‘Two-tailed’ fish thwarts gull’s ambition
Island Wild for Fri. Nov. 13, 2009


With high hopes, this over-ambitious gull snared a ‘two-tailed’ fish. Photo Jim Dubois.

This photo of a Pacific Staghorn Sculpin shows the branched (cheek) horn, the black spot at the back of the first dorsal fin and the fin banding pattern. Photo Jim Dubois.

The eyes can sometimes be bigger than the stomach. Think of a hungry mob at a smorgasbord or Uncle Albert at Christmas dinner.

In the same way, birds and fish can both be prone to over-ambition when it comes to filling their plates (or in the case of animals – gullets) beyond the point of what they can reasonably handle.

Last weekend, Campbell River photographer Jim Dubois witnessed a splashy scene starring an overly-ambitious gull doing battle with its unwilling prey.

While standing on shore, watching a gull swimming along in shallow water, he noticed as the bird began leaping into the air and diving underwater. This it did a half-dozen times, the last time a bit higher than previous attempts. Successful at last, the gull resurfaced with what resembled a sculpin…gourmet food for hungry gulls.

As the gull reached shore, treasure in beak, Dubois took a closer look through his camera’s viewfinder and noticed the fish didn't look quite right, and seemed to possess two tails. After a few fruitless attempts to get ‘the thing’ down its gullet, the bird left in search of easier prey.

In this case, the seagull’s ambition was thwarted when it could neither swallow nor disgorge the ‘two-tailed’ sculpin. Left onshore, the wild sushi likely ended up as dinner for a larger marine species that would be undeterred by the sculpin’s prickly ‘horns.’

Suspecting a monster of the deep or genetic mutant, Dubois went in for a closer look, and found an eight-inch sculpin that had tried to swallow a four-inch sculpin – now firmly lodged inside the larger fish’s mouth.

Both fish were Pacific Staghorn Sculpin (scientific name: Leptocottus armatus). Folks who grew up on the west coast commonly referred to this large-headed species as a bullhead – for obvious reasons.

This native Pacific Northwest fish possesses a large, branched spine or thorn on each operculum (cheek), which resembles a stag’s horn or antler, thus the name.

As part of Mother Earth’s marine food cycle, gulls feed on small fish, which in turn feed on smaller fish. Oftentimes, the prey become the preyed upon. Mark Steinhilber (Head of Life Sciences, Royal Alberta Museum) confirms that cannibalism is common in most fishes.

Steinhilber has often seen this “bite off more than you can chew” behaviour, with varied outcomes. “Sometimes, amazingly, the prey fish is slowly digested (the tail slowly disappears over a few days) and sometimes the “predator” dies. The opercular spines or horns are considered anti-predator adaptations and I imagine they make swallowing prey a bit more difficult.”

The Pacific staghorn sculpin is a marine dwelling fish measuring 12-15 cm at maturity. Highly recognizable because of its large, flat head, and small eyes, it’s antler-like projections with 3-4 spines are unmistakable. Markings include smooth skin (grayish olive on back, yellow on sides, white on underside), a dark splotch on the tail end of the first dorsal fin, and light barring on the other fins.