An Update From the Zoo's Lion Keepers
February 2010
Building a Pride: Part I
Lion introductions have finally started and so far, so good.
Wait, What Does “Lion Introduction” Mean?
Animal introductions can be quite a process. It’s a common misconception that lions will get along simply because they are social animals. Unfortunately, this is not always the case. By nature, females are not welcomed into a pride with unrelated females. Males, however, are successful at becoming incorporated into a pride as temporary residents, but they risk rejection, which can result in injury or even death if they’re not accepted.
During the past year Luke has had access to Naba and Shera at a door constructed of thick-gauge mesh through which the lions can safely see and smell each other. We call this a “howdy door.” We have been monitoring their behaviors carefully during this time and have been pleased with their affectionate interactions and interest in each other. The next step is to remove the barriers that separate them.
When we refer to lion introductions we are typically referring to the part of the process that involves removing the barriers between the animals. In this case, we removed the howdy door, which can safely be accomplished from outside the enclosures, so that the lions could have physical access to each other.
Doing Our Homework
Introducing lions is similar to introducing tigers, which we’ve been very successful at in recent years. Introducing multiple lions is a bit more complicated, and it’s been a few years since the Zoo has done this. To ensure that we were up to date on techniques and protocols, we contacted other institutions in the zoo community that had recently introduced and bred multiple lions. Combining this information with our own institutional knowledge, as well as taking natural history and each lion’s personality into consideration, we developed a plan that gave our lions the best shot at success. Deciding which lion to introduce first was based on each of the lionesses’ personalities. Naba shows the greatest interest in Luke, comes into heat more regularly, and approaches new situations more cautiously than Shera. Luke is easily intimidated, and so we chose to introduce Naba to Luke first.
Naba and Luke Encounters
We waited for Naba to come into heat before starting the initial introductions so that she’d be most amenable to an approach from Luke. Luke and Naba were given access to several adjoining enclosures and passageways so that they had ample space to separate themselves and prevent either of them from being cornered.
The doors separating Luke and Naba remained closed until they were facing each other to prevent any surprises. Initially Naba followed Luke around persistently, signaling her receptiveness to an approach by rolling around and crouching in front of him. Although Luke is more than 100 pounds heavier and has better "protective gear" around his neck, he was still very apprehensive about approaching her.
It wasn’t until Naba’s heat cycle tapered off that she became less assertive, and then Luke started approaching her. When Naba came into heat again, Luke responded to her invitation for an approach by breeding her. So far, we have not observed any significant aggression between the two and are continuing to monitor them closely during their introductory sessions. Shera has been able to observe introductions between Luke and Naba from an adjacent enclosure.
Shera and Luke Encounters
After Luke’s comfort level with Naba increased, we decided it was time to introduce Luke to Shera. As expected, Shera walked right up to Luke and gave him a friendly tap on the head, then started to groom his mane. It will take a little bit of time for Luke to feel as comfortable with Shera as he seems to be with Naba, but their introduction sessions are progressing well. The next step will be to give Luke access to visit with Naba and Shera together.
Sometimes Love Hurts
It’s always possible that something could go wrong during lion introductions. Some conflict is expected during this time, including growling and other vocalizations, showing of teeth, swatting, and some physical contact. Ideally, the lions will work out social issues without keeper intervention. If aggression escalates we may decide to separate the animals using CO2 canisters (basically, large fire extinguishers) and hoses. Veterinary staff is present during the first couple of introductions in case emergency medical attention is needed for the animals.
Since it’s always best to end introductions on a positive note rather than a negative one, introduction sessions are very short in the beginning, and then the time of these sessions is increased based on the behaviors observed each day. Although progression may seem slow, we’ve been progressing in a very positive direction. Continue to check back for future updates!
Losing Lusaka
On the morning of January 13 Lusaka started showing signs that she was not feeling well. When medications and fluids did not help perk her up by the next morning, we decided it was best for our veterinary team to anesthetize her to search for clues as to why she was feeling sick.
During Lusaka’s procedures we were saddened to learn that her condition was not likely to improve and our most humane option was to euthanize her. When an animal dies at the Zoo, a necropsy (similar to an autopsy) is conducted. Final results from her necropsy are pending, but it does not appear that her sudden illness was cancer related, for which she had been receiving treatment during the past several months. As the resident “queen bee” of the building, her roar always welcomed us in the morning and her wonderful demeanor made her a unit favorite. We will miss her.
