Family planning for big cats

Senior Keeper, Kate Stone with Josie

A large part of being a zoo keeper is getting to know your animals. Being familiar with their individual personalities and their day-to-day behaviour is an essential part of good animal care since changes in their behaviour could indicate injury or illness. Often their behaviour can change according to their breeding cycle.

With some animals this change can be quite radical and potentially dangerous; a normally passive, cooperative reindeer can change into a real threat to safety overnight.

When it comes to the big cats they are never considered safe. Management is always a two-person job and we have strict safety protocols in place for even the most routine tasks.

As reported here by Senior Keeper, Hannah, we recently lost the pride of our collection, Solomon, the male African Lion. He shared his enclosure with his daughter, Josie so it was extremely important that we manage their ability to breed as well as the behavioural consequences of the breeding cycle.

We always knew when changes in the lions’ behaviour were related to breeding. They would both lose interest in food and for Solomon breeding was the one thing on his mind – he wouldn’t leave Josie alone! In the wild there is only one dominant male, he is top-dog, and the rewards for being the fittest and the strongest are the rights to breed with the females. Solomon was always top-dog.

During the breeding cycle Solomon would follow her around and stand over her whenever she lay down just in case another male wanted to mate with her, despite the fact that they were the only lions in the enclosure! In all his time here the nearest male lion was in Paignton Zoo but that didn’t stop Solomon performing in every respect like a dominant male with a territory and a female to protect.

For Josie the behaviour was a little different. First, she’d begin to flirt, which Solomon didn't seem to mind at all. However, after a while the honeymoon period would come to an end and she’d grow rapidly tired of Solomon’s attention. With Solomon being her constant shadow, she would become grumpy and irritable. This is very species-typical behaviour and in the wild it would usually lead to the pair losing all interest in food and instead spending several days together mating.

Since they were related, Josie was given a contraceptive implant which would have to be replaced every three years. The most recent replacement was on 30th November 2012.

The implant is injected just under the skin, a procedure that takes about 30 seconds. However, managing big cats is never that simple. Before we can get to that point there’s a whole lot of work to be done.

In order to get close enough to Josie to perform the procedure safely she must first be sedated inside her pen in the lion house. Once she was inside, Mike our Head Keeper, who is part of the firearms team, used the dart gun to deliver the anaesthetic. Putting animals under anaesthetic, especially big cats, is quite a risky business for both keepers and cat. When dealing with an animal that has three inch long sharp retractable claws and mighty jaws containing canine teeth four inches long, which they can open to 12 inches wide, safety is all important.

However, it’s also risky for the cat. She would have to be sedated enough to ensure she wouldn't wake up during the procedure, but not given so much that she might not wake up when given the reversal drugs. An average lioness can weigh between 110kg-140kg, animals Josie's size and bigger are not really designed to be knocked out, their body weight can be quite a strain when under the influence of anaesthetic.

To keep the procedure as stress free as possible, only Mike and our vet went into the house when they were ready to dart her. Everyone else waited outside being very quiet.

Once she was darted it took around 10 to 15 minutes for the drugs to take effect. To be sure that she was fully asleep the vet checked her for reactions. It was lucky that she had decided to lie down against the mesh of her pen so the vet could touch her easily whilst he stood safely in the keeper corridor of the house.

Once the vet was happy that she was fully sedated he could enter the pen to complete the procedure by injecting the contraceptive implant under the skin between her shoulder-blades.

After only a few minutes of full sedation she was given the reversal drugs by manual injection and within 20 minutes she was up and about in the house no doubt wondering what had happened.

After this kind of procedure it was crucial that Josie remained under observation to ensure that she recovered properly. One keeper stayed in the house making sure she was behaving as expected. Once everyone was happy that she was in good health she was let back out into the enclosure with Solomon.

For keepers participating in veterinary procedures like this is a huge perk of the job, and it's not every day you get to see something like this.

Kate Stone
Senior Keeper