BURGERS’ ZOO WELCOMES MANATEE CALF

In the early hours of Tuesday morning 19 March 2019, a Caribbean manatee was born at Royal Burgers’ Zoo. The manatee calf appears to be in good health.

Arnhem, 19 March 2019 – The 5.5-year-old pregnant Caribbean manatee kept the Arnhem zookeepers and biologists in suspense for weeks, but in the early hours of Tuesday 19 March, the wait was over, and a healthy-looking manatee calf was born, most likely a male. The relatively young female is a first-time mother so that the coming period will remain exciting for the zookeepers and biologists. Royal Burgers’ Zoo is the only zoo in the Netherlands home to manatees.

Living with uncertainty 

Caribbean manatees have a gestation period between 12 and 14 months. The pregnant female showed noticeable swelling around her vulva and had visibly swollen nipples for quite some weeks. Performing an ultrasound on an aquatic mammal of this size is incredibly impractical, and the unnecessary stress it would cause is undesirable. All the zookeepers and biologists could do was keep a close eye on the animal and be patient. 

The excitement is not over

On Tuesday 19 March at 7.30 a.m., zookeepers discovered the manatee calf, which is probably a male. Male manatees have no external genital organs, and the gender of a manatee can only be distinguished by the location of the genital opening in relation to the anus. In females the opening is closer to the anus and in males the opening is more towards the middle of the abdomen and the umbilical cord. At first sight, it looks to be in good health, but as it concerns a first-time mother, the coming period will remain exciting for the zookeepers and biologists.

Normal behaviour when suckling

A manatee calf drinks from one of two of its mother’s nipples, located in the armpits behind the flippers. Normally the mother floats horizontally, and the calf swims toward the nipple. The only assistance a mother gives is to keep her flipper aside. A calf will drink from its mother for approximately two years but will often try to eat solid food as early as one or two weeks old. Usually, a young manatee will eat solid food after about forty days.

Peter Dickinson Independent International Zoo Consultant +66 (0) 93 0835 862 | elvinhow@gmail.com https://iizc.org/ | Skype: peter.dickinson48

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SUCCESSFUL USE OF CONTRACEPTION IN FISH

WORLD FIRST FOR BURGERS’ OCEAN:  SUCCESSFUL USE OF CONTRACEPTION IN FISH 

On Monday 17 December 2018, renowned professional magazine Journal of Fish Biology publishes a scientific article that makes a world first

Arnhem, Monday 17 December 2018 – Biologist Max Janse and veterinarian Henk Luten of Royal Burgers’ Zoo in Arnhem have, for the first time in the world, successfully applied contraception to a fish species. On Monday 17 December 2018, the renowned scientific Journal of Fish Biology will publish an article about the remarkable feat that has ground-breaking consequences for the international breeding programmes of fish species.

A unique situation in Arnhem

International breeding programmes for shark and ray species aim to maintain genetically healthy aquarium populations so that no more animals need to be taken from the wild. As far as protected species are concerned, animals may be released into the wild in the future. The zoo in Arnhem had a unique situation with their spotted eagle rays from the Aetobatus ocellatus species, of which Burgers’ Ocean is the largest breeder in the world. The genetic material of two of their hugely successful breeding females threatened to dominate the European population of eagle rays.

Contraception for fish

One of the adult females was successfully moved to another European public aquarium with eagle rays in their collection. The other female had a birth control implant successfully inserted in her left pectoral fin. Scientific literature shows that there has been only one earlier—unsuccessful—attempt to insert a birth control implant in two female river stingrays of the Potamotrygon falkneri. One of the females continues to produce young after the birth control implant was inserted.

Ground-breaking work

In many mammalian species, contraception using birth control implants has been successfully used for many years. In fish species, this is the first time that this method has been successful. This breakthrough has far-reaching consequences for the European breeding programmes of various fish species. With this extra method of population management, the programmes can be managed in an even more targeted way.

Peter Dickinson Independent International Zoo Consultant +971 50 4787 122 | elvinhow@gmail.com | Skype: peter.dickinson48

SCOTTISH BOAR STIMULATES ARNHEM SHE-BEARS

SCOTTISH BOAR STIMULATES ARNHEM SHE-BEARS

All the hope of Burgers’ Zoo is focused on a sun bear boar from Edinburgh, Scotland, to provide the European breeding programme with the necessary cubs 

Arnhem, 29 November 2018 – The biologists and zookeepers of Royal Burgers’ Zoo are looking forward to the incoming transport of a male sun bear on Friday 30 November 2018. All hope is on this sun bear boar from Edinburgh Zoo, Scotland, and the two Arnhem she-bears to jointly provide the European breeding programme with the much-needed growth of the species.

Small Chance

Royal Burgers’ Zoo has all the required facilities: a spacious outdoor area, several heated indoor enclosures (both open to public and private) and a specially designed birthing room for the sun bears. Still, it won’t be easy. A fertility study done by German specialists from IZW Berlin (Institut für Zoo- und Wildtierforschung) on 12 January 2018 showed that one of the bears is almost infertile. The other female has about fifty per cent chance of a successful pregnancy. Age plays a role in this: both females are over 18 years old.

A European challenge

The studbook data of the European Breeding programme for sun bears show that there is a total of 39 sun bears living in European zoos that are members of EAZA (European Association of Zoos and Aquaria): 13 boars and 26 she-bears. The average age of the sun bear population in Europe is quite high, and there is, therefore, a clear surplus of females. The European breeding programmes are very successful for most species, but this is unfortunately not the case for the sun bears.

Stimulating effect?

The hope is that the arrival of the sun bear boar will have a stimulating effect on the hormone balance of the she-bears. Both she-bears came to Burgers’ Zoo from the zoo in Cologne, Germany, on 22 April 2018 and are over 18 years old. The boar from Scotland is 15 years old. If, in time, it turns out that the presence of the new boar does not bear fruit, exchanging the she-bears for a younger she-bear might be considered. However, this decision is up to the coordinator of the breeding programme and still lies far ahead.

Peter Dickinson Independent International Zoo Consultant +971 50 4787 122 | elvinhow@gmail.com | Skype: peter.dickinson48