The trenches ran right through the front part of the park, and the building of the former animal feed factory on the site was requisitioned. Whereas this building had previously served as a warehouse, it was now used to prepare meals for the hundreds of soldiers stationed around the park. Army horses were also stabled there.

In the eight years since it opened, the park itself had developed into a fully-fledged zoo. All the major animals roamed there, and preferably in large numbers. However, according to the Dutch military command, the presence of so many predators was life-threatening. In the event of a German attack, the animal enclosures would certainly be hit by shelling. The risk of the animals escaping as a result was too great. They therefore had to be culled as a preventive measure.

With a heavy heart, director Cornelis Ouwehand carried out the order himself. He would rather kill the animals himself than have the army do so. Only the polar bears – a mother with her two cubs – did he manage to bring to safety. In the book Het vaderland spreekt tot de jeugd (published after the war), Cor Ouwehand writes: “Amidst the roar of the German aircraft still flying overhead, accompanied by the thunderous anti-aircraft fire, I made my way with heavy steps past the predator enclosures, trying as best I could to control my nerves so as not to cause the animals unnecessary suffering. One by one, my lions, tigers and bears fall...”

Major Landzaat and ‘Het Paviljoentje’

On 11 May 1940, Ouwehand was forced to leave his park. The air-raid shelter behind the house was requisitioned by the local army commander. The fierce fighting in the days that followed resulted in the destruction of most of the zoo as well. The area surrounding the zoo was valiantly defended by Major Willem Pieter Landzaat (1892–1940), commander of the 1st Battalion of the 8th Infantry Regiment. During the Battle of the Grebbeberg, he and his men defended one of the last defensive positions: ‘Het Paviljoentje’, a café at the entrance to Ouwehands Zoo. Under heavy fire, he held his ground, even as the situation became hopeless. Eventually, he gave his men permission to withdraw. He himself decided to stay behind. After the surrender, the major’s remains were found beneath the rubble of the collapsed ‘Paviljoentje’.

After the May Days, Ouwehand began to restore his park. The park reopened as early as 1940, but when the Allied armies approached in 1944, it was the German soldiers who shot the newly acquired predators and slaughtered many other animals for food. In an effort to save as many animals as possible, the keepers set off with a whole convoy from Rhenen to Veenendaal. By the end of the war, it turned out that a considerable number of animals had survived the fighting, and Ouwehand was able to rebuild his park for the third time.

The widow of Major Willem Pieter Landzaat later had a small house built on the site of ‘Het Paviljoentje’ in his memory. This little white house still stands there today. A commemorative plaque has been affixed to the front façade in memory of the major. Major Landzaat was posthumously honoured for his courage and self-sacrifice. He is buried at the Grebbeberg Military Cemetery.