rate of only about 75% thereafter. However, a second, finer-scaled analysis made clear that male loons begin to show higher mortality, increased territory loss and lower body condition starting at age 15. Perhaps in response to their physical decline, males 15 and older show increased rates of both territorial aggression and territorial vocalization. This age-related shift in behaviour
9945-554: The loon's toes are connected by webbing . The loons may be confused with the cormorants (Phalacrocoracidae), but can be distinguished from them by their distinct call. Cormorants are not-too-distant relatives of loons, and like them are heavy-set birds whose bellies, unlike those of ducks and geese, are submerged when swimming. Loons in flight resemble plump geese with seagulls ' wings that are relatively small in proportion to their bulky bodies. The bird points its head slightly upwards while swimming, but less so than cormorants. In flight,
10062-452: The lower neck-sides has longitudinal white lines becoming rows of small spots and black lines becoming very narrow. The upperparts are blackish or blackish grey, and each feather has small white spots on it. The upperwing is blackish and with small white spots on the non-primary coverts, whereas the underwing is paler with white coverts except the long black shaft-streaks on the axillaries. The underparts are pure white, but have some black on
10179-429: The male. It is used in the establishment of territorial boundaries and in territorial confrontations, and the length of the call corresponds with the loon's level of aggression. The dominant frequencies in the yodel indicate the body mass and thereby the health of males. A male that occupies a new territory appears to alter its yodel to be clearly distinguishable from the call of the previous territory owner. A loon's wail
10296-576: The maritime provinces of Canada—Nova Scotia and New Brunswick. British Columbia accounts for 25,000 territorial pairs. In far northern Canada, about 50,000 territorial pairs are known to occur, and 12,500 to 15,000 territorial pairs occur in the Prairie Provinces of Alberta, Manitoba, and Saskatchewan. In the United States, the largest breeding population is present in Alaska with 3,600 to 6,000 territorial pairs. The U.S. Great Lakes region has 5,900 to 7,200 territorial pairs which accounts for over half of
10413-497: The name refers to the loon's poor ability to walk on land. Another possible derivation is from the Norwegian word lom for these birds, which comes from Old Norse lómr , possibly cognate with English "lament", referring to the characteristic plaintive sound of the loon. The scientific name Gavia refers to seabirds in general. The scientific name Gavia was the Latin term for
10530-547: The nearest body of water that will not freeze over in the winter: western Canadian loons go to the Pacific , Great Lakes loons to the Gulf of Mexico region, eastern Canadian loons to the Atlantic, and some loons to large inland lakes and reservoirs . They appear in most of the inland waters of the United States. The South Carolina coast, the Gulf coast adjacent to the Florida panhandle , and
10647-554: The neck and the squares on its shoulders are usually smaller; the non-breeding plumage has darker neck-sides contrasting more sharply with pale areas and bill colour. The scaly juvenile plumage is retained until January or February of the year following hatching, when a lengthy moult of head and body feathers gives them a more adult-like appearance. Adults shed all their flight feathers simultaneously around this time, leaving them temporarily flightless, prior to gaining breeding plumage, but second-year birds delay this substantial moult until
10764-740: The observed 522 loons. The common loon appears on Canadian currency, including the one-dollar "loonie" coin and the previous series of $ 20 bills . It is the provincial bird of Ontario . It was designated the state bird of the U.S. state of Minnesota in 1961, and also appears on the Minnesota State Quarter . Loon Family-level: Colymbidae Vigors , 1825 (but see text ) Colymbinae Bonaparte , 1831 (but see text ) Urinatores Vieillot , 1818 Urinatoridae Vieillot, 1818 Urinatorides Vieillot, 1818 Genus-level: Colymbus Linnaeus , 1758 (but see text ) Urinator Lacépède , 1799 Loons ( North American English ) or divers ( British / Irish English ) are
10881-515: The physical environment for European economic expansion would have on exotic societies. Forster's family originated in the Lords Forrester in Scotland, from where his great-grandfather had emigrated after losing most of his property during the rule of Oliver Cromwell along with many other Scots. Forster himself was born in the city of Dirschau (now) Tczew , in the province of Royal Prussia , in
10998-400: The preceding year typically reuse the nest site from the previous year, if they hatched chicks successfully there. In contrast, pairs that lost their eggs to a predator usually shift the nest to a new location. This logical behaviour pattern appears to depend upon the male, because breeding pairs consisting of last year's male and a female not present during the preceding year continue to exhibit
11115-543: The predator by rushing at it and trying to stab it with its dagger-like bill, aiming its attacks either at the predator's abdomen or the back of its head or neck, which may be deadly to predators up to the size of a fox or raccoon. Eggs are taken by a number of mammals, including American mink , striped skunk , otters , foxes and raccoons , with the latter being responsible for nearly 40% of all nest failures. Birds such as herring gulls , northern ravens and American crows will eat unattended eggs. Because their nests are at
11232-621: The saltwater diet primarily consists of rock fish , flounder , sea trout , herring , Atlantic croaker , haddock , and Gulf silverside . When there is either a lack of fish or they are difficult to catch, it preys on crustaceans , crayfish , snails , leeches , insect larvae , molluscs , frogs , annelids , and occasionally aquatic plant matter such as pondweed , roots, moss, willow shoots , seeds, and algae . It has also been known to eat ducklings. The common loon uses its powerful hind legs to propel its body underwater at high speed to catch its prey, which it then swallows head-first. If
11349-460: The same weight as the yellow-billed loon although the yellow-billed is still larger than in linear dimensions (especially bill length) than the Maine loons. In Ontario , 20 females averaged 4.5 kg (9.9 lb) and 20 males averaged 5.46 kg (12.0 lb). In contrast, in the Gulf of Alaska , adults of both sexes reportedly averaged 4.13 kg (9.1 lb). Adult breeding plumage consists of
11466-447: The situation was not completely resolved even then, and the following year the ICZN had to act again to prevent Louis Pierre Vieillot 's 1818 almost-forgotten family name Urinatoridae from overruling the much younger Gaviidae. Some eminent ornithologists such as Pierce Brodkorb tried to keep the debate alive, but the ICZN's solution has been satisfactory. All living species are placed in
11583-437: The summer on freshwater lakes and/or large ponds. Smaller bodies of water (up to 0.5 km ) will usually only have one pair. Larger lakes may have more than one pair, with each pair occupying a bay or section of the lake. The red-throated loon, however, may nest colonially, several pairs close together, in small Arctic tarns and feed at sea or in larger lakes, ferrying the food in for the young. Loons mate on land, often on
11700-533: The summer. The adult winter plumage is attained between October and January by partial moult mainly of head, body and tail feathers. With improved gene-sequencing technology, a draft genome of the common loon has assembled and identified at least 14,169 common loon genes. 80.7% of chicken genes are found in the common loon genome. The physiological costs of deep-water diving and long distance aerial migration of loons have greatly affected loon evolution. Many identified genes are candidate genes for positive selection since
11817-423: The surface with its wings either folded or half-extended and flapping at about the same speed as when taking off") are often misinterpreted as courtship. Nesting typically begins in early May. Significantly more nesting sites are found on islands than on mainland shoreline. Breeding pairs patrol their territories routinely, even at night, defending the territory both physically and vocally. Pairs that nested together
11934-465: The timing depending largely upon the date that lakes become ice-free and inhabitable. A clutch consists of two (occasionally one) olive-brown oval eggs with dark brown spots. Incubation is carried out jointly by male and female and lasts about 28 days. Loons often place nests along steep lake shorelines where adults can quickly dive underwater when approached by predators. The eggs are about 88 mm (3.5 in) long and 55 mm (2.2 in) wide and
12051-432: The top of the food chain . The main contributors to elevated mercury concentrations in aquatic environments are coal burning power plants, waste incineration, and metal production. Although environmental mercury (Hg) is naturally occurring, methylmercury (MeHg) is a biologically toxic form that accumulates throughout aquatic environments in the northeastern United States. Methylmercury, a neurotoxin , has been shown to have
12168-471: The toxic elements in organs such as the liver. Eggs shells may also contain metal contaminants, leading to low reproductive productivity. High levels of heavy metals are linked to loons being in poor condition, males being affected more because they eat larger fish. The common loon has also faced a decline in breeding range due to hunting, predation, and water-level fluctuations, or flooding. Some environmentalists attempt to increase nesting success by mitigating
12285-413: The tremolo to communicate its presence to other loons when they arrive at a lake, often when they are flying overhead. It is the only vocalization used in flight. The tremolo call has varying three levels of intensities that correlate with a loon's level of distress, and the types are differentiated by increasingly higher pitch frequencies added to the call. The yodel is a long and complex call made only by
12402-418: The two eggs are laid with an interval of one to three days between them, and hatch asynchronously . Newly hatched chicks are dark chocolate brown in color and have a white belly. Within hours of hatching, the young begin to leave the nest with the parents, swimming close by and sometimes riding on one parent's back. Parents and chicks initially stay in shallow, isolated bays where the parents are able to defend
12519-411: The undertail coverts and vent. It has a checkered black-and-white mantle and a blackish tail. The legs are pale grey on the inner half and blackish on the outer half, and the webs between the toes are flesh colored. Adult non-breeding plumage is brownish with a dark neck and head marked with dark grey-brown. The eyes are surrounded with white, and the eyelids are pale. The bill is mostly pale grey, with
12636-519: The valid genus name for the loons. The current genus name Gavia was the Latin term for an unidentified seabird and the specific immer is derived from a Norwegian name for the bird, similar to the modern Icelandic word "himbrimi". The word may be related to Swedish immer and emmer : the grey or blackened ashes of a fire (referring to the loon's dark plumage); or to Latin immergo , to immerse, and immersus , submerged. The European name "diver" comes from
12753-468: The voyage, and made extensive collections of both natural history specimens and artefacts. The first publication after the voyage was Characteres generum plantarum , a book on the botany of the South Pacific. Based on his father's journals, Georg published A Voyage Round the World in 1777. Reinhold Forster published Observations Made during a Voyage round the World (1778). However the income from
12870-487: The water surface to get in flight. During flight, its head is slightly lower than its body, with its feet trailing behind. It has a skeletal structure made up of a number of solid bones (this is usual for the Gaviiformes and penguins but unlike most flying birds which have bones with extensive pneumatization, hollow and filled with air to make the skeleton lighter), which adds weight but helps in diving. A juvenile often has
12987-703: The water's edge, common loon eggs are especially vulnerable if the adult is absent. Chicks may be killed by common snapping turtles , large gulls, bald eagles and large fish such as northern pike and largemouth bass . The eagle in particular is a significant predator of chicks. Internal parasites of the common loon include many species of worms , including flatworms , tapeworms , nematodes and spiny-headed worms . High levels of worms may result from feeding changes due to low availability of fish, and can lead to illness and death. Protozoal infections including one caused by Eimeria gaviae and avian malaria have been recorded in this loon. The black fly Simulium annulus
13104-489: The water's surface with wings flapping to generate sufficient lift to take flight. Only the red-throated loon ( G. stellata ) can take off from land. Once airborne, loons are capable of long flights during migration. Scientists from the U.S. Geological Survey, who have implanted satellite transmitters in some individuals, have recorded daily flights of up to 1078 km in a 24-hour period, which probably resulted from single movements. North European loons migrate primarily via
13221-419: The water. The loon uses its pointy bill to stab or grasp prey. They eat vertebrate prey headfirst to facilitate swallowing, and swallow all their prey whole. To help digestion, loons swallow small pebbles from the bottoms of lakes. Similar to grit eaten by chickens , these gastroliths may assist the loon's gizzard in crushing the hard parts of the loon's food such as the exoskeletons of crustaceans and
13338-583: The west, and very rarely in Scotland , to the east. Their summer habitat ranges from wooded lakes to tundra ponds. The lakes must be large enough for flight take-off, and provide a large population of small fish. Deep lakes with warm surface waters, relatively low biological productivity and low turbidity where their fish prey are easy to see are habitats where breeding loons are more successful in raising young. For protection from predators , common loons favour lakes with islands and coves . They are rare visitors to
13455-687: The western Mediterranean off Catalonia , and off Morocco in Africa , although only a few hundred travel as far south as Iberia . Although wintering site fidelity is not well known, annually, adults are observed to return to the same wintering locations in the Pacific Ocean ( Morro Bay ), the Gulf of Mexico ( Barataria Bay ), the Atlantic Ocean ( Maryland and Massachusetts ), and the reservoir Lake Pateros . They usually winter along coasts and on inland lakes, bays, inlets, and streams, with birds migrating to
13572-448: Was referred to G. concinna , and thus could conceivably have been of "G." portisi if that was indeed a loon. The holotype vertebra may now be lost, which would make "G." portisi a nomen dubium . Johann Reinhold Forster Johann Reinhold Forster (22 October 1729 – 9 December 1798) was a German Reformed (Calvinist) pastor and naturalist who made contributions to the early ornithology of Europe and North America. He
13689-471: Was transferred from the ducks to the loons only in the 18th century. Earlier naturalists referred to the loons as mergus (the Latin term for diving seabirds of all sorts) or colymbus , which became the genus name used in the first modern scientific description of a Gavia species (by Carl Linnaeus ) in 1758. Unfortunately, confusion about whether Linnaeus' " wastebin genus " Colymbus referred to loons or grebes abounded. North American ornithologists used
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