Format

Send to

Choose Destination
Biol Lett. 2013 Aug 14;9(5):20130319. doi: 10.1098/rsbl.2013.0319. Print 2013 Oct 23.

If a bird flies in the forest, does an insect hear it?

Author information

1
Department of Biology, Carleton University, Ottawa, Ontario, Canada.

Abstract

Birds are major predators of many eared insects including moths, butterflies, crickets and cicadas. We provide evidence supporting the hypothesis that insect ears can function as 'bird detectors'. First, we show that birds produce flight sounds while foraging. Eastern phoebes (Sayornis phoebe) and chickadees (Poecile atricapillus) generate broadband sounds composed of distinct repetitive elements (approx. 18 and 20 Hz, respectively) that correspond to cyclic wing beating. We estimate that insects can detect an approaching bird from distances of at least 2.5 m, based on insect hearing thresholds and sound level measurements of bird flight. Second, we show that insects with both high and low frequency hearing can hear bird flight sounds. Auditory nerve cells of noctuid moths (Trichoplusia ni) and nymphalid butterflies (Morpho peleides) responded in a bursting pattern to playbacks of an attacking bird. This is the first study to demonstrate that foraging birds generate flight sound cues that are detectable by eared insects. Whether insects exploit these sound cues, and alternatively, if birds have evolved sound-reducing foraging tactics to render them acoustically 'cryptic' to their prey, are tantalizing questions worthy of further investigation.

KEYWORDS:

anti-predator; bird flight; foraging; hearing; insect; sound

PMID:
23945205
PMCID:
PMC3971667
DOI:
10.1098/rsbl.2013.0319
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center