During the early stage of the worldwide COVID-19 pandemic, with the sudden lack of supplies - and expected lack of supplies - due to lockdown or otherwise, many people began panic buying and stocked up on supplies of essential daily articles, particularly cleaning products. Such hoarding behaviours are commonly seen in animals, usually birds and mammals – although their target is food. In the study of animal behaviour, hoarding refers to the collection and storage of food for future use. Many animals will stock up food before winter in preparation for the food-scarce season. Even in tropical regions where animals do not need to over-winter, there are all kinds of reasons to store up food with a variety of strategies.
Hamster may be the most well-known animal that hoards food. It always hoards food, and puts it in a central storage. In the wild, the hamster lives underground with numerous rooms, and one of them is dedicated as a food stash. The hoarding behaviour has evolved due to food scarcity, and the danger of being preyed upon while foraging for food. This has greatly raised the survival rate of hamsters in the wild. Anyone who has kept a hamster as a pet will also notice that hamster loves to stuff its cheeks with food, and put the food in some hideout corner. Hamster has not lost its hoarding instinct even when well-fed as a pet!
Instead of putting all food together, some animals like to “diversify their investment” and put their food in different places. However, this approach requires a superb memory. Studies have shown that animals adopting this hoarding strategy have indeed a larger hippocampus – the part of brain that is responsible for memory. Nonetheless, no matter how good a memory the animals have, there is always a time when the animals lose count. The Eastern Grey Squirrel (Sciurus carolinensis) in North America is one such strategist that always forgets. Amazingly, its forgetfulness has an important ecological function: to help plant species to propagate. When the tiny creature buries seeds in different places and fails to dig them out later, the plants will thrive away from their parent plants.
For some other animals, the act of hoarding is not for future use but for better enjoyment of the food. Leopard (Panthera pardus) in Africa, for example, will haul its large prey up the tree to prevent other predators from stealing the hard-gained food. It can then take its time to enjoy the meal. A “little bird of prey”, the Long-tailed Shrike (Lanius schach), a common bird in Hong Kong, occasionally impales its prey – including lizards, frogs and insects – on a sharp point up high, for slow food. In Central America, the Tayra (Eira Barbara) stores unripe banana for a few days before consuming the ripe gourmet food.