Document Type

Thesis - University Access Only

Award Date

2007

Degree Name

Master of Science (MS)

Department / School

Geography

Abstract

Mixtures of legumes and non-native cool-season grasses have long been planted as avian nesting cover on wildlife management units. However in the recent past, there has been a trend toward planting native warm-season grasses. In 2000, South Dakota Game, Fish and Parks (SDGFP) began planting mixtures of cool-season and warm-season native grasses with non-native alfalfa (Medicago saliva) or red clover (Trifolium pratense) on Game Production Areas (GPAs). It is thought this mixed-vegetation planting (MVP) may better approximate native prairie. Project objectives were to (1) estimate avian nesting density, nest success and percent of eggs hatched within study sites of MVP, (2) assess the effects of stand age class on nest density and nest success, (3) compare vegetative species composition between nest sites and random locations, (4) compare nest site and above-canopy temperatures and relative humidity, and (5) to address the effects spraying of noxious weeds may have on nest success. Three fields of MVP were randomly selected from each of the 2000-2004 year-class plantings. The hockey stick search method was used to systematically search 10% of each field's total area. The 2005 field season yielded 178 nests while 362 were located in 2006. Mean apparent nest success for pheasants (Phasianus colchicus) (16.3 vs. 12.6%) and passerines (Passeriformes) (34.4 vs. 24.8%) was marginally higher in 2006 than in 2005, while lower for ducks (Anas spp.) (10.5 vs. 19.4%). Pheasant, passerine, and duck nest densities were also higher in 2006 than in 2005 ( 4.6 vs. 2.8, 1.9 vs. 1.0, and 0.6 vs. 0.2 nests/ha, respectively). Mean percentage of eggs hatched from all successful pheasant nests was similar (P = 0.92) between 2005 and 2006 (87.1 vs. 86.5%). Multiple regression analyses modeling nest density as a function of stand age class, field size and year were performed, while nest success was modeled as a function of stand age class, density, field size and year. Nest density (R2 = 0.23, P = 0.01) explained the greatest variation in pheasant nest success where success increased with density. Field size (R2 = 0.19, P = 0.02) and year (R2 = 0.17, P = 0.02) explained the greatest variation in duck nest density, while field size explained the greatest variation in nest success (R2 = 0.31, P = 0.03). Both duck nest density and nest success increased with field size. No variables entered the model to explain variation in passerine nest densities or nest success. Pheasant (P = 0.48), passerines (P = 0.13), and ducks (P = 0.31) all nested in habitat proportionate to its availability with no preference for nest sites dominated by cool season grasses, warm-season grasses or mixtures of both. Average temperatures in 2005 for all nests were similar (P = 0.89) among nest sites of cool-season grasses (22.9°C), warm-season grasses (23.1 °C), and mixtures of both (22.5°C). Temperature differentials between nest site and above-canopy were similar (P = 0.58) as well (1 .4, 1.6, and l.3°C, respectively). Humidity was similar (P = 0.84) among nest sites of cool-season grasses (55%), warm-season grasses (57%), and mixtures of both (56%), as were humidity differentials (P = 1.00) (7, 7, and 7%). Mammalian predators caused the greatest percentage of nest failure with large mammals destroying 21 and 24% of all nests located in 2005 and 2006; in addition, small mammals destroyed 21 and 22% of all nests, respectively. Abandonment rate in 2005 was twice that of 2006, being 21 and 10%, respectively. Brown-headed cowbird parasitism caused the failure of 38 and 24% of all passerine nests in 2005 and 2006, respectively. My results suggest avian nest density and nest success within MVPs are similar to those found in previous studies evaluating DNC and WSN plantings in eastern South Dakota. Seasonality in growth as well as increased structural complexity provided by MVPs is also likely to provide benefits beyond that depicted by this study. Hence, wildlife managers and habitat biologists should consider MVPs when establishing avian nesting habitat.

Library of Congress Subject Headings

Pheasant shooting -- South Dakota

Shooting preserves -- South Dakota

Pheasants -- South Dakota

Hunters -- South Dakota

Format

application/pdf

Number of Pages

93

Publisher

South Dakota State University

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