The Weighty Issue!

August 11, 2010 § 3 Comments

Lemurs go on a Diet! 

The Sclater’s lemurs here at Edinburgh Zoo have been losing weight over the last few months thanks to a few diet changes and some innovative new feeders

Sclater’s lemurs (also known as blue-eyed black lemurs) are prone to putting on a bit of extra weight and this can result in health problems such as heart disease, diabetes and difficulty breeding.  Edinburgh Zoo is one of only two zoos in the UK to house this endangered species and they are part of a European Endangered Species Breeding Programme so it is hoped that their new healthy lifestyle will mean that they produce offspring in the future. 

Sclater's Lemurs are also known as Blue-eyed Black Lemurs and they are the only primate apart from humans that can have blue eyes! Photo Credit:RZSS

  Noemie, the female has lost nearly three-quarters of a kilo and male Bobby has lost 300g.  Keepers changed the lemur’s diet last November to encourage them to lose weight.   

It's easy to tell Noemie and Bobby apart as female Sclater's Lemurs have a reddish-brown or blonde coat and males have a black coat. Photo Credit: RZSS

Lorna Hughes, Head Keeper for Primates at Edinburgh Zoo said, “In the wild, lemurs feed on seasonally available wild fruit which is naturally lower in energy than cultivated fruit which is often fed to them by zoos all year round. So we have now introduced a new diet that focuses on low-calorie healthy alternatives and have moved from a fruit to a more vegetable-based menu. The results have been really positive but we decided we needed to look at additional options to maximise the animals’ weight loss” 

“The second phase of the programme was designed to complement the diet changes by providing ways to stimulate the animals and encourage greater activity levels. Just as with humans on a diet, watching what you eat combined with increased exercise will result in a higher weight loss.  In the wild, lemurs have a 24-hour activity cycle and would eat little and often so by using the feeders we also were able to try this out by giving five smaller feeds instead of three larger ones over a 24-hour period.” 

This phase was implemented at the end of June.  Working with Brendan Duggan (a trainee researcher studying the MSc in Applied Animal Behaviour and Animal Welfare at Edinburgh University) some new feeders were introduced into the lemur enclosure.  These automated feeders were placed high in the enclosure and released the smaller feeds over 24 hours to encourage the lemurs to spend more time foraging. 

These new feeders release the five smaller feeds over a 24 hour period

As Brendan said, “In the wild lemurs will spend 32% of their day foraging and feeding as opposed to 14% in captivity, so it was important that we made these otherwise laid-back lemurs work for their food. Our results showed that once the feeders were introduced the time these lemurs spent resting decreased. The unpredictable nature of the feeding regimes meant that instead of waiting for the sound of dinner approaching with the turn of a keeper’s key, they were constantly checking the feeders never knowing when or where they might find food being dispensed. As the feeders also keep dispensing food, the novelty never seemed to wear off.” 


How much does a Polar Bear weigh? 

Weight was also the hot topic on Monday at our sister park, the Highland Wildlife Park as Mercedes the polar bear had her first weigh-in!   

Mercedes is the only polar bear in a UK zoo and she arrived at the Highland Wildlife Park from Edinburgh Zoo last October.  At Highland Wildlife Park she has a four and a half-acre purpose-built enclosure and since her arrival she has settled in extremely well.  Since arriving at Highland Wildlife Park keepers have been continuing with positive reinforcement training.  Training is done to facilitate husbandry and health checks as it means that basic checks and tasks can be carried out without causing stress to the animal and without the need for anesthetic.  Positive reinforcement involves animals getting a reward when they give the correct behaviour and keepers have been using this to encourage Mercedes to step on to mechanical scales in her enclosure.  

Mercedes on the scales. Photo Credit: RZSS

Getting a measure of Mercedes weight can help with monitoring her health as well as getting medicine or anesthetic dosages correct. Animal Collection Manager at Highland Wildlife Park, Douglas Richardson, explains the process:  

“Mercedes’ keepers have done an excellent job in gradually and gently enticing her onto the scales that are placed in a small passageway that connects her two roofed den areas.  Although Mercedes is actually quite gentle for a polar bear, we still need to be very careful when working close to her, even when separated by a wall of steel mesh, as she is very capable of harming any one of us.  The real drive to get her weighed accurately is to allow us to carry out a comprehensive health check.  She gives all the signs of being in perfect health, but she is at the upper end of a polar bear’s lifespan and we want to ensure that we are not missing any potential age-related problems that may reduce her quality of life if they are not dealt with.  All wild animals are pre-conditioned to hide illness to avoid predation or harassment, and a zoo polar bear is no exception, so her pending health check is very important.” 

Mercedes lived at Edinburgh Zoo since 1984 after being rescued from Canada where she was due to be shot.  She had taken to visiting a local town for food, at first she was captured and marked with the number 39 to allow her to be tracked but because these animals are so dangerous when she returned for a third time it was decided that she would be shot.  Luckily one of RZSS’s life members and their cousin a former minister of fisheries in Canada helped to rescue Mercedes and bring her to Edinburgh where she went on to have two cubs.  Mercedes the car company helped to fund her transport to Edinburgh, which is how she got her name. 

Mercedes in her new enclosure at Highland Wildlife Park. Photo Credit: RZSS

One Big Chimp Community! 

Edinburgh Zoo’s chimpanzee community have been getting a lot of press recently as the two groups have now been introduced to form one big community of 22 chimpanzees!  Next weeks blog will have a bit of a chimp theme with info on who’s who in the new group and an update on how everyone is getting along so don’t forget to check back next week if you want to know the latest from Budongo Trail! 

Heleen, one of the new arrivals at Budongo Trail


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§ 3 Responses to The Weighty Issue!

  • Are they actually happy with the new vegetable-rich diet? I had the pleasure of feeding Black-and-white Ruffed Lemurs, Red Ruffed Lemurs and Ring-Tailed Lemurs in Wroclaw Zoo in Poland and also in Colchester Zoo, Essex, and they all seemed to be very keen on their bananas and not so keen on their carrots 😉 How long did it take to convince them to eat the veggies?

  • rzss says:

    Hi Marta!
    Our lemurs do seem to be enjoying their new diet. As with most primates (including ourselves) lemurs may prefer the foods that are high in sugar (and therefore calories) such as fruit. The higher energy content of such foods means that they are often favoured over lower calorie foods as in the wild animals need to gain as much energy as possible as they forage. This is why lemurs may show more interest in the fruit portion of their feeds! Of course in the zoo fruit is available all year round and is higher in sugar than wild grown fruits, this is why keepers have altered the diet to contain healthier alternatives to such high calorie cultivated fruits. In the wild lemurs feed on both fruit (which is often only seasonally available) and vegetable matter (such as leaves) so this new veggie-rich diet is not too unusual for them and they seem to be doing great with it!
    I hope this answers your question!

  • Great, thanks a lot for your answer.

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