Thermoregulatory Behavior of the Hawaiian Monk Seal (Monachus schauinslandi)

The behavior of Hawaiian monk seals at French Frigate Shoals was studied in order to obtain information on their adaptation to a tropical climate. The seals were unable to remain on the dry beach platform during the day except during very high winds, extensive cloud cover, or rain. The seals characteristically moved down to wet sand on the beach slope during the day and returned to the beach platform at night. The frequency with which the seals changed their posture appeared to be related to the prevailing microclimatic conditions. For the most part, the seals lay in postures that exposed their ventral pale-colored hair coat to the atmosphere. The temperature of this surface was significantly lower than that of the darker dorsal coat. The seals were extremely inactive while ashore; their respiratory pattern included long periods of breath-holding, and the heart rate during breath-holding was low. These features were considered to be compatible with a low level of metabolic heat production and to be adaptive to heat exposure

Egg Dimensions and Shell Characteristics of Bulwer's Petrels, Bulweria bulwerii, on Laysan Island, Northwestern Hawaiian Islands

Measured values for Bulwer's Petrel eggs and eggshells from Laysan Island, Northwestern Hawaiian Islands, were within 10% of predicted values available in the literature. In the absence of published predictive equations for egg volume, fresh-egg contents, and total functional pore area of the shell, in Procellariiformes, new logarithmic relationships were developed for tropical Procellariiformes. Data are now needed for species breeding at higher latitudes to determine if these relationships are representative of all Procellariiformes

First-egg date and air temperature affect nest construction in Blue Tits Cyanistes caeruleus, but not in Great Tits Parus major

Capsule For nest construction by Blue Tits, but not Great Tits, first-egg date (FED) and air temperature significantly affected the mass of the nest as a whole and some of its component parts. Aims To test the hypothesis that use of nest materials is influenced by prevailing climatic conditions during nest construction. Methods Nests used in the study were built by Blue Tits Cyanistes caeruleus and Great Tits Parus major in nestboxes at a site in Lincolnshire, England during the 2008 and 2009 breeding seasons. Nests were dissected into their component parts and then weighed. Results Stepwise discriminant analysis showed that the asses of grasses, feathers and bark were significantly affected by species (all higher in Blue Tits) and year significantly affected the mass of wool and dust in the nests. ANOVA showed that total mass of the nest was not significantly affected by year of construction or species. By contrast, species, but not year, did significantly influence the masses of animal- and plant-derived materials in the nest. In Blue Tit nests there were significant correlations between FED and the mass of animal-derived material in 2008, but with plant-derived material in 2009. There were significant correlations between mean air temperature recorded during the seven days up to FED and the mass of the nests and their plant-derived materials. No significant correlations were observed between FED and nest components for Great Tits. Conclusion Nest construction is potentially affected by a variety of environmental factors, which may impact upon how nests function. A better understanding of how nest variability affects its function may allow better assessment of how climate change may impact upon the reproductive performance of bird

Incubation Biology and Nestling Growth of Bulwer's Petrels on Manana Island, Oahu, Hawaii

Data were gathered on incubation of eggs and growth of nestlings of Bulwer's Petrels nesting on Manana Island in the Hawaiian Islands. Mean incubation period of five eggs was 45.2 days. Duration of pipping period of six eggs, which began with star-fracture of the shell, was 4.5 days. Daily water loss from unpipped eggs was 62.6 mg/day; water loss from pipped eggs was much higher, and 36.3% of total water loss occurred from pipped eggs. Mean nestling period (hatching-fledging) of four nestlings was 62 days; body weight of eight nestlings increased to a maximum 21.2 days before the nestlings fledged and then declined. Body weight of adult Bulwer's Petrels declined over the breeding season

Basking Behavior of the Hawaiian Green Turtle (Chelonia mydas)

Observations were made on green turtles basking on the white sand beaches at French Frigate Shoals in the northwestern Hawaiian Islands. The highest rectal temperature recorded from the basking turtles was 31.3°C, but the surface temperature of the carapace attained values as great as 42.8°C. During basking, the turtles flipped sand onto their carapaces, but they did not appear to orientate their position in relation to the sun. The duration of basking was inversely related to the mean temperature of a black globe, and the basking beaches were relatively cool. The pattern of breathing during basking consisted of periods of breath-holding alternating with single breaths. The amount of time that the turtles basked varied from 0.3 to 7.5 percent of the total time they were under observation. The biological significance of basking and the advantages that might accrue to Hawaiian green turtles from their unique basking behavior are discussed

Skin Structure of the Hawaiian Monk Seal (Monachus schauinslandi)

Skin samples from the dorsal region of the torsos of Hawaiian Monk Seals were examined histologically to determine if there were any features of the structure of the skin that might explain the reputed heat tolerance of these seals. The skin structure was compatible with an animal exposed to strong solar radiation, in which nonevaporative heat loss was promoted, but little could be discerned to suggest the existence of functional evaporative cooling mechanisms

Diurnal Rhythm of Body Temperature in the Hawaiian Monk Seal (Monachus schauinslandi)

ABSTRACT: The diurnal variation of body temperature of an unrestrained Hawaiian monk seal, recorded by telemetry, was 1.0° C. Increased activity was the principal cause of increased body temperature in the seal. The body temperature of the animal was lowest when it was asleep on land in direct sunlight. In view of these results, an explanation is offered for the reported heat tolerance of Hawaiian monk seals in their natural habitat