Team Shrub guest blog – Cameron D. Eckert

It was little more than a flash in the willows, just for an instant and then vanishing, but one that stopped me in my tracks. Could that have been a hummingbird?

Qikiqtaruk is rapidly changing, and nowhere is that more evident than in the vegetation that thinly covers the island. A warming climate has brought earlier green-up, shifts in plant composition, and the expansion of shrubs. Perhaps the question I’m asked most often is how are these changes affecting the bird populations? Many bird species thrive in shrubs, so could more willows be good news? Well, it’s not that simple. Other bird species, such as American Golden-Plover and Ruddy Turnstone, prefer sparse vegetation and bare ground – and these Arctic nesting shorebirds, which face stressors throughout their ranges, have declined sharply in recent decades. Still I’m intrigued by the influence that shrub expansion may be having on Herschel Island’s bird diversity. To explore this question, I now bird the willows along east Ice Creek as part of my regular morning surveys.

Ice Creek, on the northeast corner of Herschel Island-Qikiqtaruk Territorial Park off the Yukon’s Arctic coast, flows with melting snow and ice from the surrounding rolling tundra through an alluvial fan at the base of Simpson Point, and into Pauline Cove on the Beaufort Sea. The east tributary of Ice Creek features some of the island’s biggest patches of willow (Salix richardsonii) – mostly below knee height and sparse enough that I can easily walk through the willows along the creek. Green-up in mid-June rapidly transforms this brown tundra valley into a beautiful green world of willows and wildflowers. And there are birds.

The White-crowned Sparrow, an uncommon breeder on the island, is the species expected to be most responsive to willow expansion. Their clear and distinctive song makes them easy to detect, and this past June I observed two pairs nesting along east Ice Creek, with another singing on west Ice Creek, and one more on the alluvial fan. However, it’s not clear if the population here has changed – it was known to be uncommon in the mid-1980s, though long-term breeding bird surveys conducted by Park Rangers on Simpson Point hint at an upward trend.

Common and Hoary redpolls are also common in the willows along east Ice Creek. Typical of finches, their numbers are highly variable from year to year. Here they’re not dependent on shrubs for breeding, and I’ve found a few nests in drift logs along the beach at Simpson Point. This past June, a pair of Hoary Redpolls greeted me on almost every hike up east Ice Creek. Their chittering songs and calls, and habit of collecting bits of fluff were signs of pair-bonding and nesting building.

My forays through the shrubs have yielded surprises. I’ve come across small numbers of Yellow Warblers and Yellow-rumped Warblers – common breeders on the North Slope mainland, but very rare on Qikiqtaruk. I’ve never heard one singing, and they seem fully occupied with feeding – wanderers to the island, but not breeders. In June I also spotted a female Varied Thrush, just the third island record, feeding along east Ice Creek; as well as an American Robin which is rare but regular on the island.

It was last year, on 19 June 2016, that I found the bird which would firmly enshrine east Ice Creek in my daily routine. Walking through willows along the creek, I flushed a warbler that flashed bright yellow undersides, an olive-green back, and dark grey hood. This was an Oporonis-type warbler, and the three possible species would all be an extreme rarity here; so when it landed I focused on its face to check for white eye crescents or lack thereof to confirm which species. It perched low in the willows for just a few seconds and I could see bright white crescents above and below the eye. The first MacGillivray’s Warbler for Herschel Island – 1000 km north of its breeding grounds.

Exactly a year later, on 19 June 2017, I was again walking through the willows along east Ice Creek. Watching, listening, and totally focused, when a tiny greenish flash caught my eye. It darted low to the ground along the edge of the willows. A hummingbird? Inconceivable! Over the next 15 minutes I saw the bird just three times and only for a few seconds, but it’s extremely small size (even for a hummer) and colouration (green back, pale buffy front) immediately brought to mind Calliope Hummingbird. It flew low to the ground, and was extremely hard to spot in the myriad willows. I decided to run back to camp and get my hummingbird feeder (yes, I brought a hummingbird feeder to the Arctic).

I was back and had the feeder set up in the willows within 35 minutes. I sat quietly and waited. Then by chance I looked over my shoulder and saw the hummer perched about 25 metres away. I got a great view and snapped my first photo. Then miraculously, the hummer did a fly by, circled around, and perched in the open on top of a nearby willow. I got great views in full sunlight, and much better photos. It vanished again into the willows. I carefully scanned the foliage, and there it was, just two metres away, but well hidden. I lined up a view through the branches and took a few more photos. Moments later, it flew again and appeared to be feeding on willow flowers. Then it disappeared. That was my last view of the hummer, and it never went to the feeder. My initial impression was confirmed – this was an adult female Calliope Hummingbird, the first for the Yukon and the Arctic. A staggering 1,800 km north of its breeding range.

It would be simplistic to dismiss such rarities as inconsequential, as their occurrences may well be early indicators of changing bird populations. Over time these well-documented records can reveal unexpected patterns.  I’ll continue exploring Ice Creek, tallying the familiar birds, and carefully watching for the next surprise visitor to Herschel Island.

Cameron Eckert is an ecologist who has studied the birds, wildlife, and ecosystems of the Yukon’s North Slope and Herschel Island for the past 25 years. As Conservation Biologist with Yukon Parks, he works with Qikiqtaruk Park Rangers to coordinate the island’s ecological monitoring program.

Herschel Island bird observations can be viewed or downloaded at www.ebird.org.