Modern climate change is 10x faster than historic global warming mass extinction events

There have been several mass extinction events in the history of the earth, most of them caused by global warming due to “sudden” releases of carbon into the atmosphere, and it only took an increase of 4 to 5 degrees Celsius to cause the cataclysm. The current carbon emissions rate is 10 to 100x faster than during those events. And we’re already a quarter of the way there in terms of warming.

CLICK TO ENLARGEemissions rate

The current warming trends, RCP 8.5 and RCP 4.5, refer to estimates of carbon emissions under high and moderately low projections by the International Panel on Climate Change. The straight lines on the extinction events are approximate; there may have been episodic spurts and stops as different thresholds, positive feedback loops, and other natural events occurred. But these lines connect the dots we have.

The earth is 4.5 billion years old. Land animals with backbones didn’t really evolve until 300 million years ago (mya), so we’ll start there.

The most massive mass extinction event in the history of the earth was the End-Permian extinction event (also known as the Permian-Triassic extinction event or the Great Dying) 252 mya. It was caused by a massive release of carbon. The equatorial regions, both on land and in the ocean, were too hot for most life forms, including plants. The cause of the warming event is debated, but was most likely due to a series of volcanic eruptions from the Siberian Traps that lasted two million years. The extinction occurred during an initial 60,000 year period, which is “sudden” in geologic terms. Recovery of the ecosystem, basically a whole new evolutionary period to create new animals, took 2 to 10 million years.

The End-Triassic extinction event came next, 201 mya. It was also associated with volcanic activity and the massive release of carbon, this time from the mid-Atlantic ridge. It probably triggered a positive feedback loop, with melting permafrost releasing tons of methane. The extinction period, affecting plants and animals, lasted about 10,000 years and paved the way for the rise of the dinosaurs.

The dinosaurs dominated after that, until all but the avian dinosaurs (the ones that evolved into birds) were wiped out by another mass extinction event 66 mya. This may have been caused by a comet or asteroid striking the earth, or by extreme volcanic activity creating global warming similar to the other events here (8 degrees Celsius over 40,000 years). This one is not shown on the graph.

Finally, there was the Paleocene-Eocene Thermal Maximum (PETM) and associated extinction event 56 mya. Likely caused by a combination of carbon and methane releases, this global warming event is the most recent, offers the most evidence and information, and is most analogous to climate change today. The continents were in roughly similar positions as today. The warming, 5 degrees Celsius in about 5,000 years, wiped out much benthic marine life, pushed the tropics to Wyoming and alligators to the Arctic Circle, warmed oceans to 97 degrees, and made the equatorial regions too hot for many species. The PETM is well-studied, with hundreds of papers available on-line, plus quite a bit of media coverage.

The high temperatures lasted for about 20,000 years. Eventually, the Arctic Ocean became covered with algae. These algae slowly absorbed CO2. When it died, it sank, taking the carbon with it to the bottom of the sea, lowering the carbon in the atmosphere and cooling the earth back to normal. This process took 200,000 years.

Climate change during these past events, considered rapid in geologic time, would have scarcely been noticed by animals on the ground. Animals didn’t go extinct by dropping dead; they just had a lower reproductive rate such that their populations slowly declined until none were left. Also, they evolved. In fact, there was a pulse of evolution during the PETM, producing, among other things, the first primates.

The current warming is 10 times faster than during the PETM. It is noticeable within the lifespan of an individual animal. Adaption thru evolution is not an option. Scientists mince no words:

“We conclude that, given currently available records, the present anthropogenic carbon release rate is unprecedented during the past 66 million years. We suggest that such a ‘no-analogue’ state represents a fundamental challenge in constraining future climate projections. Also, future ecosystem disruptions are likely to exceed the relatively limited extinctions observed at the PETM.”  – Zeebe (2016)

The PETM raised average earth surface temperatures 5 C. We’re at 1.1 C now, with probably up to 2 C already built into the system, meaning we’ll reach that even if we stop all carbon emissions tomorrow. We’re likely to reach 2 C even if we dramatically reduce emissions and successfully implement Direct Air Capture of ambient CO2 in the atmosphere. Assuming business as usual, we may reach PETM levels in 140 years.

Note: See hyperlinks for sources.

Magic from Isla Mocha: Pink-footed Shearwater conservation thru soccer and children’s theatre

PFSH1Many think of Pink-footed Shearwaters as a relatively common bird on West Coast pelagic trips. I like to call them the “photographer’s shearwater” because they invariably offer great photo ops off the back corner of the boat. But they are considered endangered by Chile, threatened by Canada, and vulnerable by the International Union for Conservation of Nature (IUCN). They could easily be called the Chilean or even Isla Mocha Shearwater, as the entire world’s population comes from just three islands off the coast of Chile, 85% from Isla Mocha, and the remaining 15% from Santa Clara and Robinson Crusoe Islands in the Juan Fernandez group.

The very limited breeding range of the Pink-footed Shearwater is actually pretty typical of seabirds. To use some other West Coast species as examples, about half of the world’s Ashy Storm-Petrels come from one hillside on Southeast Farallon Island, 95% of the world’s Black-vented Shearwaters come from Isla Natividad off the Pacific Coast of Baja, and 99% of the world’s Heermann’s Gulls come from tiny Isla Rasa in the Sea of Cortez.


New research (Felis et al 2019), following 42 satellite-tagged birds, describes their seasonal movements from their breeding colonies in Chile. The new paper focused on threats at sea, especially bycatch by purse seine and drift net fisheries in Peru and Chile. CLICK TO ENLARGE.

And, typical of most seabirds, Pink-footed Shearwaters face some daunting challenges at their breeding colonies. At Santa Clara Island, non-native European rabbits denuded native vegetation, caused erosion, and kicked the shearwaters out of their burrows. When the rabbits were eradicated in 2003, the number of shearwater pairs went up 40% in three years. Native plant revegetation continues. On Robinson Crusoe Island, cattle trampled burrows, but a fence installed in 2011 now serves to keep them away from the colony. Shout out to Oikonos (a non-profit based in California, Hawaii, and Chile) and the Chilean national park service (called Corporacion Nacional Forestal or CONAF) for these projects.


But the real conservation challenge is at the shearwater’s main colony on Isla Mocha. Here, the local fishing community of 800 people are accustomed to harvesting shearwater chicks from their burrows. They’ve done so since the community began in the 1930s. And each pair lays only one egg a year. Chick harvesting has been illegal since 1998, but enforcement within a small community where everyone is friend or family is difficult.


Opening ceremonies of Copa Fardela soccer tournament.

Usually seabird restoration on breeding islands means restoring habitat or, more often, eradicating non-native rats, cats, mice, donkeys, you name it. But on Isla Mocha, Oikonos and CONAF have used another approach: outreach and education designed to reduce chick harvesting. The creative part is the strategy; the goal is for the islanders to identify with the shearwater as a symbol of their unique home, and thus want to protect them. Importantly, the project is led by a local Mochano, tapping into local values and local styles of communication. Thanks to the outreach efforts, school kids now flap their wings and enact dramas of the birds returning home. Adults play in the annual Copa Fardela (Shearwater Cup) soccer tournament.

This 48 minute video (in Spanish) documents the project. The Copa Fardela opening ceremonies, which features a children’s drama showing the shearwaters returning from the sea and producing a chick, begins around 42:00.

The fardela blanca, as they call it, is becoming their shearwater.


Three-acre beach restoration project produces first nesting Snowy Plovers in nearly 70 years


Pilot study area after three years of protection and restoration. Plant cover has gone from zero to 5% coverage, which offers enough cover for plover nests.

Sandy beach restoration is simple and effective. A three-acre pilot project at Santa Monica Beach by The Bay Foundation has lead to the first nesting by Snowy Plovers in Los Angeles region in nearly 70 years. This was in 2017. Since then, plovers have remained in the area but not yet re-nested.


This tiny project demonstrated “restore it and they will come.”

In fact, only two acres were actively restored thru not much more than a sand fence to build up sand hummocks and the distribution of native plant seeds to encourage dune vegetation. Add a key final ingredient: the absence of people and “beach grooming” (raking by trucks dragging large rakes). The third acre, on the ocean side of the restored section, was left un-groomed, a rarity in southern California. This leaves the “seaweed” (aka beach wrack), home to invertebrates and food to shorebirds. The cessation of beach grooming  has already been correlated with an increase in shorebird foraging.

Furthermore, a new native plant species, or possibly a rare variant, was discovered at the site, having germinated on its on. For a very detailed report on the project, see the project website.

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Snowy Plovers, a state and federally listed species, nest on sandy beaches, often putting them in conflict with human recreation.


Predicting winter irruptions: Correlating Red-breasted Nuthatch, Pine Siskin, and Red Crossbill winter invasions with previous years’ snowfall

I can almost do it; I’m just wrong this year.


Pine Siskins in fall 2015 during the “superflight”. Davis, California.

Boreal seed-eating birds are notoriously unpredictable in their winter wanderings. Unlike a certain distinctive Dark-eyed Junco that once returned to my small apartment patio in Davis, California several winters in a row, these birds of the northern forests have no such allegiance to any patch of land. A Pine Siskin once banded in winter in Quebec turned up in California during a subsequent winter; other Pine Siskins banded in winter in New York and Tennessee spent a later winter in British Columbia; an Evening Grosbeak banded in winter in Maryland spent a later winter in Alberta; a Eurasian Siskin banded in winter in Sweden was later found in Iran; a Common Redpoll once wintered in Belgium, and later in China; another Common Redpoll banded in winter in Michigan was found during a later winter in Siberia (Newton 2006). In other winters, they hardly migrate at all. While up to 90% of band recoveries for many winter-banded species are pretty much where they were banded, that rate fall to about 1% for irruptive boreal species (ibid).

There’s a rich literature focusing on cone crop failure and irruptions of crossbills, redpolls, Clark’s Nutcrackers and other species (Reinikainen 1937, Lack 1954, Svardson 1957, Davis and Williams 1957 and 1964, Ulfstrand 1963, Evans 1966, and Eriksson 1970). To quote Newton (2006), “Clear evidence has emerged that major emigrations follow periodic crop failures.” Most recently, Wilson and Brown (2017) confirmed that Red-breasted Nuthatches are not fleeing bad weather nor are they attracted to specific food elsewhere; they are spreading across the land “because of failure of conifer seed production on the breeding grounds.” They are famine refugees. Other research has shown that, “despite the presumed benefits of irruption as an adaptive response to food shortage when population levels are high, negative population consequences can ensue.” Large irruptions are correlated with smaller numbers on Breeding Bird Surveys the following summer; they don’t all make it back (Dunn 2019).

Another factor, however, is high population densities of the birds (Bock and Lepthien 1976). Koenig and Knops (2001) reached some specific conclusions when they examined 30 years of Christmas Bird Count (CBC) data, focusing on multiple species, and compared it with data on cone crops. They found that Red-breasted Nuthatch, Black-capped Chickadee, Evening Grosbeak, Pine Grosbeak, Red Crossbill, Bohemian Waxwing, and Pine Siskin irruptions were “correlated with a combination of large coniferous seed crops in the previous year followed by a poor crop.” In short, a good year causes a pulse in reproduction, followed by a lean year which causes the expanded population to suddenly roam in search of food. There was some variation, with the good year or the bad year playing a more dominant roll for different species, but for most species, it was both. (And for Purple Finch, it seemed to be neither.) They concluded that “seed crops of boreal trees play a pivotal role in causing eruptions for a majority of boreal species, usually through a combination of large seed crop resulting in high population densities followed by a poor seed-crop, rather than seed-crop failure alone.”

RBNU Davis 10-12-15

Red-breasted Nuthatch, also in Davis in fall 2015.

A year previously, Koenig and Knops (2000) studied just the trees, and concluded that various tree species often boom and bust in sync. They noted that “the large geographic scale on which seed production patterns are often synchronized, both within and between genera, has important implications for wildlife populations dependent on the seeds of forest trees for food. In general, resident populations of birds and mammals dependent on mast are likely to be affected synchronously over large geographic areas by both bumper crops providing abundant food and, perhaps even more dramatically, by crop failures.” Newton (2006) reported synchrony in boreal conifer seed production in forests 1000 km apart. Strong et al (2015) links Pine Siskin irruptions to continent-wide winter climatic patterns.

With synchronized cone crop failures, one would expect synchronized irruptions across bird species. The literature on this is supportive but mixed. Bock and Lepthien (1976) provide nice annual maps by species illustrating “generally synchronous” irruptions in many (but not all) years. Koenig (2001) offers the most comprehensive analysis, exploring synchronous irruptions among all combinations of 15 species, including multi-year lagged effects. (Here it’s important to understand correlation coefficients, or Pearson’s r. For guidance in interpreting r, 1.00 would be a perfect match, 0 would mean no correlation, and -1.00 would mean they do the exact opposite of each other.) Koenig’s highest correlation coefficients between two species were generally between 0.30 and 0.50. He also shreds an earlier assertion from Bock (1999) that there is strong correlation between Common Redpoll and Pinyon Jay irruptions; there was, but it didn’t last long.

Here I examine 49 years of CBC data (1970-2018) for Red-breasted Nuthatch, Pine Siskin, and Red Crossbill from the northern Central Valley of California, centered around Sacramento. I used data from eight CBCs: Caswell-Westley, Folsom, Lincoln, Marysville, Rio Cosumnes, Sacramento, Stockton, and Wallace-Bellota. I didn’t have any data on cone crops, but I assumed they might be correlated with precipitation the previous year, so I looked at snowfall. In short, I find some support for Koenig and Knops, but I wouldn’t bet more than a beer on it in any given year.

Here are the results.  CLICK TO ENLARGE.


First, there are no units for the vertical axis. That’s because the units I used for the birds is basically an index. I converted them all to natural log (ln) because the numbers of siskins, which often occur in large flocks, dwarfed the nuthatches and crossbills. Converting to natural logs put them all more on a level playing field. What you’re seeing is the natural log of total individuals across all eight CBCs each year. (In most years, most birds were in the Sacramento CBC.) The blue circles are the water content (in inches) of the deepest observed snowpack from winter snow surveys at Upper Carson Pass from the previous winter. For example, the large irruption (or “superflight”) in 2015 occurred in the fall and winter of 2015-16, and the very low blue circle on that column is associated with the snowpack from the winter of 2014-15. In general, the snow surveys occurred in Jan-Apr and the CBCs in December of the same year.

A few quick observations from the chart:

  • Red Crossbills only occurred in six of the 49 winters, but 4 of those were during nuthatch/siskin irruptions. The only large crossbill irruption occurred in 2015, on top of the largest combined nuthatch/siskin invasion. The 2015 superflight also coincided with the lowest snowpack the previous winter, which came at the end of a four-year drought. So 2015, as an extreme event, tells us a few things. Previous snowpack is important, and correlation across species does occur.
  • Most of the other highest irruption years (1981, 1987, 1992, 2012) all came after low snowpack years, and all had higher snowpack the year before that, exactly what Koenig and Knops would predict.

And now for some math:

  • The correlation coefficient between nuthatches and siskins is 0.32, so they do tend to irrupt together-ish, but not always and certainly not in the same magnitude. Koenig writes, “For Red-breasted Nuthatch and Pine Siskin, synchrony over different 10-year periods varied from a high of 0.82 (1965-1974) to a low of 0.24 (1987-1996).” His sample included eastern North America, which he showed follows different patterns than the West.
  • I then looked at correlation between the cumulative nuthatch/siskin/crossbill irruptions (in natural log, so the full blue, yellow, and red columns in the graph) and a variety of other parameters. Here are the results:
    • Correlation with previous winter’s water content from snowpack (the blue circle): -0.44.
    • Correlation with water content more than 5″ below average: 0.41.
    • Correlation with multiple years of drought: 0.37.
    • Correlation with a 10″ drop in water content from the year before that (thus going from a good year to a worse year): 0.38.
    • Correlation with the same 10″ drop in water content, but only if the recent year was below average (thus, going from a good year to a bad year): 0.40.

So these correlations all lean in the right direction, supporting Koenig and Knops’ notion that bad years are bad, and bad years after good years are even worse. I would also add that bad years after bad years (a drought) are also bad.

These correlations come with some caveats. First, the correlation between snow water content and cone crop is imperfect. Koenig and Knops (1999) state that, while recent precipitation is indeed an important variable, it’s not the only one. Spring and summer temperatures play a role in cone development, as well as previous seasons. After a really good year, trees need a break, regardless of rainfall, and will produce less. An example might be 1984, where there was an irruption after an average snow year, but two really heavy precipitation years preceded that.

Another source of noise in the data is that our birds, especially the siskins, may be coming from much further afield than Tahoe. (I deliberately left out Evening Grosbeak because call types from our last invasion suggested the birds were brooksi from Washington state or somewhere up there.)

Donner Jan20-2015

Donner Pass without snow. January 20, 2015.

While it may seem that the data on irruptions and snowpack tell a compelling story, let’s not forget the present. It’s fall 2019 and we’re in the midst of a significant Red-breasted Nuthatch irruption (and I’ve seen one siskin as well). This year is not on the graph above, but we do already have the snowpack data from earlier in the year. It was way above average. Thus, we’ve just gone from an average snowpack year in 2018 to above-average in 2019, the opposite of what should prompt an irruption. If you bet me a beer, I’d owe you one.


Bock, C.E. 1999. Synchronous Fluctuations in Christmas Bird Counts of Common Redpolls and Piñon Jays. The Auk 99: 382-383.

Bock, C.E. and L.W. Lepthien. 1976. Synchronous eruptions of boreal seed-eating birds. American Naturalist 110: 559- 571.

Davis, J. and L. Williams. 1957. Irruptions of the Clark nutcracker in California. Condor 59: 297–307.

Davis, J. and L. Williams. 1964. The 1961 irruption of the Clark’s nutcracker in California. Wilson Bulletin 76: 10–18.

Dunn, E.H. 2019. Dynamics and population consequences of irruption in the Red-breasted Nuthatch (Sitta canadensis). The Auk 136.

Eriksson, K. 1970. Ecology of the irruption and wintering of Fennoscandian redpolls (Carduelis flammea coll.). Annals Zoologica Fennici 7: 273–282.

Evans, P.R. 1966. Autumn movements, moult and measurement of the lesser redpoll, Carduelis flammea. Ibis 106: 183–216.

Koenig, W.D. 2001. Synchrony and Periodicity of Eruptions by Boreal Birds. The Condor 103: 725-735

Koenig, W.D. and J.M.H. Knops. 2000. Patterns of annual seed production by Northern hemisphere trees: a global perspective. American Naturalist 155: 59-69.

Koenig, W.D. and J.M.H. Knops. 2001. Seed-crop size and eruptions of North American boreal seed-eating birds. Journal of Animal Ecology 70: 609-620.

Lack, D. 1954. The Natural Regulation of Animal Numbers. Clarendon Press, Oxford.

Larson, D.L. and C.E. Bock. 1986. Eruptions of some North American seed-eating birds. Ibis 128: 137-140.

Newton, I. 2006. Advances in the study of irruptive migration. Ardea -Wageningen 94: 433-460.

Reinikainen, A. 1937. The irregular migrations of the crossbill, Loxia c. curvirostra, and their relation to the cone-crop of the conifers. Ornis Fennica 14: 55-64.

Svardson, G. 1957. The ‘invasion’ type of bird migration. British Birds 50: 314-343.

Ulfstrand, S. 1963. Ecological aspects of irruptive bird migration in Northwestern Europe. Proceedings of the International Ornithological Congress 13: 780–794.

Wilson Jr., W.H. and B. Brown. 2017. Winter Movements of Sitta canadensis L. (Red-breasted Nuthatch) in New England and Beyond: A Multiple-scale Analysis. Northeastern Naturalist 24.

A dysfunctional conversation about climate change among evangelical Christians, annotated

This is taken from a real Facebook conversation. I’ve changed the names to protect the innocent and the guilty. My comments are in italics.

Curious Jane is a young evangelical, on the progressive side of the spectrum. But she’s a progressive fish in a conservative sea. Here she tries to swim against the current.



Curious Jane: For people who don’t believe in climate change… help me understand why? I am genuinely curious. I just can’t wrap my brain around denying the fact that our presence here has an effect on the environment and why wouldn’t we want to decrease our negative impact.

Kudos to Curious Jane! She knows her Facebook Friends include lots of evangelicals (from conservative to openly gay) and she’s going right at them. She’s concerned about climate change and she seems honest in her question.


Biz Karen:  What’s now referred to as Climate Change used to be called Global Warming. The article below may help to shed some light for you. Call it whatever we like to suit politics & agendas, the fact remains we’ve been charged by God to care for the Earth (Genesis), so yes, we should take an interest in doing what we can, as best we can.
That said, Revelation also tells us there will be a new Earth, all things will be made new. The Earth is included in the Fall, and in a state of decay – this does not abdicate our responsibility, however. Just as grace does not give us leave to behave in whatever way we like.

Whoa, we open with the classic evangelical theological roller coaster. We should behave morally, but it’s irrelevant, but we really should, ish. Biz Karen then provides a link. The link is strange—having nothing to do with Christian beliefs and hardly the kind of thing one would share to “shed light” on this issue. It’s from a fringe publication—a poorly-written piece about Margaret Thatcher promoting climate change as a tool to promote nuclear power plants. I think it’s supposed to be an example of people promoting climate change to advance a personal agenda. Who knows where Karen got this from.

Curious Jane: I am not really sure I understand the article, or what it’s point is. I agree with both of the latter points though. The idea of that we will have a new earth is an interesting concept, one i hadn’t considered, but that makes sense. But as you say, that doesn’t give us a right to do what we want. And I think historically Christians have used the idea of “dominion over the earth” as a way to justify their lack of consideration for it.

Jane is on point here, 3 for 3: the article is bizarre; the “new earth” shouldn’t affect our behavior; and the “dominion” notion has been a grossly abused concept in the past. Go Jane!

Biz Karen:  Yup. Re the article – it’s basically that the concept of GW was not scientifically supported, and in large part created to aid Margaret Thatcher’s election as a woman in a man’s world…. Simply put.

Wow, Karen is 0 for 2 here. Her strange summary doesn’t match the bizarre article.

Curious Jane: Gotcha! Thanks for the breakdown!

Oh oh.  Jane is slipping, yielding to niceties instead of holding Karen’s feet to the fire. Maybe she’s giving up on Karen’s ability to answer her question in the first place.

Biz Karen: Curious Jane ya know, that’s what Auntie’s are for.

Well, you can’t choose your relatives.

Walter: I think why people shut off to this topic on the right is because every proposal to help curb emissions is just a way to push socialism. If you read the Green New Deal that’s what it’s core is. Now if they expanded their view to include nuclear and carbon capture tech I think they would get a lot more people who don’t turn off immediately at the very thought of changing away from fossil fuels.

Walter coming in with the Fox News talking point: socialism. It’s how Republicans seek to demonize every possible government intervention. It’s how conservative American dis more developed societies in Europe. And it’s also a massive generalization. Seriously, the police department, the military, agricultural subsidies, clean water regulations, the roads, the aqueducts, education—all could be called “socialism”. But not really. Government programs and regulations do not a socialist country make.

Let’s make the case for government intervention in this case. Econ 101 tells us that climate change is a classic negative externality problem. The true consequences of using oil are not reflected in the price at the pump. The market is not sending us the right signals, so we have no incentive to change. This is why we tax cigarettes or outlaw child labor—the government is intervening to fix the market, to stop the free market from doing something we don’t want. AOC only calls it the Green New Deal (echoing Roosevelt’s “New Deal”) because she recognizes our whole economy is built around carbon fuels and must change. That’s a big lift. To do that, we need a whole lot of intervention, so that the cost of CO2 emissions is reflected in the marketplace, so that alternatives are developed, and so that the poor don’t get screwed during the transition to alternative energies. Rather than demonize this transition (because Big Oil feels threatened), the GOP should help craft it. At least they should debate alternatives, rather than demonize any proposed solution.

Curious Jane: In what ways does it push socialism? (I don’t know anything about it, so again a genuinely curious question)

Jane should probably redirect Walter back to Christianity and Jesus here—the radical Jesus that openly suggested massive land reform and the forgiveness of debts every 50 years (talk about socialism!). But instead she calls him out on the socialism claim. Okay.

Curious Jane: Also, people completely deny its existence or that the climate is changing at all. Most of these people are Christian, or Christian affiliated

Ah, here we go! Back to signal! It’s like Jane listened to me. Why are Christians, who are supposed to love and especially care for the vulnerable, holding this position that contributes to real harm? And let me remind everyone that this is a conversation that could only happen in America (and Australia) among white conservative Christians. Nowhere else in the world is this even a debate. That’s how far down a fucked-up road Jane is on here. But she’s trying to turn the car around.

Walter:  Jane, it covers housing for all, jobs for all, focuses on “historically marginalized” communities and social justice etc. I’m just saying that if the politics were removed from the argument you would see a lot more people finding common cause. People on the right feel like admitting global warming is a threat means they have to sign onto leftist resolutions to that problem. I believe we are having a huge affect on the climate, but I don’t believe wind and solar fix it.

Okay, so Walter is a bit of a conservative troller, fishing with baited hooks on multiple issues. Look Walter, forget social justice if that irks you (as a Christian). No one is stopping the GOP from running on a platform committed to developing carbon capture technology. In fact, that would be a far more legitimate position than denying the problem exists. And that’s the main reason this problem is “political”. Denial. Which is a political strategy developed by Big Oil, embraced by James Baker and the GOP in the 1990s, and funded by the Koch Bros and others now.

But the real truth, the real answer to Jane’s question why Christians deny climate change, goes back a few years before she was born. I lived thru it. In the the 1970s there were many conservative Christians who were Democrats- like most of the South. Jimmy Carter was the first candidate to say he was “born again”. But since the 1980s conservative evangelicals have been in bed with the Republican Party (largely due to one issue, abortion), and the Republican Party has been in bed with Big Oil, and Big Oil has pursued promoting climate change denial since the 1990s (even though they very much believe in it and accurately modeled it decades ago). So that’s why conservative evangelicals now deny climate change. Because they are told to.

Curious Jane: But maybe wind and solar may help? Being aware of the issue may help? What are the republicans doing to address the issue?

Go Jane! #FightingSpirit

Walter:  Jane, I think it’s definitely a big piece. And I don’t think the republicans are doing much at all. Sadly. But we have seen US emissions drop by 15% in the last 20 years because of the clean tech in natural gas plants. Nuclear plants have zero emissions. Sadly no one wants to come together and compromise. So it’s all gonna get worse 😕

Walter is caving in; he’s coming across the aisle, now supporting solar and throwing shade on the GOP. Fact check on the 15% decline in emissions: Walter is correct. Emissions have declined about that much, entirely because of the switch from coal to natural gas by electricity generating plants (really a bit of luck there for all of us—it was driven by new discoveries and economics and could just as easily have gone the other way). However, CO2 emissions from transportation (e.g. cars and planes) hasn’t changed at all—and it’s now the biggest piece of the pie. I’m not sure what compromise Walter has in mind. The current Dem proposals are insufficient to address climate change, and the GOP wants to roll them back. Seems to me we need a Green New Deal (of some kind); compromise between the current Dems and current GOP is insufficient to address the problem.

Curious Jane: It just seems like people and/or politicians feel like they can’t compromise because they would be compromising their values, or “giving in” to the other side. And they rather get nothing done then give in

Oh oh. Walter caved so now Jane is caving. Jane, there is no compromise on the table. In fact, there’s precious little on the table at all because the GOP officially denies the problem exists. They are probably the ONLY major political party in the world that takes that position.

Walter:  Jane exactly!

Oh oh. Love fest now. Walter has lured her in, a strategic psychological masterpiece. Jane has caved to the “two sides to every story” religion (aka “bias towards fairness”) and now Walter is tying the noose.

Big Dan: Jane I think it’s a mistake to say nothing is being done. There have been great strides in improving our environmental impact in the United States over the last 30 years or so. But the radical propaganda does not include this because it doesn’t fit the narrative. The United States is much less polluting than almost all other industrialized nations. The socialist controlled nations are much worse. Frankly the most environmentally horrible places in our own country are the most socialist as well.

Here comes Big Dan to shake things up. He sounds like Trump on Facebook, with a fully-automatic blast of inaccuracies to overwhelm the reader. Fact checks: All wrong. Clearly this guy has never been to Europe, which generally has stricter environmental laws. CO2 emissions per capita in Europe are about half those in the US.

Big Dan: to finish my thought (got distracted-sorry) some of us on the right are opposed to the leftists solutions precisely because we care deeply about the environment and are certain they will result in making it much worse.

An unsupported and bizarre statement.

Big Dan: I do not deny climate change. I am extremely skeptical that is it man made or that we could stop it if we tried.

I understand when people live in the cities it can seem like we have an affect. And we can locally. But the world is a very big place and nature is so powerful. The effects of solar energy absorbed by the ocean water alone is mathematically exponentially larger than all of manmade energy use.

The idea that we’ve not even explored the ocean, but we think we can steer the climate is just beyond me.

In my profession we use temperature monitoring devices all the time. And the numbers we are told on climate change are still less than 5% of the factor of error in measurement devices. I’ve literally sent guys out to read gauges, write them down, and then compare them. 5 guys will vary 3 degrees F off of the same gauge.

If you were to watch the way I live out in the country, I think you would be able to see that I am conservation minded. But I don’t see the political solutions as being effective in anything but tyranny. You will find the most socialist nations are also the most polluting.

Wow, basically Fox News diarrhea here, with mentions of “tyranny” and “socialist” and a stunning disregard for science (and with that, a stunning disregard for human life). Also, the hubris of “I know more than the scientists do” is also stunning. But don’t forget, many of these people have been primed for taking on scientists via their “creation science” battles. This is just an extension. Trump v National Weather Service is just another manifestation.

Crazy Amy: New world Order= old world
+ 💀. A very few people I know who are fervent evangelicals or witnesses are
EXCITED about the end of the world as they believe that this is according to the Book of Revelations and they are anticipating the rapture etc. It’s a piece to the Armageddon puzzle and they can’t wait to finish it. They help it along, believing it is part of the grand design.

…  um… speechless… so people are idling their Ford F150s in their driveways to bring Jesus back? And the human misery and starvation?  We’ve entered a dark cult here.

Curious Jane: I don’t think they have anything to do with finishing it 🤔🙄

Thank you Jane—and nice emojis with “blegh” and “rolling your eyes”

Crazy Amy: Jane, tell them that 😂

So, does Amy really know people like this? We haven’t heard from them directly. I’m thinking the Fox ditto-heads speak for most conservative Christians and Amy is referring to a lunatic fringe beyond the usual repulsive perimeter.

Douglas: Jane, I think mankind has evolved into man-unkind. Very un kind to the invironment thus affecting the ecology. It’s not ignorance but rather ‘arrogance’ that’s responsive for the degradation of our environment. The industrial revolution, dangerous weapons of war, paradoxically the elite are the perpetrators! Does this make sense?

Okay, Douglas is enough on-point that we think he might not be a Christian, certainly not a conservative one.

Curious Jane: Yes it does! Thanks for your thoughts Douglas.

And Jane is once again at home with her core values.

Dude Guy: Apparently Facebook only lets me post one picture per comment. So we’ll start here:  It should be noted that nobody of note denies “climate change”. As we understand it – the earth’s climate has been changing since the Earth was created. It has been in a constant stage of flux for a few billion years now, and humans are but a blip on the timeline, with our carbon footprint being an even smaller part of that. This chart demonstrates CO2 levels across various epochs in the Earth’s history. As you can see, it rises and falls irrespective of human interaction

[There’s a graph showing ups and downs over the last 4 million years, well beyond the period of Homo sapiens.]

This is the global mean temperature … [Another graph, see below.]

Carbon dioxide makes up about .0004% of our atmosphere, or about 405 parts per MILLION molecules in the atmosphere. reports that this is a record high… but that’s actually a lie…

Oh jeez, cut!  This is all a shitload of faux science built on the main conservative talking point: the climate is always changing. Fact check 1: climate usually changes at a geologic snail’s pace—and human civilization evolved in a very narrow window of it and we have evidence it’s prone to collapse outside of that window—and we’re outside that window now. Fact check 2: his “science” is all wrong and ludicrous and at odds with the scientific community. I spared you most of it. But here’s one of his graphs (left) next to one from a reputable source (right).

And don’t forget, climate change is many times more intense in the Arctic. Native communities across Alaska are suffering from massive climate change and conservative white Christians in America are acting as shills for Big Oil. This is really repulsive—there’s no other word for it. Ten years ago I told my conservative Christian friends that climate change was the biggest crisis facing the church. They are failing miserably.


dys climate graphs.jpgCurious Jane: Thanks for all the info! I appreciate a scientific response 🙂

Whaaaaaat?  Jane, say it ain’t so. Are you just being nice?

Crazy Amy: Jane….not scientific….it’s called marketing.

I think Amy is critiquing Dude Guy here.

Curious Jane: That’s what all this is… marketing! It’s all political. Everyone just wants what they want.

That’s all i have learned from this. People have taken this issue and made it political.

Jane’s Dorothy-back-in-Kansas moment, but she’s mistaken. Again, Jane is caving in here to the “two sides to every story” thing, the go-to for Americans in uncomfortable situations. This is dysfunction. Jane, it’s political because one side not only doesn’t want a solution, they deny there’s a problem. Because they are selling oil. Plain and simple. When the earth’s climate really is changing in ways that will devastate life as we know it, when a truck is bearing down on you at full speed and you’re stuck in the middle of the road, there aren’t two legitimate sides. Wake up, Jane!

Curious Jane: Also, Dude Guy, regardless of your science, we should still take care of this earth and try to reduce our negative impact.

Ah, Jane is skeptical of his “science”. Curious Jane remains curious. This is good. Dude Guy never replies.

Biz Karen: Read: Climate Gate by Brian Sussman, Meteorologist!

LOL, vomit. I’ll let the readers look this one up themselves.


We’ve come to the end. It’s no longer a question of whether Jane can shine light in the darkness of the church; it’s clear she won’t convert them. The question is, how long can she last?

Good luck, Jane. With friends like these, you’ll need better allies if you really want to follow Jesus.

In addition to Bill McKibben and Al Gore (both climate leaders motivated by their Christian faith), here are some organizations I suggest:


Evangelicals for Social Action

 Young Evangelicals for Climate Action


Finally, Jane, check this out:  The Evangelical Climate Initiative. Climate Change: A Call to Action

Buying Greenland: Destroying the planet to make some money

Trump’s apparently serious bid to buy Greenland seemed like something out of The Simpson’s or SNL. It is not. It reveals something far more treacherous, like a ploy concocted by the villain in a superhero comic.


Setting aside the massive hubris of white privilege, that land and indigenous people can be bought and sold by colonial powers (and Trump has mentioned trading some US land away to make the deal), and setting aside the question of how to pay for it (perhaps by ignoring Congress and diverting funds from another source, like he did for his wall), his proposal means he believes in climate change and wants to profit from it—from the suffering of billions and the destruction of earth as we know it.

It’s not hard to understand the mastermind of Trump. His strategies are as transparent as a third grader’s plotting to steal cookies. At the Arctic Council meeting in May, Secretary of State Mike Pompeo dismissed climate concerns and instead highlighted “new opportunities for trade” created by the melting ice, the “opportunities and abundance” created by an ice-free Arctic. In preparation for the Arctic summit, Pompeo was probably briefed about the economic opportunities of an ice-free Arctic Ocean—not just the shipping lanes but also the massive reserves of oil under the seabed. And perhaps that briefing mentioned Greenland, with massive reserves of coal and uranium and an estimated 13% of the world’s undiscovered oil reserves.

Pompeo shares the information with Trump. Trump offers to buy Greenland. Ca-ching.

They’ve also figured out that Greenland is melting. And it is melting much faster than climate scientists predicted. A new report by NASA revised its estimate of sea level rise from Greenland alone from 3 feet to 5 feet over the next 200 years. During a heat wave last month, it melted at a rate that it was not predicted to reach until 2070. While billions will be underwater, Trump sees opportunity and abundance.


A dramatic photo of pooling meltwater on sea ice off Greenland. July, 2019.

In the same way he has hijacked the Republican Party and wed it to a small and diminishing demographic (rural white men), he has wedded his personal investment strategy to “disaster capitalism”, a plan to make money off the destruction of the earth. Along with all of Big Oil and the Republican Party, he has a financial conflict of interest with curtailing CO2 emissions. If Greenland was part of his investment portfolio, he’d also have a conflict with solutions to climate change. He’d even have a conflict with a magic technological breakthrough that sequesters carbon. He’d need the ice to melt.

He has become the diabolical villain of superhero cartoons. The desire to make money off the destruction of the earth is not only an impeachable offense, it disqualifies him from any responsible role on the planet. He is a threat to all humanity and the world.

The only superhero to thwart him is us, the unorganized millions. It’s time to stop tweeting about his hair and his wife and his rudeness and his gaffes. It’s time to think strategically and take to the streets. It’s time to make his life a living hell before he does that to the planet.

My backyard fountain and the birds that come to it

I’ve been asked quite a lot about my fountain and pond (in Davis, California) and why it is so successful in attracting birds. Here are some, I think, key elements:

  • The first is the sound of falling water. Birds hear this and come to investigate. The pond is rather simple. It all begins with an amoeba-shaped pre-fabbed pond liner, about 18″ deep. A small electric pump and hose carries the water about 3 feet up, where I feed the hose through a knot-hole in a piece of wood. From there, it falls into a plastic garbage can lid, and then pours thru a small cut into another garbage can lid, and finally into the pond itself. Each fall creates more trickling sound. I’ve put a flexible pond liner under the “waterfall” so that any water that wicks under the garbage can lids still ends up in the pond. The two lid pools are 1-2″ deep for bathing. Finally, all this stuff is covered up with rocks and driftwood.
  • Second, it’s all about context. The pond is essentially in a green grotto with lots of vertical structure above it, meaning that birds can come into a high tree, descend to a medium tree, and descend again to a shrub near the fountain, and then finally into one of the pools.  They do serious recon about where they drink and bathe; an individual often takes several minutes to come in. I think the horizontal structure — what’s 15′ away from the pond, matters less than what’s above it; they come down from above.

  • At the same time, they need some visibility and escape corridors in case a cat or Cooper’s Hawk comes. I’ve trimmed all the bushes around it 18″ off the ground so any stalking cat will be clearly visible. A Cooper’s Hawk is largely thwarted by all the vegetation.

With all this cover, the pond is mostly in the shade. That’s good for controlling algae growth, but bad for taking photos. But in my experience a birdbath out in the open sun attracts only a few species. I have installed a couple iPhone holders so I can do some live video feeds (e.g. Facebook Live) of the birds coming in. I’ve also situated the pond so I get a clear view from my kitchen table, from right here as I type this on my laptop. My binoculars and camera are beside me in case anything interesting comes in.

UPDATE: I moved to Port Townsend, Washington, and quickly built another pond. It has been just as successful. Here’s a pic of it: pt-pond

For this one, I use a plastic rectangular cement batch mixing basin as the bottom receiving pool. I built this whole pond for less than $75. Here are the basic blueprints for my ponds:


Finally, there is the issue of my house in Davis, which has windows that birds sometimes fly into. See this post about how to prevent birds from flying into your windows. 

I’ve recorded over 40 species using the pond in Davis. Here are some of them.


Wilson’s Warblers


Audubon’s Yellow-rumped Warblers


Myrtle Yellow-rumped Warbler


Nashville Warbler with a Western Tanager


MacGillivray’s Warbler


Black-throated Gray Warbler


Yellow Warbler


Orange-crowned Warbler


Tennessee Warbler– this bird appeared while I was working from home on a conference call. Needless to say, I managed a photo.


Western Tanager


Black-headed Grosbeak with Wilson’s Warbler


Varied Thrush


An unusual strawberry blond Purple Finch in front of a regular one


Hooded Oriole


A White-crowned Sparrow defends a bathing spot from a Western Tanager


Hermit Thrush, typically the last visitor of any winter evening


American Robin and Cedar Waxwing


intergrade Northern Flicker


Spotted Towhee


Slate-colored Junco


Sooty Fox Sparrow in front of a Yellow-rumped Warbler


One more Western Tanager

Not shown: Anna’s Hummingbird, Wild Turkey, Willow Flycatcher, Pacific-slope Flycatcher, California Scrub-Jay, Warbling Vireo, Cassin’s Vireo, Northern Mockingbird, Red-breasted Nuthatch, Ruby-crowned Kinglet, Bushtit, Townsend’s Warbler, Hermit Warbler, House Finch, Cassin’s Finch, American Goldfinch, Lesser Goldfinch, Pine Siskin, California Towhee, Golden-crowned Sparrow, Lincoln’s Sparrow, Song Sparrow, House Sparrow… and probably some others.

A marsh in Richmond: what a restoration project taught me about racial bias, white privilege, and environmental justice

IMG_8286The people of Richmond did not like our choice for a restoration project; they wanted a different one. They called us racist. At first, we were perplexed. Eventually, I realized they were right.

As a natural resource economist for the California Department of Fish and Wildlife, it was my job to assess injuries to wildlife and habitat due to pollution events, and to seek compensation, thru restoration, to “make the public whole.” Working with partners from the US Fish and Wildlife Service, NOAA, and other state and federal agencies, we enjoyed our work— suing oil companies and using the recovered funds to do habitat restoration. We were “the trustees”; we represented the people and the natural resources and acted on their behalf. We were the Lorax; we spoke for the trees. We had been as innovative as we were successful, pioneering seabird restoration on breeding colonies in Canada, Alaska, Mexico, and even New Zealand to benefit bird species killed by oil spills in California. Those were the only places they nested, so we did what made the most biological sense.

In 2012 we began assessing damages to Castro Cove in San Pablo Bay near Richmond. It had been contaminated by oil, mercury, and lead associated with the adjacent Chevron refinery. To compensate for the injuries (in addition to cleaning up Castro Cove), we proposed to restore saltmarsh wetlands at Cullinan Ranch, part of San Pablo Bay National Wildlife Refuge, about ten miles to the north. We immediately met opposition from locals. They wanted the settlement funds to stay in Richmond; Cullinan Ranch was too far away.

We have project selection criteria set in federal regulations. Top of our list is always nexus— we aim to restore the same type of habitat and species that were injured. But there are also other things to consider: feasibility, partnering funds to make the project bigger, cost (bang for the buck), etc. When it came to evaluating restoration options, Richmond had little to offer. The refinery was merely one of several industrial or former industrial sites along their bay front. Contamination issues were everywhere. A poster child for environmental injustice, Richmond is also poor and predominantly non-white. We thought Cullinan Ranch was a good solution.

The people of Richmond wanted us to spend the funds restoring Breuner Marsh. This was a 238-acre parcel just north of Castro Cove wedged between the bay and the railroad tracks. Across the tracks was Parchester Village, a housing tract built after World War II to house African Americans enticed to move there and work in the nearby factories. It was one of the few places offering FHA home loans to non-whites. They came primarily from Louisiana, a land of marshes. They would cross the tracks and enjoy the wetlands as a place to hunt and fish. To this day, Parchester Village remains predominantly black. Whitney Dotson, and his father Reverend Dotson, have been fighting development proposals there, by a man named Breuner, for decades.

Initially, we, the natural resource trustees, fought the people of Parchester. The Cullinan project exceeded the Breuner project by most criteria. It was already part of a protected refuge. It had ten feet of elevation gain to buffer sea level rise. And the project, modifying the levee system, promised to restore 1500 acres; it had serious bang for the buck. And we asserted that ten miles away was no big deal.

But the distance was a big deal, and we didn’t understand why. I did not understand that other subcultures in the US don’t hop in their Prius and drive an hour to see a rare bird like me. They don’t throw their kayak on their Suburu and head for the boat launch. Nor were the people of Richmond, working two jobs and long shifts, going to drive to Cullinan, which had little parking and no bus service. They wanted to protect and restore their own marsh across the tracks from their neighborhood. They knew, better than we, that using our criteria, places like Marin County across the bay, one of the wealthiest counties in the nation, would win every time. No prior contamination? Check. Partnering funds? Lots. Contiguous with other protected areas? Of course.

When the people we are supposed to be compensating are complaining about our proposal, that’s a red flag that perhaps our criteria are biased, our evaluation is wrong, and that their values are not the same as our values. And they are the ones who matter. As trustees, we were supposed to ensure the compensation of the impacted people. We are obligated to see the world through their lens.


The $14 million dollar project has re-contoured the wetlands and planted native grasses, as well as extended the Bay Trail with a paved bike path, parking lot, and restrooms. When I visited recently, two Golden Eagles, normally rare next to the Bay, skirmished over a kill in the grasses. 

A similar conflict arose in Mississippi after the Deepwater Horizon oil spill. At a contentious public meeting between the predominantly African American public wanting one type of restoration and white agency scientists proposing another, one exasperated woman stood up and asked, “Why are you all white?” When the government officials told me about this, they were scoffing. But it’s a great question. We all know the answer. They got their positions in government because they had college degrees. This in turn was highly correlated with a good high school and a good neighborhood. The money that financed all that started with their parents or grandparents, who probably began accumulating their family’s wealth after a subsidized college degree and home loan thru the GI Bill, or an FHA home loan, or maybe even a free plot of Native land via the Homestead Act, all programs that built the white middle class—and largely excluded people of color. The odds of a black person qualifying for one of these government positions were slim. That’s why that panel of restoration experts was all white. And they brought their cultural values with them.

In the end, we caved in and split the funds between Cullinan and Breuner (begrudgingly). I went to the Breuner Marsh project dedication ceremony, which featured speeches by both Whitney Dotson and Representative George Miller. There I learned everything I should have known earlier. That the people of Parchester Village had been fighting to save that marsh for decades.

They have since renamed the marsh; it is now the Dotson Family Marsh.

whit! Sorting out the call notes of western Empidonax flycatchers

After a flurry of migrant Empidonax flycatchers this April in California, a number of us engaged in a discussion about their whit! call notes. Specifically, could we tell Willow from Dusky from Gray just by the whit? Personally, I’m not there yet. I usually only hear them a few times a year, which is insufficient experience, and I suspect there’s individual variation as well as the tricks that wind, humidity, and distance play on sound. But what about analyzing their sonograms with a good recording?

I looked at the very best on-line recordings from the Macaulay Library (collected via eBird, and there’s a collection of the best ones at Peterson Bird Sounds) and from xeno-canto. (Warning: the horizontal axis is different between their sonograms. Xeno-canto sonograms fit about two seconds in the space where Macaulay fits one second of recording, thus compressing the sonogram. Here, I stretched the xeno-canto sonograms horizontally to adjust for that.)

Willow whits

Dusky whits

Gray whits

It appears that Willow, with a good recording, is distinctive, with up to three harmonic tones and that downward slope after the upward slow. To the ear, the Willow whit is softer and sweeter than the others. Dusky and Gray, on the other hand, are both dry sharp whits, and virtually indistinguishable on the sonograms. Gray is more likely to go up to 10 kHz or higher, and that echo line on the first Gray sonogram was consistent on all the calls, at least for that individual recording. For the record, Least was similar to Dusky and Gray, although the triangular dark shadow to the right of the main call tended to be thicker and larger.

iPhone whit

iPhone recording

To the right is a typical iPhone recording, probably a Dusky. Based only on this sonogram, just a shadow of the good ones above, it could be any of the species. The take-home lesson is that one could probably diagnostically identify a Willow whit from a sonogram with a very good recording. The Dusky and Gray whits are too close to call.

Our discussion also focused on spring migration timing and incorporated Hammond’s (as many of these birds are silent). Again, I turned to eBird for some trends.


whit map

Spring migration for western Empids. These maps are based on 2017-18 data. I excluded a few outliers in each case. Nevertheless, these dates represent the earliest arrivals. Most birds were a week later than the dates shown.

The results are that Hammond’s is the earliest, followed by Gray and then Dusky. For all three, however, there was a pulse of records during the last week of April. Willow is a full month behind the other two. In fact, even in southern Arizona there were very few Willow records before May 10.

Kaufmann empidsMuch has been written about Empid identification. Here’s a link to the Rowland 2009 article in Birding. My personal favorite is the chapter in Kenn Kaufmann’s Advanced Birding. The diagram at left is from the old version; the new one is even better, showing variations within species.

For the Hammond’s/Dusky challenge in spring, I put together the diagram below. These identifications were confirmed by calling birds, which are easily separated (Hammond’s says peep rather than whit).


Finally, if you’re still confused, there’s this infamous meme:

empid meme

Spring Migration in the Central Valley


Compared to fall, spring migration is fast and furious. It ramps up thru April, peaks in early May, and then ends abruptly. Birds don’t stay long; they’re in a hurry. Rarities rarely last more than a day. And there are fewer birds than in the fall, winter mortality having taken its toll. But, like this Lazuli Bunting, the birds are in their best dress.

In 2010, after ten years of collecting data on morning “warbler walks” in my local patch in Davis, the Central Valley Bird Club Bulletin published my results. You can read the whole paper here:

Hampton, S. 2010. Passerine migration patterns in Davis, Yolo County—2000-2010. Central Valley Bird Club Bulletin 13(3): 45-61.

Last fall, I posted a re-visualization of the data from that paper with regard to fall migration. Here is the spring version.

I’ve divided it into two graphs, one for more common species (peaking at 1 to 4.5 birds per survey), and another for less common migrants (less than 1 per survey).




DavisMigrants2springThe same caveats apply:

  • A “survey” here is basically a morning walk lasting about 35 minutes.
    This was for my little route in north Davis (where the eBird hotspot is “North Davis Farms Subdivision”). For other locations in the Central Valley, even nearby ones, I would expect the numbers and relative abundance to vary a little. For example, I see a lot more flycatchers at Babel Slough and Grasslands Park than are reflected here.
  • Putah Creek near Pedrick Rd, a current favorite of birders, generally has more birds than is shown here because it’s a larger area, birders spend more than 35 minutes when they visit, and the habitat is slightly different.
  • A large portion of the birds in my data are “heard only”.
  • For additional details, see the full article linked above. I’m happy to provide my Excel spreadsheets of this data to anyone interested.

Some species are more common in spring than fall. These include Hermit Warbler (above), Townsend’s Warbler, and Swainson’s Thrush (with a very narrow migration window in mid-May).

I’ve also linked lots of the bird literature specific to Yolo County at my Yolo County Birding website; see the list of papers in the lower right corner of that page.

On these graphs, I’ve left out the rarer birds, species that occur at a rate of less than 0.2 birds/survey (less than 1 out of every 5 surveys). These include Hammond’s and Dusky Flycatchers. It also includes Willow Flycatcher, House Wren, MacGillivray’s Warbler, Common Yellowthroat, and Chipping Sparrow, all of which are quite regular in the fall but rarely seen in spring migration.