We have hypothesized (Negro et al. 1999) that bearded vultures, Gypaetus barbatus, deliberately stain their plumage with iron oxides to signal dominance status. The conceptual frame to which we ascribe our hypothesis is the handicap principle (Zahavi & Zahavi 1997). For a signal to convey reliable information, and thus to evolve, it has to be costly (Zahavi 1975), and we proposed that the assoc...

—We document the molt sequence of flight feathers in Turkey Vultures (Cathartes aura) based on studies of captive and wild birds, and examination of museum specimens. We found an unusual pattern of primary replacement, which appears to be a modified form of Staffelmauser, or stepwise wing molt. A Staffelmauser-like strategy for replacement of the secondaries is also described. These patterns of...

this study seeks to describe and discuss a hemistich, namely ‘‘yours the earth, mine the vulture’s feather’’, of the story of rostam and sohrab in ferdowsi's shahnameh. many commentators and interpreters of the shahnameh have different opinions on the concept and meaning of this hemistich. this has led the researchers to seek the reason of such differences, clues for the provided meanings,...

The relative contribution of personal and social information to explain individual and collective behavior in different species and contexts is an open question in animal ecology. In particular, there is a major lack of studies combining theoretical and empirical approaches to test the relative relevance of different hypothesized individual behaviors to predict empirical collective patterns. We...

Growing vulture populations represent increasing hazards to civil and military aircraft. To assess vulture flight behavior and activity patterns at the Marine Corps Air Station in Beaufort, South Carolina, we equipped 11 black vultures (Coragyps atratus) and 11 turkey vultures (Cathartes aura) with solarpowered Global Positioning System (GPS) satellite transmitters during a 2-year study (1 Oct ...

water has an important role in creating pollution problems in the mining regimes influencing the surrounding surface environment. the purpose of this study is to make an assessment of groundwater quality in an underground mine site in portugal with a view of determining the pollution potential of groundwater. in the corresponding surface area of this underground mine, intersections of fou...

Both stocking rate and housing systems are main factors influencing the occurrence of feather pecking in laying hens raised in conventional cage system. This study examines the effects of different type of cage and stock density on feather pecking behaviour in hens. Total of 216 Hisex Brown hens at 16 weeks of age were randomly selected and put into 2 types of battery cages: conventional cages ...

Vultures provide an essential ecosystem service through removal of carrion, but globally, many populations are collapsing and several species are threatened with extinction. Widespread declines in vulture populations could increase the availability of carrion to other organisms, but the ways facultative scavengers might respond to this increase have not been thoroughly explored. We aimed to det...

Sera from 19 wild caught vultures in northern Namibia and 15 (12 wild caught and three captive bred but with minimal histories) in North West Province, South Africa, were examined by an enzyme-linked immunosorbent assay (ELISA) for antibodies to the Bacillus anthracis toxin protective antigen (PA). As assessed from the baseline established with a control group of ten captive reared vultures wit...