Podiceps grisegena

Geographic Range

Red-necked grebes ( Podiceps grisegena ) are native to portions of North America, Asia, and Europe. Their precise location within these biogeographic regions depends upon the time of year because they are migratory birds that move between breeding and wintering locations. In North America, during the breeding season, they are found in a region reaching from Alaska in the north, down through western Canada, across central Canada and the northern portion of the mid United States. For the winter season, North American populations of red-necked grebes migrate to the marine waters of the Pacific coast and the Atlantic coast, reaching as far south as California and North Carolina, but the majority of birds remain in the northern portion of the continent for wintering. A fraction of North American birds spend the winter in the Great Lakes region.

In eastern Asia, red-necked grebes breed in a large region that covers most of eastern Siberia and surrounding area. Eastern Asian populations winter along the Pacific coast of Asia and in some large inland lakes in the region.

In Europe and western Asia, red-necked grebes breed in a large portion of northern Europe that stretches from the Netherlands to western Siberia to southern Russia, eastern Kazakhstan, Turkey, and Bulgaria. This population winters off the coasts of the North, Baltic, Caspian, Black, Adriatic, and Aegean Seas. Although rare, some birds winter in the Mediterranean region and northern Iran.

• Biogeographic Regions
• nearctic nearctic
  • native native
• palearctic palearctic
  • native native

• Other Geographic Terms
• holarctic holarctic

Habitat

Red-necked grebes are predominantly water birds, that is, with the exception of the time spent in migration, they spend nearly all of their time on the water. During the summer breeding season, red-necked grebes typically live and nest on small inland freshwater lakes, shallow marsh areas, and bays of larger lakes. They are also found in more obscure locations, such as irrigation ditches and bogs. The subspecies Podiceps grisegena grisegena tends to make use of smaller and shallower waterbodies that have more surrounding vegetation than those used by P. g. holboellii . During the spring and fall migrations red-necked grebes make pit stops on rivers, large lakes and ocean coastlines that are along the way to their destined range. In winter all populations of both subspecies make use of the various topography of coastal waters or large inland seas and lakes. They typically winter in inlets, bays, or river estuaries and also venture miles away from land on the open ocean.

• Habitat Regions
• temperate temperate
• polar polar
• terrestrial terrestrial
• saltwater or marine saltwater or marine
• freshwater freshwater

• Aquatic Biomes
• lakes and ponds
• temporary pools
• coastal coastal

• Wetlands
• marsh marsh
• swamp swamp

• Other Habitat Features
• riparian riparian

Physical Description

Red-necked grebes are relatively large in comparison to other species of grebes. They are 43 to 56 cm long and weigh 800 to 1600 g. Their bills are mostly black, with the exception of the base of the upper mandible and most of the lower mandible, which are orange-yellow or chrome-yellow. Their eyes contain a dark brown iris that is surrounded by a ring of yellow. Like all grebes, this species has lobed feet that they utilize as effective paddles for swimming and rudders for flying. Also, their legs are laterally compressed, which makes them more streamlined when passing through water.

This species has two different plumages depending on whether they are breeding or wintering. Their non-breeding winter plumage is marked by heads topped with black, followed by grey on the sides of the head and a white crescent reaching from the throat upwards to the lower lateral sides of the head. They have white or light gray on the anterior portion of their neck. Observing from anterior to posterior on the body of the bird, the light colors quickly darken to a gray-black; therefore the majority of the bird is dark, with exception of the sides of the head, throat, and anterior portion of the neck. The sides of the head become even lighter as a distinctive pale-gray patch develops in their breeding summer plumage. During this time, as their name suggests, the lateral portions of their neck and breast become a reddish-brown color. The rest of the bird remains relatively similar in color to its non-breeding plumage.

Male and female Red-necked grebes are alike in appearance, but on average males are larger. Juveniles resemble adults in breeding season plumage, with the addition of dark stripes on the cheeks.

On various continents, slight physical variations between populations are observed; therefore two subspecies of red-necked grebes have been identified. The populations that are native to Europe and western Asia are of the subspecies Podiceps grisenega grisegena and the populations of North America and eastern Asia are of the subspecies Podiceps grisenega holboellii . The P. g. grisegena subspecies is smaller and has relatively darker plumage on its back, cheeks, and neck than P. g. holboellii . The bill of P. g. grisegena is longer, slimmer, and not as yellow as the bill of P. g. holboellii .

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike
• male larger

Reproduction

Red-necked grebes breed every year and are seasonally monogamous. They are able to breed in their first year of life, yet they usually begin when they are two or more years of age. During mate selection, this species exhibit complex courtship rituals that include a large variety of displays. These rituals are similar to other species of grebes except they tend to be more vocal and contain extensive whinny-braying, which has been described as an eerie sound that resembles a screaming squeal of a scared young pig. One of these rituals involves the mates swimming around each other, then facing each other to make contact with their breasts while rising upright and making loud ticking sounds. Mating pairs have been observed diving to the bottom of the lake and pulling out vegetation with their bills and presenting it to each other.

The breeding patterns of red-necked grebes have some variation. In some areas it has been observed that a single breeding pair will isolate themselves from other birds and act aggressively to protect their claimed territory for breeding and feeding. In contrast, in other areas it has been observed that red-necked grebes breed in colonial groups. These birds engage in open interaction with other birds. Red-necked grebes nesting in a dispersed fashion is more common than in colonies.

Red-necked grebes also have a copulation ritual that includes a variety of actions that are accompanied by the whinny-braying call that is specific to this species. During copulation the female is present on the nest with her head low and the feathers on the back of her neck are erect. The male swims around behind the female and then hops up with his wings closed and his crest up and proceeds to make a number of steps on the female’s backside before making cloacal contact. After copulation has occurred the male then slides off the side of her and reenters the water. A common postcopulatory display involves the male diving down to the bottom of the lake, pulling out some vegetation, and presenting it to his mate.

• Mating System
• monogamous monogamous

Most breeding pairs form on wintering grounds prior to the spring migration. Because of this, most of the birds arrive at the nesting sites for breeding season already paired. If this is not the case, the birds are paired soon after.

Red-necked grebes have a breeding season that spans from May to September. Nest building typically occurs in May and most pairs lay their first clutch within the first two weeks. They often build their nests on vegetation that is floating on or anchored near the edge of bodies of water. Vegetation that forms thick mats or provides substantial cover and anchorage is preferred. Males initiate the nest-site selection process, but both sexes participate in nest building. The nest base is built out of partially decayed vegetation that is gathered from above and below the surface of the water. The rim of the nest is built out of primarily sticks and bulrushes.

Generally, a breeding pair of red-necked grebes only produces one brood per season. If the first clutch of eggs and or the nest becomes destroyed, the pair will often attempt a subsequent set. This may occur up to 5 times in one breeding season. Although rare, a pair may lay a second set even when the first set was a success. Each clutch usually consists of 4 to 5 eggs, but anywhere from 1 to 9 has been observed. The eggs are usually laid at 1 to 2 day intervals. Eggs are light blue when they are laid, but they often fade to white within one day of being laid. Over time, the wet nest material may stain them to a dark tan color. Hatching occurs 22 to 35 days after the eggs are laid. Chicks will fledge and reach independence between 9 and 10 weeks after hatching.

The behavior of red-necked grebe mating pairs differs depending on whether or not they are a part of a solitary pair or a colonial pair during the nesting season. Solitary pairs tend to leave their nest vacant and unguarded more often then colonial pairs. In the period prior to nesting, both female and male colonial birds are more aggressive towards other birds than are solitary birds. However, after the eggs have been laid and the nest has been fully established, the females of both colonial and solitary pairs lose much of their aggressive behavior. In both groups, the females spend more time near the nest during the egg-laying period than males. However, throughout the duration of the incubation period the colonial males spend much more time near the nest and their female than the solitary males do. It is believed that colonial nests are more likely to be exposed to predators because they stand out. Therefore, the nesting behavior of red-necked grebes depends on their social situation considerably. Regardless of this, they have been observed to successfully breed in both solitary and colonial aggregations.

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

Both parents participate in incubating the eggs. The young red-necked grebes leave the nest via the parents' backs soon after the last egg hatches, although in some cases the parents will leave the nest before every egg has hatched. The chicks continue to ride on the parents back until they are ten to seventeen days old, the age at which they begin swimming themselves.

The parents feed the young for six to seven weeks. The primary food source of the hatchlings is insect larvae and other small prey items. The parents also feed feathers to the young birds. The young eat directly from the parents' bill. The young are typically completely independent from their parents at the age of nine to ten weeks and usually begin flying at about this time.

• Parental Investment
• precocial precocial
• male parental care male parental care
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• 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

Over the years, populations of red-necked grebes have been banded in an effort to determine aspects of their lives including population locations, migratory routes and lifespan. However, recoveries from these studies have been insufficient to determine an estimated lifespan of this species. The little evidence that has been collected has shown that certain birds in Minnesota were still alive five years after being banded.

Behavior

Red-necked grebes are an aggressive species in which pairs typically defend large territories for feeding and breeding.

Red-necked grebes are strong swimmers and divers. On average they remain underwater for about thirty seconds, although they are capable of diving for much longer when they are searching for food. They perform underwater attack dives in an effort to oust intruders. They are awkward on land, as their mode of locomotion involves shuffling forward on their breast while kicking their feet. Red-necked grebes rarely fly when not migrating. When migrating over land they primarily fly at night and either alone or with a small loosely associated group. Some degree of coastal migratory flying occurs during the day.

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

Home Range

Territory size for red-necked grebes is unknown.

Communication and Perception

During breeding season, red-necked grebes are a very vocal species. The most common call is the drawn out "whinny-braying" call, which is used by the grebes to declare territories and in the mating rituals. During these rituals they also perform a variety of physical displays and “crick crick”, and “teck teck” sounding vocalizations. Red-necked grebes are often silent in the fall and winter, although the generic “crick crick” and “teck teck” sounds are sometimes produced.

Dancing duets between potential mates are a critical part of courtship behavior.

Like all birds, red-necked grebes use visual, auditory, tactile, and chemical stimuli to perceive their environment.

• Communication Channels
• visual visual
• acoustic acoustic

• Other Communication Modes
• duets duets

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Red-necked grebes primarily eat small fish, crustaceans, land and aquatic insects, and occasionally amphibians. In smaller lakes that do not contain an abundance of fish, fish only make a minor contribution to the overall diet. Some specific fish species that red-necked grebes eat are: sticklebacks, Pacific herrings ( Clupea pallasii ), pilchards ( Sardina pilchardus ), sculpins, topminnows, lake shiners, perch ( Perca ), and eels. Some specific crustacean species they eat are: mud lobsters, shrimp, prawn, crayfish, and various other amphipods. Some insect species they eat are: damselflies, dragonflies, water boatmen, whirligig beetles, water scavenger beetles, black swimmers, water striders, crawling water beetles, flies, wasps, ants, bees, stink bugs, lamellicorn beetles, ground beetles, and billbugs.

When eating aquatic prey, red-necked grebes typically forage underwater, picking up their prey off the lake bed or off of vegetation and consuming them while remaining underwater. However, if the prey is too large or difficult to handle they may bring it to the surface before consuming it. They are also known to capture low flying insects out of the air.

• Primary Diet
• carnivore carnivore
  • piscivore piscivore

• Animal Foods
• amphibians
• fish
• insects
• terrestrial worms
• aquatic crustaceans
• other marine invertebrates

Predation

Predators such as American crows ( Corvus brachyrhynchos ), common ravens ( Corvus corax ), gulls, bald eagles ( Haliaeetus leucocephalus ), American coots ( Fulica americana ), raccoons ( Procyon lotor ), minks ( Neovison and Mustela ), and muskrats ( Ondatra zibethicus ) are known to feed on red-necked grebes eggs and chicks. When small and young are not upon their parent’s back, they may be in danger of being eaten by large fish such as northern pikes (Esox lucius) and largemouth bass ( Micropterus salmoides ).

Great horned owls ( Bubo virginianus ) and mink often attack adult birds while they are incubating their eggs. Parasites and roundworms can also infect this species. Some breeding pairs may also display aggressive behavior towards the young of other birds, occasionally killing another pair's chicks.

In response to predators, red-necked grebes are known to jab towards them with their bills or give a hissing call. They may also cover their eggs with nesting material before leaving their nests.

Ecosystem Roles

Red-necked grebes compete with other bird species for breeding territory and with fish for food sources. They also provide a food source to their previously mentioned predators. As their primary food source, fish populations are likely kept in check by red-necked grebes.

Economic Importance for Humans: Positive

Red-necked grebes have no significant economic importance for humans.

Economic Importance for Humans: Negative

Red-necked grebes have no known negative impacts on humans.

Conservation Status

Red-necked grebes are in the category of “least concern” on the ICUN Red List. Even though the population tends appear to be slightly decreasing, there has not been a significant amount of change to consider it a vulnerable species. An increase in unnatural predators and human recreational activities are hypothesized to be causing a decline among red-necked grebe populations throughout North America although no obvious trends have been observed that indicate a major declination of this species.

Human pollution is also having an effect on red-necked grebe populations. In a study done in Turtle Mountain Provincial Park in Manitoba it was found that organochlorides, the remains of certain pesticides, are affecting the reproductive success of red-necked grebes. These chemicals primarily affect the integrity of the eggs.

Additional Links

Encyclopedia of Life

Contributors

Ryan Schmidt (author), University of Alberta, Augustana Campus, Doris Audet (editor), University of Alberta, Augustana Campus, Rachelle Sterling (editor), Special Projects.

References

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De Smet, K. 1987. Organochlorides Predators And Reproductive Success Of The Red-necked Grebe In Southern Manitoba Canada. The Condor - Journal of The Cooper Ornithological Society , Vol: 89 Issue: 3: 460 - 467.

Des Vos, A., A. Allin. 1964. Winter mortality among red-necked Grebes (Colymbus grisegena). Canadian Field-Naturalist , Vol: 78 Issue: (2): 67–69.

Dziuba, C. 2007. Adult Red-necked Grebes Podiceps grisegena feeding nestlings of the Great Crested Grebe P. cristatus - brood parasitism or adoption?. Notatki Ornitolgiczne , Vol: 48 Issue: 3: 207-209.

Fjeldsa, J. 1982. The adaptive significance of local variations in the bill and jaw anatomy of north European red-necked grebes podiceps-grisegena. Ornis Fennica , Vol: 59 Issue: 2-3: 84 - 98.

Forsyth, D., P. Martin, K. De Smet, M. Riske. 1994. Organochlorine contaminants and eggshell thinning in grebes from prairie Canada. Environmental Pollution , Vol: 85 Issue: 1: 51–58.

Gooders, J. 1975. The Great Book of Birds . New York (NY): The Dial Press.

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Klatt, P., G. Nuechterlein, D. Buitron. 2004. Frequency and distribution of behaviour of red-necked grebes breeding colonially and in classic territories. Behaviour , Mar 2004, Vol. 141 Issue 3: 263–277.

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Sachs, J., C. Hughes, G. Nuechterlein, D. Buitron. 2007. Evolution of coloniality in birds: a test of hypotheses with the red-necked grebe (Podiceps grisegena). American Ornithologists Union , Apr 2007, Vol. 124 Issue 2: 628 – 642.

Stout, B., G. Nuechterlein. 1999. "Birds of North America Online" (On-line). Accessed September 15, 2009 at http://bna.birds.cornell.edu/bna/species/465 .

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2009. "BirdLife International 2009" (On-line). IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2.. Accessed November 07, 2009 at http://redlist.org/apps/redlist/details/144597/0 .