For two months this spring, a pair of California condor dad and mom fastidiously tended to a single, monumental egg. They took turns sitting on the egg to maintain it heat, and so they routinely rotated the egg, a habits believed to promote correct chick growth.
What the birds, a part of a breeding inhabitants on the Oregon Zoo, didn’t seem to discover was that the egg was a high-tech fraud. The plastic shell, made with a 3-D printer, was filled with sensors designed to surreptitiously monitor situations contained in the condors’ nest.
For weeks, the dummy egg tracked the nest temperature, logged the birds’ egg-turning behaviors and recorded the ambient sound. The zoo hopes this information will enable it to higher replicate pure situations within the synthetic incubators which are key to its condor breeding efforts.
California condors, which might have wingspans of almost 10 toes, are critically endangered. So yearly, when the birds lay their eggs, the zoo whisks them out of the nest and into the protection of the incubators. This technique has a number of benefits, prompting some pairs to lay a second egg, enabling the zoo to monitor embryo growth and defending the delicate embryos from condor rowdiness.
“During breeding season, tensions have a tendency to run excessive,” mentioned Kelli Walker, the zoo’s senior condor keeper. “And sometimes pairs will get into a struggle within the nest room and accidentally injure the egg.” (The chicks are returned to the nest once they start hatching.)
The extra carefully the zoo can replicate pure situations within the incubators, the extra profitable it is going to be. So Ms. Walker enlisted Scott Shaffer, an animal ecologist and hen researcher at San Jose State University, and Constance Woodman, a hen scientist and skilled on conservation know-how at Texas A&M University, who collectively have made data-logging good eggs for a lot of totally different hen species.
Here’s how they introduced the condor eggs into being:
Design the eggs
Dr. Woodman created a digital mannequin of the imitation condor egg. The shell had to be skinny sufficient for the interior sensors to detect temperature modifications however strong sufficient to face up to potential avian abuse. (A macaw as soon as threw considered one of Dr. Woodman’s eggs out of its nest, two tales off the bottom.) To make sure the egg wouldn’t pop open, she designed threaded shell halves that may screw collectively tightly. “It will keep closed until you have received thumbs,” she mentioned. “Birds haven’t got thumbs, so we’re in fine condition.”
Print the shells
Dr. Woodman used a 3-D printer loaded with a plastic chosen particularly to be secure for birds, which could spend months sitting on the eggs. “I actually, actually don’t need to imply nicely and poison a hen,” she mentioned. Printing every shell took 13 hours.
To be sure that the egg was not inclined to spinning or wobbling, Dr. Woodman gave it to Loretta, her litter-box-trained “home turkey,” she mentioned. “If Loretta would not prefer it, she will not sit on it.”
Dye the eggs
The colour of hen eggs varies by species, and Dr. Woodman and Dr. Shaffer all the time tries to replicate it as carefully as doable. To match the delicate, blue-green tint of condor eggs, Dr. Woodman dipped the shells into a pot of a unhazardous dye meant for youngsters’s clothes.
Add the electronics
Small information loggers tucked contained in the shells can observe the temperature and motion of the eggs. An audio recorder captures the sounds within the nest, which the zoo will play again to the eggs within the incubator. “Developing embryos can hear issues by way of their shells,” Ms. Walker mentioned. And she used electrical tape to cowl the lights on the electronics, “in any other case it could have seemed like a flashing Christmas egg.”
Weigh them down
Some birds will reject eggs which are abnormally gentle. So Ms. Walker used a scorching glue gun to connect rocks to the within of the egg, bringing its weight to greater than half a pound.
Make the swap
The first condor dad and mom to obtain a good egg this yr have been a feminine recognized solely as quantity 762 and her mate, Alishaw. “He’s not what you’ll name a historically implausible dad,” Ms. Walker mentioned. “He’ll incubate so long as he has to, however he is not thrilled about it.” (762’s devotion to him, nonetheless, stays undimmed. “She’s type of a ride-or-die with Alishaw,” Ms. Walker mentioned.)
When each birds left the nest, zoo workers moved their actual egg to an incubator and changed it with the pretend one. The condors didn’t appear to discover. (Their chick, which has since hatched, is again with its dad and mom and doing nicely, Ms. Walker mentioned.)
Analyze the information
When the breeding season is over, Dr. Shaffer and Ms. Walker will analyze the information. The findings will inform future incubator settings and, the workforce hopes, assist deliver extra California condor chicks safely into the world. “It’s simply a actually cool use of know-how that may solely get higher,” Dr. Shaffer mentioned.