Page updated: June 19, 2018



A California Chapter of the National Audubon Society Serving the communities of Stockton, Lodi, Tracy, Manteca, Escalon, Ripon, and Lathrop--All of San Joaquin County.



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Field Checklist of the Birds of San Joaquin County


Bird Sightings in San Joaquin County

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Incredible Combination of Factors Leads to Historic Migration Flight

     There are good days birding, and then there are those spectacular days when you see hundreds of thousands of migrating warblers. Wait, you haven't had one of those?  Well, on Monday, May 28, 2018, six birders experienced exactly that, and their account, detailed in an absolutely bonkers eBird checklist, has the whole bird world abuzz. According to the report, early that morning the six birders arrived at the Tadoussac dunes, a popular birding destination in Quebec, Canada, hoping to see migrating warblers during their morning flight—a phenomenon that occurs when birds pushed off their typical migration pattern during the night reorient themselves at first light. With strong southwesterly winds the night before, the team was hopeful to see birds heading southward to correct their routes. Nine hours later, they ended up having a historic day. 

     Here's just a taste of the team's final tally: 144,324 Bay-breasted Warblers, 108,243 Cape May Warblers, 72,162 Tennessee Warblers, 50,513 American Redstarts, 28,865 Blackburnian Warblers, and the list goes on and on. Altogether, the observers estimate they saw 721,620 warblers, along with loads of other birds. And in case you have any doubts about the report's authenticity or count estimates, the group included several staffers from the Cornell Lab of Ornithology, and the person who made the eBird report was Ian Davies, a project manager at eBird itself. So yeah, these folks knew what they were doing.

     "Today was the greatest birding day of my life," Davies wrote to start out his eBird report. "On our arrival (545a), it was raining. A few warblers passed here and there, and we got excited about groups of 5-10 birds. Shortly before 6:30a, there was a break in the showers, and things were never the same." "For the next 9 hours," Davies continued, "we counted a nonstop flight of warblers, at times covering the entire visible sky from horizon to horizon. The volume of flight calls was so vast that it often faded into a constant background buzz. There were times where there were so many birds, so close, that naked eyes were better than binoculars to count and identify. Three species of warbler flew between my legs throughout the day (Tennessee Warbler, Magnolia Warbler, and Myrtle Warbler]). For hours at a time, a single binocular scan would give you hundreds or low thousands of warblers below eye level." Worth repeating: There were so many warblers, passing through so low, they were flying between his legs. Unbelievable.

     What's even wilder is that the group was able to count and calculate estimates for so many birds. Davies detailed their methodology in the report: "Movement rate estimates were made by looking through binoculars at a flight line, and counting the number of individuals passing a vertical line in that field of view, per second. This was repeated multiple times for each bin view, and repeated throughout the sky so that all flight at that moment was accounted for. The average birds/second was then used for that time period, until another rate estimate showed a different volume of movement."      And that is what makes this whole thing even more amazing: Not only were there birders at the dunes that morning, but they also belonged to an extremely small subset of people in this world that could identify and know how to count such staggering quantities of birds.

     In fact, that magnitude likely makes this group's report the largest account of warblers seen in one day by anyone. "To our knowledge, the previous warbler high for a single day in the region was around 200,000, which was the highest tally anywhere in the world," Davies wrote in the conclusion of his eBird report. "Other observers in the area today had multiple hundreds of thousands, so there were likely more than a million warblers moving through the region on 28 May 2018. There’s no place like Tadoussac."  Indeed, and after news of this incredible occurrence spreads far and wide, you can bet plenty more birders will be heading to Quebec next year hoping to experience their own bit of Tadoussac migration magic. 

Andrew Del-Colle, (June 1, 2018), Retrieved and edited from

    San Joaquin County Annual Summer Butterfly Count Results

     Saturday, June 16, 2018, F. Cranmore, J. Cranmore, K. Foley, B. Heiser, H. Higley, and leader, Katherine Schick participated in the annual San Joaquin County Summer Butterfly Count on an unusually (but welcome) cool day.  This family-friendly field trip began at 8:00 a.m. at the Nature Center at Oak Grove Regional Park where we luckily found one butterfly, a Common Checkered Skipper and a native gray fox, thanks to Barbara's sharp eyes. 

  We had more success at our next stop, the Woodbridge Wilderness Area, where we ran into the San Joaquin Audubon monthly bird census group who shared some of their butterfly finds with us. We were pleased to see a good number of Pipevine Swallowtail butterflies here but we were unable to find any larvae. Other sightings included several Western Tiger Swallowtails, Melitta crescent, Gray Hairstreak, Eastern Tailed-blue, Painted Lady, Red Admiral, Cabbage White, Mournful Duskywing, and Umber Skipper.

  Our next stop was Lodi Lake where Howard promptly spied a big orange butterfly that ended up being the first-ever-on-this-count Gulf Fritillary! Not surprisingly, the host plant was growing not far away in the Wilderness area. We added a couple of Mourning Cloak and Lorquin's Admiral, in addition to more of our previous finds. On our way home we made a brief stop at White Slough and picked up a Common Buckeye then closer to Oak Grove we found a field full of Orange Sulphur for a day's total of 16 species of butterflies and 110 individuals.

From the desk of the President:

As someone who loves reading, I’m in libraries a lot.  They also provide a way to reach the public with information about Audubon’s activities.  What a thrill this week to find that all the copies of our colorful brochure, "Highlights of the Natural Year in San Joaquin County," had been taken from the display area at Stockton’s Troke library.  I promptly restocked, adding a few more copies of our basic chapter brochure as well.  We also have brochures available at Cesar Chavez Library near downtown Stockton.

San Joaquin County is fortunate to boast 14 public libraries.  Right now, we only offer brochures at those two.  Would you be interested in getting this outreach project going at one of the other 12?  Getting permission is usually straightforward.  Then the chapter is happy to supply you with copies of the two brochures, and it’s easy to restock occasionally.  Just let me know and I can arrange everything; contact me through a note to the chapter address, PO Box 7755, Stockton, CA 95267, or at my email,

I also want to share one of the summer highlights in our natural history brochure:  two nearby colonies of Mexican Free-tailed Bats, at the Cosumnes River Preserve just north of our county, and at Yolo Bypass Wildlife Area between Sacramento and Davis.  August is a great time to enjoy the dusk fly-out, featuring thousands of these beneficial animals at both locations (Yolo’s colony is larger, though).  I believe that July and early September are also good.  It’s mesmerizing to watch the bats streaming out silently and funneling upward against the sunset, blackening the sky.  Raptors have noticed this tempting opportunity as well, and I’ve marveled at the aerobatics of Swainson’s Hawks and Peregrine Falcons trying to pick off their dinners.  Peregrines are designed for this sort of challenge . . . Swainson’s, not as much, but they’re persistent.  For more information, check out these webpages: (bat-watching by kayak) and  The Yolo Bypass educational program that precedes the bat viewing includes a close-up demonstration of live bats.

Susan Schneider

President, San Joaquin Audubon Society

Hummingbird Feeding FAQs


While native flowering plants are the best source of nectar for hummingbirds, supplementing with a well-tended sugar-water feeder can provide additional sustenance during nesting season and migration. Consult our FAQ below to ensure your feeder does no harm—and helps your hummers thrive. (Read more about creating a hummingbird-friendly yard here.)

Q: Are there any downsides to supplying a hummingbird feeder to the birds in my yard?

A: No. Your hummingbird feeder will be a supplemental source of nectar for your local hummingbirds, and can help them through times when there aren’t as many blooming flowers available nearby.

Q: Do I need to buy special food for my hummingbirds?

A: No. The best (and least expensive) solution for your feeder is a 1:4 solution of refined white sugar to tap water. That’s ¼ cup of sugar in 1 cup of water. Bring the solution to a boil, then let it cool before filling the feeder. You can make a larger batch and refrigerate the extra solution, just remember to bring it up to room temperature before you re-fill the feeder.

Q: Should I put red coloring in the nectar solution?

A: No, red coloring is not necessary and the reddening chemicals could prove to be harmful to the birds. Natural nectar itself is a clear solution.

Q: Are hummingbirds attracted to red-colored things?

A: Yes, hummingbirds are attracted to red, as well as other brightly colored objects, because they have learned to associate high-quality nectar with red flowers

Q: Should I use brown sugar, honey, or molasses instead of white sugar?

A: No, only use refined white sugar. Other sweetening agents have additional ingredients that can prove detrimental to the hummingbirds. Never use artificial sweeteners to make hummingbird nectar.

Q: How often should I empty and clean the feeder?

A: In hot weather, the feeder should be emptied and cleaned twice per week. In cooler weather, once per week is enough. If your hummingbirds empty the feeder with greater frequency, clean it every time it’s empty. Cleaning with hot tap water works fine, or use a weak vinegar solution. Avoid using dish soaps, as this can leave harmful residue in the feeder.

Q: When should I put out my hummingbird feeder?

A: In most areas of North America where hummingbirds leave during the winter, it’s best to put the feeder out about a week before they normally arrive in your yard. This date varies regionally. If you don’t know when your birds usually arrive check with your local Audubon center, chapter, or local bird club.

Q: When should I take down my feeders in the fall?

A: You can leave your feeders out for as long as you have hummingbirds around. You can even continue to provide the feeder after your hummingbirds disappear—late migrants or out-of-range species can show up into early winter. Follow the guidelines for keeping the feeders clean, even if the nectar goes untouched. Always discard any unused nectar in the feeder when you take it down for cleaning.

Q: Won’t it make my hummingbirds stay too late if I continue to leave the feeder out for them?

A: No, hummingbirds are migratory species and are genetically programmed to head south in the fall.  It’s not a lack of nectar source or colder weather that makes them leave—they know it’s time based on changes in the length of the day and the angle of the sun.

Q: I live in an area where we have hummingbirds year round.  Is it okay for me to feed them year round as well?

A: Absolutely! Just follow the guidelines for keeping your feeders clean.

Q: I put a feeder up, but no hummingbirds have come. How can I get hummingbirds to visit my feeder?

A: Planting red or orange tubular flowers that attract hummingbirds may help them discover your feeder, if you hang it nearby. (Of course, make sure to change the nectar solution and clean the feeder regularly, even if you have not seen any hummingbirds.) You can search for native plants that your hummingbirds naturally visit using our native plants database. Learn more about planting for hummingbirds, and other ways to make your yard hummingbird-friendly, here.

Q: I have a hummingbird in my area past migration time and I’d like to feed it as long as it stays around, what do I need to know?

If you live in an area where the night-time temperatures dip below freezing regularly you will need to make sure your nectar feeder does not freeze. In areas where the nighttime temperatures only dip slightly below freezing your hummingbird nectar may not freeze as the sugar solution has a lower freezing point than plain water. However, it’s better not to have your hummingbirds drink very cold nectar; this can actually cold-stun them. For cold weather feeding, either bring the feeder indoors overnight when it gets cold and put it back outside first thing in the morning (hummingbirds need  to feed as early as possible, especially when it’s cold, to keep their energy up) or you can hang an incandescent light bulb near the feeder. These bulbs give off enough heat to keep the feeder warm.

Some areas of the U.S. do see hummingbirds normally over the winter. Several species of hummingbirds regularly overwinter along the Gulf Coast, southern Arizona, and south Florida. Anna’s Hummingbirds are resident from northwestern Baja California along the Pacific coast to British Columbia, Allen’s Hummingbirds are resident in coastal Southern California, and Costa’s Hummingbirds are resident in Baja California, southeast California to western Arizona.

To learn more about the hummingbirds visiting your yard and the winter range of a particular species, download our free Audubon Bird Guide appor refer to Audubon’s online field guide

Some North American Birds Can’t Keep Up With Shifting Spring Blooms

As climate change makes the seasons less predictable, one in five studied species
are struggling to time their migrations with the greenery.

April showers bring May flowers . . . unless they’re already in bloom, that is. This proverb might soon need an update because the onset of spring has shifted in North America, as the leaf-growing start dates of trees and plants have changed by as much as a day each year over the past decade. In the West, spring is arriving later; in the East, it's arriving sooner.

That shift is bad news for migratory birds, many of which follow a strict schedule to get to their breeding grounds in spring. Once they land, they expect to feast on a bounty of insects, which are themselves gorging on the fresh foliage. If the birds miss the peak plant emergence, chances are the best food has already been snatched up—or, if they arrive early, they'll struggle while they wait for it to become available. This isn't just problematic for adults: The birth and survival of their chicks depends on nature’s seasonal buffet, too.

A new study published in Scientific Reports confirms the growing disconnect between birds’ internal clocks and the changing seasons. Researchers from across the country studied 48 migratory songbirds, and found that nine (Great Crested Flycatchers, Eastern Wood-Pewees, and Northern Parulas, to name a few) are struggling to keep pace with the onset of blooms. Across all the species they looked at, the gap between avian arrivals and the growth of spring leaves in prime breeding locations has increased by an average of half a day each year.

Scientists have tracked spring bird arrivals for decades, but this research offers a broader perspective across species. “What we were trying to do was for the first time scale this up to get a bigger picture,” says Stephen Mayor, lead author of the study and an ecologist at the University of Florida. “We haven’t been able to do that kind of thing in the past because we just haven’t had good data.”

The new analysis paired more than a decade’s worth of data from the citizen-science website eBird with information from a NASA satellite that tracks the yearly arrival of spring greenery. “A single scientist can’t study the globe, can’t study a continent, so tackling these questions requires a new approach,” says Morgan Tingley, an ornithologist at the University of Connecticut and co-author of the paper. Layering the two data sources showed that certain birds are rescheduling their migratory journeys as spring green-up starts on alternate dates. The question, however, is if they’re adjusting quickly enough, Tingley says. Mayor echoes that concern. “One week per decade can really add up pretty quickly and leave birds out of sync with their environments,” he says.

Tingley is particularly worried about the Yellow-billed Cuckoo, which is already in danger of losing its riverside habitat. He also points out that three of the most popular spring migrants—Rose-breasted Grosbeaks, Scarlet Tanagers, and Indigo Buntings—are facing jarring changes to their calendars.

To further complicate matters, the seasonal shifts are divergent on opposite sides of the continent. “As soon as we put these things up on a map, we recognized that something very different was happening in eastern North America than in western North America,” Mayor says. In parts of the West, spring is arriving later,
and out-of-sync birds are arriving before it’s in full swing. Where Eastern birds might miss the big feasts, Western birds may have to tough it out before they have the chance to rebuild their fat deposits after a long migration. “There’s lots of regional variation, but it’s a pretty stark difference,” he says.

Yet timing is only half of the climate change puzzle. Some of the northern breeding habitats that birds are flying to are becoming less suitable in terms of temperature or yearly rainfall—a double whammy for struggling populations. “They’re going to have to figure out both where and when they’ve got to arrive,” says Brooke Bateman, the director of Audubon’s Climate Watch program, who wasn’t involved in the Scientific Reports study. “That’s kind of a lot to deal with at one time.”

Because long-distance migrants have to plan their journeys from afar, they may rely solely on environmental cues. “It’s not like these birds have an app on their phone that can tell them the weather in New York,” Tingley says. “We’re changing weather patterns and changing what’s going on without giving birds an ability to respond.”

This article was originally published on on May 16, 2017.


eBird Mobile

The new eBird Mobile app makes it possible to collect and submit observations directly to eBird from the field.  iOS and Android users who were accustomed to entering eBird data using the BirdLog app are encouraged to switch to eBird Mobile, the new and official app for entering data to eBird.

Merlin Bird ID

In a breakthrough for computer vision and for bird watching, researchers and bird enthusiasts have enabled computers to achieve a task that stumps most humans—identifying hundreds of bird species pictured in photos. Build in concert with the exceedingly popular Merlin app, the Merlin Bird ID tool lets you upload an image of a bird that you’ve photographed, and if the photo shows one of the supported species, it returns the correct species in the top 3 results, 90% of the time. It currently supports 400 species in North America, but will eventually be expanding to more species in North America, and worldwide.  Give it a try.

borrowed from Audubon At Home

Plants for Birds and Wildlife

Planting for birds
Spicebush, photo courtesy USDA-NRCS Plants Database

Birds and wildlife have adapted to utilize native plants that provide food, cover, nesting sites or a combination of resources. Native plants provide food at different times of the year to birds in the form of seeds, fruit or as invertebrate host sites. The growth habits of native plants present recognizable, safe nesting sites and cover that protect birds from inclement weather and predation. The importance of these plants to birds, insects and other wildlife cannot be overstated.

Using native plants in your backyard landscape will offer the most resources to birds and wildlife and serve as rewarding attractants. On these pages you will find some examples of plants that are particularly valuable to specific birds and other beneficial organisms. A more comprehensive database with regional references is in the works at Audubon At Home and will be available online in the near future.

Plantings for birds in our area:

Nuttall's Woodpecker, Oak Titmouse, Yellow-rumped Warbler- California Live Oak

Wrentit, California Towhee, Spotted Towhee - California Wax Myrle

For more information about native plants please visit:

California Native Plant Society

Master Gardener's Program in San Joaquin County

Plants for Beneficial Insects

Predators. Parasitoids. Pollinators.

Welcome them into your Healthy Yard.

These are the insects, bugs and other organisms on the front line of pest control in your yard, guarding against destructive bugs and helping plants reproduce. Nature supplies these beneficial bugs of course, but you can encourage them to remain in your yard by providing them with some essential elements.

Nearly every plant in a natural environment will sustain at least some damage by pests…it is part of the natural balance. But pests don’t overpopulate a natural ecosystem due to the presence of natural enemies. In a healthy yard with its native plants and pesticide-free environment, pests will appear—and so will natural enemies.

THE INSECTS – Wild Friends, Natural Enemies

lady bug
Ladybug feeding on cottonwood leaf beetle eggs, photo by James Solomon, USDA Forest Service

Move Over, Lady - It has long been known that ladybugs (or lady beetles), especially in their larval stage, are "good bugs" with voracious appetites for aphids. Without dismissing the value of ladybugs as garden friends, there are other natural pest enemies that are much less conspicuous but even more valuable. The lowly "gnat" that flies by your ear may in fact be the tiny eulophid wasp – a full-grown one is just one-eighth inch – on her way to lay up to one hundred eggs in the pupae of tree-destroying beetles.

Predatory and parasitoid flies and wasps are key players in the biological control of insect pests. Many, in fact, are reared in laboratories and dispersed into crops, forests and neighborhoods to control exotic insect pests (i.e. elm leaf beetle). Click on the link below to learn more about the tiny denizens of your yard and other beneficial organisms.

THE PLANTS – Nectar for Natural Pest Enemies

hover fly
Syrphid (hover) Fly, photo by Carl Dennis, Auburn University

Nectar is an important dietary supplement for beneficial wasps and flies. Asters and their cousins (such as daisies and goldenrod) offer excellent resources and there are native varieties in every part of the country. Flowers that are composites - where many small symmetrical flowers occur in a central disk - are perfect for small wasps and flies such as the common predaceous hover fly (pictured left). Many of the beneficial insects are small and require a short flower structure in order to access the nectar.

These same flowering plants will attract a wide range of important pollinators such as native bees, butterflies and honeybees. When they produce seed, these plants will provide a valuable food source for birds and other wildlife in the fall and winter.

Plant a variety of plant types such as groundcover, trees, and shrubs, mimicking natural growth patterns to form complex habitat that will be home to a greater variety of beneficial insects.

THE INSECTS – Information and pictures of the lesser-known but effective natural enemies that occupy your backyard.

PLANTS TO ATTRACT BENEFICIAL INSECTS – Your guide to some stellar examples of the useful plants that will attract a variety of beneficial insects. Look for examples of similar native flowers occurring in your region.






Joe-pye Weed


For more information about beneficial insects please visit:

Xerxes Society

Beneficial Insects in Your Garden


If you’re interested in finding out what rare and unusual birds are being seen in California (or anywhere in the US, for that matter), you should check out Sialia, aka The Birding Lists Digest.  Sialia ( was created to help birders find out "what's going on lately" in various regions of the U.S. with a minimum of hassle. The Digest automatically compiles all posts to dozens of birding email lists and organizes them by region, by day, and by list. Birders can view the current day's messages, or browse messages from the last 30 days. This system allows birders to find information about rare bird sightings and other goings-on around the country in a timely and efficient manner.  Check it out!


April 16, 2018 – June 15, 2018
(All sightings pertain to San Joaquin County)
Submitted by Liz West

On April 19th, Dan Kopp, Mark Martucci and Jim Rowoth saw a male Calliope Hummingbird in Kiln Canyon. On May 6th and May 1lth, David Yee observed a male and a female Calliope Hummingbird, respectively, at his feeders.

A San Joaquin Audubon Field trip to Woodbridge Wilderness area saw a single Band-tailed Pigeon on one of the treetops, April 21st.

On May 2nd, Kurt Mize confirmed breeding of a pair of Say’s Phoebes in a north Stockton neighborhood. They were nesting under the eaves of a front porch and had two nestlings. James Rexroth also mentioned that he saw a Say’s Phoebe nesting at Westwood Elementary School.

May 12th, David Yee found two female Indigo Buntings one in his yard and one at Heritage Oaks Winery along the Mokelumne River. Also present along the river was a Hammond’s Flycatcher.

Terry Ronneberg saw a Brown Pelican flying over the First Congregational Church parking lot in Tracy on May 14th.

On May 23rd, David Yee spotted a Green-tailed Towhee along the river in the Lodi Lake nature area.

Breck Breckenridge found a male Blue-winged Teal at White Slough Wildlife area on June 13th.


San Joaquin Audubon Society
PO Box 7755, Stockton, California 95267

For more information contact:
San Joaquin Audubon Society President: Susan Schneider:

Send website comments or questions to:

Kasey Foley:




For San Joaquin Audubon Field Trips visit our Field Trips Page.




 Membership in the National Audubon Society includes:


San Joaquin Audubon's Hoot Owl newsletter 6 times per year.

AUDUBON magazine.

Monthly field trips led by San Joaquin Audubon members.

General Membership meetings from September-December and February-April.  We often have local experts presenting topics such as Beginning Birding, Gardening for birds and butterflies, Raptor Rehabilitation, Sandhill Cranes-our local winter wonders, Swainson's Hawk conservation, Slide presentations on trips to Mexico, Galapagos, Honduras, Florida,and much, much more.

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