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Quoting nancy dowd <nancypdowd@gmail.com>:
> On the Big Lots Rd, Northwest, Lun Co, there was a steady quacking
> of Wood Frogs late yesterday afternoon. Their dark egg masses were
> everywhere along the dirt road- in ditches, large and small
> puddles and even in shallow tire ruts. The latter two locations are
> quite a gamble unless we continue to have wet weather. Or is it
> possible for Wood Frog eggs to tolerate some degree of drying out?
* no, they just lay in the "best available site" as judged by them at
the time (they're never more than 10cm above the ground). This spring
we've got a chorus here that usually breeds in a nice Red Maple swamp,
but this year, with an unusual thawing process, they're calling from a
flooded area in a harvested Soybean field, which will almost certainly
dry up long before the tadpoles are ready to transform.
We call what you describe "rut breeding" and in Ontario it seems to be
characteristic of El Nino springs, which seem to have early warm
spells without much rain, so that little rut-like waterbodies are
thawed before the breeding ponds.
see - http://fragileinheritance.org/documents/RESULTS_Cochrane.pdf -
"In 1983, the first El Nino spring that we were aware of as such, cold
and warmth alternated so abruptly that eggs were laid in flooded tire
ruts all across Ontario, from the Niagara Peninsula to our study site
at Long Lake, south of Cochrane (48.91606N 80.97202W; see Weaving a
fabric of sound, FWS, 2001. Trail and Landscape 35(1):8-11). Again in
the El Nino spring of 2002, on the James Bay Expedition, we found that
'Most auditory records from 14-16 May around Cochrane, and at
Moosonee, were index 3 choruses, but these were not actively breeding
congresses, as the choruses could not be approached, and no
concentrations of egg masses were laid at those chorus sites that
could be visited during daylight. Scattered egg masses were laid in
the ruts along the track at Long Lake.'
"In 2010, temperatures in the first days of April reached 27°C around
Cochrane, well before lakes, or ponds the size of those where Wood
Frogs breed, were thawed. We presume that this led the frogs to move
overland and lay eggs in tiny bodies of water such as tire ruts.
Subsequent cold temperatures froze these eggs, which were in a
granular tapioca-like condition, bright green with colonizing algae,
when we surveyed them. Crystal marks on the bottoms of puddles in the
road at Long Lake suggested that small waterbodies had frozen to a
depth of 10cm. A few eggmasses, that presumably had been laid
subsequently, had hatched, or developed towards hatching, though
without a sufficient volume of water in the ruts there couldn't be
much expectation that they'd persist through the summer to
transformation.
fred.
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Frederick W. Schueler & Aleta Karstad
Bishops Mills Natural History Centre - http://pinicola.ca/bmnhc.htm
Mudpuppy Night in Oxford Mills - http://pinicola.ca/mudpup1.htm
Daily Paintings - http://karstaddailypaintings.blogspot.com/
South Nation Basin Art & Science Book
http://pinicola.ca/books/SNR_book.htm
RR#2 Bishops Mills, Ontario, Canada K0G 1T0
on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W
(613)258-3107 <bckcdb at istar.ca> http://pinicola.ca/
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