Are declines in insects and insectivorous birds related?

The average change in population size over the last 50 years of terrestrial North American bird species for which insects are an essential part of the diet at some point in their life history and bird species that never rely on insects for food. Statistical
intervals = standard deviations

Author: Tallamy, Douglas W.; Shriver, W. Gregory

Description: A flurry of recently published studies indicates that both insects and birds have experienced wide-scale population declines in the last several decades. Curiously, whether insect and bird declines are causally linked has received little empirical attention. Here, we hypothesize that insect declines are an important factor contributing to the decline of insectivorous birds. We further suggest that insect populations essential to insectivorous birds decline whenever non-native lumber, ornamental, or invasive plant species replace native plant communities. We support our hypothesis by reviewing studies that show (1) due to host plant specialization, insect herbivores typically do poorly on non-native plants; (2) birds are often food limited; (3) populations of insectivorous bird species fluctuate with the supply of essential insect prey; (4) not all arthropod prey support bird reproduction equally well; and (5) terrestrial birds for which insects are an essential source of food have declined by 2.9 billion individuals over the last 50 years, while terrestrial birds that do not depend on insects during their life history have gained by 26.2 million individuals, a 111-fold difference. Understanding the consequences of insect declines, particularly as they affect charismatic animals like birds, may motivate land managers, homeowners, and restoration ecologists to take actions that reverse these declines by favoring the native plant species that support insect herbivores most productively.

Subject headings: Bird declines; Birds; Insect populations; Insects; Plant communities; Host plants; Empirical research; Extinction

Publication year: 2021

Journal or book title: Ornithological Applications

Volume: 123

Issue: 1

Pages: duaa059

Find the full text: https://www.strategian.com/fulltext/Tallamy2021.pdf

Find more like this one (cited by): https://scholar.google.com/scholar?cites=10752204515162043&as_sdt=1000005&sciodt=0,16&hl=en

Serial number: 4164

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