Compare this to the fact that, according to the Food and Agriculture Organization of the United Nations (FAO), the worldwide human population consumes around 400 million tons of meat and fish every year. The spider’s eating habits can even be compared to those of the whales (Cetacea) in the world’s oceans, which eat an estimated 280-500 million tons of prey a year.

The particular importance of spiders in forests and grasslands

The zoologists also showed that spiders kill many times more insects in forests and grasslands than in other habitats. Spiders in these areas catch huge numbers of forest and grassland pests, whereas spiders in desert regions, in the Arctic tundra and in annual crops kill fewer insects in comparison. The spiders’ impact is lower in agricultural areas because these are intensively managed areas that offer unfavorable living conditions for spiders.

“Our calculations let us quantify for the first time on a global scale that spiders are major natural enemies of insects. In concert with other insectivorous animals such as ants and birds, they help to reduce the population densities of insects significantly," says Martin Nyffeler from the University of Basel, lead author of the study. “Spiders thus make an essential contribution to maintaining the ecological balance of nature,” he adds.

Original publication

Martin Nyffeler & Klaus Birkhofer

An estimated 400-800 million tons of prey are annually killed by the global spider community

The Science of Nature (2017), doi: 10.1007/s00114-017-1440-1

Further information

PD Dr. Martin Nyffeler, University of Basel, Department of Environmental Sciences, Tel. +41 61 702 07 03, Email: martin.nyffeler@unibas.ch