Javier Castroviejo

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

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, population genetic structure is also influenced by past isolation events and population fluctuations during glacial periods. In this study, control region sequence data from a worldwide sample of grey wolves and a more limited sample of coyotes were analysed. The results suggest that fluctuating population sizes during the late Pleistocene have left a genetic signature on levels of variation in both species. Genealogical measures of nucleotide diversity suggest that historical population sizes were much larger in both species and grey wolves were more numerous than coyotes. Currently, about 300 000 wolves and 7 million coyotes exist. In grey wolves, genetic diversity is greater than that predicted from census population size, reflecting recent historical population declines. By contrast, nucleotide diversity in coyotes is smaller than that predicted by census population size, reflecting a recent population expansion following the extirpation of wolves from much of North America. Both species show little partitioning of haplotypes on continental or regional scales. However, a statistical parsimony analysis indicates local genetic structure that suggests recent restricted gene flow.

Circadian rhythms of determined blood chemistry values in buzzards and eagle owls

1. 1. Fifteen values were determined in blood samples from six buzzards (Buteo buteo) and six eagle owls (Bubo bubo) over the 24 hr of the day. 2. 2. Glucose, urea, uric acid, triglyceride and calcium values showed diurnal rhythms in both species. Their respective patterns of diurnal variation were compared. 3. 3. Phosphorus, cholesterol and cholinesterase levels underwent circadian rhythms only in the buzzards. Albumin/globulin and amylase exhibited diurnal variations exclusively in the eagle owls. 4. 4. Glutamatic oxaloacetic transaminase, albumin, globulin, total protein and creatinine concentrations did not show diurnal rhythms in either of the species. 5. 5. Blood values of the different parameters were studied on the basis of the ranges described in birds.

market dynamics of bushmeat species in Equatorial Guinea

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.

Metabolic responses of Buteo buteo to long-term fasting and refeeding

1. 1. The effects of long-term fasting (13 days) and refeeding (15 days) on body mass and eight blood parameters were determined in the buzzard (Buteo buteo). 2. 2. Body mass decreased linearly during the first 10 days of fasting. By day 13, the buzzards had lost 26% of their initial mass. 3. 3. Urea and uric acid were significantly increased by the starvation. Blood glucose and cholesterol increased during fasting. The other blood parameters were not affected by food deprivation. 4. 4. Increase in plasma globulins at the beginning of refeecling may have produced hemodilution. 5. 5. The results suggest that tissue catabolism of proteins was strongly increased in food-deprived buzzards.

Hematocrit and blood chemistry values in captive raptors (Gyps Fulvus, Buteo Buteo, Milvus m ig Ra` s, Aquila Heliaca)

1. Eight hematological values were determined in blood samples from 88 raptors representing 10 species. 2. Means, standard errors, ranges and coefficients of variations were obtained for each parameter and species investigated. 3. The griffon vulture (Gyps fulvus) showed mean concentrations of glucose lower than those of most of the other species. 4. Concentrations of urea in the buzzard (Buteo buteo) were higher than those of the other raptors studied, and the black kite (Milvus migrans) had cholesterol values greater than the other species. 5. Blood values of individual birds of prey in good and bad states of nutrition were compared, showing significant changes in cholesterol, hematocrit, urea and total protein values.

Bioko: critically important nesting habitat for sea turtles of West Africa

We evaluate the conservation status and threats faced by sea turtle nesting populations at Bioko Island, Equatorial Guinea (Central Africa). Beaches were monitored to obtain a detailed sea turtle nest census and, where possible, tagging of adult females was undertaken. Four sea turtle species were found nesting in the area: the green turtle (Chelonia mydas), the leatherback (Dermochelys coriacea), the olive ridley (Lepidochelys olivacea) and the hawksbill (Eretmochelys imbricata); with the former two species nesting in regionally important numbers. Nesting activity was concentrated between November and February, with a peak in December–January. Tagging and recapture of green turtles in two consecutive seasons suggested an estimated 560 (interquartile range: 420–1,681) and 414 (interquartile range: 190–1,255) nesting females in the area, respectively. Estimated numbers of nesting leatherbacks ranged from 123 to 215 and 243 to 293 in the first and second season, respectively. The other two species were less abundant (olive ridley: 19–29 and 28–43; hawksbill: 4–10 and 2 turtles). Data were compared with more recent surveys in the area and contextualised with information on human related threats. Despite the size of nesting stocks, ongoing permitted and illegal take of adult turtles at the nesting site constitutes a serious threat for these breeding aggregations. Additionally, tag returns from throughout the Gulf of Guinea suggest that the level of take in regional fisheries may also be a major threat.

Species richness and endemism of birds in Bioko

The status of 50 taxonomically unique bird taxa found in Bioko is described. A complete updated species list for birds in Bioko is also given. Notes on habitat occupied and altitudinal distribution of each species as well as information on their general abundance is also included. Species distributions may have been affected by habitat modifications brought about by humans but most taxonomically unique forms are found in the montane areas. Comparisons are made with the neighbouring Mount Cameroon area.

Diversity and status of sea turtle species in the Gulf of Guinea islands

In West Africa, the Gulf of Guinea islands are important nesting places for four sea turtle species. The Green turtle (Chelonia mydas), the Hawksbill (Eretmochelys imbricata), the Olive Ridley (Lepidochelys olivacea) and the Leatherback (Dermochelys coriacea) turtles nest on Biokos southern beaches. The Green, Hawksbill and Leatherback turtles breed on Príncipe and São Tomé. The Leatherback turtle nests, at least, on Annobón. The Leatherback turtle is reported on the four islands for the first time, and the Olive Ridley turtle for Bioko. Bioko is probably the most important island in terms of number of species and nesting individuals; the Green turtle being the most abundant species. However, the nesting places are at present restricted to barely 20 km along the coastline. On Príncipe and São Tomé, the most common species is the Hawksbill turtle. Sea turtle nesting populations are being severely depleted on the four islands. The main causes of cverexploitation are the meat and egg trade on Bioko and the Hawksbill shell-craft trade on São Tomé and Príncipe.

The Spanish co-operation programme in Equatorial Guinea: a ten-year review of research and nature conservation in Bioko

The Research and Nature Conservation Programme in Equatorial Guinea was launched in 1985, financed by the Spanish Technical Co-operation Agency. The Programmes main objectives were to: (i) increase scientific research; (ii) set up a Museum of Natural History for the country; (iii) update environmental legislation; (iv) create a network of protected natural areas; (v) promote Equatorial Guineas participation in international forums on the environment; (vi) train local personnel and (vii) implement environmental education programmes. Actions undertaken and results obtained over a ten-year period are reviewed herein. The Programme has been important in raising the level of scientific awareness of the countrys resources but more importantly, it has catalysed the inception of the countrys existing legal framework for environmental protection (Ley 8/1988). Within this law, regulations with respect to wildlife, protected areas and hunting were promulgated. These include the legal basis to create other reserve areas and non-profit organizations related to wildlife protection. The Programme has been able to employ the law to stop exploitation and road-building along the south of Bioko.

Multiple Paternity in a Reintroduced Population of the Orinoco Crocodile (Crocodylus intermedius) at the El Frío Biological Station, Venezuela.

The success of a reintroduction program is determined by the ability of individuals to reproduce and thrive. Hence, an understanding of the mating system and breeding strategies of reintroduced species can be critical to the success, evaluation and effective management of reintroduction programs. As one of the most threatened crocodile species in the world, the Orinoco crocodile (Crocodylus intermedius) has been reduced to only a few wild populations in the Llanos of Venezuela and Colombia. One of these populations was founded by reintroduction at Caño Macanillal and La Ramera lagoon within the El Frío Biological Station, Venezuela. Twenty egg clutches of C. intermedius were collected at the El Frío Biological Station for incubation in the lab and release of juveniles after one year. Analyzing 17 polymorphic microsatellite loci from 335 hatchlings we found multiple paternity in C. intermedius, with half of the 20 clutches fathered by two or three males. Sixteen mothers and 14 fathers were inferred by reconstruction of multilocus parental genotypes. Our findings showed skewed paternal contributions to multiple-sired clutches in four of the clutches (40%), leading to an overall unequal contribution of offspring among fathers with six of the 14 inferred males fathering 90% of the total offspring, and three of those six males fathering more than 70% of the total offspring. Our results provide the first evidence of multiple paternity occurring in the Orinoco crocodile and confirm the success of reintroduction efforts of this critically endangered species in the El Frío Biological Station, Venezuela.