Pictured: This Brown Creeper was the last bird banded in our Fall Migration Monitoring program, 2020.
After a week of high winds and few birds, on September 30 the Lesser Slave Lake Bird Observatory completed the 2020 Fall Migration Monitoring season. And what a season it’s been! With approximately 3,944 birds banded (Table 1), this has been the busiest fall for captures in our 27 years of mist-netting.
With so many birds banded there were of course some oddities. Although we see them infrequently in the spring, we captured our first Gray Catbird during fall migration monitoring. Nashville Warblers also make this list. Range maps for this species suggest they are not found in Alberta, but we capture one or two every few years at the station. This year we captured an astonishing five Nashville Warblers!
Pictured (right): Gray Catbird banded this year. Although typically an uncommon visitor for our station, this year both spring and fall saw a few individuals on a handful of days.
Likewise, several other species broke their previous banding records, including Canada Warblers with 186 banded, surpassing the former record of 163 set in 2018. This species is designated as At Risk due primarily to habitat loss on their wintering grounds in South America. It is encouraging to see their numbers potentially on the rise.
Alongside these unusual captures were some exciting sightings. Among them was a Golden Eagle. Although juvenile Bald Eagles are commonly mistaken as Golden Eagles since it takes them about five years to get the characteristic white head and tail, Golden Eagles are actually quite uncommon locally. In fact, on September 21 we spotted our first Golden Eagle since 2001 and only the sixth Golden Eagle we have recorded in 27 years of nearly daily monitoring efforts in the fall.
Pictured: Commonly seen flying in large flocks over the canopy, Cedar Waxwings infrequently find themselves in our nets. With 30 captured, this species broke their previous banding record.
This fall we also recorded a species that we had never seen before at the station – a White-winged Dove! With a native range only extending as far north as Texas, this seems to be an impossible sighting at first glance. However, there have been occasional sightings of this species in Alberta with one bird causing a stir in June 1997 and other in 2019 when they visited Slave Lake residents’ backyards. Although I have heard this species may have historically been released in Southern Alberta for sport, this has been difficult to verify and I cannot easily explain why this bird found its way so far north. [The italicized section was edited on October 13, 2020]
The only monitoring program left to complete is Owl Migration Monitoring focusing on Northern Saw-whet Owls and Boreal Owls. This year has been slow, with only 48 Saw-whets and one Boreal banded so far. Unfortunately the recent windy conditions have interfered with this program as well. Hopefully things pick up before owl monitoring is concluded at the end of October.
Disclaimer: The numbers discussed are likely to change as I correct minor tallying mistakes – stay tuned for the official numbers in our Annual Report coming this winter.
By Robyn Perkins
Table 1. In order of capture frequency, the unofficial total number of individuals banded and total recapture records for the 2020 Fall Migration Monitoring season, with species that broke their previous fall banding records bolded.
|White-crowned Sparrow (Gambell’s)||12||0||12|
|American Tree Sparrow||6||0||6|
|Black-throated Green Warbler||5||0||5|
|Western Palm Warbler||4||0||4|
|Cape May Warbler||1||0||1|
|Le Conte’s Sparrow||1||0||1|
|TOTAL (60 species)||3944||313||4257|