Since the cranes were released in March, they have been quite the travelers. The birds moved around quite a bit in the early part of the summer. The drought that has plagued a large portion of the state encouraged the birds to move around in search of habitats they use for foraging, loafing, and roosting. With the progression of summer, the birds have started to settle down, allowing for the characterization of habitats cranes use throughout SW LA.
Tandi Perkins, a research associate studying the cranes under Dr. Sammy King at LSU, developed our sampling protocol. As we have mentioned in other blog entries, each of the birds is fitted with a transmitter that allows us to monitor their movements throughout the state. The transmitters generate data (GPS coordinates) 3 times daily. Each week Tandi downloads the GPS coordinates generated by the transmitters and selects the location points to characterize what type of habitat cranes are in and how they are using it.
If the points fall on private property, then the landowner must be contacted and permission to access their property must be obtained. Once permission is obtained then Sara, Tandi, or myself venture out in the field to start collecting data.
Once at the site, the variables to be measured include:
General habitat observations: What is the habitat type? Is it a crawfish farm, rice field, or in the marsh?
Vegetation characteristics: What is the dominate vegetation? What is the average height of the vegetation and how dense is it? These variables are collected at each of the 4 cardinal directions and from “plot center” (where we place the pole in the ground). We use a Robel pole and yardstick (see the attached photos of the orange and white pole); this allows us to measure all vegetation and hydrology characteristics uniformly.
Hydrological characteristics: Again, using the Robel pole and yard stick, we measure the water depth at plot center and in each of the four cardinal directions.
Presence of Whooping cranes and other waterbirds: Are the cranes still in the vicinity? If so, we conduct a behavioral study of any cranes present, which in a nutshell means we watch each bird for 5 minutes and document all behavior within that time frame. We have to be careful and keep a “safe distance” as we do not want to disturb the cranes and certainly do not want to alter their behavior due to our presence. If the cranes aren’t present at the time of sampling, then we make note of other types of waterbirds that utilize that same type of habitat.
The information collected at these sites is extremely important. This knowledge will help us understand what cranes need throughout the year and what we need to do to try and provide it so that they will be successful here in SW LA.
Written by Carrie Salyers