Palila: Welcome Back, Old Friends
Posted at 8:45 am December 20, 2004 by Alan LiebermanIn any release program in which we reintroduce captive propagated birds to the wild, we consider four basic steps that must be reached in order to determine that the overall program has been successful. The first step is breeding enough birds in captivity to form a release cohort. The second step is to release the cohort and support the birds to the point where they are independent in the wild and live long enough to support themselves in their new habitat (every parent’s dream for their child anxious to leave home).
Step three is the birds should live long enough to enter into a breeding season and breed successfully. The fourth step is that enough birds, both release birds and their progeny, reproduce with enough success to actually establish a flock that is more than simply self-sustaining but expands to the point of reaching the “carrying capacity” of the new habitat.
Of course, there are many, many factors that are required that are supernumerary to the actual propagation and release of captive birds that support the success of such an effort, such as; predator control, disease control, elimination of invasive plant and animal pests, and forest rehabilitation, just to name a few.
In late 2003, we released the very first two cohorts of 10 palila on Puu Mali, Mauna Kea (Step #1 completed). Of the 10 birds we now know that the majority of the birds survived to independence and indeed, two of the birds nested and laid an egg (the egg was later determined infertile). Step #2 and #3 nearly completed. We are in the process of bolstering the release by putting a new cohort of five palila in the Puu Mali habitat. This will hasten the maturation of the flock and hopefully will successfully complete the critical and final Step #4. This last step will require many generations of palila reproduction and several more seasons of releases.
Perhaps the most rewarding event that has occurred at this year’s release of the five palila is the return to the release aviary of four of the eight (we know that seven or eight of the birds survived the first release) palila that we released over a year ago. All four look great, now being truly savvy warriors of the mamane fields that surround the site. They have returned to the aviary to not only introduce themselves to the new release candidates, but to take advantage of the food treats which are fed to support the new release birds. It’s like old friends dropping by for Happy Hour (except in this case Happy Hour starts at sunrise!).
It is very encouraging to see these old friends looking so healthy. It is very polite of them to show us that, although reared in a captive environment, they are fully capable of surviving (and breeding) long term in recovering native habitat when given the support of resource management that will always be required at some level to minimize the limiting factors. Welcome back, old friends. It’s great to see you all!
Alan Lieberman is the program director for the San Diego Zoo’s Hawaii Endangered Bird Conservation Program.
One of the most important qualities of any successful conservation program is making that key connection between the program and the community. The Hawaii Endangered Bird Conservation Program works hard to keep the local population involved and informed. In some cases, the local community can actually participate in our program’s agenda.
There are so many rare species of birds in the world, more than one barroom argument has erupted over which is indeed the rarest of them all. On September 10, 2004, the po`ouli, the species that must truly be considered the rarest in the world, became part of the Maui Bird Conservation Center’s (MBCC) propagation and recovery program.
Captive propagation programs can often maximize both the quantity and quality of chick production, an advantage when dealing with very rare and endangered species. The palila propagation effort benefits from three factors: video monitoring, compatible and tolerant breeding pairs, and very talented hand-feeders.
Perhaps the most challenging task in managing a captive flock of birds, especially a flock that consistently demonstrates the reproductive anomalies consistent with inbreeding, is how to get an egg to lose the proper amount of weight.
The 2004 breeding season for ‘alala is beginning to shape up as one for the record books. The best breeding season until now was seven years ago (1997) when there were nine chicks hatched and reared. Thus far this season, the Hawaii Endangered Bird Conservation Program has hatched and is now rearing nine chicks, and the season isn’t over yet. No one likes to count their chicks before they hatch, so we must show restraint and merely say, “All is looking good for a double-digit chick season, the first ever!”
To the delight of the staff at the Maui Bird Conservation Center, a Maui parrotbill chick hatched on May 17, 2004. This is the first chick of this species to hatch at the center from a captive-laid egg. This egg was removed from the nest two weeks before to avoid damage by the parents. They had already broken the first egg laid this year and the program did not want to risk losing the second egg.
One of the most useful tools in the management of captive pairs of birds is video observation. Not only do video observations satisfy one’s curiosity as to who is doing what to whom, carefully managed observations can reveal very interesting patterns of behavior. These careful and methodical observations allow the biologists at the Keauhou and Maui Bird Conservation centers to record critical events in the breeding cycle of difficult-to-manage species like the `alala.
A flock of ten palila was reintroduced to the area of Puu Mali on the north side of Mauna Kea Volcano. This important event adds another species to the growing list of Hawaiian species propagated and released into native habitat. These ten individuals included three birds that were hatched in 1996 from wild eggs that were brought into captivity and have produced over 20 offspring since then. 