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Full-Text Articles in Ecology and Evolutionary Biology
Temperature Regulation And The Constraints Of Climate In The Eared Grebe, Hugh I. Ellis, Joseph R. Jehl Jr
Temperature Regulation And The Constraints Of Climate In The Eared Grebe, Hugh I. Ellis, Joseph R. Jehl Jr
Biology: Faculty Scholarship
Eared Grebes (Podiceps nigricollis) encounter a variety of climatic regimes in their annual cycle. The most dramatic occur while on staging areas in autumn. We investigated the thermoregulatory abilities of the Eared Grebe to determine how they coped with these climate changes during staging. The basal metabolic rate (BMR) was higher than predicted. Mass-specific BMR was 1.212 mL O2/g·h for birds averaging 317 g. The thermoneutral zone is wide and extended from 15°C to 38°C. Minimal thermal conductance and average body temperature were not unusual. We conclude that Eared Grebes live most of the year under thermoneutral conditions and that …
Energetics Of Free-Ranging Seabirds, Hugh I. Ellis, Geir Wing Gabrielsen
Energetics Of Free-Ranging Seabirds, Hugh I. Ellis, Geir Wing Gabrielsen
Biology: Faculty Scholarship
No abstract provided.
Summer Activity Cost Of Eared Grebes At Mono Lake, Hugh I. Ellis
Summer Activity Cost Of Eared Grebes At Mono Lake, Hugh I. Ellis
Biology: Faculty Scholarship
No abstract provided.
Total Body Water And Body Composition In Phalaropes And Other Birds, Hugh I. Ellis, Joseph R. Jehl Jr
Total Body Water And Body Composition In Phalaropes And Other Birds, Hugh I. Ellis, Joseph R. Jehl Jr
Biology: Faculty Scholarship
Contrary to some reviews, total body water (TBW) may fall below the expected value of about 65% in birds if measured as a percentage of total body mass. However, water constitutes a relatively stable proportion (659%-70%) of body composition when measured as a percentage of lean body mass (LBM). We demonstrate this by using data from two migratory phalaropes (Phalaropus tricolor and Phalaropus lobatus), which exhibit inverse relationships between TBW and body mass and between TBW and fat content. As the phalaropes fatten before migration, lipids increase but not at the expense of water, which also increases with gains in …
Incubation Energetics Of The Laysan Albatross, Ted N. Pettit, K A. Nagy, Hugh I. Ellis, G Causey Whittow
Incubation Energetics Of The Laysan Albatross, Ted N. Pettit, K A. Nagy, Hugh I. Ellis, G Causey Whittow
Biology: Faculty Scholarship
The energy expenditure of incubating and foraging Laysan Albatross (Diomedea immutabilis, mean body weight 3.07 kg) was estimated by means of the doubly-la- belled water technique. During incubation, the energy expenditure was similar to that of resting birds that were not incubating an egg. The energy expenditure of foraging albatross (2072 kJ/day) was 2.6 times that of resting birds. It was concluded that the energy expenditure of the tropical Laysan Albatross was not less than that of species foraging over cold, high-latitude oceans. An energy budget compiled for an incubating pair of albatross revealed that the energy expenditure of the …
Metabolism And Solar Radiation In Dark And White Herons Nesting In Hot Climates, Hugh I. Ellis
Metabolism And Solar Radiation In Dark And White Herons Nesting In Hot Climates, Hugh I. Ellis
Biology: Faculty Scholarship
Metabolism, body temperature (Tb), and feather reflectance was measured for dark Louisiana herons (LOU), little blue herons (LB), snowy egrets (SE), and cattle egrets (CE); only LOU nest preferentiallyin shade. The reflectance of LOU and adult LB was 13%-15%; it was 80%-82% for SE, CE, and immature (white) LB. Tb for all four species approximated 40 C; hypothermy was never observed. Basal metabolism (HJb) was 107% of the expected level for LOU, 85% for SE and CE, and 66% for LB. Minimal thermal conductance (C) was calculated as approximately 131% of the expected value for LOU, 115% for SE and …