Sandhill Cranes and Waterfowl of the North Platte River Valley: Evaluation of Habitat Selection to Guide Conservation Delivery { Emily Munter, Wildlife Biologist U.S. Fish and Wildlife Service Nebraska Partners for Fish and Wildlife Program
North Platte River
North Platte River
Project Need Waterfowl: Outside of mid-winter survey data, population estimates lacking. Habitat selection variables lacking. Important tenant for conservation work is providing quality and quantity of spring migration habitat to positively influence reproductive success. Cranes: Iverson et al. (1987) reported average of 131,000 cranes annually. Recent estimates closer to 55,000 to 70,000 individuals, not scientifically documented. Also noted that river roost sites and adjacent wetlands most at risk. Krapu et al. (1985) noted reduction in channel size by up to 90%. Distribution and densities of cranes function of location of suitable roost habitat and food availability. Crowding in limited roost sites puts birds at risk of catastrophic events. Based on known bird use and limited but important supporting research, North Platte River is focus area of conservation concern. NNLP, PFW Strategic Plan, Ducks Unlimited National Business Plan, NAWMP, Crane Status Survey and Conservation Plan, RWBJV Implementation Plan, others.
Project Need Little information available for spring migration habitat selection and population estimates. Multiple conservation partners delivering habitat programs to benefit priority species with limited information. Need to be efficient, effective, and proactive in utilizing limited resources. Need to identify geography and scale necessary to best meet program, plan, and population goals. Need replicable parameters and methodology to develop a landscape-scale, basin-wide conservation design and strategy.
Project Parameters End products: 1. Survey data on distribution and abundance of sandhill cranes and waterfowl during spring migration on North and South Platte Rivers. 2. High resolution vegetation map characterizing preferred crane and waterfowl habitats during spring migration. 3. Species distribution models describing and predicting habitat and habitat selection. 4. Decision support system to prioritize on-the-ground conservation actions for cranes and waterfowl.
Methodology Waterfowl Four aerial surveys conducted between February 15 and March 31. Begin 30 minutes before sunrise and conclude by 1300. Observations grouped into ducks, dark geese, light geese, and swans. Cranes Six aerial surveys conducted between March 1 and April 30. Survey eastern and western stretches on two consecutive mornings. Begin 30 minutes before sunrise and conclude by 2 hours after sunrise. Both Flight piloted by Service Flyway Biologist and experienced observer. Target altitude 400 above ground level. Pilot and observer record birds from respective side of plane. Data recorded at each observation location: GPS location, time, guild, location within river, habitat type. High priority, off-channel wetlands also identified/surveyed.
Completed Surveys Waterfowl Flights: 2014: 2/26, 3/6, 3/13, 3/20 2015: 2/19, 2/28, 3/5, 3/12 Crane Flights: 2014: 3/14, 3/21, 4/2, 4/7 2015: 3/11, 3/13, 3/19, 3/20, 3/28, 3/29, 4/1, 4/2, 4/10, 4/11 Also conducted April 3, 2014 flight with NEBRASKAland Magazine Regional Editor. Currently collaborating on magazine article on project.
Preliminary Results: Ducks
Preliminary Results: Ducks
Preliminary Results: CAGO
Preliminary Results: CAGO
Preliminary Results: Cranes 100000 80000 2014 2015 Count 60000 40000 20000 0 3/10-3/16 3/17-3/23 3/24-3/20 3/31-4/6 4/7-4/13 Survey Date Range
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Next Steps Short term: Poster presentation with preliminary results at 2016 NADS (last week.) Create high resolution vegetation map with 2014 NAIP imagery. Refine habitat variables to be evaluated (i.e. channel width, water depth, distance to woodland.) Work with USGS NPWRC in development of species distribution models and decision support tools. Conduct 2016 aerial surveys.
Next Steps Long term: Evaluate need for and secure funding for additional survey years to better account for variability in migration chronology, weather, and hydrologic conditions. Complete, publish, and distribute data and models (2016). Work with conservation partners to incorporate decision support into habitat conservation activities. Expand and apply approach at landscape level. Establish and implement long-term survey and monitoring protocols to evaluate efficacy of restoration actions. Complete NEBRASKAland Magazine article.
Questions?