Week 7: What The Fluff!? - Spizella's smallest sparrow visits Rocky Point

01-07 September

Less than one month has passed since I arrived in Metchosin to work at Rocky Point’s two migration stations. Since then, I have had the honor of seeing many birds that were new in the hand including Hutton’s Vireo and Red-breasted Sapsucker. While new birds are always a treat, I have most enjoyed observing variation in morphology among the species already familiar to me. The Rocky Mountains, Cascades, and Sierras divide western North America’s breeding zones and migratory routes. Over time, species adapt to their local environments and population pressures. This results in differences in size, color, and pattern within a single species across their range. Seeing new subspecies and color variations of Song Sparrow, Swainson’s and Hermit Thrush, Orange-crowned Warbler, and Fox Sparrow has been a wonderful opportunity to expand my understanding of these species. 

Song Sparrow from RPBO 🖼: Megan Miller

Song Sparrow from Fountain, Colorado Fall 2014 🖼: Megan Miller

The photos to the above are both Song Sparrows! The top was captured here at the Rocky Point last week while the lower image was taken in Fountain, Colorado in fall of 2024. Song Sparrows from Victoria forage in deep thickets and dark forest floors. On the east side of the Rockies, Song Sparrow forage along streams, shrubby willows, and gardens. Their coloration helps break up their silhouette while they forage. 

Pedder Bay

This week at Pedder Bay we caught 309 new birds and 53 recaptures. Captures were dominated by White-crowned Sparrows and Swainson’s Thrushes. The top ten species on the graph above make up 74% of our captures this week.  Highlights include Pedder Bay's first Ruby- and Golden-crowned Kinglet captured for the season. 

Ruby-crowned Kinglet 🖼:Sonja Futehally

Rocky Point

Rocky Point banded 520 new birds this week and processed 98 recaptures. White-crowned Sparrow shares 1st place as most banded species at both stations, followed by a surprising uptick in Savannah Sparrows! Rocky Point had many weekly highlights including Cassin’s Vireo, two Clay-colored Sparrows, Western Sandpiper, and Least Sandpiper. Again, the top ten most banded species made up 73% of total captures.

The first Western Sandpiper (left) to be banded at Rocky Point since 1999, and only the fourth-ever Least Sandpiper (right) to be banded here, following three last year 🖼: Andrew Jacobs

Strange Brew

I have spent many seasons banding and birding in the high plains and deserts of Colorado and Utah. The sparrows that dominate these dusty habitats look as if they themselves sprang from the sandy soil. No sparrow represents that more accurately than the Brewer’s Sparrow. Small and somewhat nondescript, in the fall adults can be so worn that their major plumage features can be undeterminable. This was not the case for the unique capture from Rocky Point this past Sunday. A “taverneri” AKA Timberline Brewer’s Sparrow graced the banding station. The Timberline Sparrow has darker features, a stronger facial pattern and differences in song structure. This allows them to blend with darker vegetation and rocks of their north range. Typical "breweri" Brewer’s Sparrows have a less distinct facial pattern but has maintained a strong complete eye-ring.  This is the first ever Brewer's Sparrow to be banded at Rocky Point.  

"Timberline" Brewer's Sparrow at Rocky Point (7th September)

"Breweri" Brewer's Sparrow- Colorado Springs, Colorado, USA 🖼:Julie Shieldcastle

As the season continues, a noticeable shift in species composition is beginning to occur. Fox Sparrow numbers have increased and both stations are catching kinglets almost daily. I am looking forward to watching summer slip into fall and I’m eager to see what the change of season brings with it.