Does the King Vulture Sarcorhamphus papa use a sense of smell to locate food?

Captive King Vultures were unable to find hidden food by smell: this species flies at high altitudes over forest, and it is suggested that they locate carcasses by watching the activities of the Cathartes vultures below them.     

Competition for food between Neotropical vultures in forest

Carcasses were provided at a gallery forest site in Venezuela to compare the feeding methods of four vulture species. Turkey Vultures or Lesser Yellow-headed Vultures were always the first species to arrive. Black Vultures were most likely to arrive at large carcasses or those in open situations and were the only species to form large feeding groups. King Vultures were equally likely to arrive at small or large carcasses. There were marked differences in feeding technique, food selection, rate of feeding and bill morphology between Turkey, Black and King Vultures, and the level of aggression between species was low compared to intra-specific aggression.     

Competition for food between Neotropical vultures in forest

Carcasses were provided at a gallery forest site in Venezuela to compare the feeding methods of four vulture species. Turkey Vultures or Lesser Yellow-headed Vultures were always the first species to arrive. Black Vultures were most likely to arrive at large carcasses or those in open situations and were the only species to form large feeding groups. King Vultures were equally likely to arrive at small or large carcasses. There were marked differences in feeding technique, food selection, rate of feeding and bill morphology between Turkey, Black and King Vultures, and the level of aggression between species was low compared to intra-specific aggression.     

Factors influencing perch selection by communally roosting Turkey Vultures

ABSTRACT Many birds roost communally during at least part of their annual cycle, suggesting that for them the advantages of living in a group outweigh the disadvantages. However, perch sites within a roost may vary in quality because of differences in degree of exposure to the elements, predators, and fecal droppings. Individuals should select perches in the roost that minimize costs while enabling them to experience the benefits of communal roosting. We studied communally roosting Turkey Vultures (Cathartes aura) in northeastern Iowa (USA) from late August to mid‐October, when hatching‐year (HY) birds had joined the roost and were distinguishable from after‐hatching‐year (AHY) birds. On 82 d during our 4‐yr study (2004–2007), we noted the age class and perch position of vultures on two communication towers used as a preroost site. Perches used by vultures were classified as top‐level (with no perches above them) or lower‐level (with other perches above them). Top‐level perches were preferred by Turkey Vultures. Of 1713 birds recorded, 71% were on top‐level perches, even though only 39% of available perches were top‐level. Vultures did not use lower perches if top perches on that tower were unoccupied. The percentage of birds using lower perches increased as the number of vultures present increased, suggesting that top‐level perches were occupied first. AHY birds used top‐level perches more often than expected and HY birds used top‐level perches less often than expected, implying that age‐related dominance affected perch selection. On 61 of 82 d (74%), top‐level perches of both towers were occupied and, on 8 d (10%), only top perches on one tower were occupied. However, on 13 d (16%), both top‐level and lower‐level perches were occupied on one tower while no vultures perched on the other tower, suggesting that social attraction to other vultures can override a general preference for top‐level perches. Thus, our results provide evidence that social attraction, age‐related dominance, and preference for higher perches are proximate factors influencing perch selection in communally roosting Turkey Vultures. Ultimate factors that may be responsible for Turkey Vultures preferring higher roosting perches are reduced risk of predation, less exposure to fecal droppings that might reduce their plumage quality, and better visual information for locating food sources.     

Antibodies to Clostridium botulinum toxins in free-living birds and mammals.

Naturally-occuring antibodies against Clostridium botulinum toxins were found in Cathartes aura (turkey vultures), Canis latrans (coyotes) and Corvus brachyrhynchos (crows) by the passive hemagglutination (PHA) test and verified by the serum neutralization (SN) test. The prevalence of IHA antibodies was 18 of 20 vultures (90%), 5 of 12 crows (42%) and 25 to 110 coyotes (23%). Vultures and coyotes were seropositive by the PHA test against A, B, C, D, and F toxins. The highest antibody titer 1:8192 was in vulture serum against type C. In descending order, the highest antibody levels were against type C, D, F, E, A and B toxins.     

Phylogeny and biogeography of Yellow-headed and Blue-fronted Parrots (Amazona ochrocephala and Amazona aestiva) with special reference to the South American taxa

The Yellow-headed Parrot ( Amazona ochrocephala ) has a broad Neotropical distribution, ranging from Mexico to the Amazon Basin, and a history of complex taxonomy and controversial species limits. Recent molecular analyses have started to clarify the taxonomic arrangement of the complex, but have not included a representative geographical sampling from South America. These studies have shown that the Yellow-headed complex can be divided into three main lineages, and seems to be paraphyletic, due to the inclusion of the Blue-fronted Parrot ( Amazona aestiva ) that occurs in central South America. Here we present a phylogenetic analysis based on mitochondrial DNA sequences of 45 representatives of the Yellow-headed complex from South and Central America, plus 13 Blue-fronted individuals from different localities in South America. Our analyses recover the three primary lineages found previously in the Yellow-headed complex, show that there is genetic structure in the South American lineage, which can be divided into two well-supported, closely related clades, and demonstrate that Blue-fronted samples are distributed in both clades. Differentiation of South American Blue-fronted and Yellow-headed Parrot populations does not correspond to the plumage differences used to distinguish the Blue-fronted Parrot from the Yellow-headed Parrot, nor to plumage differences used to distinguish among South American Yellow-headed subspecies. This suggests that traditional taxonomy based on plumage characters needs revision, and that this may be an interesting example of ongoing divergence-with-gene-flow related to the forest/open area ecotone in southern Amazonia.     

The Pied Crow (Corvus albus) is insensitive to diclofenac at concentrations present in carrion

Diclofenac, a nonsteroidal anti-inflammatory drug (NSAID), kills vultures (Gyps spp.) that consume tainted carcasses. As a result, vulture populations in India, Nepal, and Pakistan have been devastated. Studies on meloxicam and ketoprofen demonstrated that the toxicity of the NSAIDs is unpredictable, thereby necessitating individual testing of all available NSAIDs. Because it is no longer practical to use vultures for toxicity testing, we evaluated the Pied Crow (Corvus albus) as a model. Pied Crows (n=6) were exposed to a dose of 0.8 and 10 mg/kg of diclofenac, with no signs of toxicity, and a rapid half-life of elimination. Using primary renal cell and hepatocyte cultures, a high tolerance was demonstrated at the cellular level. Meta-analysis of pharmacokinetic data for the Domestic Chicken (Gallus gallus) and the African White-backed (Gyps africanus), Cape Griffon (Gyps coprotheres), and Turkey Vultures (Cathartes aura) showed a trend toward toxicity when the half-life of elimination increased. We conclude that the crow is not susceptible to diclofenac and, more important, that toxicity in the Gyps species is probably related to zero-order metabolism.     

Narrow sea crossings present major obstacles to migrating Griffon Vultures Gyps fulvus

The flight behaviour of Griffon Vultures Gyps fulvus was studied at a major migration bottleneck, the Strait of Gibraltar in southernmost Spain, during the autumns of 2004 to 2007. The 14‐km‐wide sea channel significantly impeded the southern migration of the species into Africa, with many birds attempting repeated passage for weeks before crossing, and others not crossing at all and overwintering in Southern Spain. Water‐crossing attempts were restricted to times between 11:00 and 14:00 h on days with light or variable winds, or on days with strong winds from the north or west. No crossing attempts were made on days with strong winds from the south or east. Vultures attempted to cross the Strait in large flocks and never attempted to do so alone. Although 29% of the birds soared during crossing attempts, at least until they flew beyond visible range of approximately 4 km, most engaged in considerable flapping flight when attempting to cross. Overall, birds flying over water flapped more than 10 times as frequently as those flying over land prior to crossing attempts. Vultures did not flap continuously, but intermittently in brief bouts of flapping interspersed with periods of gliding or soaring flight. The number of flaps per bout over water was significantly greater than the number of flaps per bout over land. Vultures flying over water that flapped at rates of 20 flaps or more per minute typically aborted attempted crossings and returned to Spain in intermittent flapping and gliding flight. There are numerous reports of Vultures falling into the Strait and drowning while attempting to cross, as well as reports of returning Vultures collapsing on the beach having reached Spain in spring ( Barrios Partida 2006 ). Our observations indicate that passage of Griffon Vultures at the Strait of Gibraltar is limited by the species’ over‐water flapping‐flight abilities, including its inability to flap continuously for even short periods of time. We suggest that even relatively short sea crossings represent significant obstacles to migrating Vultures and discuss the implications of this limitation on the distribution and abundance of the species.     

Comparison of lead contamination among related scavenging birds sharing food sources: a call for caution when using surrogate species

Lead contamination is a global problem affecting a large number of bird species around the world. Among the different avian guilds, vultures and facultative scavengers are particularly threatened by this toxic metal. However, little information is available about differences in exposure to this metal for sympatric vulture species that share food resources. We compared blood lead concentrations of two closely related sympatric obligate scavenger species, the abundant Black Vulture Coragyps atratus and the threatened Andean Condor Vultur gryphus in north-western Patagonia, Argentina. We sampled 28 Andean Condors and 29 Black Vultures trapped foraging in the same area in the steppe. We also sampled 16 Black Vultures foraging in a rubbish dump to determine whether there were differences in lead contamination among foraging sites. Andean Condors had significantly higher mean blood lead concentrations than Black Vultures. There was no difference in lead concentrations between Black Vultures trapped in the steppe and in the rubbish dump. The prevalence and probability of lead concentrations above the threshold level (20 µg/dL) was higher for Andean Condors than for Black Vultures, potentially producing different effects on their health. This disparity in lead contamination may be due to differences in their foraging habits or in their susceptibility to this toxic metal. Overall, our results suggest caution in using an abundant surrogate species to infer lead contamination in a closely related but harder to sample species.     

Use of a communal roost by Turkey Vultures in northeastern Iowa

ABSTRACT.   Communal roosts are an important aspect of Turkey Vulture ( Cathartes aura ) biology, but remain inadequately studied. We observed the use patterns of Turkey Vultures at a communal roost in northeastern Iowa from their arrival on 17 March 2005 to their departure on 19 October 2005. The roost was on a forested hillside and vultures roosted below the forest canopy in 10 live deciduous trees, spending an estimated 10–16 h per day in the roost. The birds also used nearby pre- and postroost perch sites, and formed pre- and postroost kettles near the roost site. The number of vultures using the roost ranged from about 20 early in the season to a peak of 281 on 4 October. The apparent pattern was one of moderate and fluctuating numbers early in the 7-month season, increasing numbers in the middle of the season, and high and fluctuating numbers late in the season. Hatching-year vultures began to appear at the roost during the last week of August. The mean monthly time of departure from the roost ranged from 3 min before sunrise to 131 min after sunrise. Vultures departed the roost significantly later in the morning during the summer (June, July, and August) than during other months (April, May, September, and October), probably due to differences in soaring conditions (longer thermal generation times during the summer) and available foraging time (longer days in the summer).     

Hooded Vulture Necrosyrtes monachus and African White-backed Vulture Gyps africanus nesting at the Olifants River Private Nature Reserve,Limpopo province,South Africa

Basic ecological information is still lacking for many species of African vultures. The Hooded Vulture Necrosyrtes monachus is known as a rare breeding resident in north-eastern South Africa. This study set out to monitor the nests of Hooded Vultures and, secondarily, White-backed Vultures Gyps africanus in the Olifants River Private Nature Reserve over two breeding seasons in 2013 and 2014. A total of 12 Hooded Vulture nests, placed mostly in the tree Diospyros mespiliformis, were found along the Olifants River, with an average inter- nest distance of 0.76 km. Nest success was estimated to be between 0.44–0.89 offspring pair?1 y?1 in 2013 and 0.50–0.67 offspring pair?1 y?1 in 2014, which are the first estimates for Hooded Vultures in South Africa. It is thought that nests of this species have been under-reported due to the fact that they are placed within or below the canopy of densely leafed trees and hence difficult to view from aerial surveys. African White-backed Vultures also bred along the Olifants River, with nests placed in clusters of up to six. Nesting density of this species ranged from about 1.0 to 1.2 nests km?1 and nests were predominantly placed in Ficus sycomorus trees.     

Gram-negative, aerobic, enteric pathogens among intestinal microflora of wild turkey vultures (Cathartes aura) in west central Texas.

The prevalence of gram-negative bacterial species in the intestines of 20 apparently healthy turkey vultures (Cathartes aura) was determined. Edwardsiella tarda, Plesiomonas shigelloides, Salmonella, and Arizona hinshawii (Salmonella arizonae) were each recovered from 15% of these birds. Turkey vultures may be important reservoirs of these bacterial pathogens.     

The Vulture in the Sky and the Hominin on the Land: Three Million Years of Human–Vulture Interaction

ABSTRACT

Vultures and humans have been sympatric for millions of years and evidence from the archaeological and historical records suggests interdependence over long periods. Like other species, early hominins probably used these birds to locate carcasses in the landscape. With the evolution of large-bodied and more encephalized hominins, the quest for high-quality food would have intensified. Vultures used as beacons for meat may have been particularly important to hominins dispersing out of Africa, facilitating the occupation of new landscapes. Neanderthals and prehistoric modern humans incorporated vulture parts into their culture, and while the symbolic and ritualistic significance of the birds may have varied through time and across cultures, their link with positive life forces is apparent. More recently, the intensification of farming and modern sanitary restrictions, as well as the spread of human populations, has led to the radical decline in vulture populations throughout the world. Without commitments by governments to fund vulture conservation programs, the ability to preserve many species may be limited over the long term. In this review paper we discuss the ability of vultures to act as beacons signaling meat in the landscape and our changing relationships with these enigmatic birds through a shared history. Within this narrative, we outline why vultures are fundamental to maintaining our ecosystem and should therefore be protected.     

Home-range size and movement patterns of Hooded Vultures Necrosyrtes monachus in southern Africa

Hooded Vulture Necrosyrtes monachus populations have declined dramatically in recent years, but we know little about their ecology. We radio-tagged four vultures in northern Botswana to gather data on animal movement and home-range patterns. Hooded Vultures were primarily sedentary at night. Hooded Vultures moved similar distances and speeds during the wet and dry season, and travelled over similar home ranges as measured using minimum convex polygons (MCP), but used much smaller core areas during the dry (breeding) season. We found significant differences in mean distances and speeds moved among different birds, and when comparing day to night, but not between the wet (non-breeding) and dry (breeding) season or by year. All of the variables we tested, including individual vulture differences, season, year and number of fixes, significantly influenced 95% MCP and kernel density estimate (KDE) home-range sizes. Hooded Vultures used significantly smaller KDE home-range sizes during the dry (breeding season) than in the wet (non-breeding) season. Hooded Vultures travelled smaller daily distances over smaller home ranges than most other vulture species for which data exist.     

Diet and food preferences of the endangered Bearded Vulture Gypaetus barbatus: a basis for their conservation

The Bearded Vulture Gypaetus barbatus population in the Pyrenees is managed using feeding stations to increase breeding success and reduce mortality in the pre-adult population. Nevertheless, very little quantitative and qualitative information has been published on such basic aspects of the species' ecology as feeding habits and dietary preferences. This study investigated both aspects through direct and unbiased observation of breeding Bearded Vultures during the chick-rearing period. Bearded Vulture diet comprises mammals (93%), birds (6%) and reptiles (1%), with medium-sized ungulates (mainly sheep/goats) the most important species in the diet (61%, n  = 677). Prey items were not selected in proportion to their availability, with the remains of larger species (cows and horses) being avoided, probably due to the variable cost/benefit ratios in handling efficiency, ingestion process and transport. There is no relationship between the proportion of sheep limbs in the diet and the proximity of feeding stations, suggesting that these sites are probably less important for breeding adults than for the pre-adult population. On the other hand, diet specificity seems related to productivity, with territories with greater trophic breadth being those with higher fecundity. Bearded Vultures prefer to eat limbs, although meat remains (provided principally by small mammals) can play an important role in guaranteeing breeding success during the first few weeks after hatching. The management of carrion provided by animals that die naturally in extensive livestock practices and the remains of wild ungulates which have died naturally or by human hunting, are important conservation tools for the Bearded Vulture and other carrion-eating species.     

BIRDS AS SCAVENGERS OF REFUSE IN UGANDA

Refuse tips, abattoirs and fishing villages provide an important source of food for several species of large scavenging birds in Uganda. The most numerous are Marabou Storks, Hooded Vultures, Black Kites and Pied Crows. Estimates of the populations of these species are given for Kampala, several smaller towns in Uganda and Rwenzori National Park (where there is an important fishing industry). Crows and kites are spread widely through Kampala and the population densities of both species exceed 12 km^-2 (the latter seasonally). On average there were about 200 Hooded Vultures at the Kampala abattoir and nearly as many Marabous at the refuse tips. Abattoirs and refuse tips in smaller towns often had proportionately higher populations of scavengers than Kampala. The food consumption of these birds is calculated to be nearly 100 t per year in Kampala and 800 t per year in Rwenzori National Park. It is suggested that although man, through his various activities, provides most of the food for these scavengers, they are beneficial to him in the sense that the food which they eat might otherwise become a health hazard.     

Sexing Cape Vulture Gyps coprotheres based on head morphometrics

The Cape Vulture Gyps coprotheres is considered sexually monomorphic in the literature, but visual differences in head shape between the sexes have been observed. Furthermore, head morphometrics of other Gyps species show statistically significant variation between the sexes. We show that head morphometrics can be used to determine the sex of Cape Vultures. Males generally have wider and shorter heads, and larger bill depths than females. Discriminant function analysis with data from 63 individuals identified the three most predictive variables in sex determination to be head width, head length and bill depth. We also provide an equation that can be used in conjunction with head measurements as a method to determine the sex of Cape Vultures in the field with an overall accuracy of 84% (92% accuracy for females and 72% for males).     

White‐headed Vulture Trigonoceps occipitalis shows visual field characteristics of hunting raptors

The visual fields of the Aegypiinae vultures have been shown to be adapted primarily to meet two key perceptual challenges of their obligate carrion‐feeding behaviour: scanning the ground and preventing the sun's image falling upon the retina. However, field observations have shown that foraging White‐headed Vultures Trigonoceps occipitalis are not exclusively carrion‐feeders; they are also facultative predators of live prey. Such feeding is likely to present perceptual challenges that are additional to those posed by carrion‐feeding. Binocularity is the key component of all visual fields and in birds it is thought to function primarily in the accurate placement and time of contact of the talons and bill, especially in the location and seizure of food items. We determined visual fields in White‐headed Vultures and compared them with those of two species of carrion‐eating Gyps vultures. The visual field of White‐headed Vultures has more similarities with those of predatory raptors (e.g. accipitrid hawks) than with the taxonomically more closely related Gyps vultures. Maximum binocular field width in White‐headed Vultures (30°) is significantly wider than that in Gyps vultures (20°). The broader binocular fields in White‐headed Vultures probably facilitate accurate placement and timing of the talons when capturing evasive live prey.     

4. ONE YEAR'S CENSUS AND STUDY OF BIRDS IN 2½ ACRES OF ALEANY BUSHVELD. (Part 2.) April, 1945, to March, 1946

Hooded Vultures Necrosyrtes monachus are critically endangered but little is known of their year-round use of nests or whether other species usurp Hooded Vulture nest sites. We investigated visitation rates by Hooded Vultures and other species (including potential nest predators and usurpers) to examine their effect on Hooded Vulture breeding success. We present observations of 33 species recorded by camera traps at 12 Hooded Vulture nests over a total of 93 nest-months (2 095 nest-days). Several pairs of Hooded Vultures visited their nests regularly during the non-breeding season, some adding nesting material, highlighting that pairs visited their nest(s) year round. Egyptian Geese Alopochen aegyptiaca, potential usurpers of raptor nests, were present at occupied and unoccupied Hooded Vulture nests, but we recorded no usurpation of nests by Egyptian Geese and they had no impact on vulture breeding success. Hooded Vulture breeding failure was linked to two species only: camera-trap imagery recorded one case of predation of a vulture egg by a Chacma Baboon Papio ursinus, and one case of a Martial Eagle Polemaetus bellicosus predating a vulture nestling. We recommend expanding the Hooded Vulture nest monitoring programme to include more pairs.     

Chromosomal analysis in Cathartidae: distribution of heterochromatic blocks and rDNA, and phylogenetic considerations

Three species of Cathartidae (Sarcoramphus papa, Cathartes aura and Cathartes burrovianus) were cytogenetically characterized by G- and C-banding. 18S–28S rDNA was used as a probe to map major ribosomal clusters. These species showed very similar karyotypes, with 2n = 80, 10 pairs of macrochromosomes, a submetacentric Z and a metacentric W chromosome. However, differences were found in the amount and distribution of heterochromatic blocks: S. papa showed heterochromatin only in the pericentromeric region and in chromosome W, while both species of Cathartes had heterochromatic blocks also in the long arm of two acrocentric pairs. Ribosomal clusters were found in a small pair in all three species. Karyotype analysis in Cathartidae revealed that this family has retained similarities to the putative avian ancestral karyotype, and placed Cathartidae in a more basal position in relation to Accipitridae and Falconidae. However, the cytogenetic data still cannot clarify the phylogenetic relationship between this family and other groups, such as Ciconiidae, considered its sister-group according to nucleic acid hybridization studies. J. C. Pieczarka and C. Y. Nagamachi—Researcher from CNPq, Brazil.