scholarly journals Egg discrimination by hosts and obligate brood parasites: a historical perspective and new synthesis

Chinese Birds ◽  
2012 ◽  
Vol 3 (4) ◽  
pp. 274-294 ◽  
Author(s):  
Spencer G. SEALY ◽  
Todd J. UNDERWOOD
Keyword(s):  
Historical Perspective ◽  
Egg Discrimination ◽  
Brood Parasites ◽  
New Synthesis

scholarly journals UV reflectance as a cue in egg discrimination in twoPriniaspecies exploited differently by brood parasites in Taiwan

Ibis ◽  
2013 ◽  
Vol 155 (3) ◽  
pp. 571-575 ◽  
Author(s):  
Canchao Yang ◽  
Longwu Wang ◽  
Yu-Cheng Hsu ◽  
Anton Antonov ◽  
Arne Moksnes ◽  
...  
Keyword(s):  
Egg Discrimination ◽  
Brood Parasites ◽  
Uv Reflectance

A Test for Conspecific Egg Discrimination in Three Species of Colonial Passerine Birds

The Auk ◽  
1982 ◽  
Vol 99 (3) ◽  
pp. 519-525
Author(s):  
Glen A. Lanier
Keyword(s):  
Brood Parasitism ◽  
Current Theory ◽  
Passerine Birds ◽  
Barn Swallow ◽  
Egg Discrimination ◽  
Intraspecific Brood Parasitism ◽  
Brood Parasites ◽  
Naturally Occurring ◽  
Altricial Birds ◽  
The Cost

Abstract Naturally occurring populations of three species of colonial passerine birds, the Piñon Jay (Gymnorhinus cyanocephalus), Great-tailed Grackle (Quiscalis mexicanus), and Barn Swallow (Hirundo rustica), were tested for conspecific egg discrimination and the presence of intraspecific brood parasitism that such discrimination would imply. Current theory predicts that intraspecific brood parasitism, or cheating, might occur when a brood parasite's fitness is enhanced relative to a nonparasite's. Due to the high cost of parental care in altricial birds, selection for defenses against such cheaters should also be intense. Egg rejection is the most common selection mechanism against interspecific brood parasites, and I tested for the presence or absence of this mechanism. Single eggs were switched between pairs of 19 Piñon Jay nests, 15 Great-tailed Grackle nests, and 14 Barn Swallow nests, and a fifth egg was added to each of 8 Piñon Jay nests. No significant level of rejection of introduced eggs was found, possibly either because the cost of cheating is too great or because egg discrimination and rejection are not the mechanisms of selection against cheaters in the populations tested.

scholarly journals Hosts of avian brood parasites have evolved egg signatures with elevated information content

2015 ◽  
Vol 282 (1810) ◽  
pp. 20150598 ◽  
Author(s):  
Eleanor M. Caves ◽  
Martin Stevens ◽  
Edwin S. Iversen ◽  
Claire N. Spottiswoode
Keyword(s):  
Information Content ◽  
Brood Parasitism ◽  
Colour Pattern ◽  
Egg Discrimination ◽  
Brood Parasites ◽  
Individual Host ◽  
Egg Traits ◽  
The Cost

Hosts of brood-parasitic birds must distinguish their own eggs from parasitic mimics, or pay the cost of mistakenly raising a foreign chick. Egg discrimination is easier when different host females of the same species each lay visually distinctive eggs (egg ‘signatures’), which helps to foil mimicry by parasites. Here, we ask whether brood parasitism is associated with lower levels of correlation between different egg traits in hosts, making individual host signatures more distinctive and informative. We used entropy as an index of the potential information content encoded by nine aspects of colour, pattern and luminance of eggs of different species in two African bird families (Cisticolidae parasitized by cuckoo finches Anomalospiza imberbis , and Ploceidae by diederik cuckoos Chrysococcyx caprius ). Parasitized species showed consistently higher entropy in egg traits than did related, unparasitized species. Decomposing entropy into two variation components revealed that this was mainly driven by parasitized species having lower levels of correlation between different egg traits, rather than higher overall levels of variation in each individual egg trait. This suggests that irrespective of the constraints that might operate on individual egg traits, hosts can further improve their defensive ‘signatures' by arranging suites of egg traits into unpredictable combinations.

Sleep Apnea—An Historical Perspective

1990 ◽  
Vol 23 (4) ◽  
pp. 571-575
Author(s):  
Charles F. Koopmann, ◽  
Willard B. Moran
Keyword(s):  
Sleep Apnea ◽  
Historical Perspective
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