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Volume 26, Number 4
261
LIMENITIS LORQUINI (NYMPHALIDAE) ATTACKING A GLAUCOUS-WINGED GULL
Readers of the encounter between a Monarch and a Red-winged Blackbird reported by Slansky (1971, J. Lepid. Soc. 25:294) may be interested in a similar pugnacious interlude. This occurred on the warm and sunny morning of 4 July 1970, in Beacon Hill Park, Victoria, British Columbia. On that day, along with lepidopterists JoAnne Pyle, H. Whetstone Pyle and Chuck Dudley, I was photographing butterflies for a work on the fauna of Washington. We were drawn into an ornamental rose garden by a superb, fresh Limenitis lorquini burrisonii Maynard. The Admiral, a male, was sunning on the roses and soaring slowly around the garden. There were no nectar sources, no female lorquini, nor any other attractants in view.
The butterfly was exceptionally approachable, more so than any others of its species I had encountered before. Photographing it presented little difficulty. Indeed, the "friendly" creature crawled onto my fingers and landed upon many bemused visitors to the garden. Despite considerable human activity in the area, the lorquini maintained this "tame" behavior. Then a sound, which had been constantly in the background, came nearer. A shadow passed over the garden as a Glaucous-winged Gull appeared from behind the crowns of a Douglas Fir wood. Suddenly, as the gull came directly overhead at a height of 20 to 30 feet, the Admiral darted up from his rose-blossom perch and accosted the gull. Again and again lorquini darted at the huge bird, never descending until the gull quit the area.
This remarkable spectacle occurred several times in a half-hour period. On each occasion, the pale seabird entered the arena of action and began to circle, only to be immediately enjoined by the Lorquin's Admiral. The height of engagement was consistently the same as Slansky reported for the Monarch and the blackbird—from 20 to 30 feet. Unlike the Red-winged Blackbird, however, this gull did not seem to react to what I interpreted as the butterfly's aggression. It called raucously, but no more than before or after the encounter; and it seemed to depart volitionally and not under stress. The gull made no attempt to deter or eat the Admiral.
Why was the lorquini indifferent to other movement through the garden, yet so demonstrative toward the seagull? One may speculate that the bird was recognized as a potential foe, rival male, or mate, and that the appropriate behavioral response was elicited. Attacking a potential predator would not seem very adaptive for a butterfly, and where I have seen male lorquini together before, they have passively coexisted. Therefore, the possibility of a courtship chase would seem most likely. Butterfly males have been known to pursue experimental super-female models: perhaps the same sort of perception and reaction was seen here.
It would be pleasing to see more ethological notes in this journal. I feel that, in regarding butterflies strictly as specimens for acquisition or research, we often ignore events which render these organisms fascinating in a living context: events such as this encounter between an Admiral and a seagull, which was just slightly less intriguing than a well known episode involving another kind of seabird, an albatross, and an aged seafarer.
Robert Michael Pyle, Monks Wood Experimental Station, Abbots Ripton, Huntingdonshire, England.