News Release

50-year study offers insight into effects of climate on bird reproduction

Peer-Reviewed Publication

University of Illinois at Urbana-Champaign, News Bureau

Study co-author Jeffrey Hoover

image: Avian ecologist Jeff Hoover and his colleagues explored the potential effects of global warming on bird reproductive output across the world. view more 

Credit: Photo by Fred Zwicky

CHAMPAIGN, Ill. — A new study reported in the Proceedings of the National Academy of Sciences assessed changes in the reproductive output of 104 bird species around the world between 1970 and 2019. The study reveals that a warming climate appears to have more worrisome effects on larger birds and migratory birds than on smaller, sedentary species.

Study co-author Jeffrey Hoover, an avian ecologist at the Illinois Natural History Survey describes the findings in an interview with University of Illinois Urbana-Champaign life sciences editor Diana Yates.

Some highlights:

  • Increasing local temperatures during the chick-rearing part of the breeding season tended to decrease offspring production in most migratory birds but increased the number of young produced in many small birds and in sedentary birds, which don’t migrate.  
  • Warming temperatures also were associated with less offspring production among relatively large birds.
  • For migratory species, a warming climate could create mismatches between peak food resource availability and when demand for that food is highest – for example, when adults are feeding chicks and fledglings. Migratory species also rely on a variety of habitats across their range. Climate-related impacts across their range could have detrimental effects on their reproductive output.

To read the full interview, see “How does climage change affect global bird reproduction?”

The INHS is a division of the Prairie Research Institute at the U. of I.

Editor’s note:  

To reach Jeffrey Hoover, email  

The paper “The effect of climate change on avian offspring production: A global meta-analysis” is available online and from the U. of I. News Bureau.


Michael Jeffords and Susan Post are wildlife photographers and research affiliates of the Illinois Natural History Survey at the Prairie Research Institute of the U. of I. Their photographs are available here.

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