Sleeping site selection by the golden-handed tamarin Saguinus midas midas: The role of predation risk, proximity to feeding sites, and territorial defence

Tamarin monkeys, of the genus Saguinus, spend over half their lives at arboreal sleeping sites. The decision as to which site to use is likely to have considerable fitness consequences. These decisions about sleeping sites by three troops of golden-handed tamarin Saguinus midas midas were examined over a 9-mo period at a rainforest site in French Guiana. Data are presented on the physical nature of sleeping sites, their number, position within home ranges, and pattern of use and reuse, aspects of behaviour at retirement and egress, and predation attempts on the study troops. Cumulative plot analysis indicated that a tamarin troop used 30-40 sleeping sites in a 100-day period, approximately half of which were used very infrequently, so that consecutive reuse was never greater than three nights. Sleeping trees were superior in architectural parameters and liana weight to non-sleeping trees. There were no more sleeping sites than expected within the home range boundary region of the tamarins or in areas of overlap with the home ranges of neighbouring troops. Tamarins selected sleeping sites nearest to the last feeding site of the day on 25% of occasions. The study troops engaged in a number of activities that may reduce predation risk; raptor attacks on the study troops over 9 mo were frequent but unsuccessful. Tamarins often visited a sleeping site several hours before arrival, and were more likely to visit a site before use if they had not used it recently. The decision to select a sleeping site therefore involved knowledge of the previous frequency of use of that site.

Lead and arsenic in bones of birds of prey from Spain

The bones (humerus and/or femur) of 229 birds of prey from 11 species were analyzed for Pb and As to evaluate their exposure to Pb shot. The species with the highest mean Pb levels were red kite (Milvus milvus) and Eurasian griffon (Gyps fulvus), and the species with the lowest levels were Eurasian buzzard (Buteo buteo) and booted eagle (Hieraaetus pennatus). Red kite also had the highest mean As level, an element present in small amounts in Pb shot. Elevated bone Pb concentrations (>10 microg/g dry weight) were found in 10 birds from six species. Clinical signs compatible with lethal Pb poisoning and/or excessive bone Pb concentrations (>20 microg/g) were observed in one Eurasian eagle-owl (Bubo bubo), one red kite, and one Eurasian griffon. Pb poisoning has been diagnosed in eight upland raptor species in Spain to date.