Reasons why roadkill may be significantly under-reported

Here are some reasons why the newt roadkill on Alma Bridge Rd. may be significantly under-reported.

1. Most of the time I'm not able to cover the entire 6.6 mile length of Alma Bridge Road. I walk both sides of the road, so the entire hike is 13.2 miles. It takes about 4-5 hours to walk the entire length taking pictures. Some days (during the week) I only have a couple hours to do this work. I'm keeping a spreadsheet that shows the percentage of coverage for each day I go to the site. I've only covered 100% on two weekends.
2. Carcasses disappear from the road over time. @merav and walked between Limekiln and Priest Rock trailheads one Saturday morning, and she shares this info: "By the way - I was there again in the afternoon for a hike, and was surprised to see that almost all the newts we saw in the morning just by the limekiln trailhead were gone. In the morning there were at least 10 dead newts. By 4 pm they were all gone, but 1 that was still there."
3. We have not taken into account the effect that scavengers may have on newt roadkill count. According to Greg Pauly, Curator of Herpetology, Natural History Museum of Los Angeles County, "Raccoons, skunks, otters, crows, and ravens are all known predators of newts. While garter snakes swallow newts whole and therefore get exposed to the full dose of toxins (which of course is highly variable across species and populations within species), these bird and mammal predators tend to slit the animals up the belly and then eat the muscle tissue inside, often pulling limbs out. This leaves behind most of the organs and the skin with some or all of the limbs turned inside-out."

4. I've seen crows eating the newt carcasses on several occasions:
   https://www.inaturalist.org/observations/19649069
   https://www.inaturalist.org/observations/19649066
   https://www.inaturalist.org/observations/19476078

5. I've also seen beetles that appear to be eating newt carcasses:
   https://www.inaturalist.org/observations/19375712
   https://www.inaturalist.org/observations/19354057
   https://www.inaturalist.org/observations/19184311

6. When there's a lot of rain, the carcasses tend to turn to mush rather quickly and they look like grayish splats on the road. You wouldn't even know they're newt roadkill unless you know what to look for. I'm not adding those to the project - there are a lot of them, but I can't even begin to quantify how many.

Posted on January 15, 2019 01:47 PM by truthseqr