1998-1999 Mudpuppy Nights in Oxford Mills

Field notes of Frederick W. Schueler: 1998-1999 Mudpuppy Nights in Oxford Mills, Kemptville Creek, North Grenville Township (Oxford-on-Rideau geographic township), United Counties of Leeds and Grenville, Ontario, Canada

This was the first winter of regular Mudpuppy Night outings, and light was provided with relatively feeble incadescent headlamps. Text output from the EoBase database; UTM grids NAD27 Canada in military grid notation, lat/long WGS84 (=NAD83).

28 December 1998

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 1600. AIR TEMP: 2 ca, clear, breezy. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W. Schueler. 98/245/b, visit () (E). nat.hist., walk. water high, little ice over water. There's no way Necturus could be seen from the 'usual vantage point' with this much water coming over the dam. There's a step in the ice fringing the shore, and the upper level dformed whern the water was 20 cm higher than it is now. The step is a series of smooth knobs, and the spillways are partly filled in with graceful shelves and buttresses of ice. No fresh Unionidae shells visible.

8 January 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2000-2147. AIR TEMP: -7.5, snowing, Beaufort light air. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler, Stew Hamill, Rae Johnson. 99/001/b, visit () (E). nat.hist., walk, wade. First "Mudpuppy Night in Oxford Mills". Sparkling snow flakes sifting down, and the air felt warm, as we pushed through 30-40 cm snow down to the W side of the dam. The spillways are nearly completely sheathed in filigree of yellowish ice and icicles. The shores are shrouded in ice that formed earlier in the winter when the creek was higher, a final flat, 10-15 cm deep, very slippery-smooth, that formed over about half of the width of the creek in the last cold snap, and a foot-wide bead-margined fringe, ca 3 cm thick.

At first we didn't see any Necturus, so FWS set about clearing ice with the axe, splitting away 1 x 2 m chunks without much trouble, in part because the water had fallen since the ice formed. The ice at the ledges that are the shore here was as much as 10 cm above the current water level.

The ice forms where the current is made up of eddies, so to see the bottom we had to clear floating chips of ice from areas where we had chopped the ice shelf away, and the water felt warm to the fingers. After the ice that shouded the 'usual vantage point' collapsed under him, FWS was bolder about wading, and crossed the stream a couple of times, though we didn't try to clear any ice on the east side.

To amphibian monitoring lists: This winter our museum and a local cafe [Maries' Treats & Treasures] are sponsoring weekly counts of Necturus maculosus in the flat limestone bedrock creek below an old mill dam at night. We can see 5-60 Mudpuppies on any night, walking up through the current or prowling the bottom. We've been aware of this nocturnal winter activity for several years (Anonymous (=F. W. Schueler). 1993. Mudpuppies under ice. Ontario Herpetofaunal Summary Newsletter, April 1993:3-4. ), and we've wondered what they are looking for (Sex? Food?. . . ), and why they seem, anecdotally, most numerous on the coldest nights.

[Tonight] we watched one eating a crayfish, and saw what looked like Insect and fish body parts in the eddies below the dam, and it occurred to me that the Necturus may be after animals stunned or killed by their passage over the dam, and that this food might be most abundant on the coldest nights.

On alternate weeks, I propose to put punctured tins of sardines below the spillways, on the assumption that if the Necturus are attracted by food stunned by passage over the dam they'll also be attracted to sardines, and compare numbers on baited or unbaited nights. I wonder if anybody else has studied Necturus in a similar situation, and has formed or rejected hypotheses about this kind of activity? FWS.

(same location) TIME: 2000-2147. 99/001/ba, Necturus maculosus (Mudpuppy). 10 ca adult, walk, wade. moving upstream through main current blw dam. From the 'usual vantage point, ' 1 seen 3 times or 3 seen once (ca 20 cm TL). Water levels are down to the point where this ledge is a plausible vantage point again.

Most were in the main current of the stream, 25-30 cm depth, slowly walking upstream (evidently clinging by toeholds to irregularities in the bedrock), or occasionally being tumbled down stream. We netted 2, the larger 26 cm TL, which was likely the largest we saw. There were none in the quieter water under the shelves of ice that we cleared away.

The first AKS spotted was almost coppery-looking in the brown water and warm light of the headlamp, against the rich green carpet of algae on the bedrock floor of the creek. After the first one we soon saw several more, all heading upstream. It was hard to scoop them up in the frozen net, but FWS waded into mid-stream, and hand-coaxed the largest one we had seen into the net.

The movement of one, ca 17 cm TL, caught AKS' and JHS' attention, jerking its head, grappling with a 20 mm TL Orconectes virilis, which eventually escaped with a quick flip.

When FWS released the netted ones at 2200 hr there were about the same number active, but some had moved out of the main current into the eddy areas that had been covered with ice before we cleared it.

(same location) TIME: 2000-2147. 99/001/bb, Ameiurus nebulosus (Brown Bullhead) (fish). 30 ca juvenile, seen. in eddies blw dam, where ice cleared away. This year's little Catfish and minnows and stuff that looked like broken animal parts swirling under the ice where we have cleared it away. ". . . lovely baby catfish, their distinctive long-whiskered big-headed shapes curving, and waving their tails. . ." [AKS]

(same location) TIME: 2000-2147. 99/001/bc, Rana cf catesbeiana (Bull Frog) (herp). 3 larva, seen. over-wint. tads, in eddies blw dam, where ice cleared away. ". . . large tadpoles, sluggishly wagging their tails and nosing about the the short algae tufting the stone bottom" [AKS].

(same location) TIME: 2000-2147. 99/001/bd, Rana clamitans (Green Frog) (herp). 1 adult, walk, wade. ca 65 mm SVL, motionless on bedrock bottom in 30 cm water. This was at a site where we had cleared ice cover away, originally ca 1 m from edge of ice cover. ". . . sitting perfectly motionless, slightly hunched, just the colour of the bottom, like a carving of a frog on a rock" [AKS].

(same location) TIME: 2000-2147. 99/001/be, Orconectes virilis (Northern Crayfish) . 1 juvenile, prey of predator, seen. ca 2 cm TL, prey of Necturus, in 30 cm water, escaped.

13 January 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2122-2137. AIR TEMP: -26, clear, Beaufort light air. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W. Schueler, Anita Miles. 99/004/c, Necturus maculosus (Mudpuppy). 25-30 adult, seen. moving upstream through main current blw dam. Water below dam steaming, all the ice we cleared away before (99/001/b) reformed, though thin near the shore (broke under my weight), and only thinly snow-covered. The sky was very clear, even here among the village lights. We didn't bring an axe, and the 'usual vantage point' was covered by a 1. 2 m wide lobate sheet of new ice, so we couldn't count there.

We were able to observe only from the 10 m or so on the west bank which we cleared before. The Necturus were all heading upstream in the strongest current, which seemed to pass under the shelf of ice we were on, all very parallel, a few tumbling downstream, and a couple swimming in place, so if we had had the sense to measure the speed of the current we would have estimated the swimming speed of mudpuppies at 0 C. There were a number of pairs lying side-by-side and parallel together, almost or actually touching.

15 January 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2005-2040. AIR TEMP: -10.5, snowing. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler, EOBM group. 99/002/b, Necturus maculosus (Mudpuppy). 30 ca adult, seen. moving upstream through main current blw dam, wind calm. Light snow falling through visit, and about 60 cm of snow on the ground from the recent storms. The spillways of the dam are completely shrouded with new snow, so the water boils out horizontally from the bottom of what appears to be a drift. The ice shelf on the west shore is about 10-15 cm thick, though still thin right at the shore, and slushy over its entire surface. The area where we trampled the slush will doubtless freeze solid. I cleared about 2 sq. m. of ice from the edge of the shelf, and again there aren't any Necturus under it.

The Necturus are again moving upstream, and the usual assortment of sizes. Five were visible from the vantage point, after I cleared about 1. 5 sq. m. of ice shelf away. The surface is too turbulant to see a lot of behaviour, but our lights weren't very bright.

We only saw a very few Ameiurus nebulosus, certainly not the swirls under the cleared shelf ice that we saw last week, and NO:Rana tadpoles.

(same location) TIME: 2230-2240. AIR TEMP: -10.5, snowing. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler. 99/002/c, Necturus maculosus (Mudpuppy). 30 ca adult, seen. in eddies & main current blw dam. Weather conditions the same as earlier. In the eddies, as in the main current, some of the Mudpuppies are close together, but the one pair we watched for a while didn't stay associated for long. We came down here to measure the speed of the main current, which was 0. 35-0. 52 sec/m at the surface, averaging 0.42 seconds, or 2.4 m/sec. Since swimming Necturus can just barely maintain their position in this current, though nearer the bottom, we can estimate their sprint speed in turbulent 0 C water as 2 m/sec.

19 January 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 1042. AIR TEMP: 1 ca, overcast, windy. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler. 99/003/a, visit () (E). nat.hist., drive. water little higher than Fri., spillways still ice-sheathed. There is so little increase in water level that the melt must be mostly contained in the snowpack. The ice shelves are still intact, and the 'vantage point' above the surface.

23 January 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2140-2201. AIR TEMP: 8, rainy, breezy. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W. Schueler, Anita Miles. 99/006/b, visit () (E). nat.hist., walk. much increased flow, vantage point 20 cm deep, ice rotten. Too deep to see Necturus, due to the vastly increased flow. FWS fell through the rotten ice shelves a couple of times. The current is too strong for Necturus to hold its place below the spillways. Water temperature 0 C.

29 January 1999 data entry incomplete

5 February 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2003-2030. AIR TEMP: -11, clear, calm. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler. 99/012/a, Necturus maculosus (Mudpuppy). 2 adult, wade, dipnetted. water high, ice melted back, seen from E shore & in eddy. 1 ca 24 cm ad netted as it swam up to the surface in ca 90 cm depth. And another seen in similar depth. None seen from W shore: 19 cm water over the 'vantage point, ' ice shelves melted back almost to shore (except for a big berg stuck in the central eddy) and reforming now. No fish or other Animals seen.

8 February 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 1242. AIR TEMP: 3, sunny, breezy. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W. Schueler. 99/013/b, visit () (E). nat.hist., . 15 cm yellow water over vantage point, spillways ice free. Narrow thick new ice shelves, very slippery on west shore.

12 February 1999 data entry incomplete

15 February 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 1947-1958. AIR TEMP: -6 ca, clear, calm. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W. Schueler, Aleta Karstad Schueler. 99/015/c, visit () (E). 0 nat.hist., seen. NO:Necturus seen, water high, choppy & rough. Water sloshing over Vantage Point, 10-18 cm deep. Couldn't see any Necturus from either shore, but didn't have boots to wade. Whole area clear of ice except a narrow shelf of ice along the W shore, built up 10 cm above present level by previuously higher levels.

19 February 1999 data entry incomplete

26 February 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 1959-2129. AIR TEMP: -2, clear, calm. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler, Laurie Consaul. 99/016/aa, Necturus maculosus (Mudpuppy). 20 ca adult, dipnetted, wade. 4 from Vantage Pt, most in E side eddy, little ice, full Moon. Narroww, slippery slabs of ice along the shore. We heaved one off the Vantage Point and found it barely awash, and saw 4 Necturus here in the swirling water, and several more from the west side, but most were in 15-70 cm deep eddy on the E side. None were large, dipnetted 4, ca 20 cm TL.

(same location) TIME: 1959-2129. 99/016/ab, Lethocerus (not listed) (entomological). 1 adult, dipnetted, wade. in E side eddy, little ice, full Moon. Laure also dipped up one cf Notropis, TL ca 8 cm, among a dozen seen, but it never got identified.

5 March 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2013-2044. AIR TEMP: -15, clear, calm. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler. 99/017/b, Necturus maculosus (Mudpuppy). 1 adult, seen. medium-size, crawling among rocks on in E-side eddy. Shelves of newly formed ice along W shore. I chopped off ca 1 m loose half-snow shelf from over the vantage point, 12 cm of water over the vantage point, no Necturus seen there.

The scene is dominated by the effects of the rapid return of the cold. A mist rises from the creek, and is like a thunderhead above the open spillways, hoar-frost snow flakes are growing from twigs and branches on the shore, tiny floating sparkles falling from the black starry sky, icy flakes like slush floating in the eddy, and small islets of frozen foam circling in the eddy.

A 3 m wide flat island formed from the floating ice in the big eddy, and when net-pushed out into the eddy it slowly circled almost down to the bridge, and then almost up to the dam before returning to the centre of the eddy. It was hard to see the bottom because of the steam on the surface and the flakes of ice in the water, and the water is perhaps murky from the recent thaw/freeze. saw one ca 8 cm fish.

12 March 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2011-2046. AIR TEMP: -7, snowing, calm. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler. 99/018/a, Necturus maculosus (Mudpuppy). 12 ca adult, seen. mostly small, under ice, water high, anoxic stink. About 12 cm of water over the Vantage Point. Shelves of ice and spillways mostly covered with 'snowy' ice. I cut away a 1. 5 m wide slab of ice from the W shore, and saw 5-6 Necturus under the slab just as it moved (including 2 that were tumbling in the current as if it was too fast for them). On the E shore we saw 6-7 more in the eddy, no solid shelves, but a mass of flakes floating in the eddy. All Necturus were small (>=20 cm). Is this because the current is so fast, or because the big ones are engaged in some aspect of breeding or territoriality?

19 March 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2007-2030. AIR TEMP: clear, breezy. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W. Schueler, Jennifer Helene Schueler. 99/024/a, Necturus maculosus (Mudpuppy). 2 adult, seen. medium-size, among rocks on in E-side eddy, 70 cm depth. Ice gone from spillways. Water sloshing up over the shelves of ice along the W shore, and 15-20 cm of water over the vantage point: no Necturus seen there.

Many fewer than last week, while water is deeper the viewing conditions aren't bad for this depth of water.

19 February 1999 data entry incomplete

26 February 1999 data entry incomplete

2 April 1999

Oxford Mills Dam, Kemptville Creek. UTM 18TVE 464.5 790.5 44.96486N 75.67863W. TIME: 2140-2210. AIR TEMP: 3, light rain, windy. HABITAT: brown-water creek@limestone flats blw old milldam. OBSERVER: Frederick W., Aleta Karstad, & Jennifer H. Schueler. 99/030/b, visit () (E). 12 ca survey, seen. NO:Necturus, water 0. 5 C, very high & turbulent. About 25 cm of water over ledge *above* the Vantage Point, big standing wave in mid-flow, and strong eddies on each side, and 35 cm surge washing the shores. Trees & bushes along W shore flooded 30-50 cm deep among Fraxinus (Ash) and Rhamnus. Small (30-70 cm) pans of mostly clear eroded ice on W shore, and some old snow.

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