On Monday, February 7, we welcomed three crested Screamer chicks to our San Diego Zoo family (see post, Something to Scream About). I had been eagerly checking the nest every day to see if the eggs had pipped yet. When I checked at 9 a.m., the eggs were still completely intact, but less than two hours later, they decided it was time to come out. The female screamer assisted with the hatching process, turning the eggs so that the chicks could come out more easily. By 4 p.m., all three had hatched! This was quite a surprise to us all, as it was a very quick pip-to-hatch time period. Some bird species take anywhere from 24 to 48 hours to hatch; I guess these kids were ready to see their new world. They remained on the nest with Mom and Dad taking turns brooding them for the first couple of days. On Thursday, February 10, the chicks came off the nest for the first time.
Screamer chicks are precocial, which means that upon hatching their eyes are open, they are covered with down, and they are mobile. They are able to pick up food on their own, although they may need some assistance from their parents in finding food. A precocial chick is developmentally more mature than an altricial chick, which usually hatches with eyes closed, are relatively immobile, and are also completely dependent on the adults.
So far, so good. All three chicks have been observed eating and drinking. We provide them with a mixture of nutritionally balanced waterfowl pellets that are ground up to allow for easier consumption, finely chopped romaine lettuce and fruit, as well as mealworms and young crickets. Adult screamers are herbivores, but chicks require a diet higher in protein during development, which is why we provide them with insects. Mom and Dad will care for the chicks, keeping them close by and brooding them when they are cold for 8 to 10 weeks. They will be fully independent between 12 and 14 weeks of age, although it is not unlikely that the chicks will stay close to the parents as long as their presence is tolerated.
The first several days and even weeks of a chick’s life are nerve-racking for a bird keeper. We must keep a very close eye on them and watch for any behavioral, developmental, or health abnormalities. I am thrilled that all three chicks hatched and am feeling optimistic, as this is the second parental opportunity for the female, and our male is a seasoned pro.
Stop by our Caribbean flamingo lagoon at the front plaza to see our beautiful crested screamer family. The chicks will be right next to Mom and Dad or under foot. You may even be lucky enough to see them taking a swim, which is always entertaining. Even though they’re precocial, they can still be a bit clumsy at times.
Athena Wilson is a senior keeper at the San Diego Zoo.
Update: February 21, 2011
Unfortunately, we lost all three screamer chicks. We lost one of them of unknown causes, the second one due to predation by a wild great egret. The third one went to the veterinary hospital; despite the efforts of the veterinary staff, this chick passed away a day later of unknown causes. A necropsy will be done on each one of them to determine the cause of death. I hope we will learn from them to see if there is something we can do in the future.
The good news is that we will be allowing them to breed again this year (it’s not too late). If we get chicks again, we will most likely move them to a safe place off exhibit and bring them back as a family when the chicks are big enough to not be at risk for predation. I apologize for the sad news. It was a rough few days for me as their keeper