Fluctuating asymmetry (FA), small random deviation from bilateral symmetry, often increases with stress during development. Common Terns (Sterna hirundo) typically lay two to three eggs that hatch asynchronously. I predicted that C-chicks (last of three) should have greater FA than A- and B-chicks at hatching and that FA should be higher in chicks from smaller clutches, because of differences in parental quality. Tarsus length of newly hatched chicks was measured across three years, and middle toe length was measured in one year. Sample sizes exceeded 100 chicks in two of three years. Variation in tarsus FA with hatching order and clutch size was statistically significant in one year (P < 0.01) and nearly so in another (P < 0.10). No significant differences were present for toe FA. A-chicks from three-egg clutches appeared to have the lowest tarsus FA among categories of chicks in both years, and in one year they were significantly more symmetrical than B- and C-chicks from three-egg clutches. As predicted, A-chicks from three-egg clutches were also more symmetrical than A-chicks from two-egg clutches and singletons. However, C-chicks did not differ significantly from B-chicks in tarsus FA. Fluctuating asymmetry also varied with hatching date, but no clear pattern emerged. Fluctuating asymmetry was not associated with trait size or body mass, although there was significant variation in body mass and toe size among groups, C-chicks being relatively small and A-chicks and singletons relatively large.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.