The onset of the covid-19 pandemic in late winter 2019-2020 and the measures taken in response to it led inevitably to difficulties in maintaining our monitoring regime. At the outset it was decided that the UNR contingent (Matt Forister and Chris Halsch) would cover the 5 Sierran sites and I would continue doing the 5 lowland ones. On August 19, 2020 our Gates Canyon site was largely destroyed by wildfire. There were also significant, but much less extensive and destructive, fires at Suisun (June 8) and North Sac (July 7).
A new study covering 159 species of butterfly that were monitored for over 35 years has just been published in the Proceedings of the National Academy of Sciences. This is the first major paper resulting from the remarkable research program of Professor Art Shapiro at UC Davis. Art's project consists of 11 sites which he visits every two weeks, and extend from Suisun Marsh in the Bay Area, across the central valley, and up and over the Sierra Nevada to a final point at Sierra Valley on the east side.
There’s a new butterfly in town in the Sacramento metropolitan area. Well, almost new: it’s back after about 40 years. The Gulf Fritillary has returned, and it’s even breeding in midtown.
2018 was the single worst butterfly year since this project began. It was the only year when butterflies were at a low ebb both in numbers and diversity at BOTH high (SV,CP,DP,LC,WA) and low (RC,NS,WS,GC,SM) sites. Usually wet years are good in the mountains and bad in the Valley, and vice versa for dry years. In 2018 it was bad everywhere. So it should not be surprising if 2019 was a better year.
As I said a year ago, conventional (Shapiro) wisdom has it that the first year of a
drought is good for butterflies, but the second is bad. How about the third? 2014
was the third drought year, as was much-discussed in the media. I was able to
maintain the tempo of site visits, despite a serious accident on Sept.11 that had me
in the hospital for 3 days, and knees that are increasingly unforgiving on Castle
Peak.
This is the year the drought was at least put on “pause.” In northern and central California
most stations received record or near-record high precipitation. Recall that the drought years
were consistently good for most Valley butterflies, many of which recovered to levels seen
before the systematic decline that began in the late 90s. But the butterfly seasons at higher
elevations varied from mediocre to awful, with species failing to be recorded in entire years at
most sites.
