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Full-Text Articles in Life Sciences
Body Size, Nest Predation, And Reproductive Patterns In Brown Thrashers And Other Mimids, Michael T. Murphy, Robert C. Fleischer
Body Size, Nest Predation, And Reproductive Patterns In Brown Thrashers And Other Mimids, Michael T. Murphy, Robert C. Fleischer
Biology Faculty Publications and Presentations
We describe the breeding biology of Brown Thrashers (Toxostoma rufum) in Kansas, and combine this with data from other temperate-zone breeding Mimidae to characterize reproductive patterns in this group. Brown Thrashers produced clutches of 3 to 6 eggs, but clutches of 4 predominated. Most pairs raised 2 broods per year. Incubation required between 13 and 14 days, and hatching was usually asynchronous. Though sample size was small, asynchrony appeared to increase in frequency towards the end of the breeding season. Nestlings grew rapidly, and in 10 days or less most pre-fledgingg rowthw as completed. Young fledgedn ormallya t 11 days …
Body Size And Condition, Timing Of Breeding, And Aspects Of Egg Production In Eastern Kingbirds, Michael T. Murphy
Body Size And Condition, Timing Of Breeding, And Aspects Of Egg Production In Eastern Kingbirds, Michael T. Murphy
Biology Faculty Publications and Presentations
Variation in timing of breeding in Eastern Kingbirds (Tyrannus tyrannus) was correlated only weakly with external morphological characters, but was correlated positively and significantly with estimates of body size based on measurements of skeletons and muscle weights. Small females apparently held a reproductive advantage in being able to mobilize resources for reproduction before large females. Egg weight was independent of all measures of female size, but was directly and significantly (P = 0.03) correlated with standard flight muscle weight, a relative index of body condition. Egg size was thus a function more of female body condition than size. On average, …
Brood Parasitism Of Eastern Kingbirds By Brown-Headed Cowbirds, Michael T. Murphy
Brood Parasitism Of Eastern Kingbirds By Brown-Headed Cowbirds, Michael T. Murphy
Biology Faculty Publications and Presentations
Understanding why brood parasites lay eggs in the nests of hosts that reject eggs is hampered by insuf-ficient data on the frequency with which parasites lay in rejecter nests, and by ignorance of which in-dividuals practice this seemingly inappropriate be-havior. Parasitism rates of rejecters can be deter-mined only when host nests are observed during egg laying because most parasite eggs are rejected rapidly (e.g. Scott 1977). Even then, however, a certain per-centage of parasitized nests may go undetected. De-termining the selective value of host defense mech-anisms also depends on knowledge of the frequency of parasitism, and the amount of reproductive …