Year of Award
Master of Science (MS)
Department or School/College
College of Forestry and Conservation
Thomas E. Martin
Arthur Woods, Winsor Lowe
embryonic development, incubation, incubation temperature, metabolic rate, passerines
University of Montana
Variation in embryonic developmental periods influences fitness, but causes of interspecific variation are poorly understood. Allometry, for example, does not explain variation in incubation periods among neotropical passerines. Incubation temperature can explain some variation in developmental periods, but substantial variation remains unexplained. Here we examine two previously untested alternatives. Adult metabolic rates differ among species and similar differences among embryos may explain some variation in embryonic development rates; higher metabolism may allow faster cellular proliferation. Alternatively, metabolic rates are temperature dependent, and metabolic rates might respond differentially to temperature among species and compensate for differing incubation temperatures. These alternatives are untested across any taxa. Therefore, we examined them in tropical Venezuela by measuring embryonic metabolism at four temperatures in 15 passerine species with incubation periods ranging from 12 to 27 days. Embryonic metabolic rates responses to temperature were different among species even at constant embryonic age. Furthermore, species with lower average daily incubation temperature are less sensitive to changes in temperature than species with higher average incubation temperatures. Differences in embryonic mass specific metabolic rate among species explained a significant amount of variation in incubation periods after correcting for incubation temperature. Thus, differences in the “rate of living” as manifested through metabolism can influence developmental trajectories and deserve greater attention.
Niklison, Alina Maria, "INFLUENCE OF EMBRYONIC METABOLIC RATE AND INCUBATION TEMPERATURE ON INCUBATION LENGTH VARIATION IN NEOTROPICAL PASSERINES" (2007). Graduate Student Theses, Dissertations, & Professional Papers. 574.
© Copyright 2007 Alina Maria Niklison