Introducing change: A current look at naturalized bird species in western North America

Foraging behaviour of four avian species feeding on the same temporarily available prey

Canadian Journal of Zoology ◽

10.1139/cjz-2019-0286 ◽

2020 ◽

Vol 98 (9) ◽

pp. 581-590 ◽

Cited By ~ 1

Author(s):

N.S.B. Houpt ◽

A.P.H. Bose ◽

T. Warriner ◽

N.A.W. Brown ◽

J.S. Quinn ◽

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Keyword(s):

North America ◽

Census Data ◽

Prey Availability ◽

Bird Species ◽

Bald Eagle ◽

Haliaeetus Leucocephalus ◽

Western North America ◽

Bald Eagles ◽

Tidal Cycles ◽

Plainfin Midshipman

Low tide events provide terrestrial predators with ephemeral, but predictable and abundant sources of prey. Understanding the relationships between tidal cycles, prey availability, and predator abundances is vital to characterizing the ecological relationship between terrestrial predators and their marine prey. Here, we describe the foraging tactics of four common bird species in western North America — Bald Eagles (Haliaeetus leucocephalus (Linnaeus, 1766)), Great Blue Herons (Ardea herodias Linnaeus, 1758), Glaucous-winged Gulls (Larus glaucescens J.F. Naumann, 1840), and Northwestern Crows (Corvus caurinus S.F. Baird, 1858) — feeding on the same transiently accessible fish species, the plainfin midshipman (Porichthys notatus Girard, 1854). We conducted avian predator surveys at breeding beaches of plainfin midshipman across multiple years and sites. Our census data showed that Bald Eagle and Great Blue Heron abundances were higher when the tides were receding than incoming at Ladysmith Harbour, British Columbia, Canada, but the opposite trend was found for total predator abundance at a second site in Dabob Bay, Washington, USA. Glaucous-winged Gull abundance decreased over the course of the plainfin midshipman breeding season (April–July), whereas the abundances of the other three species remained stable. Our data suggest that the foraging activities of birds in the intertidal zones of western North America are linked with the tidal cycles, corresponding to periods of high prey vulnerability.

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Changes in bird communities throughout succession following fire and harvest in boreal forests of western North America: literature review and meta-analyses

Canadian Journal of Forest Research ◽

10.1139/x06-017 ◽

2006 ◽

Vol 36 (5) ◽

pp. 1299-1318 ◽

Cited By ~ 86

Author(s):

Jim Schieck ◽

Samantha J Song

Keyword(s):

North America ◽

Populus Tremuloides ◽

Boreal Forests ◽

Large Scale ◽

Forest Type ◽

Bird Species ◽

Bird Communities ◽

Forest Birds ◽

Western North America ◽

Meta Analyses

Within boreal forests of western North America, the dominant large-scale natural disturbance is wildfire. Thus, harvesting that is as similar as possible to fire is expected to best maintain natural bird communities. We reviewed studies of birds (mainly grouse, woodpeckers, and songbirds) from boreal forests of western North America and conducted meta-analyses to compare the similarity of bird communities occurring postfire versus postharvest. We compared the bird communities at five seral stages and also summarized the effects of retaining large live trees at harvest. Bird communities immediately postharvest differed greatly from those postfire. Differences between disturbance types disappeared as the forest regenerated, and both disturbance types became dominated by relatively few bird species in 31- to 75-year-old forests. During the period 76125 years postdisturbance, old-forest birds became present and bird species richness increased. However, the trajectory of forest succession during this period influenced bird communities; old aspen (Populus tremuloides Michx.), old mixedwood, and old white spruce (Picea glauca Moench (Voss)) forests all had different bird communities. Retention of large live trees in cutblocks resulted in their use by many old-forest birds, but results were not consistent among studies. Although most bird species had clear peaks in abundance in a specific forest type, no species with more than five detections was limited to a single forest type.

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