Researchers working high in Hawai’i forests documented songbirds taking twigs and moss from other nests. The study, led by UC Riverside entomologist Erin Wilson Rankin, tracked theft behaviour in the wild for the first time. A trained team watched more than 200 native canopy nests over six months.
Observers monitored several species, notably the scarlet I’iwi, crimson Apapane and yellow-green Hawai’i Amakihi. The Apapane were both the most frequent thieves and the most common victims, a pattern the researchers link to the species’ abundance in those forests.
Most thefts happened between nests at similar heights, supporting a “height overlap” idea: birds find materials while foraging. In most cases targeted nests were already abandoned, but about 10% of thefts involved active nests. Roughly 5% of the observed nests failed after a theft, sometimes because the structure was damaged or parents left when disturbed.
The study notes risks for thieves, such as parasites or disease on stolen material and aggressive defence by some species. The researchers say understanding when and where kleptoparasitism happens could help design conservation actions for at-risk birds.
Difficult words
- document — record or describe something officiallydocumented
- entomologist — a scientist who studies insects
- nest — a bird's home made of plant materialnests
- abundance — a large number or amount
- forage — searching for food in the environmentforaging
- abandon — left empty or with no peopleabandoned
- parasite — small organisms that live on othersparasites
- kleptoparasitism — when animals steal food or materials
- conservation — careful protection of nature and wildlife
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Why might birds take materials from other nests instead of finding new materials?
- What conservation actions could help at-risk birds where kleptoparasitism happens?
- How could theft of nest materials affect bird populations in a forest you know?
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