Misplaced Pages

#924075

34-417: Pucrasia Meleagris Bonasa Tetrastes Centrocercus Dendragapus Tympanuchus Lagopus Falcipennis Canachites Tetrao Lyrurus and see text Tetraonidae Vigors , 1825 Tetraoninae Vigors, 1825 Grouse / ɡ r aʊ s / are a group of birds from the order Galliformes , in the family Phasianidae . Grouse are presently assigned to

68-504: A male defends a territory which has resources that females need, like food and nest sites. These differences in male behavior in mating systems account for the evolution of body size in grouse. Males of territorial species were smaller than those of exploded lekking species, and males of typical lekking species were the largest overall. The male birds that exhibit lekking behavior, and have to compete with other males for females to choose them, have greater sexual dimorphism in size. This suggests

102-488: A reduced cecum, which is often partially or wholly replaced by the appendix . Mammalian species which do not develop a cecum include raccoons , bears , and the red panda . Many fish have a number of small outpockets, called pyloric ceca , along their intestine; despite the name, they are not homologous with the cecum of amniotes – their purpose is to increase the overall area of the digestive epithelium. Some invertebrates, such as squid, may also have structures with

136-494: Is a direct translation from Ancient Greek τυφλὸν ( ἔντερον ) typhlòn ( énteron ). Thus the inflammation of the cecum is called typhlitis. In dissections by the Greek philosophers , the connection between the ileum of the small intestine and the cecum was not fully understood. Most of the studies of the digestive tract were done on animals and the results were compared to human structures . The junction between

170-662: Is a medium-sized elusive bird confined to high altitude forests from Afghanistan to central Nepal , and in northeastern Tibet to northern and eastern China . Upper parts of male koklass pheasant are covered with silver-grey plumage streaked velvety-black down the centre of each feather, and it has the unique feature of a black head, chestnut breast and prominent white patches on the sides of neck. The females differ from males in above characters and instead their upper parts are covered with pale brown plumage. Both sexes, however, have distinct elongated tails tipped with pale feathers. The males are known to weigh about 1135–1415 g and

204-469: Is a polytypic species, with nine recognized subspecies : This entry deals with the subspecies P. m. biddulphi , which ranges from Kashmir to Kullu in India . With exception of the subspecies P. m. nipalensis , P. m. castanea and P. m. macrolopha , which are endemic to the southern side of northwest and western Himalaya , the other five are confined to China and Mongolia . The koklass pheasant

238-420: Is a shallow depression or scrape on the ground—often in cover—with a scanty lining of plant material. The female lays one clutch , but may replace it if the eggs are lost. She begins to lay about a week after mating and lays one egg every day or two; the clutch comprises five to 12 eggs. The eggs have the shape of hen's eggs and are pale yellow, sparsely spotted with brown. On laying the second-last or last egg,

272-539: Is a species of gamebird , being closely related to progenitive grouse that lived during the Miocene . They are distantly related to pheasants and are most closely related to grouse and turkeys . Koklass are the only species in the monotypic genus Pucrasia . Both the words koklass and pucrasia have been onomatopœically derived from the bird's territorial call. Koklass are boreal adapted species which separate into three distinct species groups. They are one of

306-537: Is called sexual dimorphism . Male grouse tend to be larger than female grouse, which seems to hold true across all the species of grouse, with some difference within each species in terms of how drastic the size difference is. The hypothesis with the most supporting evidence for the evolution of sexual dimorphism in grouse is sexual selection. Sexual selection favors large males; stronger selection for larger size in males leads to greater size dimorphism. Female size will increase correspondingly as male size increases, and this

340-505: Is due to heredity (but not to the extent of the male size). This is because females that are smaller will still be able to reproduce without a substantial disadvantage, but this is not the case with males. The largest among the male grouse (commonly dubbed 'Biggrouse') attract the greatest numbers of females during their mating seasons. Male grouse display lekking behavior, which is when many males come together in one area and put on displays to attract females. Females selectively choose among

374-424: Is processed in the gastrointestinal tract and expelled as regular feces. But in order to get nutrients out of hard to digest fiber, lagomorphs ferment fiber in the cecum and then expel the contents as cecotropes , which are reingested (cecotrophy). The cecotropes are then absorbed in the small intestine to utilize the nutrients. In contrast, obligate carnivores , whose diets contain little or no plant matter, have

SECTION 10

#1732790423925

408-407: Is usually a single median structure, arising from the dorsal side of the large intestine. Birds typically have two paired ceca, as do, unlike other mammals, hyraxes . Parrots do not have ceca. Most mammalian herbivores have a relatively large cecum. In many species, it is considerably wider than the colon. For some herbivores such as lagomorphs (rabbits, hares, pikas), easily digestible food

442-406: The appendix . The connection between the end of the small intestine (ileum) and the start (as viewed from the perspective of food being processed) of the colon (cecum) is now clearly understood, and is called the ileocecal orifice. The connection between the end of the cecum and the beginning of the ascending colon is called the cecocolic orifice. A cecal carcinoid tumor is a carcinoid tumor of

476-488: The ptarmigans , have legs which are entirely covered in feathers; in winter the toes, too, have feathers or small scales on the sides, an adaptation for walking on snow and burrowing into it for shelter. Unlike many other galliforms, they typically have no spurs , although turkeys do possess very prominent spurs. Grouse feed mainly on vegetation—buds, catkins , leaves, and twigs—which typically accounts for over 95% of adults' food by weight. Thus, their diets vary greatly with

510-755: The red grouse and the ruffed grouse have benefited from habitat management. Most grouse species are listed by the IUCN as "least concern" or "near threatened", but the greater and lesser prairie chicken are listed as "vulnerable" and the Gunnison grouse is listed as "endangered". Some subspecies, such as Attwater's prairie chicken and the Cantabrian capercaillie , and some national and regional populations are also in danger. The wild turkey precipitously declined before returning to abundance, even in developed areas. The phenotypic difference between males and females

544-1010: The tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetraonidae ), a classification supported by mitochondrial DNA sequence studies, and applied by the American Ornithologists' Union , ITIS , International Ornithological Congress , and others. Grouse inhabit temperate and subarctic regions of the Northern Hemisphere , from pine forests to moorland and mountainside , from 83°N ( rock ptarmigan in northern Greenland ) to 28°N ( Attwater's prairie chicken in Texas ). The turkeys are closely allied with grouse, but they have traditionally been excluded from Tetraonini, often placed in their own tribe, subfamily, or family; certain more modern treatments also exclude them. Later phylogenomic analyses demonstrated conclusively that they are sister to

578-405: The breeding season and during autumn, revealing their presence and allowing the populations to be estimated. They remain in pairs or small family groups throughout the year. They nest on the ground and spend the nights roosting on trees, or under rock overhangs. Caecum It receives chyme from the ileum , and connects to the ascending colon of the large intestine . It is separated from

612-513: The cecum. An appendiceal carcinoid tumor (a carcinoid tumor of the appendix) is sometimes found next to a cecal carcinoid. Neutropenic enterocolitis (typhlitis) is the condition of inflammation of the cecum, primarily caused by bacterial infections. Over 99% of the bacteria in the gut are anaerobes , but in the cecum, aerobic bacteria reach high densities. A cecum is present in most amniote species, and also in lungfish , but not in any living species of amphibian . In reptiles , it

646-404: The female starts 21 to 28 days of incubation. Chicks hatch in dense, yellow-brown down and leave the nest immediately. They soon develop feathers and can fly shortly before they are two weeks old. The female (and the male in the willow grouse) stays with them and protects them until their first autumn, when they reach their mature weights (except in the male capercaillies ). They are sexually mature

680-470: The females, about 1025–1135 g, with the body length varying from 58 to 64 cm and 18–22 cm respectively. Immature and juveniles resemble adult females in plumage pattern. Like the western tragopan , it does not extend its range above the tree line. One of the less colourful pheasants, the koklass exhibits moderate sexual dimorphism . Though they skulk under bushes, which makes direct sighting difficult, they give loud chorus/predawn calls during

714-570: The few gamebirds that regularly fly uphill and are capable of sustained flights of many miles. They are monogamous with a slight tendency toward social polyandry . Both parents rear the chicks. Koklass are largely vegetarian for much of the year consuming pine nuts, pine shoots, bamboo shoots and seeds. They are highly insectivorous during the warmer months that coincide with nesting and chick-rearing. During this phase of their life cycle they live almost exclusively on ants but also are documented consuming catkins , pollen and fruit. The koklass pheasant

SECTION 20

#1732790423925

748-579: The following spring, but often do not mate until later years. Grouse make up a considerable part of the vertebrate biomass in the Arctic and Subarctic. Their numbers may fall sharply in years of bad weather or high predator populations—significant grouse populations are a major food source for lynx , foxes , martens , and birds of prey . The three tundra species have maintained their former numbers. The prairie and forest species have declined greatly because of habitat loss, though popular game birds such as

782-455: The ground at dawn and dusk, which in some are given in leks . The displays feature males' brightly colored combs and in some species, brightly colored inflatable sacs on the sides of their necks. The males display their plumage , give vocalizations that vary widely between species, and may engage in other activities, such as drumming or fluttering their wings, rattling their tails, and making display flights. Occasionally, males fight. The nest

816-410: The hypothesis of sexual selection affecting male body size and also gives an explanation for why some species of grouse have a more drastic difference between male and female body size than others. Sexual size dimorphism can manifest itself differently between grouse and other birds. In some cases, the female is dominant over the male in breeding behavior, which can result in females that are larger than

850-402: The ileum by the ileocecal valve (ICV) or Bauhin's valve. It is also separated from the colon by the cecocolic junction. While the cecum is usually intraperitoneal, the ascending colon is retroperitoneal . In herbivores , the cecum stores food material where bacteria are able to break down the cellulose. In humans, the cecum is involved in absorption of salts and electrolytes and lubricates

884-458: The largest grouse species, attaining lengths of 130 cm (50 in) and weighing up to 10 kg (22 lb). Male grouse are larger than females, and can be twice as heavy in the western capercaillie (the largest of the traditional grouse). Like many other galliforms, males often sport incredibly elaborate ornamentation, such as crests, fan-tails, and inflatable, brightly colored patches of bare skin. Many grouse have feathered nostrils, and some species, such as

918-422: The males present for traits they find more appealing. Male grouse exhibit two types: typical lekking and exploded lekking. In typical lekking, males display in small areas defending a limited territory, and in exploded lekking, displaying males are covered over an expansive land area and share larger territories. Male grouse can also compete with one another for access to female grouse through territoriality, in which

952-688: The males. Grouse are game , and hunters kill millions each year for food, sport, and other uses. In the United Kingdom, this takes the form of driven grouse shooting . The male black grouse 's tail feathers are a traditional ornament for hats in areas such as Scotland and the Alps . Folk dances from the Alps to the North American prairies imitate the displays of lekking males. Pucrasia The koklass pheasant ( Pucrasia macrolopha )

986-436: The medial wall, with the result that the point of attachment of the appendix comes to lie on the medial side. The cecum's position changes after the midgut rotates and the ascending colon elongates, and the accumulation of meconium inside the cecum may result in the latter's increased diameter. The term cecum comes from Latin (intestinum) caecum , literally 'blind intestine', in the sense 'blind gut' or ' cul de sac '. It

1020-613: The most social, forming flocks of up to 100 in winter. All grouse spend most of their time on the ground, though when alarmed, they may take off in a flurry and go into a long glide. Most species stay within their breeding range all year, but make short seasonal movements; many individuals of the ptarmigan (called rock ptarmigan in the US) and willow grouse (called willow ptarmigan in the US) migrate hundreds of kilometers. In all but one species (the willow ptarmigan ), males are polygamous . Many species have elaborate courtship displays on

1054-666: The seasons. Hatchlings eat mostly insects and other invertebrates , gradually reducing their proportion of animal food to adult levels. Several of the forest-living species are notable for eating large quantities of conifer needles, which most other vertebrates refuse. To digest vegetable food, grouse have big crops and gizzards , eat grit to break up food, and have long intestines with well-developed caeca in which symbiotic bacteria digest cellulose . Forest species flock only in autumn and winter, though individuals tolerate each other when they meet. Prairie species are more social, and tundra species (ptarmigans, Lagopus ) are

Grouse - Misplaced Pages Continue

1088-415: The small intestine and the colon, called the ileocecal valve , is so small in some animals that it was not considered to be a connection between the small and large intestines. During a dissection, the colon could be traced from the rectum , to the sigmoid colon , through the descending , transverse , and ascending sections. The cecum is an end point for the colon with a dead-end portion terminating with

1122-436: The solid waste that passes into the large intestine. The cecum and appendix are derived from the bud of cecum that forms during week 6 in the midgut next to the apex of the umbilical herniation. Specifically, the cecum and appendix are formed by the enlargement of the postarterial segment of the midgut loop. The proximal part of the bud grows rapidly to form the cecum. The lateral wall of the cecum grows much more rapidly than

1156-619: The traditionally-defined grouse, and they, along with the somewhat earlier-diverging koklass pheasant , may be treated as grouse (i.e., as basal members of the Tetraonini). This is reflected in some more recent circumscriptions. Like many other galliforms, grouse are generally heavily-built birds. The traditional grouse (excluding turkeys) range in length from 31 to 95 cm (12 to 37 + 1 ⁄ 2  in), and in weight from 0.3 to 6.5 kg ( 3 ⁄ 4 to 14 + 1 ⁄ 4  lb). If they are included, wild turkey toms are

#924075