Great Invasion of Crossbills in 1909. 337 
held them for a longer period. In those districts where food 
has been plentiful, and the birds have been unmolested, they 
have settled down, and, in many cases, remained for a con¬ 
siderable length of time. The 4 Field ; of December the 4th 
contains an interesting note recording the abundance of 
Crossbills (L. curmrostra) in West Sussex and mentioning 
the fact of a small party of the birds having daily, for the 
space of two or three months, frequented and fed on the 
cones of a large Douglas-fir at Leonardslee, under which 
tree were to be seen quite five barrow-loads of stripped 
cones lying in heaps ! The fir-tract of country in this 
neighbourhood is ideal ground for the species, affording 
abundant nutriment, and it is not surprising that the birds 
should have chosen to linger there so long. 
While on the subject of food, it may be observed that the 
recent invasion has afforded interesting cases of Crossbills 
feeding upon many substances which we should not have 
imagined would enter into their diet, and which under ordinary 
circumstances would probably not do so. In addition to the 
seeds of all species of conifers indiscriminately, the birds have 
been observed feeding on many kinds of orchard fruit, the 
seeds of various grasses and low-growing plants, as well as on 
the actual flowers of some plants and on the Aphids of different 
species. A correspondent writing from Lombardy comments 
on the unusual spectacle of large flocks of Crossbills feeding 
in the open fields in the neighbourhood of Como. As to 
the duration of last year’s Crossbill invasion, it may roughly 
be calculated to have extended over a period of about six 
months, having commenced in the spring and lasted until 
the autumn, although a certain number of the birds appear 
to have remained in some localities much later and even into 
mid-winter. 
As may be gathered from the recorded observations, there 
seems also to have been a considerable variation in the 
date of the first appearance of the Crossbills in different 
countries, but this is not to be wondered at. Allowance must 
be made for the probability, not to say the quasi-certainty, 
of the first arrivals having passed unobserved in many 
SEE. IX.—VOL. iv. z 
