Recent Bird Records from Malheur National Wildlife Refuge, Oregon

Littlefield, Carroll D.; Cornely, John E.; Thompson, Steven P.

doi:10.2307/3535465

Cited by 3 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…), principally black-billed magpies Pica hudsonia. While black-billed magpies and common ravens Corvus corax have been historically common at MNWR, American crows Coruvs brachyrhynchos have not (Litttlefield 1990). Indeed, we did not observe any crows in 2002, but recorded a single crow in 2003 and observed flocks of 30-50 crows in 2004.…”

Section: Limiting Factorsmentioning

confidence: 99%

Population decline of a long‐distance migratory passerine at the edge of its range: nest predation, nest replacement and immigration

Murphy

Redmond

Dolan

et al. 2020

Journal of Avian Biology

View full text Add to dashboard Cite

The relative importance of predators and resources (i.e. food) for the dynamics of migratory bird populations is poorly known. Resource availability may be more likely in resource poor environments, but given that nest failure in most systems is due mainly to predation, predator effects may predominate. We document a rapid decline of an isolated eastern kingbird Tyrannus tyrannus population breeding in the Great Basin Desert of eastern Oregon, USA, and evaluate whether it was driven by limited food resources (water availability ~ food), nest predation, or first‐year or adult return rate (RRJ and RRA, respectively) that reflect nonbreeding season events. Most nests failed (~68% of nests) due mainly to nest predation (> 90% of failures); nestling starvation was rare. Bioyear precipitation (October–April), breeding season precipitation, and river flow all varied widely but none could account for annual variation in either nest success (NS) or fledging success of successful nest (FSSN). Neither RRJ nor RRA varied with year, any measure of water resources, or reproductive success. Annual population growth rate (ln[Nt+1/Nt]) was independent of year, all measures of water availability, RRJ and RRA, and NS of replacement nests, but was high following years of high NS of initial nests; FSSN was also higher in years of high NS. High rates of nest predation, due likely to the expansion of the local American crow Corvus brachyrhynchos population, appeared to drive the population decline. Empirical data and population simulations indicated that replacement nests contributed little to λ, while simulations revealed that, given site‐specific vital rates, the decline would have been even greater without immigration (λ = 0.812) than the observed (λ = 0.914). Long distance dispersal may thus be critical for persistence of kingbirds in the naturally highly fragmented habitat that it occupies in the Great Basin Desert.

show abstract

Section: Limiting Factorsmentioning

confidence: 99%

Population decline of a long‐distance migratory passerine at the edge of its range: nest predation, nest replacement and immigration

Murphy

Redmond

Dolan

et al. 2020

Journal of Avian Biology

View full text Add to dashboard Cite

show abstract

“…Along streams and irrigation channels, dense, wooded riparian communities occasionally arise. Some hawks, owls, and northern shrikes prefer these areas (Littlefield 1990).…”

Section: Human Factors Of Water Policy 65mentioning

confidence: 99%

A Swamp in the Desert: Theory, Water Policy, and Malheur Lake Basin

Mandaville¹

2000

View full text Add to dashboard Cite

Basin Two perspectives are debated in current United States water policy model development. One perspective calls for policy based on normative values, such as an environmental ethic. The second perspective calls for policy based on empirical, quantifiable values, for instance, economic benefits and costs. This theoretical debate arises from differing assumptions about what is problematic in contemporary water policy, and in turn gives rise to many water policy models. Developing such models ostensibly provides frameworks useful for developing real-world water policies. This paper proposes that these water policy models are not in fact useful frameworks for policy applications because the models do not accurately account for the actual circumstances confronting water policy makers. In

show abstract

“…Fieldwork was conducted at the Malheur National Wildlife Refuge in eastern Oregon (43?52'N, 118?52'W). For a detailed description of the study site see Littlefield (1990). In 1993, we studied colonies on Boca Lake and on Malheur Lake.…”

Section: Study Sitementioning

confidence: 99%

Nest Distance Mediates the Costs of Coloniality in Eared Grebes

Hill¹,

Jones²,

Hardenbergh³

et al. 1997

Colonial Waterbirds

View full text Add to dashboard Cite

We examined the behaviors and reproductive characteristics of 4 Eared Grebe (Podiceps nigricollis) colonies located at the Malheur National Wildlife Refuge in eastern Oregon that varied in nesting density. In 1993, we studied 2 colonies found on 2 different lakes, whereas in 1994 we conducted a within-lake comparison of 2 subcolonies. During both years, nearest neighbor distances differed significantly between the colonies investigated. Breeding pairs were significantly more aggressive at those colonies with smaller distances among nests. Within each year, there was a greater rate of intraspecific brood parasitism and egg loss at the higher density colony. Infanticide occurred at high rates when nests were very densely packed, whereas a relatively high rate of predation by American Coots (Fulica americana) resulted when nests were quite dispersed. Thus, in spite of the distinct breeding characteristics of Eared Grebes, many disadvantages associated with nesting density in seabirds also have an impact on these colonially breeding waterbirds.

show abstract

Recent Bird Records from Malheur National Wildlife Refuge, Oregon

Cited by 3 publications

References 0 publications

Population decline of a long‐distance migratory passerine at the edge of its range: nest predation, nest replacement and immigration

Population decline of a long‐distance migratory passerine at the edge of its range: nest predation, nest replacement and immigration

A Swamp in the Desert: Theory, Water Policy, and Malheur Lake Basin

Nest Distance Mediates the Costs of Coloniality in Eared Grebes

Contact Info

Product

Resources

About