06 July 2026
Hummingbirds make bromeliad plants split into new species twice as fast as other pollinators do, scientists at the University of Reading have found.
The research team gathered records of which animals pollinate 403 types of bromeliad, which include pineapples and more than 3,700 species, and found three in four of these plants are visited by hummingbirds.
Published today (Tuesday, 7 July) in the journal Botanical Journal of the Linnean Society, scientists found that where hummingbirds do the pollinating, bromeliads split into species twice as fast as plants pollinated by bees, bats or moths. Hummingbird-pollinated plants formed species at a rate of 2.77 per million years, against 1.46 for the rest.
Elizabeth Forward, lead author of the study, PhD researcher at the University of Reading, said: "Bees and wasps were the first to pollinate bromeliads, the plant family that gave us the pineapple, but hummingbirds muscled in later, and not just once. Time and again, different branches of the family swapped one pollinator for another, and that swapping is still going on today.
“Our findings are particularly striking because hummingbirds and bromeliads are relatively young evolutionary lineages. Much of their modern diversity arose over the past 20 million years, which is the blink of an eye in evolutionary timescales.”
Dr Jamie Thompson, Leverhulme research fellow and senior author from the University of Reading, added: "Hummingbirds seem to act like an engine for new species. They feed high in the mountains, where plants grow in small patches split apart by valleys and peaks. Cut off from their neighbours, those groups drift apart over time until they become species in their own right."
Pineapples belong to the bromeliad family, even though they look unusual next to their relatives. They share the same ancestor and the same key features, like strappy leaves and a flower spike, but they grow in the ground and produce a large fruit. Most other bromeliads are smaller plants that grow on tree branches or rocks, and many form water-filled leaf rosettes known as “tanks”, which provide mini-ecosystems for many animals, including frogs. Popular air plants, found in millions of homes worldwide, are also bromeliads.
Pineapples and most of their relatives rely on hummingbirds to pollinate them. The birds drink the sugary nectar inside each flower, and pollen sticks to them as they feed, then rubs off at the next flower they visit. Over millions of years, the shape and colour of many bromeliad flowers have changed to suit their hummingbird visitors.
This close partnership now carries a risk. Many bromeliads grow in mountain forests that are being cleared for farming or changed by a warming climate, and 81% are possibly at risk of extinction. Similarly, one in ten hummingbird species is at risk of dying out, and six in ten are falling in number. Because so many bromeliads depend on a single type of bird, the loss of a hummingbird could mean the loss of the plants that rely on it.
Some bromeliads guard against this by accepting more than one kind of pollinator. Around one in six of the plants in the study were visited by more than one group of animals, which may give them a better chance of surviving if one pollinator disappears.
The records the team built give other scientists a base to keep studying the family, which matters now more than ever as hummingbirds and other pollinators fall in number and the plants that depend on them face an uncertain future.
Notes to editors:
The authors are available for interview. Contact the University of Reading Press Office on 0118 378 5757 or pressoffice@reading.ac.uk.
Forward, E. A., & Thompson, J. B. (2026). The origins and diversification of hummingbird pollination in Bromeliaceae. Botanical Journal of the Linnean Society. https://doi.org/10.1093/botlinnean/boag055. View: https://academic.oup.com/botlinnean/article-lookup/doi/10.1093/botlinnean/boag055
The work was funded by a Leverhulme Trust Early Career Fellowship (ECF-2025-557).
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