Author: Robert Graham H. Bromley
Publisher:
ISBN:
Category : Canada goose
Languages : en
Pages : 92
Book Description
Conservation Assessment for the Dusky Canada Goose (Branta Canadensis Occidentalis Baird)
Author: Robert Graham H. Bromley
Publisher:
ISBN:
Category : Canada goose
Languages : en
Pages : 92
Book Description
Publisher:
ISBN:
Category : Canada goose
Languages : en
Pages : 92
Book Description
Nesting and Habitat Studies of the Dusky Canada Goose (Branta Canadensis Occidentalis Baird) on the Copper River Delta, Alaska
Author: Robert Graham H. Bromley
Publisher:
ISBN:
Category : Canada goose
Languages : en
Pages : 162
Book Description
Publisher:
ISBN:
Category : Canada goose
Languages : en
Pages : 162
Book Description
Factors Associated with Dusky Canada Goose Nesting and Nest Success on Artificial Nest Islands of the Western Copper River Delta
Author: Nicole Marie Maggiulli
Publisher:
ISBN:
Category : Canada goose
Languages : en
Pages : 240
Book Description
The population of dusky Canada geese (Branta canadensis occidentalis; hereafter, dusky geese) nesting on the western Copper River Delta (CRD) in south- central Alaska has been in decline since the late 1970s. In an effort to alleviate mammalian predation, increase nest success, and avoid a listing under the U.S. Endangered Species Act, an artificial nest island (island) program was implemented on the western CRD in 1983. The installation of new islands on the CRD is the sole management action of the Pacific Flyway Council on the breeding grounds, but no comprehensive evaluation of the program has been published. I examined general trends in island use and nest success over time for three island types (donut islands, fiberglass floater islands, and sandbag islands) from 1984-2005. I used data from the island program to identify factors associated with dusky Canada goose nesting (hereafter, use) and nest success on islands from 1996-2005. I generated a series of candidate models and used logistic regression with model selection techniques to determine how variables representing pond characteristics, vegetative characteristics, interactions with conspecifics and larid species, the previous year's island status, and the distance to predator corridors were associated with island use and nest success for each year. Use of islands by dusky geese nesting on the western CRD increased between 1987 and 2005 from a low of 10% in 1987 to 44% in 2005. There was annual variability in factors associated with island use; however, use of islands was most consistently and strongly associated with the previous year's island status. The odds of a nest being placed on an island that contained a successful nest the previous year were 2.91 to 6.62 times greater than for islands not used the previous year. There was also evidence for an increased likelihood of island use further from shore and for islands with up to 55% aerial shrub cover and shrubs up to 1 m tall. Nest success was consistently high, indicating islands have long term potential for increasing dusky goose nest success on the Copper River Delta. Compared to island use, my analysis of nest success and habitat features resulted in many more competitive models (average 10 v. 2 per year) with fewer strong (95% confidence intervals for parameter estimates excluded zero) associations between explanatory variables and nest success. Explanatory variables representing vegetative characteristics, interactions with conspecifics and larid species, and the distance to predator corridors had a relatively low capacity to explain nest success on artificial islands. However, there was some evidence for an increased likelihood of nest success on islands further from shore with shorter shrubs. Lower variability in factors associated with island use is likely because factors associated with nest site selection are controlled by decisions of the nesting goose. The importance of previous year's island status on island use likely reflects high site fidelity by breeding adult geese, with fidelity being higher for birds that have successful nests. Alternately, dusky geese use cues from the previous year's nesting activity when prospecting for island nest sites. In contrast, nest success is dependent on a more complex combination of factors that vary within and among years outside the control of a nesting goose. Inter-annual variation in the timing and magnitude of eulachon (Thaleichthys pacificus) spawning runs on large sloughs of the CRD and prey-switching by important dusky goose nest predators may have considerable influence on dusky goose nest success on islands, similar to mainland- nesting dusky geese. The inability to control for eulachon presence and abundance may have confounded my analysis of habitat features important to nest success. Therefore, factors such as presence of alternate prey (and predator abundance) may be more important to dusky goose nest success on islands than habitat features. Current use of available nest islands is at a program high of 44% and nest success also remains high (63%); suggesting the artificial nest island program is valuable for dusky geese. However, the contribution of island-nesting dusky geese to the dusky goose population on the Copper River Delta is unclear. There is a need for a population model that incorporates all recent information on dusky goose reproductive ecology to determine if artificial nest islands can increase dusky goose population size, and if so, how many islands are needed.
Publisher:
ISBN:
Category : Canada goose
Languages : en
Pages : 240
Book Description
The population of dusky Canada geese (Branta canadensis occidentalis; hereafter, dusky geese) nesting on the western Copper River Delta (CRD) in south- central Alaska has been in decline since the late 1970s. In an effort to alleviate mammalian predation, increase nest success, and avoid a listing under the U.S. Endangered Species Act, an artificial nest island (island) program was implemented on the western CRD in 1983. The installation of new islands on the CRD is the sole management action of the Pacific Flyway Council on the breeding grounds, but no comprehensive evaluation of the program has been published. I examined general trends in island use and nest success over time for three island types (donut islands, fiberglass floater islands, and sandbag islands) from 1984-2005. I used data from the island program to identify factors associated with dusky Canada goose nesting (hereafter, use) and nest success on islands from 1996-2005. I generated a series of candidate models and used logistic regression with model selection techniques to determine how variables representing pond characteristics, vegetative characteristics, interactions with conspecifics and larid species, the previous year's island status, and the distance to predator corridors were associated with island use and nest success for each year. Use of islands by dusky geese nesting on the western CRD increased between 1987 and 2005 from a low of 10% in 1987 to 44% in 2005. There was annual variability in factors associated with island use; however, use of islands was most consistently and strongly associated with the previous year's island status. The odds of a nest being placed on an island that contained a successful nest the previous year were 2.91 to 6.62 times greater than for islands not used the previous year. There was also evidence for an increased likelihood of island use further from shore and for islands with up to 55% aerial shrub cover and shrubs up to 1 m tall. Nest success was consistently high, indicating islands have long term potential for increasing dusky goose nest success on the Copper River Delta. Compared to island use, my analysis of nest success and habitat features resulted in many more competitive models (average 10 v. 2 per year) with fewer strong (95% confidence intervals for parameter estimates excluded zero) associations between explanatory variables and nest success. Explanatory variables representing vegetative characteristics, interactions with conspecifics and larid species, and the distance to predator corridors had a relatively low capacity to explain nest success on artificial islands. However, there was some evidence for an increased likelihood of nest success on islands further from shore with shorter shrubs. Lower variability in factors associated with island use is likely because factors associated with nest site selection are controlled by decisions of the nesting goose. The importance of previous year's island status on island use likely reflects high site fidelity by breeding adult geese, with fidelity being higher for birds that have successful nests. Alternately, dusky geese use cues from the previous year's nesting activity when prospecting for island nest sites. In contrast, nest success is dependent on a more complex combination of factors that vary within and among years outside the control of a nesting goose. Inter-annual variation in the timing and magnitude of eulachon (Thaleichthys pacificus) spawning runs on large sloughs of the CRD and prey-switching by important dusky goose nest predators may have considerable influence on dusky goose nest success on islands, similar to mainland- nesting dusky geese. The inability to control for eulachon presence and abundance may have confounded my analysis of habitat features important to nest success. Therefore, factors such as presence of alternate prey (and predator abundance) may be more important to dusky goose nest success on islands than habitat features. Current use of available nest islands is at a program high of 44% and nest success also remains high (63%); suggesting the artificial nest island program is valuable for dusky geese. However, the contribution of island-nesting dusky geese to the dusky goose population on the Copper River Delta is unclear. There is a need for a population model that incorporates all recent information on dusky goose reproductive ecology to determine if artificial nest islands can increase dusky goose population size, and if so, how many islands are needed.
Resource Publication
Author:
Publisher:
ISBN:
Category : Wildlife conservation
Languages : en
Pages : 176
Book Description
Publisher:
ISBN:
Category : Wildlife conservation
Languages : en
Pages : 176
Book Description
Ecology of Aleutian Canada Geese at Buldir Island, Alaska
Author: G. Vernon Byrd
Publisher: Washington, D.C. : U.S. Department of the Interior, Fish and Wildlife Service
ISBN:
Category : Birds
Languages : en
Pages : 24
Book Description
Report on a study of the only known breeding population of the endangered Aleutian Canada goose (Brauta canadensis leucopareia) from 1974 to 1977 at Buldir Island, a western Aleutian island, Alaska.
Publisher: Washington, D.C. : U.S. Department of the Interior, Fish and Wildlife Service
ISBN:
Category : Birds
Languages : en
Pages : 24
Book Description
Report on a study of the only known breeding population of the endangered Aleutian Canada goose (Brauta canadensis leucopareia) from 1974 to 1977 at Buldir Island, a western Aleutian island, Alaska.
The Energetics of Migration and Reproduction of the Dusky Canada Geese [microform] : (Branta Canadensis Occidentalis)
Author: Robert Graham H. Bromley
Publisher: Ann Arbor, Mich. : University Microfilms International
ISBN:
Category : Canada goose
Languages : en
Pages : 232
Book Description
Adult female dusky Canada geese were studied on the Copper River Delta, Alaska and in the Willamette Valley, Oregon during April through July, 1977 to 1979. Author concludes environmental food resources at approximately two thirds through incubation are critical to nesting geese.
Publisher: Ann Arbor, Mich. : University Microfilms International
ISBN:
Category : Canada goose
Languages : en
Pages : 232
Book Description
Adult female dusky Canada geese were studied on the Copper River Delta, Alaska and in the Willamette Valley, Oregon during April through July, 1977 to 1979. Author concludes environmental food resources at approximately two thirds through incubation are critical to nesting geese.
Habitat Use and Productivity of Canvasbacks in Southwestern Manitoba, 1961-72
Author: Jerome H. Stoudt
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 526
Book Description
A study of canvasback (Aythya valisineria) breeding populations, nest success, productivity, and habitat requirements was conducted from 1961 to 1972 on a 181.3 square kilometer area south of Minnedosa, Manitoba.
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 526
Book Description
A study of canvasback (Aythya valisineria) breeding populations, nest success, productivity, and habitat requirements was conducted from 1961 to 1972 on a 181.3 square kilometer area south of Minnedosa, Manitoba.
An Annotated Bibliography of Literature on Alaska Water Birds
Author:
Publisher:
ISBN:
Category : Anatidae
Languages : en
Pages : 534
Book Description
Publisher:
ISBN:
Category : Anatidae
Languages : en
Pages : 534
Book Description
Inclusion of Alaska lands in national park, forest, wildlife refuge, and wild and scenic rivers systems
Author: United States. Congress. House. Committee on Interior and Insular Affairs. Subcommittee on General Oversight and Alaska Lands
Publisher:
ISBN:
Category : National parks and reserves
Languages : en
Pages : 588
Book Description
Publisher:
ISBN:
Category : National parks and reserves
Languages : en
Pages : 588
Book Description
General Technical Report PNW-GTR
Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 1022
Book Description
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 1022
Book Description