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Time and energy budgets of breeding males and females in sandgrouse Pterocles species
Author(s) -
HINSLEY SHELLEY A.,
FERNS PETER N.
Publication year - 1994
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1994.tb01094.x
Subject(s) - foraging , incubation , energy expenditure , biology , vigilance (psychology) , zoology , energy balance , parental investment , ecology , endocrinology , offspring , pregnancy , biochemistry , genetics , neuroscience
The investment of time and energy in reproduction by male and female sandgrouse (genus Pterocles ) was studied. Energy expenditure was estimated using time budgets and laboratory measurements of metabolism. Female parental expenditure was greatest during laying and incubation. Females took the larger share of daytime incubation, which reduced their time available for foraging (3.6 h compared with 4.8 h for males). To remain in energy balance, they required a higher food intake rate than males (97 kJ/h compared with 79 kJ/h, respectively) and consequently were likely to lose condition during incubation. Male parental expenditure was greatest during chick‐rearing, especially when the young were well grown but still dependent on the male for water. The role of males as water carriers increased their energy expenditure and decreased their time available for foraging. Males also took the greater share of time spent in vigilance on behalf of the young, which further reduced their foraging time (3.2 h compared with 4.9 h for females). To remain in energy balance, males with young required a higher intake rate than females (62 kJ/h compared with 44 kJ/h, respectively).