HomeScienceCompetition limits the ranges of mountain birds

Competition limits the ranges of mountain birds

master mentalism tricks

Yellow-throated Toucan. Credit: Becky Matsubara, Macaulay Library, Cornell Lab of Ornithology

A new study helps reveal why tropical mountain birds occupy such narrow elevation ranges, a mystery that has puzzled scientists for centuries. While many assumed temperature was responsible for these limited distributions, the latest research suggests competition from other species plays a bigger role in shaping bird ranges.

The study, conducted by researchers at the University of British Columbia and the Cornell Lab of Ornithology, incorporated 4.4 million citizen science observations of 2,879 bird species around the world. The findings were published in Science on July 21.

“You have this incredible biodiversity in mountain ranges, especially in the tropics. From one vista point in the Andes, you can see a mountain slope that’s home to as many species as there are in the entirety of North America,” said lead author Benjamin Freeman, a postdoctoral fellow at the University of British Columbia. “We wanted to know, how does that work?”

Freeman and his collaborators obtained the range data by analyzing records from eBird, a citizen science project run by the Cornell Lab that contains sightings from hundreds of thousands of birdwatchers worldwide. This enabled them to examine the ranges of over a quarter of the world’s bird species scattered over five continents—a scale unimaginable to past researchers.

A view of the western Andes Mountains from Ecuador. Credit: Eliot Miller.

“Aside from eBird, you just have really coarse range maps, especially on a global scale,” said co-author Eliot Miller at the Cornell Lab. “The eBird database is uniquely broad in both space and time, giving us more insight into bird distribution around the world than we have for any other organisms.”

The researchers looked for connections between elevational range size and two factors: temperature stability throughout the year, and range overlap with other species. If range size was correlated with a consistent climate, this would indicate that birds are limited by their own biology—they have become so accustomed to a particular temperature that they cannot survive elsewhere. If birds occupied smaller ranges where they overlapped many other species, then increased competition for resources may be restricting them.

The results demonstrated that a consistent climate did not predict a smaller range size. However, there was strong evidence showing that when there was more overlap among a greater number of species’ ranges, the ranges were smaller.

Despite his suspicion that competition was a key factor, Freeman says he was still caught off guard by the clarity of the results.

  • Ornate Hawk-Eagle. Credit: Sergio Andrés Cuéllar Ramírez, Macaulay Library, Cornell Lab of Ornithology
  • Black-and-chestnut Eagle. Credit: Dusan Brinkhuizen, Macaulay Library, Cornell Lab of Ornithology

“I had noticed some patterns that suggested competition might be important to bird distribution, but I was still surprised to find such a strong signal in this study,” he said.

In many cases, closely related species also restricted one another’s distributions. For example, the Ornate Hawk-Eagle, a massive raptor of tropical forests, occupied a larger span of elevations in areas where it did not coincide with the similar Black-and-chestnut Eagle. When the two inhabited the same mountain range, they avoided one another, with the Ornate Hawk-Eagle passing up elevations it would normally favor elsewhere in its range.

While this study sheds light on one aspect of mountain species‘ ranges, the authors suggest there is still much more to learn. Many details remain unknown about how other aspects of a bird’s ecosystem impact its distribution.

Identifying bird species by sound, an app opens new avenues for citizen science More information: Benjamin G. Freeman et al, Interspecific competition limits bird species’ ranges in tropical mountains, Science (2022). DOI: 10.1126/science.abl7242 Provided by Cornell University

Citation: Competition limits the ranges of mountain birds (2022, July 21) retrieved 13 August 2022 from

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Read The Full Article Here

trick photography

Popular posts

‘She-Hulk’: Every Episode 3 Easter Egg
Don’t Worry Darling review – shaky sci-fi dystopia with surface-level
10 Actors Who Were Way Older Than Their Characters
See How They Run Review: A Mediocre Mystery
Fox Business Network’s Prime Fall Lineup Includes Mike Rowe, Kelsey
The Cleaning Lady Round Table: We Love the Eye Candy
Sacheen Littlefeather, Activist Who Gave Marlon Brando’s Oscar Speech, Dies
Thora Birch Explains Why She Didn’t Return for Hocus Pocus
Taylor Swift Shares Another Track Title from ‘Midnights’: Watch
Post Malone Suffers Nasty Onstage Fall, Apologizes to Fans for
5 Seconds of Summer Blast to No
Sam Smith and Kim Petras Torch U
Louis Vuitton Hosted Two Parties on Two Coasts to Celebrate
The Best Documentaries to Watch on Netflix If You’ve Binged
Becky G Wears a Tarot Card Dress With Thigh-High Cutouts
Gwyneth Paltrow Masters the Art of Easy Summer Dressing in
Adaptation Trends and Predictions: More Scary Stories, Please!
Teen Warrior Fights to Save Her Family in This Interplanetary
Books To Read If You Like L
Familial and Systemic Struggle in Story of Ultimate Survival
Cycling vs running: Which type of cardio is best?
Experimental test promises to predict side-effects and cancer’s return in
Why rethinking time in quantum mechanics could help us unite
Scientists unveil new system for naming majority of the world’s
Hurricane Ian Is a Warning From the Future
DocuSign plans to lay off 9% of staff as part
Stephen Palumbi Says ‘Super Reefs’ Can Help Save Dying Coral
One Solution to the Food Waste Problem: Eat Your Garbage