Here is some information I received from an entomologist friend about what the warblers might be eating:
When you first wrote tiny gray insects, I thought of springtails, http://www.extension.umn.edu/distribution/horticulture/M1305.html. But when you said associated with elm, they are probably gall midge larvae, http://blog.lib.umn.edu/efans/ygnews/2010/05/little-worms-under-elm.html. These larvae usually get described as reddish or yellowish but I have received a few reports of them this spring. While I would doubt birds would eat springtails, they could be interested in these larvae. They are a short-termed event though, lasting maybe a few days. Best regards, Cyndi Elias ________________________________ From: Diana Doyle <di...@managingthewaterway.com> To: MOU-NET@LISTS.UMN.EDU Sent: Mon, May 16, 2011 11:02:23 AM Subject: [mou-net] Ground-feeding warblers The ground-feeding of canopy warblers under elm trees continues: This morning Lake Nokomis's sidewalks included large numbers of yellow, palm, yellow-rumped, tennessee, black-and-white, magnolia, and chestnut-sided all feeding on the pavement. Within the past couple of days I've also seen common yellowthroats, cape may warblers, and even northern waterthrush pavement-feeding. So this morning I checked where a large flock was feeding. I could see very tiny oblong gray insects moving on the concrete. They were very very tiny. Perhaps this is what the warblers are eating? Anyone have any ideas what kind of insect they may be? Presumably they are associated with the elms? Diana Doyle S. Minneapolis ---- Join or Leave mou-net: http://lists.umn.edu/cgi-bin/wa?SUBED1=mou-net Archives: http://lists.umn.edu/archives/mou-net.html ---- Join or Leave mou-net: http://lists.umn.edu/cgi-bin/wa?SUBED1=mou-net Archives: http://lists.umn.edu/archives/mou-net.html
