Changes in Breeding Bird Populations in North Dakota: 1967 to 1992-93
Abstract: We compared breeding bird populations in North Dakota using surveys conducted in 1967 and 1992-93. In decreasing order, the five most frequently occurring species were Horned Lark (Eremophia alpestris), Brown-headed Cowbird (Molothrus ater), Western Meadowlark (Sturnella neglecta), Red-winged Blackbird (Agelaius phoeniceus), and Eastern Kingbird (Tyrannus tyrannus). The five most abundant species - Horned Lark, Chestnut-collared Longspur (Calcarius ornatus), Red-winged Blackbird, Western Meadowlark, and Brown-headed Cowbird - accounted for 31-41% of the estimated statewide breeding bird population in the three years. Although species composition remained relatively similar among years, between-year patterns in abundance and frequency varied considerably among species. Data from this survey and the North American Breeding Bird Survey indicated that species exhibiting significant declines were primarily grassland- and wetland-breeding birds, whereas species exhibiting significant increases primarily were those associated with human structures and woody vegetation. Population declines and increases for species with similar habitat associations paralleled breeding habitat changes, providing evidence that factors on the breeding grounds are having a detectable effect on breeding birds in the northern Great Plains.
Table of Contents
Tables
- Table 1 -- Breeding bird populations in 128 randomly selected quarter-sections in North Dakota.
- Table 2 -- Composition of breeding birds and mean number of indicated pairs on 128 randomly selected quarter-sections in North Dakota, by year, breeding habitat, and migratory status.
- Table 3 -- Land use changes on the 128 quarter-sections surveyed in 1967, 1992, and 1993, and percentage change between the two periods (1992 and 1993 averaged).
Appendices
- Appendix 1 -- Statewide frequencies of occurrence (confidence interval) of common bird species (i.e. species with frequencies greater than 10%) in North Dakota.
- Appendix 2 -- Statewide breeding population estimates (1,000's of pairs with confidence intervals) of common species of birds (i.e. species with statewide frequencies greater than 10%) in North Dakota.
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This resource is based on the following source (Northern Prairie Publication 0983):
Igl, Lawrence D., and Douglas H. Johnson. 1997. Changes in breeding bird populations in North Dakota: 1967 to 1992-93. The Auk 114(1):74-92.
This resource should be cited as:
Igl, Lawrence D., and Douglas H. Johnson. 1997. Changes in breeding bird populations in North Dakota: 1967 to 1992-93. The Auk 114(1):74-92. Northern Prairie Wildlife Research Center Online. http://www.npwrc.usgs.gov/resource/birds/birdpop/index.htm (Version 31JUL97).
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