We have not received any satellite-tracking data for the Lake Woodruff kite since Sunday, September 17, 2000. There are a number of possible explanations, although at this point, we are not able to say which is the most likely. Because the transmitter is a prototype design, there may be a malfunction in the radio itself, although a similar transmitter on another migrating kite has been performing quite well. And, of course, the bird may have died, leaving the transmitter's solar collector unable to gather enough light to power the radio.
Migration is a very challenging time for birds and it can be a substantial source of mortality.
The kite no doubt encountered strong winds and heavy rains once onshore, which could have limited its ability to forage after its arduous flight. In fact, September 13, when it arrived in Mexico, until we last heard from the bird on September 17, it remained in roughly a 50 square mile area rather than continuing its southward migration. The effects of the long over-water flight and the subsequent bad weather, in combination with any possible lingering effects from the original wing injury, could have put the bird at risk even after it reached the relative safety of Mexico. At this stage, and based on what we have learned from prior satellite tracking of Swallow-tailed Kites, there are several other things to consider before we attribute the lack of data to either radio failure or mortality. The transmitter is programmed to broadcast for 10 hours, then to be off for 20 hours.