Standardization and calibration of heated mounts illustrated with day-old mallard ducklings
No abstract available.
Physiological and Biochemical Zoology↗
Geology topics
P.S. Reynolds
Publications and source records attributed to P.S. Reynolds.
Metabolic response to air temperature and wind in day-old mallards and a standard operative temperature scale
Most duckling mortality occurs during the week following hatching and is often associated with cold, windy, wet weather and scattering of the brood. We estimated the thermoregulatory demands imposed by cold, windy weather on isolated 1‐d‐old mallard ( Anas platyrhynchos ) ducklings resting in cover. We measured O 2 consumption and evaporative water loss at air temperatures from 5° to 25°C and wind speeds of 0.1, 0.2, 0.5, and 1.0 m/s. Metabolic heat production increased as wind increased or temperature decreased but was less sensitive to wind than that of either adult passerines or small mammals. Evaporative heat loss ranged from 5% to 17% of heat production. Evaporative heat loss and the ratio of evaporative heat loss to metabolic heat production was significantly lower in rest phase. These data were used to define a standard operative temperature ( T es ) scale for night or heavy overcast conditions. An increase of wind speed from 0.1 to 1 m/s decreased T es by 3°–5°C.
Physiological and Biochemical Zoology↗
Thermoregulatory effects of radiotelemetry transmitters on mallard ducklings
Many telemetry transmitter attachments disrupt downy insulation, and may bias survival studies during cold weather by making ducklings more susceptible to chilling. We compared thermal responses of untreated 1-day-old mallards ( Anas platyrhynchos ) to ducklings carrying external sutured backpack or subcutaneously implanted transmitters. Ducklings carrying external transmitters showed areas of increased surface temperature in thermographic images. However, open-circuit respirometry studies at 5, 10, 15, 20, and 25 C and wind speeds of 0.1, 0.2, 0.5, and 1 m/s indicated no biologically significant differences in total heat production, net heat production, or short-term body mass loss. These results do not exclude the possibility of other negative effects of transmitters on duckling behavior and survival.
Journal of Wildlife Management↗