Vulture populations in southern Africa have been on the decline for years, which unlike the Asian vulture crisis, has no one specific cause. Reasons attributable are deliberate and secondary ...poisonings, drowning, power line injuries, electrocutions, traditional medicine (“muti” trade) and calcium deficiencies. However, lead toxicity as a potential causal factor is hardly mentioned. The potential for lead toxicity needs to be considered as substantial game hunting occurs in the region with little regulatory control on bullet types. In this study, we determined the whole blood lead concentrations of captive and wild vulture populations in South Africa and Namibia (n=185). Results were compared to previous published ranges indicative of background exposure (<10μg/dL), non-toxic point exposure based upon the range established from captive birds and subclinical exposure. In general, whole blood lead concentrations were higher for wild African White-backed vultures (Gyps africanus)(AWBV) than Cape vultures (G. coprotheres)(CGV) at 15.54±12.63μg/dL vs 12.53±8.88μg/dL (non-significantly different), while in the Bearded vultures (Gypaetus barbatus) no indication of exposure was evident. Very similar exposures resulted irrespective of the birds being in captivity or under wild, free-roaming conditions. A proportion of wild birds did, however, appear to be exposed to another source of lead than purely environmental (±12% and 30.6% for AWBV and CGV respectively). One bird, which had a whole blood concentration of 100μg/dL, died soon after capture. To find the relationship between whole blood lead concentration and likely exposure factors, birds were compared by their rural/urban location, vicinity to mines and surrounding soil lead concentrations. With no relationship being present for the latter factors, we believe that this is evidence that the portion of southern African vultures being exposed to unknown source of lead, which we suggest arises from leaded ammunition remaining from hunting
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•Whole blood concentrations were measured in various captive and wild colonies of White-back and Cape griffon vultures.•Whole blood lead concentrations had a range of <3–84µg/dL.•12% of birds had concentrations had higher than expected whole blood lead concentration, when compared to the captive birds.•Based on the high whole blood lead concentrations, it is likely that leaded bullets could be the source of exposure.
Avian mortality is one of the most negative impacts of wind energy. Consequently, techniques that effectively reduce avian collision rates are necessary. One of such method is the stop-turbine ...system, otherwise known as a Turbine Shutdown System (TSS). Here, we analyzed changes in mortality during 15 years, starting two years before the application of a selective stopping protocol (2006–2007) and after 13 years of application (2008–2020). This protocol was applied in Cadiz area (southern Spain) to 20 wind farms, totaling 269 wind turbines. The priority in the shutdown protocol was to avoid large soaring birds, mainly raptors, collisions. In total, 2903 birds and 354 bats were found to have collided with wind turbines in this 15-year period. This represents a rate of 0.830 birds/turbine/year and 0.101 bats/turbine/year. After implementation of the selective stopping protocol, we found a significant reduction of 61.7 % in mortality of soaring birds (mainly raptors and storks). Considering only mortality records of Griffon Vultures, a reduction of 92.8 % was achieved. Counts of Griffon Vultures increased more than 7-fold during the study period, and number of turbine stops due to vultures at risk in wind farms, also increased by around 2.5 times. Our finding of Griffon Vulture mortality being reduced by over 92 % through turbine shutdowns was associated with only an estimated loss of less than 0.51 % in energy production. This substantial disparity in conservation benefits versus industrial costs suggests that this mitigation method could have net-beneficial application elsewhere.
Flying is the main means of locomotion for most avian species, and it requires a series of adaptations of the skeleton and of feather distribution on the wing. Flight type is directly associated with ...the mechanical constraints during flight, which condition both the morphology and microscopic structure of the bones. Three primary flight styles are adopted by avian species: flapping, gliding, and soaring, with different loads among the main wing bones. The purpose of this study was to evaluate the cross‐sectional microstructure of the most important skeletal wing bones, humerus, radius, ulna, and carpometacarpus, in griffon vultures (Gyps fulvus) and greater flamingos (Phoenicopterus roseus). These two species show a flapping and soaring flight style, respectively. Densitometry, morphology, and laminarity index were assessed from the main bones of the wing of 10 griffon vultures and 10 flamingos. Regarding bone mineral content, griffon vultures generally displayed a higher mineral density than flamingos. Regarding the morphology of the crucial wing bones involved in flight, while a very slightly longer humerus was observed in the radius and ulna of flamingos, the ulna in griffons was clearly longer than other bones. The laminarity index was significantly higher in griffons. The results of the present study highlight how the mechanics of different types of flight may affect the biomechanical properties of the wing bones most engaged during flight.
“This study is based on comparative analysis about the possible effects of flying style on morphometric aspects of the wing bones of greater flamingo (Phoenicopterus roseus) (a) and griffon vulture (Gyps fulvus) (b). Our experiments underline that the griffon’s wing bones display both higher laminarity index and bone mineral content than flamingo. The study may support evidence that the mechanics of different types of flight may act on both biomechanical and morphometric properties of the bones most engaged in flight.”
This work describes the aerodynamic characteristics of an aircraft wing model with a Rüppell’s griffon vulture (RGV)-type winglet. A computational fluid dynamics (CFD) study using ANSYS 15.0 was ...conducted to study the effect of the RGV winglet on a rectangular wing. The NACA 65(3)-218 wing consists of 660 mm span and 121 mm chord length where the aspect ratio is 5.45. Eight different winglet configurations have been studied. Furthermore, the study is extended to study effect of cant angle and different angles of attack (AOA) to the winglet. A comparative study is done on aerodynamic features such as lift coefficient (CL), drag coefficient (CD), lift/drag ratio (CL/CD) and tip vortices to get the best RGV winglet design. The RGV winglet achieved highest CL compared to other types of winglets configuration. Based on contour plot analysis, the RGV winglet shows lower vortex formation compared to without winglet. The results show about 15 to 30% reduction in drag coefficient and 5 to 25% increase in lift coefficient by using an RGV winglet.
Understanding the movement pattern and ranging behavior of the Griffon vulture population in Serbia is of great importance for prioritizing conservation action. In 2011, an immature vulture was the ...first bird to be equipped with a satellite transmitter in Serbia. Our study aims to define the vulture?s foraging areas, home ranges, core and basic areas, and to investigate movement patterns across different years and seasons by analyzing satellite telemetry data. We tracked the movements of the vulture for over three years and obtained satellite tracking data for 34 bird-months (1976 GPS fixes) between October 2011 and July 2014. We determined that the overall foraging area of the vulture across the entire study period was 11654.34 km2. The overall area used by the vulture was larger during spring and summer than during winter periods. Combined ranges across all years identified one basic area and its associated core area around the Uvac colony and nearby feeding site; we identified three core areas in its proximity. This study showed that areas of traditional stock-raising practices are important vulture foraging areas and that supplementary feeding sites have a vital role. Our maps can be used for future planning of vulture conservation measures.
This work describes the aerodynamic characteristics of an aircraft wing model with a Rüppell’s griffon vulture (RGV)-type winglet. A computational fluid dynamics (CFD) study using ANSYS 15.0 was ...conducted to study the effect of the RGV winglet on a rectangular wing. The NACA 65(3)-218 wing consists of 660 mm span and 121 mm chord length where the aspect ratio is 5.45. Eight different winglet configurations have been studied. Furthermore, the study is extended to study effect of cant angle and different angles of attack (AOA) to the winglet. A comparative study is done on aerodynamic features such as lift coefficient (CL), drag coefficient (CD), lift/drag ratio (CL/CD) and tip vortices to get the best RGV winglet design. The RGV winglet achieved highest CL compared to other types of winglets configuration. Based on contour plot analysis, the RGV winglet shows lower vortex formation compared to without winglet. The results show about 15 to 30% reduction in drag coefficient and 5 to 25% increase in lift coefficient by using an RGV winglet.
Griffon vultures (Gyps fulvus), by virtue of their position at the top of the food chain and as obligate scavengers, are at risk of accumulating and concentrating heavy metals in their tissues and ...may be more predisposed to their toxic effects. The aim of this study is to investigate heavy metal concentrations in Griffon vultures in Portugal and Catalonia, Spain and to determine if heavy metal concentrations in the blood of weak and/or injured Griffon vultures admitted to wildlife rehabilitation centres (WRC) reflect contamination profiles in the local, free-living and outwardly healthy population. Whole-blood samples taken from 121 Griffon vultures caught in the wild or admitted to WRC in Portugal and Catalonia, Spain were examined for cadmium (Cd), mercury (Hg) and lead (Pb) by inductively coupled plasma mass spectrometry (ICP-MS). Cd and Hg were not detected in most samples (98.3% and 95%, respectively), while Pb was detected in all birds in concentrations ranging between 4.97 and 300.23µg/dl. Birds admitted to WRC had significantly lower Pb concentrations (24.15±15.07 and 25.98±18.04µg/dl in Portugal and Catalonia, Spain, respectively) than animals caught in the wild (29.67±13.19 and 42.22±50.08µg/dl in Portugal and Catalonia, Spain, respectively) (p<0.05). This may be explained by the fact that malnutrition was the main cause of admission of Griffon vultures to WRC, as ingestion has been described as the most significant pathway for Pb exposure in raptors. Therefore Griffon vultures admitted to WRC do not seem to be representative of the local, free-flying populations, so it remains necessary to continue catching when one intends to monitor Pb exposure in this species. The population of vultures captured in Catalonia, Spain showed the highest mean blood Pb concentration, perhaps due to the municipal rubbish dump located near the feeding station, with rubbish providing a significant fraction of their trophic needs. The ingestion of game meat with bullet fragments in carcasses or with Pb shots embedded in their flesh could also be the cause of the high blood Pb concentrations found in some vultures. The potential risk of Pb exposure in Griffon vulture populations must be given consideration, since most individuals evaluated had Pb concentrations between 20 and 100µg/dl, which is considered to be subclinical exposure to Pb, and which is above the threshold level at which Pb can affect antioxidant system in this species (15µg/dl).
•Cd and Hg were not detected in most of blood samples in Griffon vulture.•Pb was detected in all blood samples and most vultures exhibited subclinical exposure.•Vultures admitted at WRC do not reflect blood Pb levels of local populations.
Gamla Nature Reserve (GNR) used to host the largest colony of Eurasian griffon vultures (Gyps fulvus) in northern Israel. Since the early 2000s, the colony has suffered a drastic decline, which could ...lead to its extinction. In this descriptive study we present the population dynamics at GNR based on an analysis of data collected over 15 years (1999–2013). A monitoring scheme of monthly counts, developed at GNR, provided a database, facilitating a mathematical analysis of the population decline trends and their seasonal fluctuations. The analysis revealed a decline in the population size, which appears similar to an inverse-sigmoid and indicates a potential extinction of the colony by 2020. The analysis also indicates that, in addition to the overall pattern, the number of vultures fluctuates seasonally, with smaller numbers in spring and greater numbers in autumn and winter. Furthermore, this model suggests that latent factors might have influenced the decline; poisoning, thought to be a root cause, might not be the only factor influencing extinction. We demonstrate the importance of combining frequent data collection with modeling techniques for the analysis of raptor population trends.
Two hypotheses have been proposed to link population regulation to density‐dependent changes in demographical parameters: the habitat heterogeneity hypothesis (HHH) states that, as population density ...rises, an increasing proportion of individuals are forced to occupy low‐quality territories, which provokes a decline in average per‐capita survival and/or productivity although some individuals show no decline in fecundity; and the individual adjustment hypothesis (IAH), which suggests that increased densities lead to reductions in survival and/or fecundity by enhancing agonistic interactions, which affect all individuals to a similar extent. However, density‐dependent effects can be affected by density‐independent factors (DIF), such as weather. We test the effects of density dependence on annual reproductive success in Griffon Vultures Gyps fulvus at four spatial scales, nest‐site, cliff, colony and metacolony, in northern Spain from 2008 to 2015. Our results showed most support for the HHH at all scales. At the colony and cliff scale, IAH and DIF had similar importance, whereas there was little evidence of IAH at the metacolony and the nest scale. The best protected eyries (caves, potholes and sheltered ledges) produced the most fledglings and were used preferentially, whereas low‐quality eyries (exposed ledges or open crevices) were used only when the number of breeders increased. The significant interaction between breeding failure and density found for the more exposed eyries suggests that at higher densities, breeding pairs are forced to use poorer nesting areas, and the negative effect of density at the cliff scale could be due to the combined effect of a higher proportion of pairs using low‐quality eyries and the negative effect of rainfall.
Once a widespread species across the region of Southeast Europe, the Griffon vulture is now confined to small and isolated populations across the Balkan Peninsula. The population from Serbia ...represents its biggest and most viable population that can serve as an important reservoir of genetic diversity from which the birds can be used for the region's reintroduction programmes. The available genetic data for this valuable population are scarce and as a protected species that belongs to the highly endangered vulture group, it needs to be well described so that it can be properly managed and used as a restocking population. Considering the serious recent bottleneck event that the Griffon vulture population from Serbia experienced we estimated the overall relatedness among the birds from this population. Sex ratio, another important parameter that shows the vitality and strength of the population was evaluated as well.
During the annual monitoring that was performed in the period from 2013-2021, we collected blood samples from individual birds that were marked in the nests. In total, 169 samples were collected and each was used for molecular sexing while 58 presumably unrelated birds from different nests were used for inbreeding and relatedness analyses. The relatedness was estimated using both biparentally (10 microsatellite loci) and uniparentally (
and
of mitochondrial DNA) inherited markers.
The level of inbreeding was relatively high and on average it was 8.3% while the mean number of relatives for each bird was close to three. The sex ratio was close to 1:1 and for the analysed period of 9 years, it didn't demonstrate a statistically significant deviation from the expected ratio of 1:1, suggesting that this is a stable and healthy population. Our data suggest that, even though a relatively high level of inbreeding can be detected among the individual birds, the Griffon vulture population from Serbia can be used as a source population for restocking and reintroduction programmes in the region. These data combined with previously observed genetic differentiation between the populations from the Iberian and Balkan Peninsulas suggest that the introduction of foreign birds should be avoided and that local birds should be used instead.
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