Document Type

Thesis - Open Access

Award Date

2010

Degree Name

Master of Science (MS)

Department / School

Wildlife and Fisheries Science

First Advisor

Kristel K. Bakker

Keywords

ring-necked pheasants, ducks, nests, habitat, conservation, south dakota, fragmented landscapes

Abstract

Grassland ecosystems in South Dakota have experienced significant transformations over the last 100 years. Landscapes are currently dominated by large agricultural fields interspersed with small, isolated grassland patches. These isolated grassland patches are hypothesized to experience decreased nest survival rates for ring-necked pheasants (Phasianus colchicus) and dabbling duck species due to small size and high degrees of fragmentation. Several natural resource agencies currently conserve grasslands throughout eastern South Dakota, but wildlife managers seek more information on how the size and spatial arrangement of grasslands affect targeted conservation strategies. Therefore, the objectives of this study were to: (1) evaluate the relationship of duck and pheasant nest survival and nest density between different grassland patch sizes, (2) evaluate the effects of woody cover (i.e., shelterbelts) on duck and pheasant nest survival and nest density, and (3) evaluate how landscape composition and the spatial arrangement of landscape features affect duck and pheasant nest survival and nest density in eastern South Dakota. I located duck (n=1,008) and ring-necked pheasant (n=595) nests on 44 patches that ranged in size from 3.64 to 56.66 ha in 12 counties in eastern South Dakota during the nesting seasons of 2008 and 2009. I analyzed nest survival data in Program MARK and developed models that best explain the interactions between nest survival and vegetation variables, patch size, presence of woody cover, and landscape composition. Three out of four duck species exhibited increased nest survival in landscapes with larger proportions of grassland and wetlands. For example, blue-winged teal (Anas discors) nest survival rates increased approximately 10% when the wetland area increased from 10% to 30%. Ring-necked pheasant nest survival decreased significantly in areas with larger proportions of farmsteads within 1,600 m. In landscapes with 1% farmstead area, nest survival was approximately 13%, but when the farmstead area was increased to 2% nest survival decreased to 6%. Additionally, ring-necked pheasant nest survival decreased with larger proportions of cropland within the surrounding landscape. Grassland patch size, the presence of woody cover, and the distance to woody cover were weakly supported in nest survival models for duck species. However, the presence of woody cover and the distance to woody cover did not affect ring-necked pheasant nest survival. Patch size, grassland proportions, and wetland proportions within the surrounding landscape increased nest densities of most species. Therefore, wildlife managers need to evaluate current landscape composition when determining locations to implement habitat conservation strategies that are intended to maximize duck and ring-necked pheasant production.

Library of Congress Subject Headings

Ring-necked pheasant -- Nests -- South Dakota
Ducks -- Nests -- South Dakota
Ring-necked pheasant -- Habitat -- Conservation -- South Dakota
Ducks -- Habitat -- Conservation -- South Dakota
Fragmented landscapes -- South Dakota

Description

Includes bibliographical references (page 52-62)

Format

application/pdf

Number of Pages

119

Publisher

South Dakota State University

Rights

Copyright © 2010 Keith Fisk

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