Evaporative Water Losses of Some Small Australian Lizards

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/119114/1/ecy1966474589.pd

Evaporative losses of water by birds

1. 1. Birds lose water in evaporation from the respiratory tract and, in many species, through the skin. Anatomical arrangements in the nasal passages contribute to conservation of water and heat from the expired air in the absence of heat loads. However, most species still expend more water in evaporation than they produce in metabolism when either quiescent or vigorously active. Certain small birds, several of them associated with arid environments, represent exceptions to this and their more favorable situation appears in part to reflect an ability to curtail cutaneous water loss.2. 2. Birds typically resort to panting in dealing with substantial heat loads developing in hot environments or accumulated over bouts of activity. In a number of species this form of evaporative cooling is supplemented by gular fluttering.3. 3. The ubiquitousness of active heat defense appears to reflect more the importance for birds of dealing with heat loads existing following flight or sustained running than any universal affinity for hot climates. Panting can be sustained for hours, despite progressive dehydration and, in some instances, hypocapnia and respiratory alkalosis. The prominent involvement of thermoreceptors in the spinal cord in its initiation is of considerable interest.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24124/1/0000381.pd

Temporal pattern of foraging and microhabitat use by Galápagos marine iguanas, Amblyrhynchus cristatus

We observed a colony of marine iguanas ( Amblyrhynchus cristatus ) on Isla Fernandina, Galápagos, Ecuador, while measuring local micrometeorological and tidal conditions. We found size-related differences in foraging mode, with smaller iguanas feeding intertidally during daytime low tides and larger iguanas feeding subtidally. Despite having greater opportunity, subtidal foragers did not time their foraging bouts or exploit their environment in ways that optimized their period at high body temperature. Instead, the foraging schedule of these iguanas served to maximize their rate of rewarming following emergence from the cool sea. Intertidal feeders, by contrast, showed much greater behavioral flexibility in attempting to exploit their thermal environment. We suggest that size-ordered differences in marine iguana thermoregulatory behavior reflect underlying ontogenetic changes in costs and benefits of thermoregulation due to differences in predator pressure, quantity of food and electrolytes taken at each feeding, mode of foraging, and agonistic tendencies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47800/1/442_2004_Article_BF00318031.pd

Seasonal acclimatization to temperature in cardueline finches

1. Seasonal variation in metabolism and insulation was measured throughout the year in American goldfinches ( Spinus tristis ) and during winter in pine siskins ( S. pinus ).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47118/1/360_2004_Article_BF00692302.pd

Shoreline change and coastal vulnerability characterization with Landsat imagery : a case study in the Outer Hebrides, Scotland

Peer reviewedPostprin

Observations on the temperature regulation and water economy of the galah (Cacatua roseicapilla)

1. 1. Galahs (Cacatua roseicapilla), like many other birds, undergo controlled hyperthermia in hot environments.2. 2. Basal metabolism of galahs (271 g) at night during summer averages 0.93 cm3O2 (g-hr)-1 vs 0.90 predicted.3. 3. They can evaporatively dissipate heat at 1.4-1.7 times the rate of metabolic heat production at high ambient temperatures (Ta).4. 4. Under moderate Ta and humidity, galahs must minimally drink 7.3 g H2O/24hr. Without water they lose 2.2% body mass/24 hr. Some of these birds benefited from drinking 0.3 M NaCl.5. 5. Galahs occupy arid Australia through good powers of heat defense, some resistance to dehydrating conditions, and mobility allowing them to reach both water and food.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24081/1/0000334.pd

Highly selective CO2 vs. N2 adsorption in the cavity of a molecular coordination cage

Two M8L12 cubic coordination cages, as desolvated crystalline powders, preferentially adsorb CO2 over N2 with ideal selectivity CO2/N2 constants of 49 and 30 at 298 K. A binding site for CO2 is suggested by crystallographic location of CS2 within the cage cavity at an electropositive hydrogen-bond donor site, potentially explaining the high CO2/N2 selectivity compared to other materials with this level of porosity