Young females begin leaving the brood one or two weeks later than their brothers, and they normally disperse about three times as far. Occasionally a hen and her brood will remain together as late as mid-January, but this is unusual, and most groups of grouse encountered in the fall and winter are composed of unrelated individuals who gather together temporarily to share a choice food resource or piece of secure cover.
After all, young grouse in their first fall have never been confronted by something that can be seen through but not flown through, such as glass!
Ruffed Grouse normally have a short life span. From a brood of 10 or 12 hatched in late May or early June, usually 5 or 6 will have died by mid-August. So from chicks hatched in late spring, about normally survive to early autumn, survive to the following nesting season, 80 are alive a year later, 36 live to breed a 3rd time, 16 may breed a 4th time.
One out of chicks hatched may live as long as 8 years. Most Ruffed Grouse die a violent death to provide a meal for one of a number of meat-eating predators, for in the natural scheme of things, Ruffed Grouse are one of the first links in a complex food chain. Some also die from disease and parasites, or from exposure to severe weather, or accidentally by hitting trees or branches while in a panic flight after being frightened.
Across the major portion of the Ruffed Grouse range, the winged predators or raptors are most efficient at taking these birds. Although the goshawk is certainly the most efficient of all grouse predators, they are relatively uncommon and the horned owl probably kills more grouse across their range annually than any other predator. This is due to the cosmopolitan distribution of these owls and the likelihood that any woodland capable of supporting grouse will have resident horned owls, or at least be regularly visited by them.
Yet, where cover is adequate, grouse can find security and maintain their abundance even when goshawks and horned owls live and nest nearby. Conditions are seldom static in the world of the Ruffed Grouse and their numbers fluctuate from year to year, and from decade to decade. In the Lake States, for example, periods of abundance usually coincide with years ending in 0, 1 or 2, and the bottom of the depression in years ending with 5 or 6.
This is not invariable, but a general, regional trend. The factors responsible for these periodic fluctuations remain poorly understood, and appear to involve a number of different factors interacting with one another in different ways at different times.
The one factor which does not appear to be important in annual grouse fluctuations is hunting. Generally, regulated hunting during the fall season removes grouse that are in excess of winter carrying capacity, so does not impact either grouse survival rates or population trends. The primary causes for the short-term fluctuations in Ruffed Grouse abundance appear to be related to weather trends and variations in the quantity and quality of food resources.
These are interrelated to a large degree. Superimposed upon these two basic factors is that of predation — as predators take advantage of grouse placed in jeopardy by unfavorable weather conditions or inadequate food resources. A favorable combination of weather factors and food resources may allow these grouse to survive the winter nearly immune to predation. These combinations of factors also affect annual production. If grouse spend the winter feeding on poor quality foodstuffs, or have to use an excessive amount of energy to keep warm, hens may not have sufficient reserves to produce a clutch of viable eggs, or vigorous, healthy chicks in the spring.
Across most of their range, the most productive and most abundant Ruffed Grouse populations are those living where they spend most of the winter burrowed into 10 inches or more of soft, powdery snow, and emerge for only short periods once or twice a day to take a meal of the male flower buds of the aspens.
There also seems to be a poorly understood relationship between the color-phase of a Ruffed Grouse and its ability to survive severe wintering conditions, and its vulnerability to predation. Longer term changes in Ruffed Grouse abundance reflect how we have treated our woodlands and forests. These birds depend upon the food and cover resources produced by a group of short-lived trees and shrubs e.
In earlier times, fire and windstorm were the ecological agents periodically renewing forests and creating satisfactory habitat for Ruffed Grouse and many other species of forest wildlife. The book called "The Complete Birds of North America", is a book recommended to be part of any birders library. This book covers all the native and vagrant species of birds seen on the North American Continent. It provides information on all the birds listed on the ABA bird list.
This book goes into great details, describing the individual species and their races. That aside, their website provides wonderful information pertaining to many articles regarding nature. It was initially formed for the preservation of egrets and herons as well as waders, who were being hunted and killed, so their feathers could be used in the clothing industry. Today, there are many chapters of the NAS all over the continent and all individual groups have a common goal, to educate the public.
In doing so, creating awareness of the birds and their plights. They were the driving force in promoting the original international laws, protecting migratory birds. Today, their website has made information available on articles, images and sounds, relating to all the native birds seen in North America.
I hope you will take advantage of these suggested websites. I have used each of them, in one way or another, throughout the years in my quest to better identify and understand our fine feathered friends.
Enter Bird's Name in Search Box: www. Click on the bird names listed below to see pictures of the Grouses seen in North America. These species need undisturbed sagebrush areas with very few trees present. Like the lesser prairie chicken, the Gunnison sage-grouse is the most vulnerable, and they are limited to a very small area of Colorado and Utah.
They live seemingly very different lives and occupy a different part of North America than most game birds. Most ptarmigan specialize in northern boreal or tundra habitats with little vegetation and lots of rocky slopes. To help them blend into their surroundings better, all these species develop white feathers before winter. Ryan Lisson is a biologist and regular content contributor to several outdoor manufacturers, hunting shows, publications, and blogs.
He is an avid small game, turkey, and whitetail hunter from northern Minnesota and loves managing habitat almost as much as hunting. Ryan is also passionate about helping other adults experience the outdoors for their first time, which spurred him to launch Zero to Hunt, a website devoted to mentoring new hunters.
This site uses Akismet to reduce spam. Learn how your comment data is processed. All rights reserved. Lytchett Fields The reserve has seen more than thirty species of wading birds. Arne Heathland home to more than species. Get out, get busy and get wild! Fun factoids for all the family Find out more about the nature and wildlife outside your window.
Black grouse While male blackbirds live up to their name, confusingly, females are actually brown, often with spots and streaks on their breasts. Read more. Capercaillie A huge woodland grouse, the large black males are unmistakable. Ptarmigan A plump gamebird, slightly larger than a grey partridge. Red grouse The red grouse is a medium-sized game bird.
0コメント