Was this the fifth year of drought? Here are my numbers of site visits:

Sierran sites dried up and the season ended preternaturally early.

We’ll look at MIGRATORS and LOW-ELEVATION SITES first.

Riparian vegetation fared well again and only showed marked water stress late in the season when Oregon Ash, Poison Oak, Elderberry, Snowberry and (to a lesser extent) Wild rose showed damage.

There were no significant arson or other fires in my Sacramento-area (or other) sites in 2016. The authorities ran goats in North Sacramento in midsummer, which reduced the potential fuel mass while having surprisingly little impact on the butterflies. The goats also led to the exodus of homeless from the area, many of whom either did not return or did so only very late in the season. Blue Oak did not drop leaves early. As in 2015, Euthamia, Aster, Ammi and Helianthus were all below par; many plants did not bloom or bloomed hardly at all; Ammi bloomed but mostly in dwarfed condition. Hemizonia, Heliotropium, and Trichostema had a good year, as did Eriogonum nudum and wrightii at Rancho Cordova. Heavy “pineapple express” rains in late autumn led to flood-control releases from area reservoirs, resulting in flooding of the gravel bars in Rancho Cordova and the Yolo Bypass in mid-December. Alamo Creek at Gates Canyon was dry much of the second half of the season, but the vegetation remained in decent shape and Blue Oak did not drop leaves early.

The CA Tortoiseshell, Nymphalis californica, returned from limbo. Hibernators were first recorded at Gates Canyon on ii.8 and though not numerous, persisted through ii.25. Most interestingly, they bred on “Jim Bush” in the canyon for the first time since before the drought. Fresh individuals were first seen on iv.29 and again on v.13. None were seen at Gates in autumn. Hibernators were present at Washington ii.13-iii.18 and fresh ones v.11-v.24 with several presumed migrants viii.1. At Lang, hibernators iv.17-v.29, then nothing. Hibernators were present at Donner iv.17-vi.19 with a token presence on ix.10 and ix.16, presumably dispersing downslope. At Castle Peak no hibernators were observed but fresh animals were present on vii.22 and viii.6 and a few probable dispersers on ix.7. An unambiguous migration was observed at Sierra Valley on vii.12—about 150 fresh ones going NE>SW in a very narrow, well-defined band. On vii.22 a similar group was observed at Sonora Pass. On vii.26 a large movement was observed N>S at Lake Tahoe and on viii.1 an even larger movement >S over Mount Lassen. If they were at or near ground level at Donner and Castle, I never saw them (Donner vii.12, vii.30, viii.10; Castle vii.7, vii.22, viii.6). At any rate, the beast is back! No reports of where in the high country the S-bound ones estivated, but singletons as usual began showing up near sea level in fall (SM xi.9, xi.16; Rancho Cordova x.18; North Sac x.10). Earlier records were Rancho, v.14, Suisun vi.1; North Sac v.19 – these were the new brood dispersing upslope and eastward; compare Gates dates! Here are day-positives for the Sierran sites:

It was a very poor year for the Painted Lady, Vanessa cardui. The first immigrants were noted: Rancho Cordova, ii.23; Suisun, ii.4; West Sac, iii.23 (!); North Sac, ii.9; Gates, iii.17 (!). The two very late dates presumably just reflect the impact of scarcity on probability of detection. Numbers of late winter immigrants were minuscule and never really picked up. The southward movement in fall was barely detectable even in the Sierra, where rabbitbrush bloomed out early. Here are the numbers counted in the first and second halves of the season at low elevation:

Numbers were poor in the mountains as well. At Washington a singleton was recorded on iv.6 and another on v.11 – period. At Lang, one on iv.6 and one vi.24. At Donner, two on vi.4, two vi.19, one ix.10, two ix.16, and one on x.8. Castle: one vii.7 and one ix.7, for a season total in the Sierra of 14 animals! This may be an alltime low.

Things were much rosier for the Buckeye, Junonia coenia, which seemingly overwintered at mid-elevation on the Sierran west slope. It was present at Washington from iv.30-ix.10; Lang, v.17-ix.16; Donner, vi.4-viii.25; Castle Peak vii.7 only; Sierra Valley vii.12-ix.8. Here are individual counts at low elevation:

Once again, the usual seasonal Buckeye pattern was reversed: greatest abundance in the first half of the season, dropping off at the time when it usually maxes out in September!

The Fiery Skipper, Hylephila phyleus, had been expected to decline because its larvae are the preferred prey of the European Paper Wasp, Polistes dominula. But it didn’t do so when the wasp was abundant. In 2016 the wasp population crashed, remaining below detectable levels until near the end of the season—but the skipper population did decline, presumably for other reasons.

Now for the species seemingly in peril of local extinction:

It was a better year for Satyrium at low elevations.

S. sylvinus: WS 2012:0 2013: 7 2014: 0 2015: 4 2016: 4, NS 2012: 20 2013;22 2014:44 2015:10 2016:83, GC 2012: 8 2013: 5 2014: 4 2015: 10 2016: 2

S. californica: GC 2012: 13 2013: 16 2014: 40 2015: 61 2016: 102, RC 2012: 2 2013: 6 2014: 4 2015: 4 2016: 34

S. tetra: GC 2012: 2 2013: 1 2014: 0 2015: 3 2016: 1

S. auretorum: GC 2012: 3 2013: 9 2014: 17 2015: 7 2016: 25

S. saepium: GC 2012: 3 2013: 3 2014: 2 2015: 3 2016: 6

All Satyrium had probably their worst year of record in the Sierra. At Washington, one sylvinus vi.24 and no others. At Lang, one each auretorum, sylvinus and californica vii.8, and one saepium vii.30. Donner: several sylvinus vii.30 and viii.10 and no others! Only one fuliginosum at Castle, vii.2; none seen at Donner; at Sierra Valley one fuliginosum vi.19, several behrii and one each californica and tetra vi.30, several each behrii, sylvinus and californica vii.12,still several behrii and one saepium vii.30.

Great Copper, Lycaena xanthoides:

NS 2012: 5 2013: 12 2014: 31 2015: 22 2016: 12
WS 2012: 2 2013: 1 2014: 1 2015: 0 2016: 0
SM 2012: 4 2013: 4 2014: 1 2015: 2 2016: 0 (extinct?)

The Yuma Skipper, Ochlodes yuma, rose from 4 at Suisun last year to 13 this year. The Silvery Blue, Glaucopsyche lygdamus, had a very good year in the Valley:

NS 2012:0 2013: 12 2014: 3 2015: 8 2016: 49
RC 2012: 15 2013: 4 2014: 6 2015: 125 2016: 137

Pyrgus scriptura had a very strong year at SM and WS but may be extinct as a breeder in NS:

NS 2012: 0 2013: 1 2014: 0 2015: 1 2016: 1
WS 2012: 38 2013: 29 2014: 35 2015: 55 2016: 189 (best in many years)
SM 2012: 2 2013: 3 2014: 8 2015: 13 2016: 41 (again, best in a long time)

And Pholisora catullus deteriorated in WS and was not seen in NS, though a city resident across the river from my site (Dick Wood) reports it continues to breed in gardens and vacant lots there:

WS 2012: 37 2013: 23 2014: 17 2015: 71 2016: 29
NS 2012: 4 2013: 5 2014: 0 2015: 1 2016: 0

But two individuals were seen at SM (iv.5, iv.13) and one in Davis (viii.11), in both cases the first in over a decade; but no breeding seems to have ensued. (Also, there was a female Phyciodes campestris in West Sacramento on x.12—the first of that species there since two in 2002!)

Speaking of dark skippers, Erynnis tristis has nothing to be mournful about:

RC 2012: 10 2013: 24 2014: 25 2015: 32 2016: 37
SM 2012: 1 2013: 9 2014: 20 2015: 50 2016: 42
WS 2012: 9 2013: 42 2014: 31 2015: 76 2016: 126
NS 2012: 59 2013: 42 2014: 31 2015: 88 2016: 125
GC 2012: 27 2013: 31 2014: 12 2015: 66 2016: 62
Totals 106 148 119 312 392

Ochlodes sylvanoides and Poanes melane famously returned to the Valley a few years ago. How are they doing?

Lorquin’s Admiral, Limenitis lorquini, had its best year yet!

RC 2012: 8 2013: 34 2014: 14 2015: 29 2016: 36
GC 2012: 38 2013: 67 2014: 38 2015: 47 2016: 69
WS 2012: 37 2013: 61 2014: 21 2015: 31 2016: 54
NS 2012: 6 2013: 11 2014: 29 2015: 26 2016: 23
Totals 90 173 102 133 182

The Variable Checkerspot, Euphydryas chalcedona, continues to wobble near extinction at Gates, with 7 seen in 2014, 14 in 2015, and 7 again in 2016.

The Mourning Cloak, Nymphalis antiopa, went down sharply in 2015 and stayed down in 2016:

RC 2012: 22 2013: 4 2014: 12 2015: 6 2016: 3
SM 2012: 2 2013: 1 2014: 1 2015: 0 2016: 0
WS 2012: 5 2013: 10 2014: 12 2015: 2 2016: 1
NS 2012: 15 2013: 10 2014: 3 2014: 4 3016: 1
GC 2012: 49 2013: 40 2014: 27 2015: 20 2016: 32
Totals 99 68 55 32 37

The Pygmy Blue, rephidium exile, had a terrible year everywhere. At its metropolis, Suisun, it peaked early, on ix.28, at only 622 individuals.

The Western Tiger Swallowtail, Papilio rutulus, famously recolonized Davis after a decade of absence and has now been regionally strong for five years:

SM 2012: 12 2013: 21 2014: 22 2015: 19 2016: 28
GC 2012: 40 2013: 90 2014: 47 2015: 94 2016: 71
WS 2012: 44 2013: 63 2014: 27 2015: 47 2016: 75
NS 2012: 28 2013: 25 2014: 31 2015: 38 2016: 54
RC 2012: 42 2913: 57 2014: 46 2015: 40 2016: 75
Totals 166 256 173 238 303

The Pale Swallowtail, Papilio eurymedon, was up at GC:

2012: 70 2013: 53 2014: 8 2015: 32 2016: 51

The Anise Swallowtail, Papilio zelicaon, had a good year at some but not other sites:

RC 2012: 5 2013: 4 2014: 2 2015: 2 2016: 3
SM 2012: 58 2013: 13 2014: 27 2015: 16 2016: 50
WS 2012: 3 2013: 4 2014: 1 2015: 3 2016: 2
NS 2012: 20 2013: 31 2014: 18 2015: 36 2016: 44
GC 2012: 8 2013: 3 2014: 1 2015: 2 2016: 5
Totals 94 55 49 59 104

And finally, the Gulf Fritillary, Agraulis vanillae, survived a severe freeze (21-22F) and bounced back:

RC 2012: 5 2013: 18 2014: 38 2015: 12 2016: 15
WS 2012: 0 2013: 4 2014: 12 2015: 18 2016: 16
NS 2012: 11 2013: 16 2014: 31 2015: 38 2016: 24
SM 2012: 0 2013: 12 2014: 18 2015: 47 2016: 47
Totals 16 50 99 115 102

It was a very poor year for subtropical strays, with one Phoebis sennae at Suisun, vi.12, and one Leptotes marina, also at Suisun, vii.27. Lots of Heliopetes ericetorum, though: SM iv.25, NS iv.28, GC ix.1 and RC ix.20, plus a sighting of many at McLaughlin Reserve ix.16 (Eric LoPresti), apparently breeding.

GENERAL OBSERVATIONS—LOW ELEVATION

The drought years (2012-16) have been remarkable for the restoration of the seasonal patterns of the 1970s in the Valley—nearly constant and high numbers of species and individuals flying virtually the entire season. Here are the 2016 seasonal species maxima by site, with dates: SM 24, ix.3; GC 29, v.13 (28 on v.31); WS 22 on v.4 and ix.5; NS 24 on vi.6; RC 21 on vi.7. None was near record territory, though, unlike last year. Last year’s seasonal maxima, for comparison, were: SM 20 (ix.18 and x.3); GC 30, v.1; WS 26 on ix.25; NS 27 on v.26; RC 17 on iii.25, x.7 and x.16.

Willow Slough (vii.4, as always) had 23 species and 913 individuals, compared to 20 and 1624 in 2015, 19 and only 317 in 2014, and 22 and 918 in 2013. After very poor performance in 2013-2014, Pieris rapae had shot up to 1094 individuals last year, or 2/3 of the total for all species. This year it fell back to only 335, while Colias eurytheme remained stable around 300. A reminder that the high species numbers during the drought years have been a dramatic reversal of a long-term, essentially monotonic, decline in species richness, as demonstrated in our paper with Mike Rosenzweig (O’Brien et al., Biol. Cons., 2011).

While we’re thinking about Colias eurytheme, we should note that there was a massive outbreak of this species in the Valley in mid-July, the first since x.2012. They clogged car radiators and urban gardens alike. Later there were several localized outbreaks, apparently not synchronized. One more seeming return to the pattern of the “good old days!”

Phenologically, there were lots of early and especially late bugs, but very few records: Lycaena helloides in RC on iii.1, Erynnis tristis in NS on iii.2, Ochlodes sylvanoides at SM on vii.19, and Papilio rutulus in Davis on xi.15. Phyciodes mylitta on ii.1 just missed the GC record by one day. Danaus plexippus somehow reached SV on iv.3!

GENERAL OBSERVATIONS—SIERRA NEVADA

It was a terrible year in the Sierra, marked by low numbers of both species and individuals everywhere, with many things either not seen at all or in drasticallyreduced numbers. Melt-out was not very early so there were few early-season surprises except the Monarch at SV in early April. At Washington the number of species peaked at 25 on v.11 (in 2015 it peaked at 24 on v.2) and was down to 8 on viii.12 (6 on viii.6.15). At Lang it peaked at 26 on vi.24 (vs. 28 on vii.1.15) and was down to 5 on viii.27 (vs.10 on viii.19.15). At Donner, the peak was 41 on vi.30, vs. 37 on vi.18.15); at Sierra Valley the peak was 26 on vii.12, vs. 21 on vi.28.15. But in both years the end of the season dragged on (7 species on x.21.16, 5 on x.10.15). Castle Peak was unspeakable, peaking at 34 on vii.7 and dropping to 8 on ix.7. In 2015 the peak was 37 on vi.25 and there were 4 on ix.19. Rabbitbrush bloomed 2-6 weeks early and was done at Donner by mid-September. Enough persisted in bloom at SV to allow the latest species to persist, too. The general drying of the herbaceous vegetation at Donner was similar to 1992. In both years there was essentially zero summer rain—the monsoon fizzled. The list of things that were either not seen or were extremely rare is very long. Mitoura “siva” was almost absent at SV. Ditto Plebeius shasta and Satyrium fuliginosum on Castle Peak, and Pyrgus ruralis and the usual summer Hesperia entity at Lang. All the species of Speyeria remained rare, as in 2015, with S. callippe the worst-off. Polygonia zephyrus was very rare, and again totally missing at rabbitbrush in autumn. Two big winners that don’t normally overwinter were the Buckeye, Junonia coenia, whose dates were already given, and the Acmon Blue, Plebejus acmon, which was flying at Donner on vi.30—last year it was out on iv.17! but I think, given the later meltout this year, that it may have overwintered again.

The most striking thing about these drought years is the difference between the Valley, where everything seems hunky-dory, and the Sierra, where the butterfly fauna is in free fall. And we can’t blame that free fall on habitat change, or pesticides. It HAS to be climate- (or at least weather-) driven.

Monitoring is an open-ended soap opera. As of December 23 the northern Sierran snowpack is only about 2/3 of the 30-year mean, though total precip is between 150-210% of mean (the snow line has run very high most of this precip season). Our data, properly coddled and massaged, should have many stories to tell us. At least some of them should give us glimpses into the future.