Sandhill Crane Survey

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Muleshoe and Grulla National Wildlife Refuges recently developed a protocol to formalize their approach to monitoring sandhill cranes


Separated by less than 20 miles, Muleshoe and Grulla National Wildlife Refuges are both critically important to sandhill crane conservation. Grulla National Wildlife Refuge, in fact, is one of the few refuges that was established for the purpose of providing habitat for migrating and wintering sandhill cranes. Moreover, at Muleshoe National Wildlife Refuge, peak numbers of wintering sandhill cranes average over 70,000 annually! That means 15% of the Midcontinent Population of Lesser Sandhill Cranes calls Muleshoe National Wildlife Refuge home during winter months. The cranes roost on the refuges’ large saline lakes at night, and forage off refuge in cropland during daylight hours. Together, the complex of shallow saline lakes and nearby foraging grounds make the complex of refuges and surrounding croplands both attractive and essential to migrating and wintering sandhill cranes. Sandhill cranes can be found on the two refuges from October through March.

Sandhill cranes that use Muleshoe and Grulla National Wildlife Refuges are part of the same impressive congregation that visits the Platte River during spring migration. These cranes travel through the central plains and prairies of Canada and United States, and most summer in the arctic. Texas Tech University recently put GPS trackers on 30 plus sandhill cranes on and near Muleshoe National Wildlife Refuge to determine how the cranes used the areas around the refuges and also see where they traveled during other times of the year.  What they found out was these birds really move. Birds spent summers in Nunavut, Northwest Territories, Alaska, and even Siberia!

Muleshoe and Grulla National Wildlife Refuges recently developed a method to track the numbers of cranes spending winters at the refuges and have formalized this approach in a protocol entitled: “Site-specific Protocol for Monitoring Sandhill Cranes: Muleshoe and Grulla National Wildlife Refuges”. This protocol was developed in cooperation with Texas Tech University’s Department of Natural Resources Management and the National Wildlife Refuge System’s Inventory and Monitoring. Although both refuges have long surveyed cranes, the protocol’s purpose is to standardize collection of information needed to inform sandhill crane conservation at the refuge and regional level. The protocol standardizes such things as time of day the survey is conducted, number and location of observation points, data sheets (or field sheets), and data storage. The protocol also identifies the roles of refuge staff members, including activities such as arranging for vehicles, volunteers and equipment. Additionally, this protocol allows for the survey data to be stored in a centralized database along with other waterbird and waterfowl survey data from throughout the National Wildlife Refuge System. Data storage is critical, as data are of no value if lost. The centralized database also allows for easy production of reports that help inform management actions concerning sandhill crane habitat. Essentially, the protocol standardizes all things related to how the data are collected and how the data are stored to insure continuity as individuals involved in the survey change through time.

This protocol doesn’t simply focus on cranes using the two refuges, but also covers multiple large roost sites found in the surrounding landscape. Coverage of off-refuge roost sites is important because the cranes using the local area rely on multiple roost sites, and individual cranes even alternate roost sites throughout the winter. Thus, when trying to gauge how many sandhill cranes are in the area, it is important to identify and estimate crane abundance on all saline lakes to avoid greatly underestimating sandhill crane use of the region.

The U.S. Fish and Wildlife Service works with cooperators and with partner driven initiatives to conserve sandhill cranes throughout their range. Information derived from this protocol will provide conservation partners with a baseline of crane numbers. These baseline numbers will be used to estimate food requirements, in terms of both calories and acreage needed, of the local crane population. This will enable conservation partners to develop long-term conservation initiatives that take into account cropland acreage and types, and cropland proximity to roost sites, in order to insure the refuges and region continue to contribute to crane conservation.

The sandhill crane monitoring protocol is available for public download at https://ecos.fws.gov/ServCat/DownloadFile/150802.  Information collected as part of the protocol is available to partners involved in implementing sandhill crane conservation initiatives. For more information, please contact the Refuge Biologist at 806-499-3382.

Additional information on sandhill cranes can be found at the following locations:

USFWS Migratory Birds:  https://www.fws.gov/birds/surveys-and-data/webless-migratory-game-birds/sandhill-cranes.php

Texas Tech University research project on sandhill crane landscape suitability the Southern High Plains, including Muleshoe and Grulla NWRs (video by Kathryn Brautigam):  https://www.youtube.com/watch?v=b_ZsaFsd8xY

Sandhill Cranes on Paul’s Lake, Muleshoe NWR (video by GIL Lamb Advertising / Channel 6, Muleshoe, TX):  https://www.youtube.com/watch?v=vCioEa0RcDU