What’s more amazing than baby otters? Nothing! This year, our 4 year old female North American river otter gave birth to her first litter. First time moms often make keepers nervous since we never know how they will do, but Ginger has turned out to be a pro!
Ginger joined us here at the Oakland Zoo in 2008, when she was just one year old. North American River otters are not very prolific breeders, so AZA makes annual breeding recommendations. When Ginger came to us, she was still a bit too young to breed, but we knew that the AZA eventually wanted her to breed with our 12 year old male, Heath.
River otters are one of the few species that exhibit a phenomenon called delayed implantation. Essentially, otters breed in the spring but the fertilized egg doesn’t actually implant until fall! So how does one plan for such a unique pregnancy? As it turns out, hormone levels can be measured in otters’ feces! Our keepers collected samples from Ginger four times each week and mailed them off to Cincinnati to be tested. In December, we got the word that Ginger’s progesterone had spiked and that she was likely pregnant with a due date sometime between February 15th and 23rd.
Now the preparations really ramped up! The keepers had meetings with the vet staff to prepare for any and all possibilities. Cameras were set up in denning area. Supplies such as extra towels, an infant scale and thermometer, and data recording sheets were prepared and brought down to the night house. We also requested additional help from our Behavioral Observation Team, a group of dedicated volunteers who spent hours each week watching Ginger and observing her for any changes in her behavior. We also kept close tabs on Ginger’s weight and appetite at this time. The keepers had been training her to jump on a scale using positive reinforcement since she arrived, so they were able to monitor her weight several times each week and increase her food as necessary.
On February 15th, keepers arrived to find Ginger not only ravenous, but cranky as well! She wanted nothing to do with the two male otters with whom she shares her exhibit. A quick peek confirmed that she had given birth to TWO pups overnight (two to three is average for otters)! We quickly weighed them and put them back to cause as little disturbance as possible. The pups then had their first vet visit the following day where they were pronounced healthy!
The work doesn’t end there, however. Our otter observers now had to watch Ginger and the pups on a closed circuit monitor to ensure that Ginger was keeping them warm and that they were nursing. Otter pups are born blind and helpless, about the size of a stick of butter, so they depend on their mother for everything! Thankfully, Ginger is the best otter mom we could have hoped for and the pups quickly thrived under her care!
Twice each week, someone from the vet staff would come down to examine the pups. We monitored their temperatures, weight gain, hydration, respiration, and heart rates. Since Ginger had to be separated from the pups during the vet visits, we kept the checks down to no more than 10 minutes to minimize the stress on both the mother and the pups.
We are so happy to have healthy baby otter pups and we are so proud of Ginger. For more photos and video of our otter pups check out our otter webpage!