Interview with Rubén Moreno-Opo about the Cinereous Vulture in SpainDate of the interview: 31 December 2009 In this interview Rubén Moreno-Opo talks about the conservation of the Cinereous Vulture in Spain.
Rubén Moreno-Opo: According to the latest national coordinated census conducted in 2006 there are 1629 breeding pairs (1845 observed pairs), distributed over a total of 35 different breeding colonies. This data appears in the monograph edited by SEO/BirdLife (De la Puente et al. 2007), that was the NGO coordinating the survey in collaboration with the Autonomous Communities and the Spanish Ministry of Environment. The coverage of this census can be regarded as very satisfactory.
In general, all the regional administrations promote annual monitoring programs of the species, though the data are not always compiled in coordinated national forums.
The most important region for the Cinereous Vulture is Extremadura. It holds nearly the half of the existing breeding pairs. The species is distributed in the southwestern area of Spain, with other important sub-populations in Castilla-La Mancha, Castilla y Leon and Andalusia. Also notable for its conservation relevance is the only known cinererous vulture island population, present in Mallorca. Markus Jais: Do all pairs nest in colonies or are there single pairs away from colonies too?
Rubén Moreno-Opo: Most Cinereous Vultures breed in colonies, so that the individuals benefit from the advantages of breeding in colonies though they maintain intraspecific territorial behaviour, with nests of different pairs located at varying distances and, generally, not close from each other. The colony size is also variable, the largest is located in the Sierra de San Pedro, Extremadura, with 336 pairs, followed by Monfragüe (287), Cabañeros (165) and Umbria de Alcudia (126) and, on the other hand, there is a colony with only 2 pairs. There are very few isolated pairs breeding outside colonies (5 according to the 2006 national census).
Adult Cinereous Vulture at vulture restaurant.
© Fundación CBD-Habitat
Rubén Moreno-Opo: I consider this is a very important conservation measure that can allow the contact among different Palearctic populations of the species. However, this continuous geographical connection seems a hard to reach short-term achievement. It should be priority to address in-situ conservation actions for the most threatened nuclei, such as the Balkans, and then to promote the establishment of intermediate reintroduced populations, as has happened in France and as, presumably, will occur in Spanish Pyrenees. The last project now has the continued and stable presence of Cinereous Vultures around the release areas. Markus Jais: In Monfragüe National Park I saw Griffon Vultures breeding in tree nests built by Cinereous Vultures. Is this a phenomenon only in Monfragüe and is competition with Griffon Vultures for breeding territories a problem for the Cinereous Vulture?
Rubén Moreno-Opo: This is an issue only registered in two Iberian Cinereous Vulture colonies at the moment, in Monfragüe and in a small colony in the Madrid region, with about 10 Cinereous Vulture pairs. In this colony, nest usurpation by the Griffon Vulture is a major conservation problem. In general, Cinereous Vulture has not competition problems for nesting sites with the Griffon Vulture, unlike the Black Stork and the Bonelli's Eagle in certain areas.
Cinereous Vulture nest in a cork oak outside breeding season.
© Fundación CBD-Habitat
Rubén Moreno-Opo: It is very important. Both the Cinereous Vulture and other scavenger raptors have developed their foraging and feeding behaviour coexisting with the livestock management practices conducted in large areas of Spain during the last centuries. There is also a significant association between the main vulture foraging locations and the areas with greater abundance of extensive livestock in Spain, mainly sheep.
In recent years the farming practices, and hence, food availability for Cinereous Vultures has been modified. First, intensive porcine exploitation increased exponentially since the 1970s, which led to the establishments of many vulture restaurants (in northern Spain) where the vultures could obtain abundant food at predictable sites. This allowed the increase of vulture populations, particularly of Griffon Vultures. Currently, this source of food as well as the extensive livestock carcasses heterogeneously distributed in the territory have been altered and reduced considerably.
The conservation and promotion of traditional livestock exploitation is undoubtedly the best tool to solve food availability problems for Iberian vulture popultations. Markus Jais: What is the current situation in Spain for leaving dead livestock in the countryside as food for vultures and other scavengers like eagles?
Rubén Moreno-Opo: At present, the abandonment of carcasses in the field outside the authorized feeding stations is not possible. This “muladares” are, on the other hand, too scarce to meet the whole biomass requirements of vulture populations.
Since the coming into effect of EC Regulation 1774/2002, livestock carcasses removal insurances have been establish widely, so the only legal way for intended vulture feeding is through feeding stations and wild animal carcasses. This situation has caused various problems and threats to scavenger raptors from different points of view. First, nowadays the balance of nutritional requirements vs biomass availability is negative in Spain and food demand is not satisfied for vultures. There is a negative affection on reproductive parameters such as productivity, which has decreased along for all species, according to density dependence principles.
The number of starved vultures admitted in official rehabilitation recovery centres has significantly increased. The dependence of fixed and predictable sources of food is causing adverse effects: inter-specific and intraspecific competition for food and nesting sites, changes in population parameters and dynamics depending on the distance from the nest to the vulture restaurant, reducing the possibilities for dispersal and occupation of new territories, attracting generalist scavengers close to feeding station surroundings and increasing levels of pharmaceutical contamination in several body tissues by feeding on carcasses of intensive livestock (Donázar et al. in press).
The number of incidents on live cattle has also augmented in recent years, according to the regional administrations databases.
Eagles, however, are less dependent on carrion, although for species like the Red Kite and Black Kite the changes in food availability are a major threat.
Following the publication of EC Regulation 1609/2009 a wider range of possibilities for vulture feeding has been opened. It is hopefully a clarification about the regulating actions in the future development regulation about animal by-products of the European Commission. This future legislation could extent the carcass availability for necrophagous species according to natural occurrence conditions, ensuring human and animal health conditions.
Nesting and foraging range of Cinereous Vulture.
© Angel Arredondo
Rubén Moreno-Opo: The Cinereous Vulture has a close relationship with the big game. Most of the breeding territories in Extremadura, Castilla-La Mancha and Andalusia are private estates whose main inputs come from the hunting exploitation. These areas are typical of Mediterranean forests, where during the winter months many hunting events are conducted. As a result of these hunts, Cinereous Vultures have the most important source of winter food from the abundant ungulate remains and carcasses generated (Moreno-Opo et al. In press). However, in certain regions restrictions are being imposed on this food source by not taking into consideration the hygienic role of vulture species in eliminating potential transmission of pathogens and diseases. This then means that it is not possible to use the remains of big game animals for vultures feeding.
The big game became one of the biggest land management motor since the last 20 years in southwestern Spain, due to its important economic profits. Markus Jais: How has the diet of the Cinereous Vulture changed during the last decades in Spain?
Rubén Moreno-Opo: There are several studies conducted by researchers at the University of Extremadura (Costillo, E. et al. 2007, Corbacho, C. et al. 2007) showing the plasticity of the diet of Cinereous Vultures in Spain, as a result of changes in the availability of different sources of food. Thus, the large reduction in rabbit populations occurred in areas where the Cinereous Vulture is distributed, has led to a decline in the importance of this lagomorph in the diet, from the 1970s to the present. The ingestion of livestock species carcasses has remained stable, though with important differences in the species of origin (diminishing the occurrence levels of extensive livestock and growing intensive livestock ones).
Remarkable is the increase of game wild ungulates remains in the diet in recent years, in relation to the pioneer studies about the species.
Subadult Cinereous Vulture feeding at a vulture restaurant.
© Fundación CBD-Habitat
Rubén Moreno-Opo: Electrocution or collision with power lines is not a major threat to the Cinereous Vulture. Although there are records of at least 30 dead birds from this cause in a compilation of information for Spain (Moreno-Opo & Guil 2007), the species usually does not perch in open areas. Resting on the ground is much more common in these open areas as is resting in trees in communal forest roosts.
In a specific survey to evaluate mortality in power lines in areas inhabited by the Cinereous Vulture, only 3 individuals were found from a total of 343 dead birds (among them, 19 Spanish Imperial Eagles and 15 Bonelli's Eagles, for which electrocution is the most non natural mortality threat, Fundación CBD-Habitat 2007).
The biggest problems have resulted from the collision to power lines cables near predictable food sources during adverse weather conditions. Markus Jais: How many birds die because of poisoning?
Rubén Moreno-Opo: Pesticide poisoning is the leading cause of non natural mortality of Cinereous Vultures in Spain. The number of individuals found since official records began (around 1990) have amounted to 501 (up to 2006, Hernandez & Oria 2007, Hernandez & Margalida 2008). At present, it appears that the number of cases in which one or more Cinereous Vultures have been affected by poisoning have decreased to about 10 a year.
However, every year the effort made by the administration leads to the detection of the indiscriminate use of pesticides (carbofuran and aldicarb primarily) associated with malpractice hunting and livestock management.
Cinereous Vulture adult and chick poisoned in their nest.
© Fundación CBD-Habitat
Rubén Moreno-Opo: It is urgent researching and offering a commercial alternative to lead as a material for bullets used for big game hunting.
Different investigations are being performed today, although the use of lead as ammunition is still widespread. As discussed before, the remains of hunted ungulates are a major source of carrion for the Cinereous Vulture, so removing this type of food may reduce the overall availability and further aggravate the situation. There are no published papers on blood lead levels of Cinereous Vultures (yes in the bearded vulture), but I hope that detailed data will be released soon.
In various public workshops the prevailing potential impact to vultures, based on data from sampling programs, has been shown: there is evidence of sublethal levels of lead (>200 ppm) in both Griffon and Cinereous Vulture in about 23-35% of the population in Castilla-La Mancha (Mateo 2009). Markus Jais: In Spain, hundreds of Griffon Vultures died because of collision with wind mills. How is the situation for the Cinereous Vulture and how will the development of future wind farms, for example in Extremadura, effect the species?
Rubén Moreno-Opo: For the moment, thanks to the wind power development having occurred outside the distribution area of Cinereous Vulture, collisions with wind turbines is not a serious threat to the species. Only two known cases of death of Cinereous Vultures have been registered in relation to more than 1,000 dead Griffon Vultures in wind farms in the Iberian mountain range (NE Spain, Camina com. Comm.) without adding those in other important areas for vultures and wind energy development (particularly the Strait of Gibraltar and northern plateau).
It is necessary to perform continuous monitoring programs in the wind farms near breeding areas in the Central System and Montes de Toledo, to assess eventual impact on Cinereous Vulture.
Undoubtedly, the early development of wind energy in the Extremadura region would seriosly affect the conservation of the Cinereous Vulture.
All regions have the right to develop economically, but the geographical and ecological characteristics of this region make the development of wind farms and the safety of various species of raptors and other endangered birds (eg eagles, vultures, storks, cranes, bustards, etc.) incompatible in a large area of the Extremadura.
Nevertheless, the Extremadura administration is aware about this situation and it is implementing the most completed environmental regulation about wind farms and biodiversity in Spain. Markus Jais: Disturbance can be a serious problem for raptors. What activities are causing disturbance for the Cinereous Vulture and what can be done to avoid it?
Rubén Moreno-Opo: Fortunately, the management of various human activities in important areas to the Cinereous Vulture is regulated according to existing legislation and the already approved conservation plans. This would be a definitive tool for protection, although legal compliance is not always possible in Spain: we have one of the best environmental legislation but its satisfaction is often not reached.
The administrations have regulated several measures to protect the breeding colonies, and it has been achieved that disturbances and habitat loss are currently not a major threat factor.
However, there are four types of management actions affecting Cinereous Vulture during the breeding season:
- 1) hunting activity can sometimes be extended until February, at which time a significant percentage of pairs have began incubation. It is necessary to restrict this activity, as no later than January 20.
- 2) cork harvesting has great economic importance in Mediterranean forest areas and could determine the chicks survival if they are younger than 30-40 days (death by dehydration). It is required that the work would be done according to an established program in order to avoid affecting to the same nest on more than one consecutive day. It is also necessary to stop working in nesting areas before noon to allow the presence of adults so that they can shade and protect the chick (Margalida et al. In rev).
- 3) the settlement and opening of tracks and firebreaks is usually done in spring, at which time chicks are in the nest. It is recommended to enforce plans prior to any activity, establishing protected areas during the period of incubation and chick rearing, similarly to cork harvesting.
- 4) other forest management activities in Mediterranean forests -like picking/harvesting, pruning, fumigation with planes, plantations or livestock management -must be developed taking into account the distance to nests, establishing protected areas around the nests (usually 500 m) before any human activity. Pine wood exploitation is done in a sustainable and compatible way with the presence of Cinereous Vultures in the largest colonies of the Central System mountains (Iruelas, Peñalara and Valsaín).
Cinereous Vulture in flight.
Rubén Moreno-Opo: The juvenile Cinereous Vultures start a dispersal period during its first winter until their settlement as breeder (generally from the 4th calendar year, although there are records of birds that breed even earlier, in their 3rd year calendar). The general observed movement patterns are directed throughout the western quadrant of the Iberian peninsula, and most commonly in the surroundings of the breeding colonies (central, western and southwestern Spain, Costillo 2005).
In recent years, observations of Cinereous Vultures in the north, northeast and east of the Iberian Peninsula are becoming more frequent. There are two records of young birds reaching sub-Saharan Africa (Senegal and Mauritania) during the last decade.
The level of individual exchange with other reintroduced nearby nuclei (France and Spanish Pyrenees in Catalonia) is not known. Markus Jais: What conservation programs do exist for the species in Spain at the moment and who is involved?
Rubén Moreno-Opo: Currently, there are ongoing monitoring and conservation programs in all regions inhabited by the species, led by the regional administrations. Monitoring and census are annually conducted with the participation of expert technicians, who also implement conservation actions (Madrid, Balearic Islands and Andalusia), while in other regions efforts are more localized in time, although it has the continued support from environmental rangers (Extremadura, Castilla-La Mancha and Castilla y Leon).
Several NGO projects have allowed to progress in the settlement of appropriate conservation measures in the decades of 1990 and 2000 (CBD-Habitat Foundation, BVCF, SEO / BirdLife).
Today, with the aim of resolving the conflict caused by the alteration in food availability, the Ministry of Environment and Rural and Marine Affairs has initiated a research and management line for the implementation of conservation measures to Cinereous Vulture and other necrophagous species. Among these are the development of a national conservation strategy, participation in the process of amending the European and Spanish legislation, testing best management practices for food supply, both in and outside feeding stations. Markus Jais: What other raptor species will benefit from conservation programs for the Cinereous Vulture?
Rubén Moreno-Opo: When establishing conservation measures for Cinereous Vultures other scavenger species in unfavorable conservation status are favored, such as the Egyptian Vulture and the Red Kite. This is one of the main objectives in developing a feeding management strategy for necrophagous species. Furthermore, as a result of efforts to protect the nesting areas of Cinereous Vulture, many other species are benefiting from the regulation of human activities and are indirectly protected. This is the case, for example, of the Black Stork and forest raptors such as Short-toed Eagle, Booted Eagle or Goshawk.
Cinereous Vulture, Monfragüe Nationalpark, Extremadura.
© Markus Jais
Rubén Moreno-Opo: The population trend shown by the species in recent times makes us optimistic about their future. Spain has advanced in protecting nesting areas and learning about the details of threats. Great efforts have been undertaken to increase the populations and these have shown a significant recovery.
However, it is very important to remain vigilant and maintain conservation efforts at the highest level and in all territorial areas. Especially, there are three threats that may lead to significant problems for the species in the short to medium term: mortality caused by ingestion of toxic baits, reduction and alteration in food availability, especially for carcasses decreasing from extensive livestock (sheep and goats) and wild ungulates (deer and wild boar) and the widespread development of wind farms in the distribution area of the species in central and southwestern Spain. Markus Jais: What was your most fascinating experience with Cinereous Vultures?
Rubén Moreno-Opo: Monitoring of species as Cinereous Vulture offers many exciting moments, almost daily. Examples are: capturing and radiotagging days, the discovery of new nests in colonies you thought to know perfectly and the observation of active feeding of vultures is one of the most fascinating shows in nature. Undoubtedly, one of the best memories was in the spring 2006 when in the framework of managing a cork harvesting, it was essential to remove a small chick from the nest to prevent its death from dehydration. Following their protection from heat in the hottest hours of the day, it was returned to its nest with the uncertainty of whether the parents would accept it (there were no experiences of such rescues of chicks in nests for the species). Although during that day the adults did not turn to the nest, the next day they resumed the chick rearing and, finally, it could fledge without any problems that season. Sad times also accompany the work with Cinereous Vulture, and the findings and rescues of adult and chick poisoned in their own nests are particularly hard, which unfortunately are common each year. Markus Jais: Rubén, thank you very much for the interview.