Condor Egg Loss

This dummy egg looks just like a real California condor egg and serves as a placeholder.

This dummy egg looks just like a real California condor egg and serves as a placeholder.

As keepers, we often have the privilege to witness or even help usher in a new hatch or birth into the world. Of course, working alongside our excellent veterinary staff, we provide assistance and supportive care to maximize survivability, but sadly, sometimes it isn’t enough. We experienced this recently at our California condor breeding facility at the San Diego Zoo Safari Park when one of our condor eggs failed to hatch. This egg was expected to hatch under our experienced Condor Cam parents, Sisquoc and Shatash, who for the last two years have raised their chicks, Saticoy and Cuyamaca, under the watchful and adoring eyes of thousands of their fans. Saticoy is now flying free in Southern California, and Cuyamaca was recently sent to Arizona to be prepared for release there.

We usually remove the egg after it is laid so we can artificially incubate it and monitor its development without disturbing the very protective parents. While we are caring for the real egg, we give the parents a fake egg (called a dummy egg) to incubate. This dummy egg serves as a placeholder until the real egg is ready to hatch; without it, the parents would not accept the real egg when we would try to replace it in their nest.

While we were caring for Sisquoc and Shatash’s egg, we weighed it daily to track its weight loss, and we candled it periodically to monitor development inside the shell. During incubation, we noticed that the embryo was slightly in the wrong position to hatch—a malposition. Some malpositions are lethal or need our help to hatch successfully. This embryo’s malposition was not extreme and would not normally need our assistance. What was more concerning was the condition of the membranes surrounding the embryo: loose and saggy when they should have been taut. Concern grew that these membranes would cause difficulty in breathing for the embryo once it moved into the egg’s air cell to begin pulmonary respiration. The loose membranes could adhere to the embryo’s nostrils, suffocating it.

Despite 24-hour care from our keepers and a valiant effort from our veterinary staff, the embryo stopped breathing partway through the hatching process on Sunday, March 16, 2014. The egg was expected to hatch around March 20. The embryo and egg are now at our Pathology Lab; hopefully, we will have more information regarding the cause of death.

Egg mortality is highest at the beginning and at the end of the egg’s incubation period. Sometimes there can be a genetic issue causing the embryo to stop developing. Sometimes the egg can get too hot or too cold during incubation, the egg can get jostled, humidity can be too high or too low, etc. Despite setbacks such as this, our “hatchability” rate at the Safari Park is still very high at over 85% success, much higher than wild eggs that have to contend with nest predators, competitors, and a lack of veterinary support.

So, what’s next for Sisquoc and Shatash? They are still incubating their dummy egg perfectly and are being considered as potential foster parents if another condor egg needs to be parent-reared. They will still sit on the dummy egg, even after the due date of their original egg, but only for about a month or so. After that, they will start to tend to the egg less. We see this behavior in birds that are incubating an infertile egg or an egg that died during incubation. If another condor egg needs to be foster-reared, we can return that egg to their nest, and they will hatch it and raise it as their own. Their drive to care for an egg/chick is so strong that they don’t know or care if it’s not their egg. If another egg doesn’t need fostering, we will remove the dummy egg from their nest. They will then shift from nest-caring duties and spend more time in their flight pen. It may seem sad, but that is what happens to wild birds whose eggs do not hatch.

What’s next for Condor Cam? We have moved the camera to a different nest to show you another of our awesome condor pairs, Sulu and Towich, whose egg is due mid-April. Stay tuned for a blog introducing the new pair.

Thanks so much for all of the comments and condolences regarding the loss of Sisquoc and Shatash’s egg. There are still 30 other California condors at the Safari Park that need us to give them the best care we can. With hope, luck, and your support, we can continue to maximize success for these magnificent birds!

Ron Webb is a senior keeper at the San Diego Zoo Safari Park. Read his previous post,
Egg-citing News on Condor Cam

11 Responses to Condor Egg Loss

  1. Thank you Ron for the update on the condors. It’s sad to lose any animal but that’s the way nature works sometimes .we look forward to the next hatching and hope all gos well for the next one Thank you to the team for all you do.

  2. I was very sad to hear this. I was very much looking forward to seeing the new baby condor. I watched Saticoy and Cuyamaca. I hope that Sisquoc and Shatash will have a successful egg next year. I am now looking forward to the new egg and new parents.

  3. Thank you, Ron, for a clear explanation; look forward to observing the other pair on which Condorcam focused after Cuyamaca had fledged, I think. You all do sterling work.

  4. I am so sorry to hear about the loss…I have been watching with anticipation. I am so glad that you switched cameras to another couple and will, again , watch eagerly..thanks Ron.

  5. Hello from Kansas!
    Thank you Ron and Condor Team for the explanation on the loss and what will happen now. Thank you for all you do for these wonderful creatures. The previous posts have said all that I would have wanted to say! We look forward to watching the new set of parents and the new little hatchling with just as much aaaawwww! Please keep up posted on Sisquoc and Shatash! I’ve come to know those two as though they were right in my own zoo! 😉 Thank you for the update.

  6. Hi Ron I was wondering if we are getting close to the next egg hatching ? I know you said this month.

  7. I hope every thing is ok with the condor egg has I only see the wall in the nest?

  8. Are Towich and Sulu sitting on a real egg or a dummy? We can’t wait for the hatching process to begin. Hopefully all is going well.

    Monitor’s note: All is well. We’ll have a new blog soon that will update Condor Cam viewers.

  9. I noticed that the condors are leaving the dummy egg more. Offen is that ok I don’t remember them doing that last year?

  10. I am sorry to hear you may have problems we this next egg. We know you will do all you can to help this egg to survive.wishing for good news

  11. Wonderful news baby condor arrived safety . Thank you to the great team.