Guest Author: Glenn H. Olsen, Patuxent Wildlife Research Center
So, how do we go about parent-rearing whooping crane chicks at the USGS Patuxent Wildlife Research Center? We originally developed the parent-rearing technique long before we developed costume-rearing for the ultralight-led and direct autumn release programs. We have used parent-rearing releases first for endangered Mississippi sandhill cranes and later for Whooping Cranes released in Florida in the 1990s. Some Mississippi Sandhill Crane chicks are still parent-reared by our partners at White Oak Plantation for release into the wild. As we developed the Eastern Migratory Population in the Wisconsin to Florida corridor, we had survival of our introduced birds that was similar to the survival of Whooping Cranes in the wild Wood Buffalo-Aransas flock, and this was great. However, our introduced Whooping Cranes seemed to have problems rearing chicks.
After thinking hard about this, I became concerned that in addition to black flies, predators, etc., that maybe our costume-reared Whooping Crane chicks were missing some “early childhood education” by not being with their parents. Whooping Crane chicks stay with the adults for almost a year, learning the migration route, but they must be learning other behaviors, also. In 2013 I was able to start a small research project looking at ways to parent-rear and release Whooping Cranes in Wisconsin. The idea was that these birds would grow up to pair with other costume-reared birds from ultralight and direct autumn release reintroductions and be better parents, but more on this in another report.
What do we do when we are parent-rearing young Whooping Crane chicks? The first step is to get the parent birds to build nests and lay eggs. This means keeping them healthy all year. Even so, not all adult Whooping Cranes lay eggs each year. We have 12 pairs that could be potential parents, but only 9 of them laid eggs and were parents this year.
Ideally, the parent birds will sit on their own eggs, but some of our parents at Patuxent have difficulty with incubation, sometimes because of old wing injuries or other problems that mean they do not always incubate well, even though they may be excellent parents. So we sometimes swap out their eggs for wooden ‘dummy’ eggs and let them incubate the wood egg until near hatching when we swap an egg about to hatch.
After hatching, the chick is treated similarly to the chicks we costume-rear as far as health and well-being is concerned. We make daily veterinary examinations to check for any health or developmental problems. The Whooping Crane parents do the rest, though. They feed the chick insects, worms, meal worms and pelleted feed (both of which we supply) and they keep the chick warm, brooding it at night and in inclement weather.
Two years ago we had a female who was going through a severe molt cycle and it would have been difficult for her to brood her chick and keep it dry in rainy weather. We were concerned about her and her chick until we discovered that she was keeping the chick dry and healthy in the covered shed where the birds come to feed. Smart mama crane!
Here are some additional photos explaining the parent rearing process.
Ed. Note: There are currently 14 Whooping crane chicks being reared by parents for release this fall in the Eastern Migratory Population. 9 at Patuxent, 3 at the International Crane Foundation and 2 at the Calgary Zoo’s Devonian Wildlife Conservation Center.