Grandview Cemetery, Fort Collins (Larimer) on 3Oct2020

[DAVID A LEATHERMAN]

[I tried sending this twice last night with three photos and apparently it didn't go thru.  It showed up in my "sent" files but I never saw it in my in box per normal.  Not sure what happened.  Let's try again with a two-photo version.]

All the "action" today at Grandview Cemetery in Fort Collins was in hackberry trees because of the on-going emergence of hackberry gall-making psyllid insects.  Two types of galls are present, nipplegalls and blistergalls.  I believe the overwhelming majority of psyllids drawing the attention of several bird species were the smaller blistergall-making species.  Birds nitpicking on the gnatlike adult psyllids were: 5 warbler species (orange-crown (1), yellow-rumped (at least 6), Wilson's (1), Townsend's (2) and a nice Nashville (I believe found by John Shenot and told to me by EJ Raynor (thank you both); chipping sparrows, black-capped chickadees, brown creepers, red-breasted nuthatches, downy woodpecker, ruby-crowned kinglets and house finches.  Out of the 18 species observed at the cemetery today, fully 12 of them were feeding on psyllids.  I would not be surprised if two other species (mountain chickadee and northern flicker) were eating them, too, I just didn't observe this.  After standing under the trees for over an hour, my jacket was covered with dozens of psyllids.  They were on the ground, headstones, leaves, trunk bark, everywhere.  Their mission is to find overwintering sites in bark crevices.  Hackberry bark is OK for them, spruce bark even better.  As the emergence proceeds and the adults begin finding such sites, the birds will follow them.  If things go like normal, the initial feeding frenzy is in hackberry, and in a few days it will be a little harder to witness as the birds follow the insects into the dark interior of large conifers.  At Grandview in the past, birders following the birds that are following the psyllids has resulted in discoveries of goodies like Blackburnian, Cape May, Yellow-throated, Northern Parula, Black-throated Green, Palm, Tennesee, other Nashvilles, Golden-crowned Kinglets, and, well, you get the idea.

         

Suffice it to say, if you can identify a American (aka Northern) Hackberry in your urban birding haunts over the next week (or a Netleaf Hackberry in your native habitat haunts), I would check them for migrant songbirds.

Dave Leatherman

Fort Collins

[DAVID A LEATHERMAN]

All the "action" today was in hackberry trees because of the on-going emergence of hackberry gall-making psyllid insects.  Two types of galls are present, nipplegalls and blistergalls.  I believe the overwhelming majority of psyllids drawing the attention of several bird species were the smaller blistergall-making species.  Birds nitpicking on the gnatlike adult psyllids were: 5 warbler species (orange-crown (1), yellow-rumped (at least 6), Wilson's (1), Townsend's (2) and a nice Nashville (I believe found by John Shenot and told to me by EJ Raynor (thank you both); chipping sparrows, black-capped chickadees, brown creepers, red-breasted nuthatches, downy woodpecker, ruby-crowned kinglets and house finches.  Out of the 18 species observed at the cemetery today, fully 12 of them were feeding on psyllids.  I would not be surprised if two other species (mountain chickadee and northern flicker) were eating them, too, I just didn't observe this. 

                                                

            Chipping Sparrow juv and adult nipping adult psyllids from a headstone near hackberry tree.

     

                                    

In this cropped view you can see the blistergalls (off-color rectangles on the leaves) and white pupal skins of recently emerged adult blistergall psyllids.  Birds like this Yellow-rumped Warbler can usually get several adult psyllids from one leaf during days like today when emergence is in high gear.

Suffice it to say, if you know what a hackberry looks like, I would check them over the next week. 

Dave Leatherman

Fort Collins