Two Brown Bear Populations In Spain In Danger of Extinction Have Been Isolated For Past 50 Years
The non-invasive analysis of 146 samples has allowed for the identification of 39 bears in the western sub-population, and 9 in the eastern one, so as to show the genetic structure of the population. In order to obtain the individual genotypes of the bears, scientists have employed 18 micro-satellite markers in a joint fashion, and a sex marker with high-class genetic technology.
"The level of genetic diversity was 45% in the western sub-population, and 25% in the eastern population¨, explain Trinidad Pérez and Ana Domínguez Sanjurjo to SINC, authors of the study and researchers at the Department of Functional Biology (Genetics) at the UO.
ECOLOGY AND BEHAVIOR OF 3 WILD ORPHANED BROWN BEAR CUBS IN SPAIN The brown bear is a typical K-selected species, with a long life and low birth rate. Maternal care includes nutri- tion and protection and almost certainly conditions later adaptive behavior. In European populations maternal care extends for about 18 months and weaning occurs at 1 year (Camarra 1989). The study of wild, motherless bear cubs provides in- sight into instinctive versus learned behavioral patterns. For the small, fragmented South European brown bear populations that presumably are near or under minimum viable population numbers (see Berducou 1990 for a re- view), this information can help managers decide whether to leave alone or capture orphaned cubs, which could be used for reinforcement programs. The survival of orphaned black (U. americanus) and brown bear cubs older than 5 months has been reported by Erickson (1959), Johnson and Leroux (1973), Payne (1975), and Jonkel et al. (1980). As far as we know, however, detailed information on monitored wild orphan cubs has never been published. This study provides gen- eral information on the ecology and behavior of 3 wild orphaned brown bear cubs over autumn, denning, and den emergence periods, including details on diet, habitat use, and interspecific relationships. The 3 cubs were sighted with their mother on 23 and 26 May 1991. The female, easily identified by her miss- ing hind leg, had been regularly observed in the area since 1984, with litters in 1984 and 1989. From late July 1991 the cubs were always observed unaccompanied and the female was no longer located. Given her previous observability, her disappearance strongly suggested that she had died. From 3 October 1991 to 6 May 1992, the orphans were sighted on 47 days (109 hours and 52 min- utes of observation time), and their recent tracks were located 6 other days. From 9 May to 1 November bears were observed on 7 days and their tracks detected on 4 other days (Table 1). Autumn From 3 October 1991, when regular monitoring began, to 3 December 1991, when denning started, the cubs were observed for 27 hours and 45 minutes. They spent 97.5% of observation time foraging, 1.5% walking, and 1.5% playing. In October we observed them feeding only on hazelnuts (Corylus avellana) (n = 6 days); in November, on rowan (Sorbus aucuparia) berries (37.5% of the ob- servation days), grass (37.5%), and hazelnuts (25.0%; n = 16 days); and in December, on grasses (75.0%) and rowan berries (25.0%; n = 4 days). To feed on hazelnuts and rowan berries they often climbed trees, showing great skill in handling branches despite their lack of knowl- edge of never having eaten such fruits. They were active during all daylight hours, but mainly in the early hours of the morning and late in the afternoon; if these observa- tions roughly reflected their daylight activity pattern, it was similar to that of the radiotagged Cantabrian adult male studied by Clevenger (1991). Cubs were always sighted walking and foraging a short distance apart and were never located at the den. Their general appearance was excellent, and they obviously gained weigh Intra- and Interspecific Interactions Several times we recorded interactions between the orphans and other potentially dangerous species. On 13 April 1992, when the yearlings were about 15 months old, they encountered an adult bear. The adult and the yearlings watched each other from 100 m apart for 2 min- utes. Following a small landslide nearby, they ran off in opposite directions. On several occasions we noticed the presence of wolves in the same area as the orphans, but we did not observe an interaction. The orphans shared the range with wolves for months without injury. Free- ranging dogs also were present. On 12 May 1992, an orphan stopped grazing and ran away from sheep dogs. We recorded 2 types of interactions with humans. Most of the time the orphans could hear the usual noises from the village and the road <1 kilometer away. Even when noises were especially loud (shouting, car horns), the bears appeared attentive only for a few seconds. However, on 6 occasions they noticed the unusual presence of people (wardens, hikers, researchers) 100-500 m away. On these occasions they were alert, looking around and sniffing. In addition, once they moved away, once hid in bushes, and once ran away; but they always reassumed their ac- tivity in the same area when danger disappeared. Thus, they seemed able to distinguish non-dangerous from po- tentially dangerous human presence. In developed areas cubs may learn this behavior early from their mother. The attitude toward chamois, roe deer, and cows was indifference or curiosity. Once a chamois group ran away startled and once a roe deer looked alarmed and barked near them; the cubs always ran away and hid in bushes, suggesting an interspecific recognition of alarm signs. www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_9_2_/Palomero_Blanco_Vol_9_2_.pdf