Populations index of black grouse in the Brembana valley (Italian Central Alps): preliminary results
2000
Artuso, I. (Dipanimal, Company Scienze della produzione, Cognola (Italy))
The aim of the study was to define the status of black grouse Tetrao tetrix populations in Brembana valley (Italian Central Alps) during the period 1996-2000 and to study the difference between the protected and hunting areas. A hundred operators per year performed spring and summer censuses over 5800 ha with respect to a suitable total area of 12,000 ha. In the spring of 1999, 145 males were counted on 34 leks and 38 sing points. During the end of the summer, a total of 482 grouse were counted. The total summer number was constituted by 120 adult hens (46 hens without brood and 74 with brood), 62 adult males (+ 5 adults unclassified) and 295 juveniles. Juveniles density was 5.05/100 ha and the rate juveniles/adult 1.62. The total density in the studied areas was 1.27/100 ha, with average of 3.99 juveniles per brood. In 1999 a good reproductive success was recorded, compared with the years before, the total number of males and brood was constant. In 1999, the density index showed no significant difference between hunting areas and reserve areas (7.8/100 ha), except the males of less density in hunting areas (0.9/100 ha vs. 1.4/100 ha). The research was supported by ®Comprensorio Venatorio Alpino alle Brembana (BG)¯.
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