Showing posts with label Tetraonidae. Show all posts
Showing posts with label Tetraonidae. Show all posts

Saturday, 16 February 2013

Ruffed grouse

Bonasa umbellus

Photo by Guy Monty (Flickr)

Common name:
ruffed grouse (en); galinha-montesa-de-colar (pt); gélinotte huppée (fr); grévol engolado (es); kragenhuhn (de)

Taxonomy:
Order Galliformes
Family Phasianidae

Range:
This species is found throughout most of Canada, and also in Alaska and the northern United States as far south as Georgia, Utah and northern California.

Size:
These birds are 40-50 cm long and have a wingspan of 50-64 cm. They weigh 450-750 g.

Habitat:
The ruffed grouse is found in temperate, boreal and mountain forests, typically in quiet areas with dense cover, preferring mixed deciduous forests rich in aspen, poplar and birch. They also occur in thick scrublands and sheltered swamps.

Diet:
They are omnivorous, with a varied diet including leaves, buds, seeds, berries and fruits, as well as insects and other invertebrates. In winter, they mainly eat buds, particularly aspen catkin buds which are rich in sugar and protein. Poplar and birch buds are also frequently eaten. In the spring, the ruffed grouse feeds on new leaves and shoots of a variety of plants, including trees, scrubs and dandelions. Ripening fruits and berries, such blackberries and blueberries, form the basis of their diet in the summer and the chicks feed on small insects and spiders.

Breeding:
The ruffed grouse breeds in April-July. The males performs a noisy courtship display involving drumming and rapid wing flapping. They can mate with several females during the breeding season and have no further part in the breeding process. The nest is a hollow scrape in the ground, lined with dry leaves, pine needles and some feathers, usually located at the base of a tree or near a fallen log in an area which is well camouflaged by low vegetation. There the female lays 9-12 buff-coloured eggs with a few reddish speckles, which she incubates alone for 23-26 days. The chicks leave the nest within 24 hours of hatching and are immediately able to feed themselves. They fledge about 12 days after hatching.

Conservation:
IUCN status - LC (Least Concern)
This species has a very large breeding range and a global population estimated at 8 million individuals. This species is a popular game bird in most of its range but the current levels of hunting are not believed to have an impact on the population. The ruffed grouse has undergone a small decrease over the last decades, mainly due to habitat loss and fragmentation through rural and suburban development.

Wednesday, 16 May 2012

Dusky grouse

Dendragapus obscurus

Photo by Ian Maton (Internet Bird Collection)

Common name:
dusky grouse (en); tetraz-sombrio (pt); tétras sombre (fr); gallo de las Rocosas (es); felsengebirgshuhn (de)

Taxonomy:
Order Galliformes
Family Tetraonidae

Range:
This species is found in western North America, from south-eastern Alaska and the Northwest territories south to California, Arizona, New Mexico and Colorado.

Size:
These birds are 39-53 cm long and weigh 750-1.300 g.

Habitat:
The dusky grouse is found in deciduous, mixed and coniferous forests, both in temperate and boreal areas. They are found from sea level up to an altitude of 3.600 m.

Diet:
They mostly eat leaves, flowers and conifer needles, namely fir and douglas-fir needles, occasionally also hemlock and pine needles, and also other green plants such as Pteridium, Salix, and the berries of Gaultheria, Mahonia, Rubus, Vaccinium. During summer, and especially the juveniles, also eat some insects, particularly ants, beetles and grasshoppers.

Breeding:
The males sing to attract females, but have no further part in the breeding process after mating. The nest is a shallow scrape in the forest ground, sparsely lined with dead twigs, needles, leaves, and feathers. There the female lays 5-10 creamy-white eggs with brown spots, which she incubates alone for 25-27 days. The chicks leave the nest shortly after hatching and are able to feed themselves, but rely on their mother for warmth and protection.

Conservation:
IUCN status - LC (Least Concern)
This species has a very large breeding range and the global population is estimated at 3 million individuals. The population has undergone a small decline over the last 4 decades, but it is not considered threatened at present.

Saturday, 12 March 2011

Rock ptarmigan

Lagopus muta

Photo by Jan Haugseth (Wikipedia)

Common name:

Taxonomy:
Order Galliformes
Family Tetraonidae

Range:
This sedentary species breeds across most of Arctic and sub-Arctic Eurasia and North America, including Greenland. There are a few isolated populations in mountainous areas of Scotland, the Pyrenees, the Alps, Bulgaria, the Urals, the Pamir mountains, the Altay mountains and Japan.

Size:
The rock ptarmigan in 34-36 cm long and has a wingspan of 54-60 cm.

Habitat:
These birds favour upland habitats. They prefer to live in areas where rocks are interspersed with carpets of moss and lichen, with plenty of dwarf birch and willows.

Diet:
The rock ptarmigan feeds primarily on birch and willow buds, and catkins when available. It will also eat various seeds, leaves, flowers and berries of various plant species. Developing young also eat insects, spiders and snails.

Breeding:
These birds start laying eggs in May. Males may breed with 2-3 females within their territory. The nest is a shallow scrape lined with vegetation and feathers, where the female lays 5-8 eggs. The eggs are incubated for 21-23 days and the chicks leave the nest within a day of hatching. Each female tends to her young, but they feed for themselves. The chicks are able to fly 10-15 days after hatching and are fully fledged at 20-26 days. They become fully independent after 10-12 weeks.

Conservation:
IUCN status - LC (Least Concern)
This species has an extremely large breeding range and a global population of 8 million individuals. The population has declined locally owing habitat loss, especially due to over-grazing by sheep and mountain tourism, including establishment of ski-resorts. The species is not thought to be vulnerable to over-hunting and not considered threatened at present.