Animal Diversity Web

Ge­o­graphic Range

White-billed divers, also known as yel­low-billed loons, are found in north­west­ern North Amer­ica and in north­ern Eura­sia. Their breed­ing range in­cludes the north­ern parts of Rus­sia, Canada, and Alaska. White-billed divers are densely pop­u­lated in the Alaskan pe­tro­leum fac­tory re­gions ex­tend­ing from the Coleville River west to Wain­wright, AK. Their win­ter range in­cludes north­ern coastal re­gions of the Pa­cific Ocean. This in­cludes the west coast of the United States and Canada, the north­ern coast of Fin­land, and some­times coastal areas of Japan and China as well. How­ever, their sum­mer range has ex­panded and they are now also found in large lakes or reser­voirs in many US states in­clud­ing Nevada, Arkansas, Mon­tana, Ari­zona, New Mex­ico, Utah, Illi­nois, west Texas, Col­orado and Wash­ing­ton. They have been found as far south as cen­tral Mex­ico. (El­ph­ick, et al., 2001; North, 1994a; North, 1994b; Reed, 1965; Wells, 2007)

• Biogeographic Regions
• nearctic
  • native
• palearctic
  • native
• arctic ocean
  • native
• pacific ocean
  • introduced

• Other Geographic Terms
• holarctic

Habi­tat

White-billed divers live in low-ly­ing tun­dra re­gions along fresh­wa­ter and salt­wa­ter coast­lines. Their choice of habi­tat is highly de­pen­dent on their safety from preda­tors, pro­tec­tion from egg and nest dam­age caused by strong waves and food avail­abil­ity. They are most com­monly found on the shore­line be­cause they pre­fer to fish in shal­low water and nest along the shore­lines. (Bis­sonette, 1989; North, 1994a)

• Habitat Regions
• polar
• saltwater or marine
• freshwater

• Terrestrial Biomes
• tundra

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• coastal

• Wetlands
• marsh
• swamp

• Other Habitat Features
• riparian
• estuarine

• Average elevation

  580 m

  1902.89 ft

• Range depth

  61 (high) m

  200.13 (high) ft

Phys­i­cal De­scrip­tion

White-billed divers are dis­tin­guished by yel­low and white stripes along the chest and neck. Com­mon loons (Gavia immer), which they are often con­fused with, have fewer and thin­ner white stripes. White-billed divers are the largest of the loon species. Com­pared to other loons, they have much wider white spots on their back, sides and lower rear. They have smaller eyes as well. Their heads and bills re­main in a mostly tilted-up po­si­tion. Their necks are much thicker than other loons, and they have a vis­i­ble fore­head bump. In the non-breed­ing sea­son, the black part of their body changes to a lighter brown color. Their bod­ies are well-de­signed for their aquatic lifestyle. Their legs are found at the very rear part of their body and are de­signed to push water rather than for use in walk­ing. The po­si­tion of their legs ac­tu­ally makes it im­pos­si­ble for them to take flight from the land. Young white-billed divers are minia­tures of the adults, ex­cept that they are much paler in col­oration. Males typ­i­cally weigh 4 to 5.8 kg while fe­males are slightly larger and weigh 4.025 to 6.4 kg. Males are 838 to 920 mm long and fe­males are 774 to 831 mm long. (North, 1994b; Reed, 1965)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

• Range mass

  4 to 6.4 kg

  8.81 to 14.10 lb

• Range length

  838 to 920 mm

  32.99 to 36.22 in

• Range wingspan

  361 to 395 mm

  14.21 to 15.55 in

• Average basal metabolic rate

  unknown cm3.O2/g/hr

Re­pro­duc­tion

White-billed divers form a mat­ing pair when they ar­rive at their breed­ing ter­ri­tory, which is around late May or early June. They are sea­son­ally monog­a­mous but their sex ratio is un­known. The courtship dis­play is not well un­der­stood but jerk swim­ming has been doc­u­mented prior to cop­u­la­tion. The male fol­lows the fe­male ashore and cop­u­la­tion lasts 12 to 19 sec­onds. Then, the male re­turns to the water and the fe­male stays on shore. At a later date, the male re­turns and as­sists the fe­male with nest site se­lec­tion. (North, 1994b)

• Mating System
• monogamous

in mid-June, male and fe­male white-billed divers work to­gether to con­struct a nest made of ma­te­r­ial they find nearby. Fe­males usu­ally lay 2 eggs that are 89.40 mm long by 15.15 mm wide, on av­er­age. Eggs weigh 146 to 161 g and are mostly brown with dark brown spots. In­cu­ba­tion pe­ri­ods are 27 to 28 days long. The time in­ter­val be­tween the lay­ing of the first and sec­ond eggs is not known. About 1 day prior to hatch­ing, chicks begin peck­ing in­side the eggs. Pre­co­cial chicks weigh 146 to 151 g at birth, are fully feath­ered with down, and can swim al­most im­me­di­ately. White-billed diver chicks fledge in 30 to 55 days. They are in­de­pen­dent of their par­ents at around 5 weeks. Re­pro­duc­tive ma­tu­rity is ap­prox­i­mately 4 years. (North, 1994a; North, 1994b; Sjölan­der and Ågren, 1976)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

• Breeding interval

  White-billed divers breed once yearly.

• Breeding season

  White-billed divers breed between late May an early June.

• Range eggs per season

  1 to 2

• Range time to hatching

  27 to 28 days

• Range fledging age

  30 to 55 days

• Average time to independence

  5 weeks

• Average age at sexual or reproductive maturity (female)

  4 years

• Average age at sexual or reproductive maturity (male)

  4 years

Males and fe­males share re­spon­si­bil­i­ties for rais­ing young. Fe­males are pre­sent for 52.1% of the in­cu­ba­tion pe­riod, and males are pre­sent of 47.8% of the time. After hatch­ing, par­ents work to­gether to care for the young dur­ing the 3 days they spend in the nest. Par­ents care for the young full-time for the first 9 days after the young leave the nest, and then care slowly de­creases. Some chicks are found on their par­ents' back for up to a few weeks after hatch­ing, but is un­com­mon after a the first few days. Adults for­age deep in the water to feed the young for about 45 days. The pair bond­ing be­tween par­ents lasts up to the fall mi­gra­tion. (North, 1994b; Sjölan­der and Ågren, 1976)

• Parental Investment
• precocial
• pre-hatching/birth
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifes­pan/Longevity

The lifes­pan of white-billed divers is not well stud­ied. In the wild their lifes­pan is around 18 years, but they can live up to 25 or 30 years. There is no in­for­ma­tion on the lifes­pan of yel­low-billed loons in cap­tiv­ity. ("U.S. Fish & Wildlife Ser­vice an­nounces com­ment pe­riod on loon con­ser­va­tion agree­ment", 2006)

• Range lifespan
  Status: wild

  25 to 30 years

• Average lifespan
  Status: wild

  18 years

Be­hav­ior

White-billed divers are di­ur­nal birds that hunt fish, swim, dive, and fly. They spend time car­ing for them­selves, sleep­ing, roost­ing, and sun­bathing. They care for them­selves by pick­ing, bathing, head scratch­ing and stretch­ing. They mostly per­form pick­ing while swim­ming in a cir­cu­lar mo­tion. They pick on de­bris or arrange their feath­ers if they are out of place. They use head scratch­ing with their legs since they can’t reach the head area with their beak. White–billed divers splash the water re­peat­edly to bathe them­selves. While rest­ing, they oc­ca­sion­ally stretch their legs out of the water. How­ever, it is much eas­ier for them to es­cape dan­ger from the water than from the land be­cause their legs’ po­si­tion makes it dif­fi­cult for them to run. White-billed divers mi­grate sea­son­ally be­tween their win­ter and breed­ing range. They are thought to mi­grate along the coast, though over­land mi­gra­tion is also pos­si­ble. They are gen­er­ally soli­tary birds, though they form loose as­so­ci­a­tions with other in­di­vid­u­als dur­ing spring and fall mi­gra­tion. (North, 1994a; North, 1994b; Sjölan­der and Ågren, 1976; U.S. Fish and Wildlife Ser­vice, 2009)

White-billed divers mi­grate sea­son­ally be­tween their win­ter and breed­ing range. They are thought to mi­grate along the coast, though over­land mi­gra­tion is also pos­si­ble. They are gen­er­ally soli­tary birds, though they form loose as­so­ci­a­tions with other in­di­vid­u­als dur­ing spring and fall mi­gra­tion. (North, 1994a)

White-billed divers are very ter­ri­to­r­ial against birds of their own and other species. Com­pet­ing species in­clude Pa­cific loons (Gavia paci­fica) and red-throated loons (Gavia stel­late). They use dif­fer­ent ways of scar­ing in­trud­ers from their ter­ri­to­ries. For ex­am­ple, both sexes use bill dip­ping, in which they dip their bill and eyes quickly and re­peat­edly while ap­proach­ing in­trud­ers. Both sexes also use jerk swim­ming, which is slowly swim­ming to­wards their op­po­nent while mov­ing their head and neck up and down to scare them away. (North, 1994b; Sjölan­der and Ågren, 1976; U.S. Fish and Wildlife Ser­vice, 2009)

• Key Behaviors
• flies
• natatorial
• diurnal
• motile
• migratory
• solitary
• territorial

• Range territory size

  138000 to 1000000 m^2

• Average territory size

  380000 m^2

Home Range

White-billed divers some­times use rivers or other lakes out­side their breed­ing ter­ri­tory for feed­ing, loaf­ing, and rest­ing. Their small­est recorded ter­ri­tory is 138,000 square me­ters, their largest is over .1 square km. The me­dian ter­ri­tory size in the Colville River Delta in Alaska is ap­prox­i­mately 380,000 square me­ters. (North, 1994a)

Com­mu­ni­ca­tion and Per­cep­tion

White-billed divers com­mu­ni­cate with other mem­bers of their species using sev­eral unique calls. The choice of vo­cal­iza­tion is de­ter­mined by an in­di­vid­ual's stand­ing in a fam­ily group (e.g., a mother loon com­mu­ni­cat­ing with her young), by en­vi­ron­men­tal con­di­tions like weather, and other out­side forces, such as the pres­ence of ter­ri­to­r­ial in­trud­ers. A low call is a very low-pitched call per­formed in calm weather sit­u­a­tions. A slower call named tremolo is per­formed in times of dan­ger. Dif­fer­ent sexes and stages of life share dif­fer­ent vo­cal­iza­tions. Gen­er­ally vo­cal­iza­tions per­formed by males are slower and lower in pitch than those per­formed by fe­males. A pair of males, one of which is young and the other an adult, per­forms choked yo­del­ing but less is known about the pur­pose of this call. Young white-billed divers de­velop their vo­cal­iza­tion skills and sense of ter­ri­tory while spend­ing time with their par­ents. Chirp­ing, an­other form of vo­cal­iza­tion is only per­formed by young loons. Moan­ing is most often used be­tween a breed­ing pair to com­mu­ni­cate, or be­tween a par­ent and its young. Wail­ing which is like yo­del­ing but with a mo­not­one pitch, can be used by a loon de­fend­ing its ter­ri­tory. There are two types of yo­dels: long yo­dels, which are used mostly by males for long-dis­tance com­mu­ni­ca­tion (for ex­am­ple be­tween lakes), and short yo­dels which are trun­cated ver­sions of the long yo­dels, and less is known about their use. (Bark­low, 1979; Sjölan­der and Ågren, 1976)

When other white-billed divers in­vade their ter­ri­tory, they per­form a va­ri­ety of rit­u­al­ized be­hav­iors and pos­tures in­tended to fend off the in­truder. These in­clude rais­ing their neck and front, dip­ping their bill, swim­ming with a jerk­ing mo­tion, div­ing to make splashes, and run­ning along the water's sur­face while flap­ping wings. These dis­plays are used to com­mu­ni­cate ter­ri­to­r­ial bound­aries. (North, 1994a)

• Communication Channels
• visual
• acoustic

• Other Communication Modes
• duets
• choruses

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

White-billed divers are pri­mar­ily car­ni­vores that eat small to mid-size fish up to about 25 cm long. They rarely feed on in­ver­te­brates and veg­e­ta­tion. They pre­fer clear water lakes and rivers to catch their prey be­cause they are vi­sual and di­ur­nal preda­tors. Spe­cific in­for­ma­tion about their diet is clas­si­fied as lim­ited and anec­do­tal. In ma­rine wa­ters they eat Pa­cific staghorn sculpins (Lep­to­cot­tus ar­ma­tus), sculpins, Pa­cific tom­cods (Mi­cro­gadus prox­imus), isopods, and shrimp. In fresh water lakes along the Colville River Delta in Alaska, they eat nine­spine stick­le­backs (Pun­gi­tius pun­gi­tius) and Alaska black­fish (Dal­lia pec­toralis). In Rus­sia, they eat stick­le­backs and salmon. White-billed divers also some­times eat gas­tropods and spi­ders. Loons have a much smaller feed­ing ter­ri­tory dur­ing the sum­mer than they do in win­ter. They also have to dive deeper in the sum­mer. The larger feed­ing ter­ri­tory and a shorter dive in depth com­pared to the sum­mer dive in­di­cate that there is more food abun­dance in the coastal areas dur­ing the win­ter. (El­ph­ick, et al., 2001; McIn­tyre, 1978; North, 1994b)

Be­cause they are highly de­pen­dent on their sight for catch­ing prey, for­ag­ing only takes place be­fore sun­set. Even though most prey is caught near the sur­face, larger white-billed divers can dive as deep as 250 feet tak­ing an av­er­age of 40 sec­onds. A pair of the white-billed divers and their young may con­sume up to 908 kg of fish dur­ing the breed­ing sea­son. They also reg­u­larly swal­low peb­bles to aid their di­ges­tive sys­tem. (El­ph­ick, et al., 2001; McIn­tyre, 1978; North, 1994b)

• Primary Diet
• carnivore
  • piscivore

• Animal Foods
• fish
• insects
• terrestrial non-insect arthropods
• mollusks
• aquatic crustaceans

Pre­da­tion

There are no re­ported preda­tors of adult white-billed divers. How­ever, their eggs and chicks are vul­ner­a­ble to pre­da­tion. Com­mon preda­tors are glau­cous gulls (Larus hy­per­boreus), jaegers (Ster­co­rar­ius par­a­siti­cus), com­mon ravens (Corvus corax), arc­tic foxes (Vulpes lago­pus), snowy owls (Nyctea scan­di­aca), er­mine (Mustela er­minea), mink (Neo­vi­son vison), red foxes (Vulpes vulpes), griz­zly bears (Ursus hor­ri­bilis), north­ern pike (Esox lu­cius), and hu­mans (Homo sapi­ens). Some of their adap­ta­tions to avoid pre­da­tion are by lying low if preda­tors like arc­tic foxes or hu­mans ap­proach the nest. If the preda­tor keeps ap­proach­ing or stays near the nest, they start yodel or make tremolo calls which are calls in times of dan­ger. Some­times they rush after in­trud­ers and try to chase them away. (Loftin, et al., 2010; U.S. Fish and Wildlife Ser­vice, 2009)

• Known Predators

  • glaucous gulls (Larus hyperboreus)
  • jaegers (Stercorarius parasiticus)
  • common ravens (Corvus corax)
  • arctic foxes (Vulpes lagopus)
  • snowy owls (Nyctea scandiaca)
  • ermine (Mustela erminea)
  • mink (Neovison vison)
  • red foxes (Vulpes vulpes)
  • grizzly bears (Ursus horribilis)
  • northern pike (Esox lucius)

Ecosys­tem Roles

White-billed divers loons host many in­ter­nal and ex­ter­nal par­a­sites. Flukes (Pseudop­silostoma var­ium, Diplostro­mum colymbi), tape­worms (Di­gramma in­ter­rupta, Polypoceo­halus, Di­phyl­loboth­rium ditremum, Ligula colymbi, Ligula in­st­ti­nalis) spiny headed worms (An­dra­can­tha gravida, An­dra­can­tha mergi, An­dra­can­tha pha­lacro­co­racis, Coryno­soma stru­mo­sum), round­worms (Eu­strongylides tubifex, Bar­us­cap­il­laria car­bo­nis, Bar­us­cap­il­laria mer­gic, Cy­athosta phenisci) and tongue worms (Reighardia lomviae, Reighardia ster­nae) are thier in­ter­nal par­a­sites. Ex­ter­nal par­a­sites in­clude leeches (Pla­cob­della or­nata), mites (Brephosce­les for­fi­ciger), lice (Craspe­donir­mus colym­bi­nus) and flies (Simulium eu­ryad­minicu­lum, Pseudolfesin fu­mipen­nis). They are also prone to in­fec­tion by avian cholera, as­pergillo­sis, avian bot­u­lism, and avian in­fluenza. (Storer, 2002; U.S. Fish and Wildlife Ser­vice, 2009)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

White-billed divers are il­le­gally hunted pri­mar­ily for taxi­dermy, even though it is pro­hib­ited to hunt loons. In some arc­tic areas, loons are hunted as a food source. Their skin and feath­ers are used in dec­o­ra­tions, arts and crafts, and for cer­e­mo­nial pur­pose like re­li­gious rit­u­als. Be­cause they are con­sid­ered rare by bird­watch­ers, white-billed divers also gen­er­ate eco­nomic value through eco­tourism. (Ehrlich, et al., 1988; North, 1994b; Reed, 1965; U.S. Fish and Wildlife Ser­vice, 2009)

• Positive Impacts
• food
• body parts are source of valuable material
• ecotourism

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known neg­a­tive ef­fects of white-billed divers on hu­mans. (U.S. Fish and Wildlife Ser­vice, 2009)

Con­ser­va­tion Sta­tus

In some parts of their range, pop­u­la­tions are dras­ti­cally de­clin­ing. The IUCN Red List states that they are “near threat­ened." Rus­sia is the only coun­try which con­sid­ers them en­dan­gered. The United States con­sid­ered them “not at risk" in 2009, though they are pro­tected under the Mi­gra­tory Bird Act. White-billed divers are at risk partly be­cause they have a very low an­nual re­pro­duc­tive rate and are highly sus­cep­ti­ble to dis­tur­bance. Most of their breed­ing and win­ter­ing habi­tats are within the areas of Alaskan and Russ­ian oil com­pa­nies. Dis­tur­bances from oil com­pa­nies such as pedes­trian and ve­hi­cle traf­fic cause them to flee from their nests. Lake draw­downs by oil com­pa­nies for drilling, the use of pes­ti­cides, and over­fish­ing are con­tin­u­ously af­fect­ing the fish pop­u­la­tions that loon con­sume. Oil spills af­fect their lives in every way. In Alaska alone, there were 3,696 oil spills from July 1995 to June 2005 that leaked 6.8 mil­lion liters of oil into the en­vi­ron­ment. If the oil reaches and coats the eggs at the shore it suf­fo­cates un­hatched chicks and kills them. Many loons drown be­cause of ex­haus­tion and de­hy­dra­tion try­ing to clean the oil off their body by over-preen­ing. Oil also kills their prey and the shore veg­e­ta­tion and shrubs where they nest. Al­though white-billed divers are af­fected by dis­eases such as avian cholera, as­pergillo­sis, avian bot­u­lism, and avian in­fluenza, it isn’t a major cause of death. Hunt­ing of mul­ti­ple loon species is still going on, even though it is pro­hib­ited by United States law and those of other coun­tries. (Bis­sonette, 1989; Ehrlich, et al., 1988; North, 1994a; North, 1994b; U.S. Fish and Wildlife Ser­vice, 2009)

• IUCN Red List

  Near Threatened

• US Migratory Bird Act

  No special status

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

alazar fedlu (au­thor), Rad­ford Uni­ver­sity, Karen Pow­ers (ed­i­tor), Rad­ford Uni­ver­sity, Kier­sten Newtoff (ed­i­tor), Rad­ford Uni­ver­sity, Melissa Whistle­man (ed­i­tor), Rad­ford Uni­ver­sity, Cather­ine Kent (ed­i­tor), Spe­cial Pro­jects.

Ref­er­ences

U.S. Fish and Wildlife Ser­vice. U.S. Fish & Wildlife Ser­vice an­nounces com­ment pe­riod on loon con­ser­va­tion agree­ment. INDFED0020060316e23e001a3. Wash­ing­ton, D.C.: Fed­eral Reg­is­ter. 2006.

Alvo, R., M. Berrill. 1992. Adult com­mon loon feed­ing be­hav­ior is re­lated to food fed to chicks. The Wil­son Bul­letin, 104/1: 184-185.

Bark­low, W. 1979. Graded fre­quency vari­a­tions of the tremolo call of the com­mon loon (Gavia immer). The Con­dor, 81/1: 53-64.

Bis­sonette, J. 1989. Feed­ing and chick-rear­ing areas of com­mon loons. Jour­nal of Wildlife Man­age­ment, 53/1: 72-76.

Earnst, S., R. Platte, L. Bond. 2006. A land­scape-scale model of yel­low-billed loon (Gavia adam­sii) habi­tat pref­er­ences in north­ern Alaska. Hy­dro­bi­olo­gia, 567/1: 227-236.

Earnst, S., R. Stehn. 2005. Pop­u­la­tion size and trend of yel­low-billed noons in north­ern Alaska. Con­dor, 107/2: 289-304.

Ehrlich, P., D. Dobkin, D. Wheye. 1988. The Birder's Hand­book. New York: Simon And Schus­ter Inc.

El­ph­ick, C., J. Dun­ning, JR, . Sib­ley. 2001. The Sib­ley Guide To Bird Life And Be­hav­ior. New York: Al­fred A. Knopf.

Loftin, H., S. Loftin, S. Olson. 2010. Bi­o­log­i­cal, ge­o­graph­i­cal, and cul­tural ori­gins of the loon hunt­ing tra­di­tion in Carteret County, North Car­olina. Wil­son Jour­nal of Or­nithol­ogy, 122/4: 716-724.

McIn­tyre, J. 1978. Win­ter­ing be­hav­ior of com­mon loons. The Auk, 95/2: 396-403.

North, M. 1994. "Yel­low-billed Loon (Gavia adam­sii)" (On-line). Birds of North Amer­ica On­line. Ac­cessed Sep­tem­ber 26, 2012 at http://​bna.​birds.​cornell.​edu.​proxy.​lib.​umich.​edu/​bna/​species/​121.

North, M. 1994. Yel­low-billed loon. Birds of North Amer­ica, 121: 1-24.

Reed, C. 1965. North Amer­i­can Birds Eggs. New York: Dover Pub­li­ca­tions, Inc..

Sjölan­der, S., G. Ågren. 1976. Re­pro­duc­tive be­hav­ior of the yel­low-billed loon, Gavia adam­sii. The Con­dor, 78/4: 454-463.

Storer, R. 2002. THE META­ZOAN PAR­A­SITE FAUNA OF LOONS (AVES: GAVI­IFORMES), ITS RE­LA­TION­SHIP TO THE BIRDS' EVO­LU­TION­ARY HIS­TORY AND BI­OL­OGY, AND A COM­PAR­I­SON WITH THE PAR­A­SITE FAUNA OF GREBES. Mis­cel­la­neous Pub­li­ca­tions of the Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan, 191: 1-44.

U.S. Fish and Wildlife Ser­vice, 2009. En­dan­gered and threat­ened wildlife and plants; 12 month find­ing on a pe­ti­tion to list the yel­low-billed loon as threat­ened or en­dan­gered - Part 1 of 2. Fed­eral Reg­is­ter, 74/056: 1-38.

Wells, J. 2007. Birder's Con­ser­va­tion Hand­book. New Jer­sey: Prince­ton Uni­ver­sity Press.