Zeev Arad - Academia.edu (original) (raw)
Zoologist and ecophysiologist. Professor Emeritus
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Papers by Zeev Arad
Comparative Biochemistry and Physiology Part A: Physiology, Aug 1, 1975
ABSTRACT 1.1. The effect of long-term (8–10 hr) exposure to heat stress (40–45°C) on acid base ba... more ABSTRACT 1.1. The effect of long-term (8–10 hr) exposure to heat stress (40–45°C) on acid base balance of Abdim's stork (Sphenorhynchus abdimii) was investigated.2.2. Body temperature reached a maximum of 41·15°C (at 45°C Ta), as compared to about 40·0°C at 24–30°C Ta.3.3. Normal respiratory rates (10 c/min) increased to 100–112 c/min at ambients of 40, 42 and 45°C.4.4. Normal arterial pH, PCO2 and [HCO3−]were 7·564, 27·9 and 25·09, respectively. After 10 hr of intensive panting, values were 7·571, 25·5 and 23·09.5.5. These results are discussed in relation to a possible shunt mechanism, effective in preventing washout of gas-exchange surfaces in a flying bird's lungs.
Journal of Zoology, Apr 1, 1992
Journal of Zoology, Feb 1, 1993
International Journal of Biometeorology, Dec 1, 1993
Physiological and Biochemical Zoology, 2016
Comparative Biochemistry and Physiology Part A: Physiology - COMP BIOCHEM PHYSIOL PHYSIOL, 1975
Acta Oecologica, Apr 30, 1998
This study analyses the fruit syndrome of the Egyptian fruit-bat, Rousettus aegyptiacus, the only... more This study analyses the fruit syndrome of the Egyptian fruit-bat, Rousettus aegyptiacus, the only fruit-bat found in East Mediterranean habitats. Two different sets of bat-fruit syndromes were revealed. One follows the general bat-fruit syndrome and one represents a special case of bat-dispersed fruit syndrome only found in East Mediterranean habitats. The latter syndrome is characterized by dry fruits with a relatively high protein content. Fruit species that belong to this syndrome are available mostly in winter (when the fruit-bat faces a ...
Physiological Zoology, 1989
Journal of Experimental Biology, 2008
Journal of Experimental Biology, 2004
Journal of Experimental Biology, 2005
Canadian Journal of Zoology, 2007
Air-breathing divers should attempt to maximize foraging efficiency under the constraint of limit... more Air-breathing divers should attempt to maximize foraging efficiency under the constraint of limited oxygen availability. For diving water birds, high buoyancy (owing to the air in the plumage) and the associated change in buoyancy with diving depth impose further constraints on the adaptation to aquatic life. Diving birds are expected to descend as fast as possible to escape the higher buoyancy near the water surface, but in practice, shallow-diving cormorants (genus Phalacrocorax Brisson, 1760) are often observed descending the water column in relatively small angles with respect to the water surface. We derive a theoretical biomechanical model for the energetics of the descent phase of a dive of foot-propelled cormorants feeding on benthic prey at shallow depth. The model shows that visually guided benthic feeders benefit energetically from diving at small descent angles when optical conditions and bottom depth allow. The model also explains the high variation in descent angles ob...
Comparative Biochemistry and Physiology Part A: Physiology, Aug 1, 1975
ABSTRACT 1.1. The effect of long-term (8–10 hr) exposure to heat stress (40–45°C) on acid base ba... more ABSTRACT 1.1. The effect of long-term (8–10 hr) exposure to heat stress (40–45°C) on acid base balance of Abdim's stork (Sphenorhynchus abdimii) was investigated.2.2. Body temperature reached a maximum of 41·15°C (at 45°C Ta), as compared to about 40·0°C at 24–30°C Ta.3.3. Normal respiratory rates (10 c/min) increased to 100–112 c/min at ambients of 40, 42 and 45°C.4.4. Normal arterial pH, PCO2 and [HCO3−]were 7·564, 27·9 and 25·09, respectively. After 10 hr of intensive panting, values were 7·571, 25·5 and 23·09.5.5. These results are discussed in relation to a possible shunt mechanism, effective in preventing washout of gas-exchange surfaces in a flying bird's lungs.
Journal of Zoology, Apr 1, 1992
Journal of Zoology, Feb 1, 1993
International Journal of Biometeorology, Dec 1, 1993
Physiological and Biochemical Zoology, 2016
Comparative Biochemistry and Physiology Part A: Physiology - COMP BIOCHEM PHYSIOL PHYSIOL, 1975
Acta Oecologica, Apr 30, 1998
This study analyses the fruit syndrome of the Egyptian fruit-bat, Rousettus aegyptiacus, the only... more This study analyses the fruit syndrome of the Egyptian fruit-bat, Rousettus aegyptiacus, the only fruit-bat found in East Mediterranean habitats. Two different sets of bat-fruit syndromes were revealed. One follows the general bat-fruit syndrome and one represents a special case of bat-dispersed fruit syndrome only found in East Mediterranean habitats. The latter syndrome is characterized by dry fruits with a relatively high protein content. Fruit species that belong to this syndrome are available mostly in winter (when the fruit-bat faces a ...
Physiological Zoology, 1989
Journal of Experimental Biology, 2008
Journal of Experimental Biology, 2004
Journal of Experimental Biology, 2005
Canadian Journal of Zoology, 2007
Air-breathing divers should attempt to maximize foraging efficiency under the constraint of limit... more Air-breathing divers should attempt to maximize foraging efficiency under the constraint of limited oxygen availability. For diving water birds, high buoyancy (owing to the air in the plumage) and the associated change in buoyancy with diving depth impose further constraints on the adaptation to aquatic life. Diving birds are expected to descend as fast as possible to escape the higher buoyancy near the water surface, but in practice, shallow-diving cormorants (genus Phalacrocorax Brisson, 1760) are often observed descending the water column in relatively small angles with respect to the water surface. We derive a theoretical biomechanical model for the energetics of the descent phase of a dive of foot-propelled cormorants feeding on benthic prey at shallow depth. The model shows that visually guided benthic feeders benefit energetically from diving at small descent angles when optical conditions and bottom depth allow. The model also explains the high variation in descent angles ob...