As we enter the third week of May, the golden hued Grey Fox mayfly begins to hatch on our Ontario streams. And the Grey Foxes are like gold to the fly angler as they are a big enough meal to attract even the largest trout to the surface. With a good artificial and a good presentation, the table is set for some great dry fly action during the three weeks of the Grey Fox hatch.
For the longest time, entomologists recognized two early season mayfly hatches which both involved the Stenonema genus. The March Brown hatch was associated with the Stenonema vicarium species, while the Grey Fox hatch was associated with the Stenonema fuscum species. Now, however, the entomologists have realized that what were described as two species are actually the same species and have eliminated S. fuscum in favour of S. vicarium. But fly anglers seem to prefer the Grey Fox moniker for the hatch rather than March Brown, so Grey Fox has stuck.
More recently the entomologists have been at it again and most of the mayflies that use to belong to the Stenonema genus, including vicarium, have been reclassified to a new genus, Maccaffertium–named after Purdue University professor of aquatic entomology, Patrick McCafferty.
The Grey Fox nymph is an example of a clinger type nymph in that it lives in the faster water in a stream where it clings to the bottom of rocks. The nymph’s flattened, streamlined body and stiff legs make ideally suited to its habitat. The natural is yellowish in colour with brown markings, including distinctive lines on its legs, and it has three tails. I tie a yellow artificial nymph to match the natural. I weight the artificial by tying in two pieces of lead wire on either side of the hook shank and then flatten the dubbed rabbit fur body by wrapping the thorax with gold coloured wire. The nymph pattern can be fished by either casting into the shallows downstream where the current will take the fly into faster water and cause it to rise to the surface, or it can be cast into faster water and directed into the shallows. This latter approach is a good one to try when it comes to the Grey Fox nymphs since they tend to migrate into slower, shallower water a few days before they hatch.
The Grey Fox nymphs rise to the surface of the stream where their nymphal skin splits at the wing case and the dun crawls out. If the weather is cool, the hatching of the duns will be heavier during the warmer part of the day, but as the end of May stretches into the beginning of June and the weather becomes generally warmer, the duns will be hatching throughout the day. The Grey Fox dun is creamy gold colour with brown tones and has only two tails as opposed to the nymph’s three. The dun’s legs are creamy coloured with the distinctive brown lines displayed by the nymph still present. Its wings are slightly translucent with some creamy yellow colouration and thin black vein-like markings. I match the Grey Fox dun with a size 10 Comparadun or Haystack pattern. This style of dry fly is tied without hackle wound at the throat, so it floats low in the water and presents a more realistic silhouette. I dub urine stained belly fur from a vixen fox for the body of the fly. This body material was made famous in a classic style dry fly recipe developed by American, Preston Jennings in the 1920’s. Remember that a trout typically will not move far to the right or left to take a fly, so try to cast directly upstream of a rising fish. Usually I target an area about four or five feet upstream because this distance provides some forgiveness if my presentation is not as fine as it could be.
The newly emerged Grey Fox dun then flies off to the safety of streamside vegetation where it moults into a sexually mature spinner by shedding its dun skin. The Grey Fox spinners are the same basic colour as the duns, although the colours are sharper and less creamy and the wings are now transparent, but with the same black vein-like markings. The Grey Fox spinners appear at dusk to do their spinner dance and mate. After mating the females extrude an egg ball at the end of their abdomens and deposit the egg ball in the stream by dipping their abdomens in the water. The female spinners then fall to the surface of the stream to join the already expired males, producing another great feeding opportunity for the fish and another great fishing opportunity for the angler. When the spinners initially fall to the surface of the stream they don’t necessarily assume a spent wing position. Consequently, I keep fishing a Compardun pattern until it seems not to be working and only at that point will I switch to a size 10 spent wing pattern.
Grey Fox Nymph Recipe
Hook: nymph No. 10, 2X long
Thread: yellow, 6/0
Weight: strips of lead wire on either side of hook shank
Tail: wood duck feather filaments
Body: yellow rabbit fur dubbing
Ribbing: gold coloured wire
Wing case: pheasant tail wing segment
Legs: wood duck feather filaments
Grey Fox Comparadun Recipe
Hook: dry fly, No. 10
Thread: yellow, 6/0
Wing: deer hair
Tail: deer hair
Body: dubbed urine stained belly fur from a vixen fox
Grey Fox Poly Wing Spinner Recipe
Hook: dry fly, No. 10
Thread: yellow, 6/0
Tail: deer hair
Body: dubbed urine stained belly fur from a vixen fox
Wings: white polypropylene yarn
Dan is a fly fishing and outdoors writer who has been writing about the outdoors since 1983 when he first had an article published in Ontario OUT OF DOORS magazine. He was the magazine’s fly fishing editor from 1998 through 2015. Dan enjoys fly fishing in all its dimensions, from the heritage, history and literature of the sport, to fishing for trout and alternate species. He has been an adjunct lecturer in outdoor recreation at the University of Waterloo. In 2008, Dan won the Greg Clark Award for outstanding contributions to the arts of fly fishing at the Canadian Fly Fishing Symposium. He has been a popular guest speaker at fly clubs across the province, at the Canadian Fly Fishing Forum and at the Grand Opportunities Fly Fishing Forum and has been a fly tying instructor at the Canadian Fly Tying Symposium. Dan retired in 2019 as the Director of Engineering and Planning Services for the Township of Woolwich. Dan has also been a long time member of the KW Fly Fishers and in 2020 he became the President of the Club. Dan lives in Rockwood with his wife Jan, cats Tiger and Finnegan, and golden retriever Mitchell.