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On 4/7/2016 12:00 AM, Stephen Shaw wrote:
> Obviously, the dead ones would have stayed on the road to be observed where they died and could have accumulated over 24 hours (or more, if not scavenged) if Fred surveyed once a day, but probably most of the smaller numbers of live ones that he observed over a few minutes each time actually did manage to cross the road successfully (within a few minutes?), to be replaced by another batch that also crossed mostly successfully (in the next few minutes?). Without knowing the numbers of anurans attempting to cross per time interval, and the time period over which the kills accumulated, you can't estimate the kill rate, but it's not going to be up in the 87% range: putting in largely fanciful extra numbers, I came up with perhaps a 4% road kill. Perhaps Fred has a more solid estimate?
* that's right, and one problem with using roads, and especially these
roads, to detect movement is that in the village there's almost no
traffic between midnight and 06h00 - so the late night movements get
away undetected except when I'm out there to see them, while some
carcasses can be identifiable as scraps for a week after they've died.
On the other hand, there are roads with more traffic where almost
nothing makes it across the road, a pattern you can observe in the
location of all the squashed carcasses in the lane next to the source of
movement.
> One of the most remarkable statistics in Bev's link is that the road section Fred surveyed was 246 m long (1/4 km) and that this full length apparently was sampled each walk, resulting in an average of ~4 animals observed per meter. Over the 3 years surveyed, Fred therefore would have been making ~1000 observations total per walk, in a sampling time averaging about 7 minutes per walk. That's walking at ~2 km/h, by itself not unreasonable, but it means somehow recording numbers and identifying species at a rate of ~140 records per minute, or >2 per second. Even standing still I couldn't imagine how such a tally rate could possibly be achieved, so must be missing something.
* that's a confounding of the various classes of totals: 990 records in
572 outings means less than 2 species per outing on average - the "3.9
individuals per metre in 2004, 5.8/m in 2005, 3.9/m in 2006" was for the
entire years.
With an additional decade of observations (even with 2 summers mostly
away from home), I'm now up to 4020 records of species on this transect,
and 803 outings when nothing was seen on the streets, and I really ought
to find a winter to write it up as a book-length publication. Lots of
things have changed over the years - huge fluctuations in Amphibian
numbers, declines in alien Cepaea snails, many fewer Giant Water Bugs,
and the increase in the alien Yellow Underwing Moth caterpillars.
Our pitch for others doing this kind of project is at
http://pinicola.ca/AdoptX.htm and you could snag the datasheet from
http://pinicola.ca/wasted_lives.pdf - I discuss other aspects of road
ecology at http://pinicola.ca/rd_ecol_10_quest.pdf
Wikipedia has a sketchy 'road ecology' page, with links to other pages
with adequate coverage of related issues. OREG has moved with Dave
Ireland to the ROM and has a not-very-up-to-date webpage at
https://www.rom.on.ca/en/collections-research/research-community-projects/community-projects/the-ontario-road-ecology-group
- which announces a 2014 meeting to form a Canada-wide road ecology
group, but not much seems to have happened on this front...
fred.
======================================================
> From: naturens-owner@chebucto.ns.ca [naturens-owner@chebucto.ns.ca] on behalf of bev wigney [bkwigney@gmail.com]
> Sent: Tuesday, April 5, 2016 11:28 AM
> To: naturens@chebucto.ns.ca
> Subject: [NatureNS] A shout-out for Road Ecology
>
> All,
>
> This morning, I wrote a post to my naturalist friends on Facebook concerning road ecology. Gale MacLean suggested that members of NatureNS might find this of interest too, so I’m reposting here. Read on:
>
> ----
>
> I’m posting this link to a document written by friends, Fred Schueler<https://www.facebook.com/bckcdb> and Aleta Karstad<https://www.facebook.com/aleta.karstad>, as I think it may be of interest to some of you. It is entitled, "Reckoning Wasted Lives: Thirty Years of Road Ecology in North Grenville.”
>
> http://pinicola.ca/wasted_lives.pdf
>
> Now, before you think, "Well, where's North Grenville and what does it have to do with me?" - let me just say that it is what Fred and Aleta have been doing that should be of interest to you. For more than thirty years - actually, it's getting closer to forty years - they have been "doing the roads" in their area - studying what is happening on them, in what is now known as 'road ecology'. That involves keeping records of the movement of creatures that are crossing roads - both successfully, but very often unsuccessfully.
>
> To give you some idea of just what may be seen by surveying a small section of road, let me quote from the document (page 18):
>
>>From 2004 - 2006, Fred was out 572 times on 392 days. Each survey took 4 - 10 minutes. This produced 990 species records, of 3,342 individuals of 48 taxa; 3.9 individuals per meter in 2004, 5.8 per meter in 2005, 3.9 per meter in 2006. There was a range of mortality rates, and in the middle of the range, about 87% of each species of frogs and toads was killed.
>
> [My note: Yes, you read that right. 87% of the frogs and toads seen on the road were DOR (dead on the road). Argh!! Kind of points to why studying road ecology is relevant, doesn't it?!]
>
> I like the final statement in the document:
>
> "We recommend this exercise to anyone who lives near a road."
>
> Well, that's just about all of us, isn't it? Just think of what we might learn by studying the roads around our own homes. I have done a little of this around my own area, but not in any methodical way. I mean to rectify that situation this season while at my place at Round Hill.
>
> By the way, if you go to check out Fred and Aleta's document - it's a quick read with many photos and graphs - you'll find quite a number of my photos of frogs and turtles interspersed with the text. I'd sort of forgotten about that. Nice to see them included in such a useful document. Please do read it if you have a few minutes.
>
> ** Note: Fred Schueler is a member of NatureNS, so if you have questions about road ecology study, I’m sure he would be available to reply.
>
> Bev Wigney
> Round Hill, Nova Scotia
>
>
--
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Frederick W. Schueler & Aleta Karstad
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Vulnerable Watersheds - http://vulnerablewaters.blogspot.ca/
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