The gray partridge,, has a vast Palearctic range that starts in northern Spain, and stretches eastward across Europe through central Russia. The southernmost tips of its range include central Turkey, extending eastward through Armenia, Georgia, and Azerbaijan, with the southernmost tips of its range stretching into northern Iran. The northernmost portions of the gray partridge’s range include the southern tip of the United Kingdom, stretching eastward into Denmark, southern Sweden, and along the southern coast of Finland. The gray partridge is native to its Palearctic range.
The gray partridge has a comparatively smaller Nearctic range, in which it was introduced. This range includes all of the southernmost providences of Canada that border the United States, with its largest Canadian range stretching through southern Alberta, Saskatchewan, and Manitoba.
In the United States, the gray partridge has a range that extends from the eastern half of Washington and north Oregon, eastward through all the northernmost midwestern states—Idaho, Montana, Wyoming, the Dakotas, Minnesota, northern Iowa, and Wisconsin. The gray partridge can be found as far south as the northeastern tip of Nevada, and eastward into northern Utah. (Alderfer, 2006; Mullarney and Zetterstrom, 2009)
The gray partridge inhabits natural open meadows, grazing land, and agriculture land used to produce grain and row crops. During daylight hours, these areas are used for foraging. When threatened by predators, the gray partridge often makes use of the dense vegetation and shrubbery surrounding open grassy areas.
At night, the gray partridge foregoes the seclusion of dense undergrowth surrounding fields and cropland to roost in more loosely packed vegetation in fields where predators can be seen as they are approaching. (Carroll, 1993; "Habitat suitability index models: Gray partridge", 1984; Mullarney and Zetterstrom, 2009; Tillmann, 2009)
The adult gray partridge stands between 30.5 and 33 cm tall and weighs between 345 and 500 grams. Finely barred gray feathers cover much of the body, while distinct dark brown and gray barring runs longitudinally down the sides of folded wings.
The beak of the gray partridge is gray and curves moderately to a pointed tip that is used to crack grains and pick tender leaves and shoots. Adult gray partridges have gray-brown legs that are darker than the body feathers. They are anisodactyl—each foot has four digits, three of which face forward and with a single backwards-facing toe. The positioning of the legs and feet make the gray partridge more adept at running instead of perching. Males are larger than females and can be identified by a u-shaped chestnut patch on their lower abdomen and orange head and throat. Females have a comparatively smaller or entirely absent patch on the abdomen, as well as a more subdued brown-beige throat and head.
Gray partridge hatchlings are precocial and covered in a dense down at hatching. They are identified by four broken black stripes running from above the top of the beak rearward to the back of the head. Two black stripes run parallel to the chick’s spine to the end of the tail. Latitudinal stripes run from these stripes down along the sides of the bird. Yellow abdominal down changes to gold-brown along the back of the hatchlings, remaining more yellowed around the eyes and beak. The wings of the young gray partridge have broken black stripes. Unlike adults, hatchlings have yellow legs and feet.
Juveniles have dull buff-colored body feathers with a slightly darker head. Wing feathers are dark brown and barred with varying brown and black stripes. Juveniles do not have an abdominal patch, instead possessing lighter buff feathers from mid-breast to tail. (Alderfer, 2006; Carroll, 1993; Mullarney and Zetterstrom, 2009; Starck and Ricklefs, 1998)
In late winter and early spring, typically from January to March, gray partridges begin to form monogamous pairs for the upcoming breeding season. Pairs are typically formed from two members of different, unrelated coveys. Males utilize vocalizations to attract females. Males with longer and more frequent calls are generally more successful at pairing up. Once paired, females will approach the male holding her head parallel to the ground and bobbing her head. The female will circle the male, and the two will end courtship by rubbing necks. After these displays, pairs typically go about normal foraging behaviors together. When the female is ready to breed, she flattens herself against the ground, signaling to the male to copulate with her.
During early breeding season, aggression is seen between both sexes towards members of the same sex. Once pairs are established, birds of either sex will defend their mate from members of the same sex and will actively chase away and attack attempted courting behavior from other gray partridges. (Carroll, 1993)
Gray partridges form breeding pairs during late winter and then lay eggs during early spring. Typically, one clutch of 9-20 eggs are laid, which hatch after 23-25 days. At birth, hatchlings weigh less than 10 grams, though they grow and feather quickly. By 16 days, hatchlings are capable of short flights. The young will stay with parents for 7 to 8 months, until the following winter, when the adults separate and form new pairs.
When dense vegetation is available, females remain within their home range and create shallow nests beneath taller foliage. When vegetation is not ideal, females will move to a more suitable location that offers concealment for their nest. Nests are predominantly lined with grasses and leaves. (Baichich and Harrison, 2005; Beani and Dessi-Fulgheri, 1993; Carroll, 1993; Cucco, et al., 2012; Jenkins, 1961; Møller, 2006; Pis, 2012; Starck and Ricklefs, 1998)
After the creation of a nest, the female gray partridge will begin to lay eggs. Until the last egg is laid, the female will remain close to the nest. When the entire clutch is laid, the male will begin to stay close to the nest. During the start of incubation, females will pluck feathers from their breasts to better keep the eggs warm. The plucked feathers may be added to the nest for additional warmth and cushion. The female may leave the nest several times a day to forage and feed. During this time, the male accompanies her, though both stay close to the nest.
After hatching, the young gray partridges stay with their parents until the following breeding season. Adults introduce their young to food by gathering food sources and dropping them near the young. (Baichich and Harrison, 2005)
During periods of nesting, gray partridge females are significantly more prone to predation. Exhaustion, decreased flight ability due to increased weight from eggs prior to laying, and vulnerability while nesting are all causes for increased mortality of females during this time. Both sexes are susceptible while forming pairs due to courtship displays that draw predators. Older birds generally spend less time finding a mate, and therefore have lower mortality rates during this period.
The gray partridge is a social bird that lives in coveys of up to 25 individuals. Members of coveys are often composed of related adults and offspring, though a small number of members may be unrelated individuals that did not successfully form breeding pairs. Birds within a covey stay within close proximity to one another, and they will move, feed, and roost together. Covey members, especially those in smaller coveys, are vigilant for predators and actively keep watch. During the night, group members stay close together.
When not feeding, the gray partridge may preen, dust bathe, or roost on the ground.
When threatened, a gray partridge will fly or run a short distance. A white shoulder spot is displayed when a gray partridge is distressed. Adults protecting a nest may show aggression, or even attack, predators, though inter-species aggression is typically only seen during breeding season. (Carroll, 1993; Jenkins, 1961)
Coveys of gray partridges often live closely to one another in overlapping home ranges. The home range of a gray partridge covey outside of breeding season or of individual pairs during breeding season averages between 2670.92 m^2 and 12140.56 m^2. (Jenkins, 1961)
The gray partridge communicates predominantly through a series of vocalizations. Vocalizations are most common during the hours just before sunset and after sunrise. The frequency of calls increases during spring months when mate choice is influenced by calls, especially those emitted by males. The gray partridge female shows preference for longer, more frequent calling, and will pair with males that exhibit these vocalizations. During summer months, vocalizations are less frequent due to females attending nests and hatchlings.
The gray partridge also uses the visual display of a white patch of shoulder feathers to show alarm or intent to flee. Distressed gray partridges will also exhibit rapid tail movement and vocalizations in conjunction with the display of the shoulder patch. (Beani and Dessi-Fulgheri, 1993; Carroll, 1988; Moreby, et al., 2006; Rotella and Ratti, 1988)
Gray partridges are largely grain and plant eaters, though occasionally eat insects. They also feed upon the crops and tender grasses in the fields in which they live. Grains like rye (Secale cereale), wheat (Triticum spp.), sorghum (Sorghum spp.), and corn (Zea mays) are staples of the partridge’s diet during warmer months. Grain-bearing plant leaves, winter cereal grains and cover crops make up much of the gray partridge’s winter diet.
Gray partridge chicks born amongst grain crops feed largely upon aphids and other agricultural pests that can be found at ground level. Those born away from cropland also feed predominately on a large supply of insects, which supply the protein vital for growth and development. (Borg and Toft, 2000; "Habitat suitability index models: Gray partridge", 1984; Orłowski, et al., 2011)
In the United States, adult gray partridges are susceptible to predation during flight from birds of prey, including the great horned owl (Bubo virginianus), red-tailed hawk (Buteo jamaicensis), prairie falcon (Falco mexicanus), peregrine falcon (Falco peregrinus), and snowy owl (Nyctea scandiaca). European birds of prey include the northern goshawk (Accipiter gentilis), sparrowhawk (Accipiter nisus), Eurasian eagle-owl (Bubo bubo), common buzzard (Buteo buteo), marsh harrier (Circus aeruginosus), northern harrier (Circus cyaneus), Montagu's harrier (Circus pygargus), peregrine falcon (Falco peregrinus), red kite (Milvus milvus), and tawny owl (Strix aluco).
Nesting females, eggs, and hatchlings are susceptible to predation and nest destruction during breeding season from terrestrial mammals and birds, including domestic dog (Canis lupus familiaris), American crow (Corvus brachyrynchos), domestic cat (Felis catus), striped skunk (Mephitis mephitis), raccoon (Procyon lotor), coyote (Canis latrans), and red fox (Vulpes vulpes) in the United States. In the European range of the gray partridge, terrestrial predation of adults, eggs, and young comes from domestic dog (Canis lupus familiaris), domestic cat (Felis catus), stone marten (Martes foina), European badger (Meles meles), short-tailed weasel (Mustela ermine), northern polecat (Mustela putorius), and red fox (Vulpes vulpes).
The gray partridge is considered a game bird, and is hunted by humans (Homo sapiens) for sport in the United States and Europe.
Avoidance of avian predators includes erratic flight patterns and retreat to dense vegetation. Adult gray partridges will fly or run short distances when approached by terrestrial predators. Earthy-colored feathers also allow for camouflaging in tall grass and vegetation. When hatchlings are threatened, adult gray partridges will attempt to distract predators by acting injured or will attack the predator. (Tillmann, 2009; Watson, et al., 2007)
The gray partridge can disperse seeds in its feces.
The ring-necked pheasant (Phasianus colchicus) parasitizes grey partridge nests, laying its eggs for the female partridge to incubate and then care for after the young pheasants hatch. During this nest parasitism, the pheasant chicks are born larger and can out-compete gray partridge hatchlings.
The gray partridge is prone to several internal parasites, including: strongyle worms (Trichostrongylus tenuis), tapeworms (Cestoda), gapeworms (Syngamus trachea), and threadworms (Capillaria). (Brownea, et al., 2006; Carroll, 1993; Orlowski and Czarnecka, 2013)
The gray partridge can be kept by humans (Homo sapiens) for breeding purposes, egg production, and butchering. Additionally, birds are often raised until adults, released, and then hunted.
Wild or captive-bred and released birds are hunted for sport or meat throughout its European and North American range. (Carroll, 1993)
Although the grey partridge will feed upon some agricultural grain crops and can spread undesirable native or invasive seeds in its feces, they do not cause a significant economic cost for farmers. (Orlowski and Czarnecka, 2013)
The gray partridge is a species of "Least Concern" on the IUCN Red List, and hold no special status on other U.S. or international lists. While it is estimated that the total worldwide population remains around 4,000,000 birds, drops in both European and North American populations have been recorded.
Since World War II, dramatic declines in the European gray partridge population have been documented. The drops were largely caused by changes in agriculture practices. Increases in insecticidal usage has caused a decline in arthropods upon which hatchlings feed, meaning fewer protein sources available for growth. Destruction of hedgerows-the main cover source for the gray partridge-attributed to increasing agricultural expansion has also lead to decreases in gray partridge numbers. In areas of Europe where more traditional farming practices are utilized, gray partridge populations remain stable. These agricultural methods preserve vital food supplies for the birds while also providing cover from terrestrial and aerial predators.
Like European populations, North American populations have been negatively impacted by changes in agricultural methods. In addition, increasing urbanization has also destroyed prime habitat. Additionally, an increase in the coyote (Canis latrans) population has likely attributed to declines in the gray partridge population.
Management plans have been established throughout Europe to stabilize or potentially rebuild gray partridge numbers. Maintaining and creating habitat-particularly the thick cover preferred by the partridges-have served as a basis for these management plans. Increases in cereal cover crop usage has been proposed to provide better foraging and habitat for the arthropods that hatchlings feed upon. Monitored insecticide and herbicide usage is also recommended in these management plans. Changes in hunting laws and regulations, particularly removing the gray partridge from its classification as a game species, has been proposed in Italy. Throughout the last few decades, the release of captive-bred and raised gray partridges has been attempted in many countries in an attempt to increase populations. However, captive-raised partridges have poor survival rates in the wild and have also lead to a decrease in genetic variation within gray partridge subspecies. ("Perdix perdix", 2012; "Management Statement Italian Grey Partridge Perdix perdix italica", 1999; Potts and Aebischer, 1995)
Courtney Odenthal (author), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Emily Clark (editor), Radford University, Cari Mcgregor (editor), Radford University, Jacob Vaught (editor), Radford University, Genevieve Barnett (editor), Colorado State University.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses sound to communicate
living in landscapes dominated by human agriculture.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
A substance that provides both nutrients and energy to a living thing.
an animal that mainly eats seeds
An animal that eats mainly plants or parts of plants.
An animal that eats mainly insects or spiders.
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
parental care is carried out by males
Having one mate at a time.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the business of buying and selling animals for people to keep in their homes as pets.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
young are relatively well-developed when born
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