OVERVIEW INTRODUCTION TO SHOREBIRDS MANAGEMENT FOR SHOREBIRDS TVA REGIONAL SHOREBIRD PROJECT ESTIMATING SHOREBIRD NUMBERS

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1 SHOREBIRD CONSERVATION AND MONITORING RESOURCES US SHOREBIRD CONSERVATOIN PLAN WATERFOWL MANAGEMENT HANDBOOK - MANOMET CENTER FOR CONSERVATION SCIENCES & International Shorebird Survey (ISS) Migratory Only Program for Regional and International Shorebird Montiroting (PRISM) Breeding and Migratory Western Hemisphere Shorebird Preserve Network (WHSRN) Significant Breeding and Migratory Stop- over Sites OVERVIEW INTRODUCTION TO SHOREBIRDS MANAGEMENT FOR SHOREBIRDS TVA REGIONAL SHOREBIRD PROJECT ESTIMATING SHOREBIRD NUMBERS 1

2 WHAT ARE SHOREBIRDS? s Dowitchers Plovers Oystercatchers Avocets Stilts 214 SPECIES WORLDWIDE 50 REGULARLY OCCUR IN U.S. 31 OCCUR IN TN RIVER VALLEY Painting by James Coe MIGRATORY SPECIES RED KNOT 20,000 MILES IN 1 YEAR BAR-TAILED GODWIT 6,000 MILES NON-STOP NICHE PARTITIONING AMERICAN GOLDEN PLOVER AVOCET VARING BILL SHAPES AND LENGTHS ALLOW MULTIPLE SPECIES TO FORAGE IN SAME AREA 2

3 EXAMPLES OF SHOREBIRDS IN TN RIVER VALLEY KILLDEER GLEANS PREY FROM MUD TO UPLAND ZONES BLACK-BELLIED PLOVER SIMILAR FORAGING STRATEGY AS KILLDEER PECTORAL SANDPIPER FORAGES WITHIN VEGETATION AND MUD ZONE INCLUDING VERY SHALLOW WATER 3

4 GREATER YELLOWLEGS PRIMARILY FORAGES IN WATER SNIPE SHALLOW WATER AND MUD ZONE, OFTEN AROUND VEGETATION DUNLIN SHORT-BILLED DOWITCHER WADES IN DEEPER WATER, NOTE LONG BILL 4

5 MANAGEMENT OF SHOREBIRD HABITAT-BREEDING PROMOTE NATIVE GRASSLANDS SHOREBIRDS PREFER TO NEST IN GRASSLAND HABITATS. USE OF THESE HABITATS VARIES BY SPECIES, SOME (AVOCETS) PREFER SPARSELY VEGETATED HABITATS. OTHER SPECIES (UPLAND SANDPIPER) PREFER GRASSLANDS WITH MORE VERTICAL STRUCTURE. PRESCRIBED BURNING - A USEFUL TOOL FOR DEVELOPING SHOREBIRD NESTING HABITAT. ESTABLISH BREEDING SITES NEAR FOOD SOURCE NECESSARY FOR MOST SPECIES, ALTHOUGH NOT NEEDED FOR PLOVERS, AS THEY ACTIVELY FEED IN VEGETATIVE ZONE. RED KNOT MANAGEMENT FOR SHOREBIRDS - MIGRATION MOIST MUD FLAT HABITAT WITH <20% VEGETATIVE COVER SHALLOW WATER <20 CM DEEP LARGER FLATS ARE BETTER REDUCES IMPACTS FROM DISTURBANCES. TIMING IS CRITICAL - HABITAT MUST BE AVAILABLE WHEN BIRDS ARE PASSING THROUGH. MIGRATORY PERIOD BEGINS MID-JULY-OCTOBER, ADULTS MOVE THROUGH AREA BEFORE JUVENILES. ALSO PROVIDE HABITAT FOR WINTERING SPECIES (DUNLIN, LEAST SANDPIPERS). MANAGED SUB-IMPOUNDMENTS SHOULD BE DRY IN SUMMER, DISK VEGETATION, FILL AND SLOWLY DRAIN. EXOTIC VEGETATION CAN BE PROBLEMATIC. HOW DID TVA GET INVOLVED WITH SHOREBIRDS? TVA S RIVER OPERATION STUDY 5

6 Regional Assessment and Management of Inland Stopover Habitats for Shorebirds in the Tennessee Valley Partnerships Tennessee Valley Authority Tennessee Wildlife Resources Agency U.S. Fish and Wildlife Service Kentucky Department of Fish and Wildlife Resources Alabama Department of Conservation and Natural Resources University of Tennessee, Knoxville US Army Corps of Engineers Overview Construction of TVA dams over the past 60+ years has created extensive inland mudflat habitats in the Tennessee river valley through fall drawdown of the reservoir system There have been several major changes in the way TVA manages fall drawdown: 1970 s, 1980 s saw major changes system wide Other, smaller-scale changes on individual reservoirs Latest change: Reservoir Operations Study (ROS), an extensive study of environmental impacts caused by different reservoir management scenarios One area of special concern in the ROS was the impact of extended summer reservoir levels, delaying the creation of mudflat habitats used by migrating shorebirds. There has never been a valley-wide, systematic study of shorebird habitat use. No evidence that any of the past reservoir management scenarios has been optimal for creating shorebird habitat. 6

7 Project Goals As part of the ROS record of decision, TVA will fund a 5 year study of shorebird resources across the Tennessee River Valley. Primary objectives of the study: What shorebird species migrate through the valley, and in what numbers? When do they migrate through? Look at individual species and total number of individuals in all species. Where do shorebirds stopover in the valley? Do mudflats on TVA managed reservoirs play a key role in long-term migration stability? How does TVA management of the river system affect stopover habitats? Can we identify an ideal river management scenario that provides the best combination of timing and extent of habitat availability? Key point: Although we are tasked with assessing management impacts of ROS, the scientists involved in the study are most interested in an overall assessment of shorebird resources both on and off TVA lands, in cooperation with other state and federal agencies and public interest groups. Tennessee River Valley TVA manages 9 mainstem reservoirs and 40 tributary reservoirs. Multiple use management system. Tributary reservoirs provide little habitat due to local geomorphology steep sided, deep lakes with few mudflats. Mainstem reservoirs are shallow and provide a lot of habitat. Of these Kentucky and Wheeler reservoirs encompass the most. Douglas and Chickamauga provide key habitat in the eastern valley. Reservoir Operations Study Five year study to examine all aspects of TVA s management of the Tennessee River System. ROS results guide daily management of the river system. Multiple use: Navigation, flood control, power production, recreation, resource conservation. Key public concern was to keep docks and marinas open through Labor Day. Extension of summer pool was accepted on some reservoirs, rejected on others. No change on Kentucky lake, which has a majority of valley shorebird habitat. Changes in the 1990s were evaluated by TVA and other agencies, and determined harmful to habitat and flood control. River Operations Group continues to evaluate ROS. Our study will provide valuable information on shorebird habitats and timing, and help make better decisions. ROS is an adaptive management plan. 7

8 Mudflats Start Lots of Mudflats Changes in reservoir levels under ROS Kentucky Lake Wheeler Lake Changes in reservoir levels under ROS Chickamauga Lake Douglas Lake Regional habitat assessment Collaborative effort, with TVA helping to organize surveys identify areas to monitor. May 2005: first regional meeting with TVA, TWRA, USFWS, KYFWS and other interested parties to begin organizing this valley-wide effort. Other, regional meetings to follow. Includes identification workshops, protocol review, identification of habitats. International Shorebird Survey protocol: Survey sites each third of the month starting in July and ending in October Conduct surveys throughout the valley on the same day as weather and logistics permit Alternative guidelines for less intensively monitored sites. Monitoring by agencies on key sites, citizen scientists on other sites Periodic monitoring to gauge overwintering possibilities. 8

9 Techniques to identify and assess key habitats Expert opinion captured as valley-wide map series, identifying both on and off reservoir habitats Historic maps showing pre-impoundment elevations to highlight locations where unknown mudflats may exist Cooperative work with Corps of Engineers for bathymetry and aerial photography LIDAR and aerial photography on key flats to quantify mudflat availability at different reservoir levels Vegetation study to quantify habitat suitability for overwintering waterfowl Habitat Mapping Habitat Mapping 9

10 How much habitat A critical question is how much exposed mudflat is required to support the number of birds migrating through at any given time Trying to identify the best scenario to provide ideal habitat to the highest number of birds and species: When is habitat exposed, and how much is exposed at any given elevation? Is this best for birds? LIght Detection and Ranging (LIDAR) Laser Data Acquisition Technology Airborne system for rapid coverage of difficult terrain and applications Laser points are positioned by highly accurate GPS and Inertial Measurement System Produce very precise digital elevation models (DEMs) Acquires 15,000 points per second, 1 point every square meter on the ground Typical vertical accuracy inches Typical horizontal accuracy inches Systematic Shorebird Surveys 10

11 Reservoir Level 990 Reservoir Level 987 Reservoir Level

12 Reservoir Level 983 Reservoir Level 980 Reservoir Level

13 Lesser Yellowlegs 0.2% Gr eat er Yellowlegs 1.8% Pect oral 0.6% Killdeer 12.9% Other 0.5% Peeps 3.0% Dunlin 81.0% Solitary 0.1% Reservoir Level 970 Historic Patterns & Citizen scientists Semipalmat ed Plover 1.5% Peeps 33.7% August (n=2465 birds, 19 visits) Solitary Spot t ed 3.4% 2.0% Ot her 2.8% Pectoral Nove m ber (n=1756 birds, 7 visits) Killdeer 27.1% Dunlin 0.0% Great er Yellowlegs 2.3% Lesser Yellowlegs 7.0% September Solitary (n=1552 birds, 14 visits) Spotted Greater 0.2% Semipalmat 1.1% Yellow legs 0.5% ed Plover 6.7% Killdeer 34.2% Pectoral 0.6% Peeps 38.1% Pectoral Other 5.2% 11.1% Decem ber (n=166 birds, 2 visits) Peeps 22.3% Lesser Yellow legs 3.0% October Solitary (n=544 birds, 9 visits) Spotted Peeps 0.2% Pectoral 11.2% 0.4% 7.5% Other 0.4% Dunlin Lesser 43.4% Yellow legs 1.5% Killdeer 34.6% Greater Yellow legs 0.9% Killdeer 77.1% Migration Timing 13

14 Migration Timing University studies TVA is funding university studies on specific habitat questions: University of Tennessee, Department of Geography: role of mudflat shape and reservoir level in creating mudflat habitats during fall migration. University of Tennessee, Department of Forestry, Wildlife and Fisheries: waterbird use of mudflats in east Tennessee. Examining vegetation development, abundance of invertebrates, and seasonal use of flats by shorebirds and waterfowl. Other studies as funding and needs warrant: Similar waterbird study in west TN. What have we learned? 1. Historical shorebird data does not adequately depict presence of species throughout fall migration. We need data to be acquired systematically, throughout migratory period. 2. Approximately 150 mud flats exist throughout the Valley, only a fraction provide optimal habitat for shorebirds. 3. Delaying drawdown results in an overall reduction in vegetative biomass and species diversity. 4. Reservoir drawdown should be slow and steady, dramatic drawdowns result in poorly developed vegetative communities; limiting the establishment of moist soil species. 14

15 Questions? Contact information: Roger Tankersley, Jr.: GIS and habitat assessment Travis H. (Hill) Henry: Shorebird monitoring Michael Roedel: Tennessee Wildlife Resources Agency APPLICATION OF DRAWDOWN MODEL A MODEL TO DETERMINE SHOREBIRD HABITAT AVAILABILITY UNDER DIFFERENT DRAWDOWN REGIMES. 15