We conducted multiple Common Goldeneye (Bucephala clangula) aerial surveys between 1 May and 31 July 2004 and 2005 on the Péribonka River, where a new hydroelectric reservoir will be created in 2007. We also conducted single pair and brood surveys on randomly chosen 5 × 5-km plots on the River drainage basin. Objectives were to assess the validity of the impact assessment surveys of 2002, examine the variation in pair and brood numbers, and determine recruitment and habitat characteristics related to productivity. During both years, the number of indicated breeding pairs (IBPs) declined steadily through May, whereas the social index (paired males/lone males) remained stable, declining only when few IBPs were located. However, backdated number of paired and lone males from observed broods suggested that the number of pairs remained maximal and constant during a three-week period centered on the fourth week of May in 2004 and the second week of May in 2005. IBP density (IBPs/10 km of shoreline) was 1.40 on the River and 0.64 in its drainage basin on average in 2005 (no surveys in 2004). When compared to results of the Black Duck Joint Venture (BDJV) surveys, IBP density was higher on the River by 0.69 IBPs in 2002, whereas densities in the two areas differed only by 0.07-0.29 in 2004 and 2005. No difference in brood density was perceived among survey sections and years. Recruitment rate was 0.15 in 2002, but increased to 0.57-0.67 in 2005 and 2004. Variables related to wetland area and distance to wetlands explained most variability in IBP and brood locations. We believe that timing of surveys and weather were the primary factors that affected difference in productivity estimates between 2002 and the 2004-2005 period.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 31 • No. 1