Last month, the 27th to be exact, the 2011 LA whooping cranes achieved a major milestone. Although there was no celebration and to the birds it was just another day, it was still a great accomplishment and a big step forward for this project. You see December 27, 2012 marked the one year anniversary of their release from the top-netted pen into the open pen and surrounding marsh at the White Lake WCA. From that day forward the cranes were free to come and go as they pleased and were no longer under our complete control and protection. The release of the birds is both an exciting and a nerve-wracking time for us, (or at least it is for me). It is after all, what we’re all working towards, to have whooping cranes living in the wild in LA. And of course it is a fantastic sight to see those birds finally fly free but with that freedom comes vulnerability for these still young and naïve birds and the reality that not all of them will survive.
We were especially wary and apprehensive since the survival of our 2010 cohort had been so low – only 3 out of those 10 birds were still alive one year after release. Not all of the 2011 birds survived, and we were saddened by each loss, but at the one year anniversary 12 out of 16 were still alive. 75% survival is a great number and a much needed improvement over the first year. Young birds, or young animals of any kind, for that matter, are more vulnerable and we expect higher rates of mortality early on, esp. for our birds which are raised in captivity and then released. This is not to say we won’t have future mortalities but now that these 12 birds, plus the remaining 2 birds from the 2010 cohort, have lived a year or more in the wild they have clearly learned some things about how to avoid predators, where to find food, safe places to rest, etc. and that knowledge should help them continue to survive.
Of the 12, 2011 survivors, 7 of these birds (3 males, 4 females) are still together as one group and I, for one, am curious to see when and how this group splits up into smaller groups and pairs. The remaining 5 birds consist of a single female, a trio of 2 males and a female, and a female who recently began associating with the remaining male from our 2010 cohort.
Update written by Sara Zimorski