Diario del proyecto Pacific Newt Roadkill (Main Project)- Lexington Reservoir

I added a new subproject to track the number of juvenile Pacific Newts found on Alma Bridge Road, since juvenile mortality has a disproportionate impact on population dynamics.

Pacific Newts (Dead Juveniles) - Lexington Reservoir Area
https://www.inaturalist.org/projects/pacific-newts-dead-juveniles-lexington-reservoir-area

This is a summary of our newt roadkill study at Lexington Reservoir, Santa Clara County, CA for the 2019-2020 migration season. This study has been ongoing for two full seasons and part of a third season (2017-2018).

First of all, I'd like to thank our fantastic volunteers - @merav, @newtpatrol, @sea-kangaroo, @anudibranchmom, and @joescience1 - for a job well done!

2019-2020 Newt Migration Season Highlights

• The team recorded 5,292 newt roadkill observations, which is 411 more deaths this season than last. The cumulative death toll is 10,644.

• The team has also recorded 361 observations of 67 other species of animals killed on Alma Bridge Rd.

• 50 data collection surveys were performed this season compared to 42 last season.

• Three times the number of dead juveniles were observed this season compared to last (100 vs. 32). This is important because juvenile deaths have a disproportionate impact on population dynamics.

• The rainy season started later this year and lasted longer than last season: 11/27/19 through 05/20/20 (global warming?)

• It's a widely held misconception that newts only migrate on rainy nights. We have a lot of data to disprove this:

• During Feb, there were only 2 days of rain (total 0.02 inches), but the team found 904 newt corpses during Feb.
• Also, we’ve observed and documented 121 newts alive and walking around during the daytime.
• It seems the only time we find no dead newts on the road during the 5-month migration season is when the temperature drops below 40 degrees F and there’s snow on the mountains.

Here's our umbrella project from which you can access all the subprojects (e.g., newt roadkill for each season, juvenile deaths, live & injured newts, and our decomposition study data):
https://www.inaturalist.org/projects/pacific-newts-all-lexington-reservoir-area

This journal post is an addition to Anne's post about the newt season summary - https://www.inaturalist.org/projects/pacific-newts-all-lexington-reservoir-area/journal/38733-2019-2020-newt-migration-season-summary 361 observations of 67 species of other roadkills along the Alma Bridge Rd. were documented by @truthseqr, @merav, @newtpatrol, @sea-kangaroo, @anudibranchmom, and @biohexx1. For a presentation I did recently, I've decided to create a couple of figures using the other roadkill data collected as part of the Lexington newt study. I think looking at the first figure, although it's not very informative, as you cannot see the details, it's amazing to see just how many newts die on the road each year, compared with all other animals combined. After removing over 10,000 newts (second figure), you can see the other groups represented more clearly. The largest group is insects, with beetles and hymenopterans (bees and ants) being the most common organisms. There were some interesting seasonal patterns, some organisms were very common during the end of the winter, disappeared later, and were replaced by others. In the winter there were many earthworms, beetles and Jerusalem crickets, for example, and also large millipedes. They were all gone later, and replaced by bees and ants, and many other insects. In addition, in the winter there were many reptiles and other amphibians. Most snakes were found in January and February. Among the other amphibians, we documented frogs and toads, Arboreal Salamanders, Slender Salamanders, and even an Ensatina. Often we were unable to identify them to species. Here's the actual data - for 2 seasons, 2018-2019 and 2019-2020 - Newts 10145 Insecta 148 Amphibia 51 Diplopoda 43 Reptilia 29 Mammalia 20 Arachnida 11 Aves 7 Clitellata 7 Vertebrate 7 Gastropoda 5 Chilopoda 2 Actinopterygii 1 Arthropod 1 Broken into smaller groups - Amphibians: American Bullfrog 5 California Toad 3 Frogs and Toads 2 Sierran Tree Frog 4 Typical Frogs 1 Western Toad 23 Arboreal Salamander 5 California Slender Salamander 2 Ensatinas 1 Salamanders 1 Amphibians 4 Reptiles: Aquatic Garter Snake 2 Coast Range Fence Lizard 3 Colubrid Snakes 1 Garter Snakes 4 Ringneck Snake 2 Santa Cruz Aquatic Garter Snake 2 Sharp-tailed Snake 2 Snakes 1 Southern Alligator Lizard 1 Western Alligator Lizards 1 Western Fence Lizard 8 Western Skink 1 Western Whiptail 1 Mammals: Deer 4 Broad-footed Mole 5 California Mouse 1 California Pocket Mouse 1 California Vole 1 Eastern Gray Squirrel 1 North American Deer Mice 1 Rodents 2 Western Gray Squirrel 3 Arthropods: Arachnida - Araneae 6 Opiliones 3 Scorpiones 2 Chilopoda 2 Diplopoda 43 Spirobolida 7 Insects - Coleoptera 46 Diptera 6 Hemiptera 4 Hymenoptera 35 Lepidoptera 23 Orthoptera 34