Pacific Newt roadkill & rainfall for 4 seasons
Updated 3/6/2021
Pacific Newt roadkill for 2020-2021 is significantly lower than 2019-2020. Is this due to less rainfall or population decline???
Updated 3/6/2021
Pacific Newt roadkill for 2020-2021 is significantly lower than 2019-2020. Is this due to less rainfall or population decline???
Comments
I wonder based on Merav's new experiment if we get an idea about the time of the day, most of them are getting squashed. If the majority is night time and this year fewer people are using that road at night compared to previous years, maybe that can be a factor as well.
@karangattu, yes traffic patterns are essential to unlocking these mysteries. I hope POST was right about traffic counting equipment remaining in place for the duration of the population study.
Ever since I started this project in Nov 2017, I've had the dreadful feeling I've been watching the annihilation of this population of newts. I'm fearful that the reduction in roadkill reflects a reduction in the population itself - beyond its capacity to recover.
I love these figures. I wonder what February 2021 is going to look like.
Anne - I'm hopeful the different pattern this year reflects the lower precipitation, cause the other option would be population reduction.
Karan, I'm not sure we will learn much about the time they are getting killed. I don't have the capacity to check that out. I ended out checking the flags only at 2 time intervals - 9 am and 4 pm, and again at 9 am the next day, and 3 days later. I was hoping we would check the road more often, but I cannot do it all...
@merav, you've done a phenomenal job with this endeavor. Not only have you collected data for >5,000 dead newts, but you've led the team in collecting data for multiple studies, coordinated with other teams, worked with other agencies, and spent countless hours in the field and in front of the computer. I know you'd like to do more, but unless you can clone yourself or turn into Super Woman, I don't see how you could possibly do more than you're doing now. Please don't burn yourself out. We need you!
Thanks, Anne! I do wish I could do more, but I think that's it...
It is a very interesting question, though, and I wish we could have answered that...
@merav, @karangattu, I think you can get a pretty good idea about when the newts are most active (and thus when most of them get killed) from other studies. The study done in Santa Cruz with the long-toed salamanders clearly showed peak movement after dusk (e.g. 5pm to midnight or thereabouts). There's also a paper about the Tilden Park newts that describes the time of peak movement. Also, the Chileno Valley project shows the most activity after dusk too (lots of live newts between 5-7pm).
• Fall 2013 Amphibian Mortality on Roads: A Case Study in Santa Cruz Long-toed Salamander Habitat (Michael Thomas Hobbs, San Jose State University, 2013)
Migration Patterns of Taricha torosa in Tilden Regional Park (Peter Claggett, 1989)
https://www.inaturalist.org/observations?place_id=any&project_id=2020-2021-chileno-valley-newt-brigade-winter&subview=table&verifiable=any
I forgot to take into account the deaths that occur within the HTH study boundaries. They haven't been sharing their data with us, so I can only guess a considerable number of newts have died within their boundaries as well.
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