Cathy Nowak, Wildlife Biologist on the Ladd Marsh Wildlife Area presented the results of research described below on Sandhill cranes at a professional meeting in January, 2017. Her presentation is attached via the following link:
A paper based on the information in the presentation is in press. We hope to post a link to it when it is published.
Project Description and Background:
The Oregon Department of Fish and Wildlife initiated the Sandhill Crane Satellite Telemetry Project in spring 2015 with the assistance of Dr. Blake Grisham (Grisham Climate Response Lab, Texas Tech University), Friends of Ladd Marsh and others. On this page you will find information about the project including capture, color banding and some of the birds’ movements since being fitted with transmitters. This page is a work in progress with information added as time permits so please check back for updates.
Project Partners and Sponsors:
- Oregon Department of Fish and Wildlife
- Friends of Ladd Marsh
- Grisham Climate Response Lab at Texas Tech University
- US Fish and Wildlife Service
- Oregon Wildlife
- The Wildhorse Foundation
- The Norcross Wildlife Foundation, Inc
- The Oregon Chapter of the Wildlife Society
- Oregon Birding Association
Ladd Marsh Wildlife Area is host to at least 25 nesting pairs of Greater Sandhill Cranes plus fifty or more non-breeding birds that arrive on the wildlife area in spring, disappear for the summer, then return to stage and presumably migrate with the nesting birds in the fall. Ladd Marsh staff and partners initiated color banding of cranes hatched on the marsh in 2007 in an effort to learn where these birds winter. By spring 2015, we had received no reports of banded birds on the wintering area. In 2015 Friends of Ladd Marsh applied for and received grants and private donations begin attaching GPS satellite transmitters (PTTs) to sandhill cranes in collaboration with Dr. Blake Grisham and Texas Tech University. A variety of funding sources have contributed to the purchase of additional transmitters as well as funding ongoing data acquisition through the Argos Satellite System.
In 2018, the project’s 4th year, we have learned much about sandhill crane movements during the summer breeding season, fall migration, overwintering and spring migration. We have now placed PTTs on 10 adults and 2 hatch year colts. One adult (captured in 2015) died on Ladd Marsh of unknown causes, possibly a powerline strike, in spring 2016. Another adult (captured spring 2016) died of unknown causes in southeastern Washington in summer 2016. It was found by a farmer and the transmitter was returned. Six of the transmitters have failed. One of those was recovered when the bird was recaptured this spring so we were able to see the cause of the failure: the panel attaching the antenna to the PTT was completely gone (see photo). The crane may have pulled it off or the plastic may have become brittle with time. We have no way of knowing how it occurred. As of late summer 2018, the project has 5 functioning PTTS on cranes in addition to nearly 30 cranes with color-bands only, no transmitter.
In fall 2015, we electronically witnessed the first documented migration of Ladd Marsh cranes to their wintering area. All 3 birds with PTTs, including a hatch year colt traveling with its parents, went to California’s Central Valley. All 3 birds traveled to the general area of Chico, CA. In December, one of the adults moved south to the area of Stockton (for maps, see the slideshow at the link “Long Term Monitoring of Greater Sandhill Cranes_TN”).
In fall 2016, 4 of 5 cranes with functioning PTTs went to the Central Valley in California but one adult (A43), with its mate and fledged chick from that summer, migrated to the lower Colorado River Valley on the border of Arizona and California. This was just the second documented case of sandhill cranes from two different populations using one breeding area. Unfortunately, the PTT on that crane failed shortly after its arrival in Arizona. Its movements during that winter and subsequent spring migration were a mystery. A43 and it mate were seen on Ladd Marsh in spring and summer of 2017.
We were unable to capture any adult cranes in 2017 but we did catch a pre-fledging colt and fit it with a PTT. In fall 2017, PTTs were functioning on 3 cranes: 2 captured in 2015 (1 as an adult and 1 as a colt, now a 3rd year bird) and the colt captured summer 2017. All 3 birds traveled to the Central Valley for the winter.
We had a successful capture season in spring 2018, with help from an entire crew of Texas Tech University faculty and students. We caught 7 birds and placed PTTs on 2 of them. The others were marked with color bands. The first bird captured was A43, the crane that wintered in Arizona 2016-2017. We removed the broken PTT and replaced it with a shiny new GPS transmitter and new leg bands. A43 is now LM026. This fall we will have the opportunity to again track LM026 during his (we believe it to be a male) fall migration and determine whether he follows a similar pattern to 2016 and what kind of movements he makes during the winter.
The other adult fitted with a PTT this year was also a recapture of a previously marked bird. “VEE” was captured as a pre-fledging colt in his natal territory in 2011, before we began using PTTs and even before we had numbered bands. His tall green band had a letter “V” engraved on it. When we recaptured him in 2018, we replaced that band with a new one holding the PTT. He is now LM024.
We believe LM024 and LM026 are male based on their size relative to their mates as well as their behavior during unison calling with their mates. We have no way of determining the sex of cranes when they are captured other than taking blood and this project does not have the capacity, or the need, to do that.
Color banding and satellite telemetry have made it clear that we have more crane pairs nesting on Ladd Marsh than previously thought. We have also been able to identify the individual birds or pairs occupying several nesting territories so we will be able to track whether those change over time. During the 2017 and 2018 nesting seasons, we located 19 sandhill crane nests on the wildlife area. After the eggs hatched, and when the cranes and their colts were a safe distance from the nest site, we found and measured the structures. We learned there is great variety in the size of sandhill crane nest structures with the largest over 6 feet in diameter and the smallest just 2 feet.
Capture and transmitter attachment will continue at least through 2019 and the greater sandhill cranes of Ladd Marsh Wildlife Area will continue to contribute to not just our knowledge of them, but the overall understanding of sandhill crane populations in the western United States.