Why do we do research?

Researchers from Utrecht University are currently studying the mating behavior of vultures in places like Safaripark Beekse Bergen. They are investigating the role of sound in the reproduction of these impressive birds. By recording mating sounds and playing them in various zoos, researchers are trying to determine whether sound can stimulate the mating behavior of vultures. Diergaarde Blijdorp and Avifauna are also contributing to the research.

Vultures make a lot of noise during mating. Sound plays an important role in communication between these birds. By investigating whether mating sounds can prompt other members of the species to mate, researchers hope to better understand how this natural process works. Biologist Stijn Berger is involved in the research from Beekse Bergen. "If we know which stimuli influence mating behavior, we can further optimize the conditions for successful reproduction," Berger explains.

In Beekse Bergen, mating sounds from vultures from the other participating zoos are played. This is done deliberately, as it would be confusing for the animals to hear their own mating sounds from the surroundings. Then it is observed whether playing these sounds actually leads to an increase in mating behavior.

The research provides valuable insights into the role of sound and communication in reproduction. This knowledge contributes to the conservation of vulture species, both in zoos and in the wild. Beekse Bergen is proud to contribute to this research and play an active role in nature conservation.

Hart van Nederland covered the research.

In the morning hours, a noticeable sound is often heard in the Safari Park: the singing of the Lar gibbons. A pair of Lar gibbons sings a duet together. This way, they let bystanders know that this is their territory and that they are dealing with a strong couple here. Some parts of the duet are sung exclusively by male or female animals.

When the caretakers of Beekse Bergen heard that the male gibbon seemed to sing the entire duet by himself, the help of two students from Leiden University was enlisted. They investigated whether the gibbons in Beekse Bergen indeed sing an unusual duet and tried to find out why they do this.

The researchers found out that both animals sing a duet, but never with each other. The male animal makes a good attempt to imitate the great-calls of the females, and the female animal also sings the male intermezzos. The solo of one often leaves the other cold. When there was singing, the other animal was often nowhere to be seen or hardly responded to each other's singing.

The research provides us with new insights into the role of the duet within this species and how it comes about. The first piece of the puzzle has been laid, but there is certainly more research needed to find out more about this.

In the morning hours, a noticeable sound is often heard in the Safari Park: the singing of the Lar gibbons. A pair of Lar gibbons sings a duet together. This way, they let bystanders know that this is their territory and that they are dealing with a strong couple here. Some parts of the duet are sung exclusively by male or female animals.

When the caretakers of Beekse Bergen heard that the male gibbon seemed to sing the entire duet by himself, the help of two students from Leiden University was enlisted. They investigated whether the gibbons in Beekse Bergen indeed sing an unusual duet and tried to find out why they do this.

The researchers found out that both animals sing a duet, but never with each other. The male animal makes a good attempt to imitate the great-calls of the females, and the female animal also sings the male intermezzos. The solo of one often leaves the other cold. When there was singing, the other animal was often nowhere to be seen or hardly responded to each other's singing.

The research provides us with new insights into the role of the duet within this species and how it comes about. The first piece of the puzzle has been laid, but there is certainly more research needed to find out more about this.

They can cough or snort, of course, but otherwise you rarely hear giraffes. Still, they can make sounds. How that sounds? Scientists from Austria are now doing research into that. Also with us. In one of the giraffe stables there is now a microphone. It measures the sounds the giraffes make at night.

This is quite deliberate. In fact, during the day, animals communicate mainly with their eyes. They keep a close eye on each other and mainly watch each other's body language. When it gets dark, of course, this becomes much more difficult and giraffes would become more vocal (is the theory). Many of the sounds giraffes make are too low for the human ear to hear, so you need good microphones to record it.

In a few weeks the researcher will come to collect the recordings and hopefully we will be able to let you hear what sound a giraffe makes.

Not always research focuses on animals. Sometimes animals play an important role in human research. Erasmus MC is currently doing research on fighting cancer with viruses. After all, a virus can make people deathly ill, but it can also help cure them. For this study, they used poop from great apes from four different zoos, including Beekse Bergen.

From the poop of gorillas, chimpanzees, orangutans and bonobos, the research team isolated 42 cold viruses. In the end, six of the monkey viruses were indeed found to be effective against cancer cells in the lab.These viruses are administered to humans and go in search of tumor cells. The virus then divides into the tumor cells and destroys them. This wakes up the immune cells and allows them to attack the broken tumor cells, thus fighting cancer. It seems that the viruses can reach even the most elusive cancer cells, but the approach has worked in only a few patients so far. More research is therefore being done to find the cause.

The Rüppell's vulture is critically endangered in the wild. Blijdorp Zoo is the coordinator of this species and in cooperation with other parks ensures a healthy reserve population. Now with great results: a pair of Griffon vultures from Beekse Bergen has adopted and raised a young Rüppelsgier. Remarkably, the egg was laid in Avifauna Bird Park and hatched in Blijdorp Zoo.

To arrive at these beautiful results, a natural phenomenon was used. Vultures usually lay one egg per season, but when it is lost, the pair often lays a second egg. Keepers applied this knowledge by removing the egg and letting it hatch in the incubator at Blijdorp Zoo. The pair of Rüppellsgieren then laid a second egg, increasing the number of young of this endangered species.

Once the chick hatched, it was hand-fed for several days so that it was fit and strong. Then the chick was returned to its parents and swapped with the second egg. This second egg hatched and then suitable foster parents were searched for this chick. The pair of Griffon vultures in our park raised the foster chick as their own. With the use of knowledge about these animals and cooperation between different zoos, together we can ensure that as many young of this critically endangered species as possible are born.

Many birds have the good habit of cleaning their cutlery (beak) after eating. They do this through beak wiping: they wipe their beak along, for example, a branch. This behavior is also used to sharpen the beak and to communicate. But every bird is different, and therefore different species also wipe their beaks in different ways.

Robin Geveke and Robin Louis from Leiden University, in collaboration with Beekse Bergen, observed for four months how this beak wiping differs among various birds in the park. They discovered that all birds wipe their beaks except for some water birds like the African penguin and the African spoonbill. Instead of wiping their beak along a branch, they do it in the water. This is also done by the Bald eagle Maya, which makes sense since this species is often found near water.

They did not only focus their research on Maya and the other birds of prey seen during the birds of prey safari but on all birds in the park. They discovered that beak wiping differs per bird. All yellow-billed kites, the palm-nut vulture, and the hooded vultures prefer to do this high on a branch, just like the Egyptian vulture Gijs, but the Egyptian vulture Stekel prefers to do it on the ground, just like the secretary birds and the Abyssinian ground hornbill. Many birds of prey also use their feet to get the meat off their beak. The secretary bird is an extra interesting case, as it wipes its beak on its own leg!

Extra special is the data found about the yellow-billed kites and the Abyssinian ground hornbill. It was even discovered that they have a preference for which side they start with. Where most people prefer to write with their right hand, these birds prefer to start wiping their beaks on the left. Why exactly this is the case needs further investigation.

Many people think that bonobos are sweeter than chimpanzees. But is that really true? That is what student Marie-Ornelia Verger is currently researching.

French Animal Behaviour student at Paris' Sorbonne University closely monitors the behavior of the 12 chimpanzees by following each monkey for 10 minutes several times a day. In doing so, she pays attention to aggression, social interaction and sexual behavior. Consider the reaction to food: do they share their portion, keep everything for themselves or steal from others?

Others have done the same with bonobos in other parks. At the end of March, Marie-Ornelia will compare her findings from chimpanzees with those of bonobos. As a result, we will soon know for sure whether it is true that chimpanzees have shorter fuses than bonobos, or whether, on the contrary, it has nothing to do with the species at all, but is a matter of personality.

Rhythm is an important aspect of our language and naturally in music. Why do we find rhythmic music so pleasant to listen to? Is our language rhythmically by chance, or is our preference for rhythm evolutionarily deeper rooted than just in humanity?

For a long time, it was thought that only humans were rhythmic. Ape species like Rhesus monkeys were found to be not rhythmic at all. To investigate whether this is also the case with apes that are evolutionarily closer to humans, it is being studied in the safari park whether chimpanzees have a sense of rhythm.

Students from Leiden University investigated rhythmic movements (often display behavior) and studied the sounds the animals make. And what turned out, in both cases the students found isochronous rhythms!

The students discovered that rhythm is not exclusive to humans, which provides new insights into the evolutionary origin of our sense of rhythm and our language!