Introduction. Introduction Wetland Management -53% -60% Tennessee

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1 Waterbird and Food Resource Responses to Winter Drawdown in the east Tennessee River Valley John W. Laux M. S. Candidate University of Tennessee Knoxville Department of Forestry, Wildlife and Fisheries Introduction Wetland Loss -53% Dahl % Tennessee Introduction Wetland Management Waders Rails Cranes Waterfowl Shorebirds 1

2 Introduction Shorebirds Follow 3 Main Corridors through NA: - Atlantic Coast - Pacific Coast - Interior U.S. North America (~50) Tennessee River Valley (31) Introduction Shorebirds Over ½ of All Species in Decline! (USSCP) Introduction Migratory Stopovers: Critical for Survival Replenishment of Fat Reserves Shallowly Flooded Mudflats Tennessee River Valley INVERTEBRATES! 6 grams/day + 2 grams/day 8 grams/day (Loesch et al. 2000) x Stopover Duration (Pectoral Sandpipers) = 8-12 days (Lehnen & Krementz 2005) These areas serve as re-fueling areas between breeding and wintering grounds 2

3 Introduction Tennessee River Valley (TRV) 7 Southeastern States Historically Exposure Dependent Upon Precipitation Introduction Tennessee Valley Authority (TVA) 1933 Predictable Hydrology Year-Round Navigation Flood Control Electricity Generation Cool Nuclear Reactors Historically, reservoir downdowns began in June - July Increased Pressure to Delay Drawdowns (recreation) East TN: Douglas & Chickamauga 2004 Changes to Drawdown Schedules Purpose The goal of my research is to determine the influence of a delayed drawdown on waterbird use and food abundance Early vs. Late 3

4 Objectives Determine the influences of different drawdown dates in two east TRV reservoirs on: 1) Temporal Availability (Acreage) of Mudflats 2) Waterbird Use and Activities on Mudflats 3) Food Resource Abundance (i.e., invertebrates, moist-soil seeds, and vegetative browse) 4) Food Preferences (Least Sandpipers) 5) Proximate Factors of Habitat-use Patterns (i.e., soil moisture and compaction, H 2 0 depth, and vegetative structure) Study Sites Douglas Reservoir East Tennessee Rankin Bottoms WMA Near Confluence of the Nolichucky River French Broad River Near Confluence of the Study Sites Douglas Reservoir Douglas Reservoir Operating Guide (2006) Nolichucky River East Tennessee Mudflat Exposure Late July Early Aug. Rankin Bottoms WMA Early Drawdown French Broad River 4

5 Study Sites Chickamauga Reservoir East Tennessee Hiwassee Wildlife Refuge Near Charleston, TN Hiwassee River Study Sites Chickamauga Reservoir Chickamauga Reservoir Operating East Hiwassee Guide Wildlife (2006) Refuge Tennessee Near Charleston, TN Mudflat Exposure Early October Late Drawdown Hiwassee River Methods 1) Temporal Availability (Acreage) of Mudflats Quantified Weekly at Each Mudflat Trimble GeoExplorer XM Unit 5

6 Methods 1) Temporal Availability (Acreage) of Mudflats Quantified Weekly at Each Mudflat Week #1 Week #2 ESRI ArcGIS 9.1 Methods 2) Waterbird Use and Activities on Mudflats Quantified 2X / Week / Mudflat Species-Specific Abundance Scan Surveys Swarovski ST-80 (20-60X) Sunrise 11:00 a.m. Permanent Location Systematic Viewing Rotation Methods 60X (Mudflat) X 60X Survey Location Approximately the same viewing area was sampled at each mudflat 6

7 1 Methods First-Five - Instantaneous Activity 5 Random Individuals / Flock / Mudflat Example: Species 2 1. Least SP Least SP Least SP 5 4. Least SP 4 5. Least SP Activity FA FA FA FA WALK Waterbird Activities Food Acquisition Preening Inactive Alert Sleeping Antagonistic Courtship Walking Stretching Flying Swimming Tipping Diving One-Minute Activity Budgets Methods 2 Individuals / Species / Mudflat 7

8 Methods (Field) 3) Food Resources (i.e., invertebrates, moist-soil seeds, and vegetative browse) Quantified Every 2 Weeks Water Mudflat 988 Methods (Field) 3) Food Resources (i.e., invertebrates, moist-soil seeds, and vegetative browse) Quantified Every 2 Weeks Water 1-ft Mudflat 988 Methods (Field) 3) Food Resources: Vegetative Response Quantified Every 2 Weeks at Each Mudflat At Each Contour Midpoint 1-m 2 plots % Vertical Cover Species Richness Nudds Average (1977) Height Board % Horizontal Cover 8

9 Methods (Field) 3) Food Resources: Vegetative Response Above-ground Seed Biomass Production (0.5-m 2 plots) Vegetation Transect Water Mudflat Randomly Selected Individuals Methods (Field) 3) Food Resource Abundance: Invertebrates / Seed Quantified Every 2 Weeks at Each Mudflat Benthic Core Sampling New Transect 10m 20m Water 10m 20m Mudflat 988 Methods (Field) 3) Food Resource Abundance: Invertebrates / Seed Core Samples 8.8-cm Diameter 10-cm Depth 1 at shore 5 on land 5 in water Previous midpoint Wildco Bucket 9

10 Methods (Lab) Vegetative Biomass / Seed Production Seed Production: Biomass: Sorted to Species Seedheads Threshed Dried at 60 C for 24 hrs Dried at 60 C for 24 hrs Weighed to Nearest 0.01g Weighed to Nearest g Average Dry Seed Wt. Represented X as Dry Biomass (g/m 2 ) Stem Density in 1-m 2 plots Methods (Lab) Core Samples Seeds: Sorted to Family Inverts: Sorted Into 3 Categories Dried at 105 C for 24 hrs Moist-Soil Tree Weighed Seeds to Nearest Cocklebur g Dried at 60 C for 24 hrs Weighed to Nearest g Represented = as Dry Biomass (g/m 2 ) 2 ) Methods (2006) 4) Food preferences in the TRV 30 per month (Aug Jan) Upper Digestive Tract (Least Sandpipers) Pathogen Analyses 10

11 Acknowledgements Dr. Matthew Gray Dr. Roger D. Tankersley Billy Minser Hill Henry Wally Akins Jonathon Campbell Chase Grubb Questions 11