Bordignon L., Carabella M., Guenzani W., Guerrini M., Grattini N., Lardelli R., Piotti G., Pistono C., Saporetti F., Sighele M., Tosi A., Viganò E., Volcan G.
After first breeding in Italy in 1996 the Goosander has rapidly increased its breeding range in northern Italy: we analyzed the
progressive expansion of Goosander in the lakes and rivers in a wide belt covering three-quarters of the sub-alpine Italian area (~45°N Lat). The study period covers the nesting seasons from 2010 to 2017. Each water body was assigned to a local coordinator that oversaw the monitoring operation during the breeding season, through a standardized census realized from the shores of each potential breeding area in the first week of June. Overall we censused a total of 282 broods (or families) in the whole period, distributed over 8 different water bodies, with the bulk of the population concentrated in the largest lakes, Maggiore, Como and Garda. The first census in 2010 estimated 12 broods while the maximum of 51 broods was reached in the last year of the survey (2017) suggesting a still ongoing increasing population trend. The number of chicks per brood ranged between 1 and 19, with a mean value of 6.9 ± 0.22. In literature brood size above 14 chicks are considered as due to brood amalgamation, which may therefore occur in north-Italian lakes. From 2011 the number of families was almost stable on the west of the study area (Lake Maggiore), while a non-significant decrease was revealed in the Lake Como, and a steady increase in the eastern Lake Garda. Overall, our findings describe the occurrence of a successful and still ongoing colonization towards east, possibly harbinger of further expansion.
Logging can affect breeding performance and offspring survival in birds, but such effect can change over time. We investigated this question, deploying nest boxes for blue tits (Cyanistes caeruleus) in four forest stands, differing in the time since the last harvesting event occurred: 2, 10, 20 and 45 years ago. We recorded laying date, clutch and brood size and number of fledglings in the four stands over two years (2014-2015). We modelled reproductive success as a function of laying date and number of offspring. In the first year, the first laying date was about ten days earlier in the older stands, while in the second year the laying date did not differ among stands. Clutch size differed between stands in the first year but in the second year. Brood size dropped in 2015, except in one of the oldest stands. Reproductive success changed markedly between years and stands and was determined mainly by laying date. Though our results should be considered preliminary, we acknowledge that such year-to-year variability is likely attributed to climatic and structural differences between years and stands, respectively.
Since 1994 BirdLife International embarked on a very important initiative by producing and updating (in 2004 and 2017) a list of Species of European Conservation Concern (SPECs). Notwithstanding, the present authors noted some flaws in the compilation of data and propose improvement to the methodology followed by BirdLife. In particular, the importance to consider local populations, in most cases described as subspecies; as already highlighted by many researchers, the SPECs methods do not consider them as such. Their conservation is necessary for the potential evolution and acquisition of unique characteristics, which represent important components of biological diversity. The effort to consider subspecies has already been carried out by the 2009/147 EU Directive. Some particular cases are reported and commented upon.
