Migration Fallout

Birds Falling Out of the Sky

Summer Tanager

On Wednesday and Thursday, Oct. 26 and 27, the northeast had over 100 mm rain, fog, and winds up to 100 km/h out of the south and southeast.  That severe weather forced a lot of migrating birds to 'fallout'.    When migrating flocks meet severe weather such as heavy rain and/or opposing winds, they look for the nearest landfall and put down.  Here they rest and feed to replenish energy reserves. This rare phenomenon is difficult for the birds but exciting for birders.  It often brings rare species into areas in which they are not normally seen.  For decades birders have made the connection between bad weather and good birding opportunities.

This is exactly what happened in the Passamaquoddy Bay, Bay of Fundy area over the weekend.  Rare birds sought landfall in Grand Manan, Campobello and Nova Scotia.  Flocks of rare species were found in these areas on Friday, Saturday and Sunday.  In some cases there were 12 to 20 individuals seen of species which we don't normally see here.

Birders in these 3 areas found basically the same species, indicating that the flocks were mixed with these same species.  There were likely also smaller flocks of single species.  These birds will likely remain in place for a few days until they have sufficiently fed and the weather provides favourable winds to continue their migration.  

Summer Tanager

Birders in these areas reported the birds feeding furiously on insects or whatever they could find for food.  According to one seasoned birder, Sunday, Oct. 29,  was his 'most memorable [day] for bird rarities all concentrated together'.  Most birders reported the same group of species.

Seen were the following species:  Summer Tanager (as seen above), Yellow-billed Cuckoo, Black-billed Cuckoo, Hooded Warbler, White-eyed Vireo, Yellow-throated Vireo, Cattle Egret, Golden-winged Warbler, Indigo Bunting.  There were dozens of Indigo Buntings.  The vireos were seen in many places.  The Golden-winged Warbler is very rare.  The Hooded Warbler is also very rare here and 8 were seen.  All of the above represent fabulous birding.

Hooded Warbler [Internet Photo]

 A fallout is risky for the birds.  They are forced to put down in unfamiliar territory.  Whether they find food safely is sometimes questionable.  Their safety from predators, pollution, human interference, etc. is a big risk.  It appears the birds that put down here in our area are safe and are feeding well.  

Shown below are two photographs taken by Ralph Eldridge on Machias Seal Island of a fallout of warblers.  A flock had put down because of bad weather and were literally everywhere around the lighthouse buildings.  There are several kinds of warblers in the group.  The warblers left the next day when the weather cleared and the winds were favourable.

Migration Fallout of Warblers on Machias Seal Island [Ralph Eldridge Photo]

Migration Fallout of Warblers on Machias Seal Island [Ralph Eldridge Photo]

I will close with an interesting bird fallout story to illustrate just how extensive this phenomenon can be.  In April, 2013, a team of 6 birders created a record in Texas by seeing 294 species in one day due to a fallout which had occurred in that area due to bad weather and large flocks migrating northward.  Migration is indeed an event of huge magnitude and we can get a small glimpse into it when weather interferes.