Jacob González-Solís

Learn More
The importance of sympatric speciation (the evolution of reproductive isolation between codistributed populations) in generating biodiversity is highly controversial. Whereas potential examples of sympatric speciation exist for plants, insects, and fishes, most theoretical models suggest that it requires conditions that are probably not common in nature,(More)
We studied the mercury contamination of 13 species of seabirds breeding on Bird Island, South Georgia, in 1998. Total mercury concentrations in body feather samples of birds caught at their breeding colonies were determined. Among the species, grey-headed albatross (8933 ng g–1) and southern giant petrel (7774 ng g–1) showed the highest, and gentoo penguin(More)
It has been suggested that sexual size dimorphism (SSD) may influence sex ratios at different life stages. Higher energy requirements during growth associated with larger body size could lead to a greater mortality of the larger sex and ultimately to an overproduction of the smaller sex. To explore the associations between SSD and hatching and fledging sex(More)
We performed a line transect survey (352.4 km) of primates in the Serra de Paranapiacaba, at one of the largest relatively undisturbed fragments of the Atlantic rainforest of Southeastern Brazil (ca. 1400 km2), in August 1998. The brown capuchin, Cebus apella nigritus, was the most common species found in the area (20 groups, density estimate: 5.31 ± 2.05(More)
Offspring of long-lived species should face costs of parental trade-offs that vary with overall energetic demands encountered by parents during breeding. If sex differences exist in how parents make the trade-off, sex-specific differences may exist in the contribution of each parent to those costs. Adaptations of offspring facing such costs are not well(More)
We analysed concentrations of cadmium, lead, mercury and selenium in blood from males and females of the 2 sibling species of giant petrels, the northern Macronectes halli and the southern M. giganteus, breeding sympatrically at Bird Island (South Georgia, Antarctica). Blood samples were collected in 1998 during the incubation period, from 5 November to 10(More)
A central point in life history theory is that parental investment in current reproduction should be balanced by the costs in terms of residual reproductive value. Long-lived seabirds are considered fixed investors, that is, parents fix a specific level of investment in their current reproduction independent to the breeding requirements. We tested this(More)
Global wind patterns influence dispersal and migration processes of aerial organisms, propagules and particles, which ultimately could determine the dynamics of colonizations, invasions or spread of pathogens. However, studying how wind-mediated movements actually happen has been hampered so far by the lack of high resolution global wind data as well as the(More)
We investigated phylogenetic relationships and the biogeographic history of the Calonectris species complex, using both molecular and biometric data from one population of the Cape Verde shearwater Calonectris edwardsii (Cape Verde Islands), one from the streaked shearwater C. leucomelas (western Pacific Ocean) and 26 from Cory's shearwater populations(More)
The diets of two potential competitor species, Audouin's Larus audouinii and yellow-legged gulls Larus cachinnans, were examined while they bred at the Chafarinas Islands during 1993, 1994, and 1995. Data were collected during two commercial fishing regimes: (1) trawling and purse seine fisheries, and (2) diurnal trawlers only. Since the food supply for the(More)