Hand-rearing Hawaiian Honeycreepers

caption

Hungry palila chicks greet the research assistant enthusiastically!

Breeding season is the most anticipated time of the year at Keauhou Bird Conservation Center, one of two captive propagation centers run by San Diego Zoo Global’s Hawaii Endangered Bird Conservation Program (HEBCP). This is when all of the hard work, sweat, and occasional tears that are put into the daily care and management of our flock of endemic Hawaiian birds pays off. The reward? Brand new offspring that will one day augment existing populations of birds in the wild or even be the founding members of future reintroductions. 2015 was an exciting season for us because we had our most successful year with palila Loxioides bailleui since 2000—producing 14 fledglings from 5 different pairings! Additionally, eight of these chicks were produced from females with “wild” genes not yet represented in the flock, which will add to the genetic diversity of the species. For me personally, it has been even more thrilling because this is my first year working with the program as a new staff member and being able to participate in my favorite aspect of aviculture: hand-rearing chicks.

Newborn birds fall under one of two categories of development. One type is called precocial, meaning that the young are born with their eyes open, downy feathers, and overall requiring minimal parental care after hatching. An example of this type of bird would be the nēnē, also called the Hawaiian goose. Just hours after the goslings hatch they are able to take their first steps and may even begin to forage for food. They only rely on their parents for protection, learning behaviors, and extra warmth. The other variety is called altricial, which is the stage of life that the majority of birds enter the world in. Altricial chicks are born blind, naked, and helpless. They are unable to feed themselves or maintain their own body temperature. They rely completely on their parents during the early part of their life and the adults invest a considerable amount of time and energy into the care of their chicks. We know first-hand just how committed these birds are to their young because here at KBCC we often take on the role of the parent bird and care for newborn chicks.

caption

Palila hatchlings are altricial and get focused care.

There are many reasons why it may be more favorable for one of our research associates experienced in hand rearing to raise chicks rather than the parents themselves. Some birds are simply poor parents from the start and build haphazardly constructed nests or don’t incubate their eggs adequately. Some birds incubate their eggs diligently, but then act bewildered at the sight of a newly hatched chick in the nest. This can stem from several reasons, but often is due to a lack of experience—something generally seen in younger birds. In some cases, certain chicks can be so genetically valuable that it is not worth risking the chance of losing them to unfavorable conditions, so they are immediately pulled from the nest for artificial incubation and hand-rearing as soon as the eggs are laid. Pulling eggs in this manner also means the females have a chance to lay another clutch of eggs and produce additional young. Parental abandonment or unforeseen medical emergencies are also reasons eggs or chicks may be pulled from the nest. Our team puts considerable thought and planning into the management strategy of eggs and chicks, with the ultimate goal being the survival of the greatest number of quality offspring to ensure the future of each species.

Hand-rearing duties start each day at 6 a.m. and continue until 8 p.m. Newborn chicks are fed once every hour for a total of 15 daily feedings. They may occasionally be given additional feedings if they require extra hydration. The number of feedings will gradually decrease over the course of weeks as the chicks grow. Each day, depending on the weight and age of the chick, an appropriate amount of food intake is calculated and measured out to be fed each hour. Food items start out very simple and then slowly grow in complexity as the chicks develop. The actual feeding is a delicate task, as items have to be warmed up to match the internal body temperature of the chicks. If food is fed too hot it will burn the crop, an organ in birds that stores food prior to digestion. This is often fatal. If food is fed too cool it will not pass through the crop properly and can begin to back up and ferment, a condition known as “sour crop.” It is critical that food or liquid does not unexpectedly fall into the chicks mouth as they beg. This will result in the chicks inhaling food and liquid into their lungs, a condition known as aspiration. Food items must carefully be placed behind the glottis, or airway, with small forceps when feeding. Care has to be taken to not only feed chicks accurately, but also in a timely manner too, as young chicks will quickly tire out from begging and can miss hitting their target intakes. After feeding, chicks are cleaned up as necessary and then placed back into the brooders to warm up and sleep until their next feed.

Although rearing chicks is challenging and frequently very stressful, there are few greater feelings than watching a tiny chick grow up and become an adult bird. This has been a very successful year for the team at KBCC. We continue to strive to have even greater successes to come and continue to work tirelessly to ensure a bright future for these incredibly unique birds.

Donnie Alverson is a research associate at the Keauhou Bird Conservation Center in Volcano, Hawaii. Read a previous blog post he co-authored, Gather The Goslings Before The Gale!

Comments are closed.