I found this recently killed
Golden-crowned Kinglet at Tommy Thompson Park in Toronto on 14
October 2017. Giant Burdock trapped this Golden-crowned Kinglet in
its barbed seed head. The more the kinglet struggled to get free the
more entrapped it became, until it finally succumbed.
The culprit is either Giant Burdock
Arctium lappa or Common Burdock Arctium minus, non-native
invasive plants, introduced from Europe. We need to do more to get
rid of this deadly plant. Tommy Thompson Park on 14 October 2017.