Water-vapor pressure in nests of the San Miguel Island Song Sparrow

Michael D. Kern; Mark K. Sogge; Charles van Riper

doi:10.2307/1368696

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Water-vapor pressure in nests of the San Miguel Island Song Sparrow

Michael D. Kern·Mark K. Sogge·Charles van Riper

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Abstract

The water-vapor pressure (P N ) in nests of the San Miguel Island race of Song Sparrows ( Melospiza melodia micronyx ) averaged 16 torr, but varied considerable 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 ambien vapor pressure (P 1 ). Daily rates of water loss from nest eggs (M H 2 O ) averaged 28 mg day -1 , but also varied considerable within and between nests and did not correlate with changes in P 1 . M H 2 O increased 6-33% after the third day of incubation. P N was significantly higher and M H 2 O significantly lower in nests located in sheltered gullies than in nests from a windswept slope. These data suggest that Song Sparrows do not regulate P N to achieve hatching success.

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Source-reported bounding extent: 34.013708° to 34.076544° latitude; -120.452691° to -120.295491° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Michael D. Kern, Mark K. Sogge, Charles van Riper. 1990. Water-vapor pressure in nests of the San Miguel Island Song Sparrow. https://doi.org/10.2307/1368696

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