Whooping Crane Telemetry Project:
Interview with a Researcher
Jessica Rempel is a researcher with the Crane Trust. This organization owns or manages more than 10,000 acres of land along an important crane migration stopover: Nebraska's Platte River. Ms. Rempel manages a new research project in which two wild Whooping cranes from the western flock (the only natural flock) became the first birds to fly with a GPS device attached to their legs. Find out more about this research project that could provide information to make migration safer for endangered Whooping cranes.


Q. When did the first Whooping crane captures and bandings take place to start the project?

A. In December 2009 we captured the first two individuals on the flock's Texas wintering grounds at Aransas National Wildlife Refuge. We will attempt to capture more cranes in Canada in August.

Q. What first gave you the idea for this project? What are your goals?

A. The Whooping Crane Recovery Plan (WCRP) calls for the protection and enhancement of the breeding, migration, and wintering habitat for the Aransas Wood Buffalo population (AWBP) of Whooping Cranes. The most serious current threat to the AWBP is mortality that occurs during migration. Efforts to reduce mortality throughout the migration corridor cannot be accomplished without better data and information as to the causes, locations, and conditions under which Whooping Crane mortality occurs. The objective of the telemetry project is to gain a greater understanding of Whooping Crane migration behavior and in particular identify the potential causes and locations where mortality may occur. Specifically, we want to:
  1. Gain a better understanding of stopover areas, habitat use patterns, and factors influencing habitat use at different spatial and temporal scales
  2. Define a current migratory route to compare to previous route models and determine environmental and anthropogenic factors that influence migratory behavior
  3. Identify causes, locations, and conditions of actual or potential mortality, and
  4. Expand current knowledge of winter and breeding ground use through high resolution GPS technology.

Information generated by this study will help us in developing and implementing activities that attempt to reduce threats and ultimately influence levels of mortality during migration.

Q. Who decided how, when, and which cranes would be "radioed," and why were those cranes chosen?

A. Dr. Felipe Chavez-Ramirez of The Crane Trust in Nebraska developed the telemetry project proposal in collaboration with other crane biologists at the Trust and with other crane researchers. In the previous radio telemetry study that was done in the 1980s, only juvenile cranes were radioed. We wanted a broader representation of the population, including adults, subadults, and juveniles, so we decided to trap white (adult and subadult) birds on the wintering grounds in Texas and juveniles on the breeding grounds in Canada. Logistics are simpler on the wintering grounds, so we decided to attempt to trap the white birds there. Also, on the wintering grounds, we can spread out our capture attempts over the entire season (November through March). On the breeding grounds in Canada, we will only be able to catch juveniles before fledging age. Therefore, we are working within a short window of time when the cranes are large enough to trap and put a transmitter on, but have not fledged yet (about a one week period of time in August).

The captures were opportunistic — whatever crane came along. We set up our leg snares in locations where we know there are cranes and hope one gets trapped! We sit in blinds close to the snares so we can run out to the bird, control it, and put a hood on it to calm it down as soon as possible after being snared. We spend long hours sitting in the blinds. When we capture more cranes in Canada in August, the capture technique is different, as we will be trapping nestlings who have not fledged yet. We use a plane to locate the cranes and then a helicopter to drop us off close to the crane. Then we chase it and grab it and do all the same processing that we do in Texas (as shown in the slideshow story).
Q. How many Whooping cranes in all will be banded for the project?

A. We plan to radio 60 cranes over the next three years (2010-2013). Whether or not we will radio more cranes after that depends on the results of the current project, the permission of the Whooping Crane Recovery Team, and funding. We will attempt to capture 10 cranes on the wintering grounds and 10 cranes on the breeding grounds per year for the next three years for a total of 60 cranes. We will attempt to capture cranes from throughout their wintering and breeding ranges to get as randomized and representative a sample of the population as possible.

Q. How long will the cranes wear the leg bands, and how long will the GPS transmitters last?

A. The cranes will wear the leg bands for life. However, some bands may fall off due to normal wear and tear, but we expect most bands to remain attached to the birds for many years. The GPS transmitters are solar-powered. They
weighs less than 3 ounces and are expected to function for 3-5 years.
Q. How do the devices work? How often will data be transmitted?

A. The solar-powered tracking device records its position every six hours and uploads the information to a satellite. We are collecting 4 high-resolution GPS fixes per bird per day. These GPS fixes are within about 50 meters of the actual location of the bird. Data are transmitted to the Argos satellite every 56 hours and we access these data via a password-protected logon to the Argos website. If the GPS signal remains in one loation for 12 hours, we may conclude that something happened and search for the bird. This could lead us to a critical piece of information for the birds' survival.

Q. What will you do with the data? (What can this data identify to you, or what questions could the data answer, or what new questions might be raised as data come in?)

A. As soon as new data is available, I download these data and plot them in computer mapping programs (ArcGIS and Google Earth). I check to make sure the data are being collected as expected and that the cranes are alive and moving. By plotting these data with other data layers (e.g., aerial photographs, political boundaries, roads, water bodies, etc.), we can determine where the birds are spending their time. We can identify roost sites and feeding sites and can characterize site and landscape level features of these locations.

Once we collect multiple seasons and years of data, we will be able to determine if the current migratory route is similar to the one that has been estimated based on opportunistic observations of migrating cranes, if cranes use the same or similar migratory routes in the spring and the fall and year-to-year, and if there are important stopovers that have been overlooked. We will be visiting the locations cranes stopped to collect data, describe the locations, and determine what site and landscape features appear to be important to migrating cranes. We will also be collecting weather data during migration to examine how weather patterns affect migration.

Q. What hurdles had to be overcome before you could start the project?

A. First we got permission from the Whooping Crane Recovery Team. Then, we were required to obtain or update a number of permits and authorizations to be allowed to capture and handle the Whooping Cranes. In the United States, we updated an existing threatened and endangered species federal fish and wildlife permit to include the Whooping Crane telemetry project, we updated an existing federal bird banding permit to include marking Whooping Cranes, we obtained a special use permit for research and monitoring at Aransas National Wildlife Refuge, and the Texas Parks and Wildlife Department granted us a scientific research permit for trapping activities in two counties in Texas. In Canada, we are working with a colleague at the Canadian Wildlife Service (Lea Craig-Moore) to obtain or update all of the required permits and authorizations for trapping and marking Whooping Cranes in Canada. These include a federal scientific permit, bird banding office permit, SARA (species at risk act) permit, provincial permits, and park permits. All permits and authorizations required submission of a detailed project proposal, lists of individuals working on the project, and answers to specific questions listed in each application.

Q. What could go wrong?

A. Handling Cranes. Whenever handling wildlife, there is the risk of the animal experiencing stress or injury. That is why only experienced crane experts and veterinarians have been involved in the project. We follow the "Guidelines for Field Capture and Safe Handling of Whooping Cranes to Avoid Capture-Related Stress and Injury" established by the International Crane Foundation and make every effort to minimize the amount of time the crane is in hand and minimize stress to the crane. If a crane were to become injured because of our activities, the crane would immediately be put in the care of an experienced veterinarian, all efforts would be made to release the crane back into the wild if at all possible, and all trapping attempts would cease until the USFWS performs an investigation and determines whether we would be allowed to continue trapping or not.

Other Dangers for Cranes. In regards to things that could go wrong in general, the list of threats to Whooping Cranes is long. On migration, collision with power lines is the number one known cause of death. Shooting, disease, and predation are other known mortality factors. Habitat loss is also a threat on migration and on the wintering grounds where an expanding population is establishing new territories on state, private, and other properties outside the protected area of Aransas NWR.

Journal or Discussion Questions
  • What makes migration such a dangerous time for cranes?
  • How do researchers work as a team on this project?
  • What are your views about this research project?
  • What can you think of that might help cranes have safer migrations?