Javier Castroviejo

Bio: Javier Castroviejo is an academic researcher from Spanish National Research Council. The author has contributed to research in topics: Canis & Population. The author has an hindex of 15, co-authored 27 publications receiving 1304 citations.

Mitochondrial DNA phylogeography and population history of the grey wolf Canis lupus

Abstract: The grey wolf (Canis lupus) and coyote (C. latrans) are highly mobile carnivores that disperse over great distances in search of territories and mates. Previous genetic studies have shown little geographical structure in either species. However, populatio

Impact of Market Hunting on Mammal Species in Equatorial Guinea

Abstract: :The impact of commercial hunting on forest mammals was studied in two regions on Bioko and Rio Muni in Equatorial Guinea, west Africa. Harvests were assessed from carcass counts in the main markets in the areas. A total of 10,812 carcasses of 13 species were recorded in Bioko, and 6160 carcasses of 30 species were recorded in Rio Muni. Biomass of harvested mammals was 111,879.63 kg in Bioko and 66,447.87 kg in Rio Muni. For the 12 prey species selected for study in Bioko, harvests totaled 7.15 animals/km2 or 62.93 kg/km2. Harvests for the 17 prey species in Rio Muni were 3.22 animals/km2 or 24.06 kg/km2. We used a model developed by Robinson and Redford (1991) to estimate potential harvests based on animal production rates. Total production was 147.90 animals/km2 and 139.12 animals/km2 in Bioko and Rio Muni, respectively. Potential harvest figures varied considerably by species. Comparison of actual and potential harvests showed that five primate species (Cercopithecus erythrotis, Cercopithecus nictitans, Cercopithecus pogonias, Cercopithecus preussi, and Mandrillus leucophaeus) and one ungulate (Cephalophus ogilbyi) in Bioko were being hunted unsustainably. Only two of the 17 species (Cercopithecus nictitans and Cephalophus dorsalis) in Rio Muni were being hunted unsustainably. Percent deviation of actual from potential harvests averaged 4.98 times greater than sustainable harvest in Bioko and 1.03 times greater in Rio Muni. For the two sites together figures ranged from close to 28 times greater than potential to 0.08% of the potential harvest. Although hunting methods and the commercialization potential of species may affect their presence in markets, these figures show that Bioko animals are heavily exploited, some of them unsustainably. This poses severe risks for the conservation of the island's unique fauna that must be addressed immediately. Impacto de la caza comercial sobre las especies de mamiferos en Guinea Ecuatorial Resumen: El impacto de la caza comercial de mamiferos de la selva fue estudiado en dos regiones, en Bioko y Rio Muni, en Guinea Ecuatorial, Africa Occidental. Las cosehas fueron estimadas a partir del conteo de animales muertos en los principales mercados del area. Un total de 10,812 animales muertos de 13 especies fueron documentados en Bioko y 6160 animales muertos de 30 especies fueron documentados en Rio Muni. La biomasa de los mamiferos recolectados fue de 111,879 kg en Bioko y 66,447.87 kg en Rio Muni. Para las 12 especies de presas seleccionadas para su estudio en Bioko, la recolleccion totalizo 7.15 animales/km2 o 62.93 kg/km2. La recoleccion para las 17 especies de presa en Rio Muni fue de 3.22 animales/km2 o 24.06 kg/km2. Utilizamos un modelo desarrollado por Robinson y Redford (1991) para estimar las cosechas potenciales basadas en las tasas de produccion animal. La produccion total fue de 147.90 animales/km2 y 139.12 animales/km2 en Bioko y Rio Muni respectivamente. Las cifras sobre la cosecha potencial varariaron considerablemente entre las distintas especies. Las comparaciones de las recolecciones reales y las potenciales mostraron que cinco especies de primates (Cercopithecus erythrotis, Cercopithecus nictitans, Cercopithecus pogonias, Cercopithecus preussi y Mandrillus leucophaeus) y un ungulado (Cephalophus ogilbyi) en Bioko estaban siendo cazadas en forma no-sostenible. Solamente 2 de las 17 especies (Cercopithecus nictitans y Cephalophus dorsalis) en Rio Muni estaban siendo cazadas en forma no-sostenible. La desviacion del porcentaje de recoleccion real con respecto al potencial, fue en promedio 4.98 veces mayor al de la recoleccion sostenida en Bioko y 1.03 veces mayor en Rio Muni. Para los dos sitios juntos, las cifras oscilaron entre 28 veces mayor que la cosecha potencial a un 0.08% de la cosecha potencial. Si bien los metodos de caza y el potencial de comercializacion puede afectar su presencia en los mercados, las cifras actuales muestran que los animales en Bioko estan severamente explotados, alguno de los cuales en forma no-sostenible. Esto plantea severos riesgos para la conservacion de la singular fauna de la isla, por lo que este problema debe ser tratado en forma inmediata.

market dynamics of bushmeat species in Equatorial Guinea

Abstract: 1. Wild animals are an important protein source in many countries in West Africa. Studies of numbers and fluctuations of game species entering markets can provide vital information on wildlife use and exploitation in the consumer regions. 2. Two market sites in each of the most important towns, Malabo (Bioko Island) and Bata (Rio Muni) in the Republic of Equatorial Guinea, central Africa, were studied from October 1990 to October 1991. 3. 15 and 38 species of mammals, birds and reptiles were recorded in Bioko and Rio Muni, respectively. A total of 18012 carcasses was counted; 61.2% in Bioko and 38.8% in Rio Muni. 4. Abundance and availability of individual bushmeat species were described by: (a) the daily abundance of species (DA) as the average number of carcasses species -1 day -1 during all sampled days; (b) the carcass volume (CV) for each species as the average number of carcasses species -1 day -1 sold during available days, and (c) the species availability (MA) in markets as the percentage number of days per month during which a species was present for sale. 5. Two species, Cephalophus monticola and Cricetomys emini, in Bioko and C. monticola and Atherurus africanus in Rio Muni accounted for more than half of all carcasses brought into markets. 6. Seasonal differences in number of carcasses entering markets in Bioko were observed between dry and wet periods. In Rio Muni, increases were observed during the short dry and long rains periods. 7. Monthly changes in number of carcasses of species (>50 year -1 ) were compared between markets using Spearman rank correlation tests. Two main clusters appeared in relation to abundance of species in markets. 8. Bushmeat demand in the large towns in Equatorial Guinea may possibly exceed supply at present. Studies of bushmeat dynamics in markets can be used to monitor use of wildlife resources in the country.

The problems with hybrids: setting conservation guidelines

Abstract: Rates of hybridization and introgression are increasing dramatically worldwide because of translocations of organisms and habitat modifications by humans. Hybridization has contributed to the extinction of many species through direct and indirect means. However, recent studies have found that natural hybridization has played an important role in the evolution of many plant and animal taxa. Determining whether hybridization is natural or anthropogenic is crucial for conservation, but is often difficult to achieve. Controversy has surrounded the setting of appropriate conservation policies to deal with hybridization and introgression. Any policy that deals with hybrids must be flexible and must recognize that nearly every situation involving hybridization is different enough that general rules are not likely to be effective. We provide a categorization of hybridization to help guide management decisions

Avian Clinical Biochemistry

Abstract: This chapter presents basic concepts related to avian clinical biochemistry. Avian medicine and surgery is recognized as an official specialty in veterinary medicine in three continents: Europe, Australia, and North America. The increasing demand for veterinary care for individual birds with a high sentimental or economical value and efforts to conserve endangered species facilitated this awareness. The introduction of micromethods in clinical laboratories and the public demand for veterinary care for individual birds have removed many obstacles of this field. This chapter begins with discussing how blood samples of birds can be collected in the most efficient way. The chapter then discusses starvation, flight, and postprandial effects. The chapter also elaborates the biochemistry of plasma proteins, renal function, and hepatobiliary disease in birds. The chapter emphasizes that all efforts should be made to obtain a blood sample before any treatment is given. Treatments administered before samples are collected may severely affect plasma chemical values, which may jeopardize a correct diagnosis at a later stage. The time interval between restraint and blood sampling should be kept to a minimum to prevent stress-associated changes in clinical chemistry parameters. Blood samples should be obtained before an extensive clinical examination is performed to avoid iatrogenic changes in the samples.

Genetic Evidence for an East Asian Origin of Domestic Dogs

Abstract: The origin of the domestic dog from wolves has been established, but the number of founding events, as well as where and when these occurred, is not known. To address these questions, we examined the mitochondrial DNA (mtDNA) sequence variation among 654 domestic dogs representing all major dog populations worldwide. Although our data indicate several maternal origins from wolf, >95% of all sequences belonged to three phylogenetic groups universally represented at similar frequencies, suggesting a common origin from a single gene pool for all dog populations. A larger genetic variation in East Asia than in other regions and the pattern of phylogeographic variation suggest an East Asian origin for the domestic dog, ∼15,000 years ago.