Généralités et Environnement

Envoyé par : FB (Adresse IP journalisée)

Date : Mon 25 May 2009 13:09:32

Urban mockingbirds quickly learn to identify individual humans

1. Douglas J. Leveya,1,
2. Gustavo A. Londoñoa,b,
3. Judit Ungvari-Martina,b,
4. Monique R. Hiersouxa,b,
5. Jill E. Jankowskia,b,
6. John R. Poulsena,
7. Christine M. Straceya,b and
8. Scott K. Robinsona,b

Author Affiliations

1.
aDepartment of Biology, University of Florida, Gainesville, FL 32611-8525; and
2.
bFlorida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800

Edited by John Terborgh, Duke University, Durham, NC, and approved April 6, 2009 (received for review November 12, 2008)

Abstract

Practically all animals are affected by humans, especially in urban areas. Although most species respond negatively to urbanization, some thrive in human-dominated settings. A central question in urban ecology is why some species adapt well to the presence of humans and others do not. We show that Northern Mockingbirds (Mimus polyglottos) nesting on the campus of a large university rapidly learn to assess the level of threat posed by different humans, and to respond accordingly. In a controlled experiment, we found that as the same human approached and threatened a nest on 4 successive days, mockingbirds flushed from their nest at increasingly greater distances from that human. A different human approaching and threatening the nest identically on the fifth day elicited the same response as the first human on the first day. Likewise, alarm calls and attack flights increased from days 1–4 with the first human, and decreased on day 5 with the second human. These results demonstrate a remarkable ability of a passerine bird to distinguish one human from thousands of others. Also, mockingbirds learned to identify individual humans extraordinarily quickly: after only 2 30-s exposures of the human at the nest. More generally, the varying responses of mockingbirds to intruders suggests behavioral flexibility and a keen awareness of different levels of threat posed by individuals of another species: traits that may predispose mockingbirds and other species of urban wildlife to successful exploitation of human-dominated environments.


Bon l'expérience est jolie. Mais le résultat n'est pas si surprenant que ça quand même.
Honnêtement des français auraient fait la même expérience avec les mêmes résultats, ça aurait surement pas fait un PNAS.
C'est bien d'être anglophone des fois... (et peut être de connaître les éditeurs !!!).

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