Editing Red-throated loon (section)

==Behaviour==
[[File:Red-Throated Loon Iceland.jpg|thumb|Among the loons, the red-throated loon is exceptional in its ability to take off from very small bodies of water.|alt=Adult loon in breeding plumage, reared up on the water with its wings spread.]]
Because its feet are located so far back on its body, the red-throated loon is quite clumsy walking on land, but it can use its feet to shove itself forward on its breast.{{sfn|Sibley|2000|p=23}} Young use this method of covering ground when moving from their breeding pools to larger bodies of water, including rivers and the sea.{{sfn|Haviland|1915}} It is the only species of loon able to take off directly from land.{{sfn|Mead-Waldo|1922}} If frightened, it may submerge until only its head or bill shows above the surface of the water.{{sfn|Cramp|1977|p=44}} It differs from other loons by nesting in small lakes but feeding in larger lakes or the sea. The nesting lake may host several nests, close to another, with much agonistic behavior among pairs. This territorial behavior is performed pairwise, with vocalisation (long call, plesiosur race).

The red-throated loon is a [[diurnality|diurnal]] [[bird migration|migrant]], which travels singly or in loose groups, often high above the water.{{sfn|Sibley|2000|p=23}} In eastern North America (and possibly elsewhere), it tends to migrate near the coast rather than farther offshore;{{sfn|Powers|Cherry|1983}} Siberian populations travel for hundreds of miles over land en route to their southern European wintering grounds.{{sfn|Carboneras|1992|p=168}} It is a strong flier, and has been clocked at speeds between {{convert|75|and|78|km/h|mph}}.{{sfn|Davis|1971}} Like all members of its family, the red-throated loon goes through a simultaneous wing [[moult]], losing all its [[flight feather]]s at once and becoming flightless for a period of three to four weeks. Unlike other loons—which undergo this moult in late winter—the red-throated loon loses its ability to fly sometime between late summer and late autumn.{{sfn|Wolfenden|1967}}

===Food and feeding===
[[File:Red-Throated Loon juvenile eating fish.jpg|thumb|right|Once they are 3–4&nbsp;days old, the young are fed fish—which can be quite large compared to the size of the chick.|alt=Two small fuzzy blackish chicks—one swallowing a silver fish—float on water beside a larger bird with a black back and grey neck.]]
Like all members of its family, the red-throated loon is primarily a [[Piscivore|fish-eater]], though it sometimes feeds on [[mollusc]]s, [[crustacean]]s, [[frog]]s, aquatic [[invertebrate]]s, [[insect]]s, fish [[spawn (biology)|spawn]] or even plant material.{{sfn|Carboneras|1992|p=171}} It seizes rather than spears its prey, which is generally captured underwater.{{sfn|Ehrlich|Dobkin|Wheye|Pimm|1994|p=2}} Though it normally dives and swims using only its feet for propulsion, it may use its wings as well if it needs to turn or accelerate quickly.{{sfn|Townsend|1909}} Pursuit dives range from {{convert|2|-|9|m|ft|abbr=on}} in depth, with an average underwater time of about a minute.{{sfn|Carboneras|1992|p=171}} Its fish diet increases the red-throated loon's vulnerability to [[persistent organic pollutant]]s and [[heavy metal (chemistry)|heavy metals]], both of which [[bioaccumulation|bioaccumulate]], thus potentially causing greater problems for long-lived species (such as the loon) at or near the top of the [[food chain]].{{sfn|Dickson|Gilchrist|2002}} Its main diet has also led to several of the loon's British folk names, including "[[sprat]] borer" and "spratoon".{{sfn|Cocker|Mabey|2005|p=3}}

For the first few days after hatching, young red-throated loons are fed aquatic insects and small crustaceans by both parents. After 3–4&nbsp;days, the parents switch to fish small enough for the young birds to swallow whole. By four weeks of age, the young can eat the same food—of the same size—as their parents do.{{sfn|Cramp|1977|p=46}} Young birds may be fed for some time after [[fledging]]; adults have been seen feeding fish to juveniles at sea and on inland lakes in the United Kingdom, hundreds of kilometres from any breeding areas.{{sfn|Hart|Jardine|Colin|1998}}{{sfn|Barber|2002}}

===Breeding and survival===
[[File:Gavia stellata MWNH 0489.JPG|left|thumb|Eggs, Collection [[Museum Wiesbaden]]]]
[[File:Plongeon catmarin oisillon.jpg|thumb|right|Chicks are competent swimmers, able to accompany their parents soon after hatching.|alt=Small fuzzy black chick floats beside a larger bird on calm water with a muddy bank and tall grass in the background]]
The red-throated loon is a [[Animal sexual behavior#Mating systems|monogamous]] species which forms long-term pair bonds. Both sexes build the [[bird nest|nest]], which is a shallow [[bird nest#Scrape|scrape]] (or occasionally a [[bird nest#Platform|platform]] of mud and vegetation) lined with vegetation and sometimes a few feathers, and placed within a {{convert|0.5|m|in}} of the edge of a small pond. The female lays two [[bird egg|eggs]] (though [[clutch (eggs)|clutches]] of one and three have also been recorded); they are [[avian incubation|incubated]] for 24–29&nbsp;days, primarily by the female. The eggs, which are greenish or olive-brownish spotted with black, measure {{convert|75|x|46|mm|in|abbr=on}} and have a mass of {{convert|83|g|oz|abbr=on}}, of which 8% is shell.{{sfn|Ehrlich|Dobkin|Wheye|Pimm|1994|p=2}}<ref name=BTO/> Incubation is begun as soon as the first egg is laid, so they hatch asynchronously. If a clutch is lost (to predation or flooding, for example) before the young hatch, the red-throated loon usually lays a second clutch, generally in a new nest.{{sfn|Schamel|Tracy|1985}} The young birds are [[precocial]]: upon hatching, they are downy and mobile, with open eyes. Both parents feed them small aquatic invertebrates initially, then small fish for 38–48&nbsp;days. Parents will perform [[distraction display]]s to lure predators away from the nest and young.{{sfn|Ehrlich|Dobkin|Wheye|Pimm|1994|p=2}} [[Ornithology|Ornithologists]] disagree as to whether adults carry young on their backs while swimming with some maintaining that they do{{sfn|Ehrlich|Dobkin|Wheye|Pimm|1994|p=2}} and others the opposite.<ref name="Cornell"/>

In the wild, the oldest known red-throated loon lived for more than two decades.{{sfn|Carboneras|1992|p=171}} It was found, oiled and dead, on a beach in Sweden 23&nbsp;years and 7&nbsp;months after it had been [[bird ringing|ringed]] (banded).<ref>{{cite web |author1=Staav, Roland |author2=Fransson, Thor |year=2008 |publisher=EURING: The European Union for Bird Ringing |url=http://www.euring.org/data_and_codes/longevity-voous.htm |title=European longevity records |access-date=14 July 2009}}</ref>