Water-Vapor Pressure in Nests of the San Miguel Island Song Sparrow
Kern MD, Sogge MK, Van Riper C. 1990. Water-Vapor Pressure in Nests of the San Miguel Island Song Sparrow. The Condor. 92(3):761-767
The water-vapor pressure (PN) in nests of the San Miguel Island race of Song Sparrows (Melospiza melodia micronyx) averaged 16 torr, but varied considerably between nests and within individual nests during successive days of incubation. Large daily fluctuations occurred throughout the incubation period and did not parallel concurrent changes in ambient vapor pressure (PI). Daily rates of water loss from nest eggs (ṀH2O) averaged 28 mg day^-1, but also varied considerably within and between nests and did not correlate with changes in PI. ṀH2O increased 6-33% after the third day of incubation. PN was significantly higher and ṀH2O significantly lower in nests located in sheltered gullies than in nests from a windswept slope. These data suggest that Song Sparrows do not regulate PN to achieve hatching success.
- Type
- Journal Article
- Authors
- Kern, Michael; Sogge, Mark; Van Riper, Charles
- Units
- CHIS
- Keywords
- Animal Studies, Eggs, Nests & Nesting, San Miguel Island Channel Islands National Park CA, San Miguel Island Song Sparrow (Melospiza melodia micronyx)