POTTERS H (2020) Remarkable winter concentrations of Blue Tits Cyanistes caeruleus in Golden Larch Larix kaempferi plots. LIMOSA 93 (2): 89-91.
After huge numbers of migrating Blue Tits had been
recorded in autumn 2019 in the Netherlands, the species
remained exceptionally abundant in the following months.
Early January 2020 several flocks of 30-130 birds were seen
in the western part of the Dutch province of Noord-Brabant.
The largest flock comprised of 320 individuals. No other
species accompanied these Blue Tits. Flocks were mainly
or exclusively seen foraging in Golden Larch stands. These
relatively dense stands (mean distances between trees 5-10
m) of at least 15 m high larches measured 0.7-3.2 ha. Blue
Tits foraged on branches and twigs; the cones were almost
completely ignored. While foraging the Blue Tits behaved
very actively high in the trees. It remained unknown what
type of food the tits were feeding on, presumably as food
items were very small. When visiting the same locations later
in January, flocks were much smaller, as was also noted in
other parts of the country. This decrease could be due to
depletion of the food source and/or return migration to
[pdf only for members] [dutch summary]