ABSTR•C?.--Allometry, the study of the consequences of body size on form and function, has been a powerful investigative tool in avian biology. Comparison of phenotypic data with allometric reference equations permits the identification of possible adaptations and the formulation of hypotheses for testing. The standard allometric equation that relates total evaporative water loss (TEWL) to body...

Birds are often considered seed predators of less importance when compared to rodents or granivorous ants in studies of seed predation using selective exclosures. However, it is possible that the role of granivorous birds interacting with seeds on the floor of Neotropical forests is being underestimated, if the selective exclosures designed to allow exclusive access to small rodents do not work...

Determining the impact of forest disturbance and fragmentation on tropical biotas is a central goal of conservation biology. Among tropical forest birds, understory insectivores are particularly sensitive to habitat disturbance and fragmentation, despite their relatively small sizes and freedom from hunting pressure. Why these birds are especially vulnerable to fragmentation is not known. Our d...

Plasma glycerol and triglyceride levels and creatine kinase (CK) activity may increase during long-distance flights in migratory birds, but plasma profiles of these metabolites have not previously been reported for small birds during thermoregulation in cold climates. We measured early morning levels of plasma glycerol, triglycerides and CK activity in four species of small birds overwintering ...

Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concentrate and cross over the world's temperate regions during migration, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pel...

BACKGROUND Many avian species soar and glide over land. Evidence from large birds (m(b)>0.9 kg) suggests that soaring-gliding is considerably cheaper in terms of energy than flapping flight, and costs about two to three times the basal metabolic rate (BMR). Yet, soaring-gliding is considered unfavorable for small birds because migration speed in small birds during soaring-gliding is believed to...

This study was conducted to investigate the effects of different levels of zinc sulfate and chromium picolinate on performance, body temperature, carcass characteristics, tibia ash and serum biochemical parameters of Japanese quails under heat stress condition. The birds (n = 540; 7-d-old) were randomly assigned to 9 treatment groups consisting of 3 replicates of 20 birds each in a 3 × 3 factor...

salmonellosis is one of the most important zoonotic diseases worldwide. salmonella infections in wild birds are reported frequently. the objectives of this study were to isolate salmonella serovars from a large collection of samples obtained from pet birds in tehran, iran, and then to determine the serotypes and antimicrobial susceptibility profile of the isolates. between october 2007 and augu...

Recently there has been much work done on the energetics of homoiotherms. One parameter of energetics, body temperature, is relatively easy to measure and, thus, has been often studied. An analysis of the body temperatures of mammals was proposed by McNab (1966), but none has been made of bird temperatures. The purpose of this report is to analyze the factors responsible for the level of body t...