San Luis National Wildlife Refuge Complex

Summer Speaker Series -- Join us on Saturday, August 3, 10 a.m. at the visitor center of the San Luis NWR for our 3rd installment in our Summer Speaker Series. Rick Lewis is a wildlife and nature photographer who spends countless hours on the three refuges of the San Luis NWR Complex taking amazing pictures of the wildlife and landscapes here in the San Joaquin Valley. If you follow our page, you've seen many of Rick's photos. On Saturday, August 3, Rick will present a selection of photos taken during the past year and will share his experiences observing wildlife and getting the shots. Rick's presentation will last about an hour with time for questions and answers. For more information call the visitor center at 209-826-3508, ext. 127 or check upcoming events on the website at https://ow.ly/cHKc50SBWmV Western kingbirds (Tyrannus verticalis) have been feasting on cicadas this summer at the San Joaquin River NWR. This photo was taken earlier this month, courtesy of Rick Lewis.

Summer Speaker Series -- Join us on Saturday, August 3, 10 a.m. at the visitor center of the San Luis NWR for our 3rd installment in our Summer Speaker Series. Rick Lewis is a wildlife and nature photographer who spends countless hours on the three refuges of the San Luis NWR Complex taking amazing pictures of the wildlife and landscapes here in the San Joaquin Valley. If you follow our page, you've seen many of Rick's photos. On Saturday, August 3, Rick will present a selection of photos taken during the past year and will share his experiences observing wildlife and getting the shots. Rick's presentation will last about an hour with time for questions and answers. For more information call the visitor center at 209-826-3508, ext. 127 or check upcoming events on the website at https://ow.ly/UnTU50SGrCa This spotted towhee (Pipilo maculatus) was recently caught in full song somewhere along the Pelican Nature Trail at the San Joaquin River NWR, courtesy of Rick Lewis.

It's mid-July and in a couple of weeks or so, the tule elk at the San Luis NWR will begin their breeding season or the "rut." The rut is usually a good time to observe the tule elk. Bulls will be bugling to announce their presence to the cows and to other bulls. Individual bulls will also listen to the bugles of other bulls to determine their location. Also during this season, elk will display interesting -- and sometimes amusing -- behaviors. Remember, however, the best time for wildlife viewing is early morning and the second-best time is late afternoon/early evening. That is even more so during these hot, dog days of summer. Visitors will generally not find the tule elk out and about during the heat of the day. This photo of tule elk bulls with their full-grown polished antlers was taken about 3 weeks ago, courtesy of Gary R. Zahm.

The California thrasher (Toxostoma redivivum) is a bird not often seen at the San Luis NWR Complex. The species is listed as "rare" at all three refuges of the complex, but when it is seen, it's usually at the San Joaquin River NWR. That's where this thrasher was photographed a couple of weeks ago somewhere along the Pelican Nature Trail. Thrashers are members of the bird family Mimidae along with our northern mockingbird. They are collectively known as "mimids" or the mimic thrushes. The Mimidae family of songbirds is found in the Western Hemisphere. They are known for being excellent songsters that imitate the songs of other bird species and incorporate them into their own. The California thrasher is found almost exclusively in California, but also inhabits a small portion of northern Baja California. The species is non-migratory being found throughout it's entire range year-round. Although the thrasher is fairly common in its range, it is not often seen because it is a denizen of dense shrubby habitat consisting of shrubs and small trees almost always shorter than about 15 feet tall. They're ground-feeders that forage for insects and other arthropods by sweeping their long, downward-curved bill through leaf litter looking for prey. When they detect movement on the ground they will excavate in search of food by inserting their bill into the ground, then forcing it open -- a behavior known as "probing and gaping." Just about any ground-dwelling invertebrate is fair game -- larvae, beetles, earwigs, sowbugs, millipedes, spiders, moths, ants, wasps, and bees. In late summer, they may transition to eat more fruits and berries like elderberries and blackberries. Photo courtesy of Rick Lewis.

A summer nesting resident of the San Luis NWR Complex, the black-headed grosbeak (Pheucticus melanocephalus) has a massive bill (hence the name "gros" beak) perfectly suited for cracking seeds, as well as sn**ching and crushing hard-bodied insects and snails. In fact, about 60% of a grosbeak's breeding-season food consists of insects, spiders, and other invertebrates. The remaining portion of their diet is made up mostly of seeds and fruits like elderberries. Berries are especially favored during migration. This female or immature black-headed grosbeak was observed recently along the Pelican Nature Trail at the San Joaquin River NWR, dining on the fruit of black elderberry (Sambucus nigra), a native shrub found throughout the San Joaquin Valley and elsewhere in California. Elderberries are loaded with vitamins A and C, minerals like calcium, zinc, and magnesium, and are a favorite food of many birds and small mammals like squirrels and rabbits. The shrub also provides dense cover for birds and small mammals. It provides perching and nesting sites for birds. Insects, like mason bees and the threatened elderberry longhorn beetle, nest in its hollow stems. The insects, in turn, provide another food source for birds -- important because 96% of North America's terrestrial bird species feed their growing young insects. Photo courtesy of Rick Lewis.

Being a flycatcher, it's no surprise that the western kingbird (Tyrannus verticalis) is primarily an insectivore or an insect-eater. However, insectivore or not, some 96% of terrestrial bird species feed their chicks insects. While many species of birds rely on seeds and fruits for their winter fare, insects are the best food for growing chicks. Consider the lowly cricket, for example. Ounce for ounce, crickets contain 2 to 3 times more protein than beef and they're full of iron, vitamins, and fiber. While unappealing to a human, insects like crickets, and other morsels like fly maggots, and spiders are life-saving foods full of fat and protein for growing young birds. Chicks need to grow and develop muscle tissue quickly because winter is fast-approaching and they need to be ready and able to leave their nest and fly, catch food for themselves, and in some cases, migrate long distances just a few months after hatching. Like this western kingbird parent photographed recently at the San Luis NWR, bird parents all over the refuge complex are busy catching billions of insects and other invertebrates to give their youngsters a good start on becoming a full-grown bird. Photo courtesy of Gary R. Zahm.

Eighty-two species of butterflies and moths have been documented in Merced County, home of the San Luis and Merced NWRs and 117 species have been documented in Stanislaus County, home of the San Joaquin River NWR. This little butterfly was photographed last week at the San Joaquin River NWR somewhere along the Pelican Nature Trail. It's a western pygmy-blue (Brephidium exilis) and appears to be resting on a coyote bush. Coyote bush flowers are rich with nectar and attract numerous pollinators like bees, wasps, and butterflies, but the shrub blooms late in the season. The coyote bush in this photo does not appear to be flowering, so, why is the pygmy-blue attracted to it? On hot summer days, the leaves of coyote bush become sticky with resinous oils that impart a fragrance described by some as "honey-like." Perhaps that is what has attracted the western pygmy-blue butterfly to check it out. There are many more species of butterflies throughout the San Luis NWR Complex. Keep your eyes open and see how many you can spot on your next visit. Photo courtesy of Rick Lewis.

Join us this coming Saturday, July 13, at 9 a.m., to hear naturalist, birder, nature photographer, and frequent refuge visitor, Steve Johnston, share his experiences observing and photographing the flycatchers of the San Luis NWR Complex. From kingbirds to phoebes to wood pewees, flycatchers are masters at swooping out from their perch to pluck flying insects from midair. There are many species of flycatchers that make the refuges of the San Luis Complex their home during at least some part of the year and Steve gets great enjoyment observing them, and sharing that enjoyment with others. For more information about Steve's talk or for directions to the visitor center, call 209-826-3508, ext. 127. This ash-throated flycatcher (Myiarchus cinerascens) was observed and photographed by Steve Johnston recently along the wetland nature trail across from the visitor center at the San Luis NWR. The ash-throated flycatcher is a species in the family Tyrannidae -- the "tyrant" flycatchers.

There are at least 30 different species of dragonflies and damselflies in California and quite a few have been observed and photographed throughout the San Luis NWR Complex. Many of them have shown up here on our refuge complex page. This dragonfly, believed to be a "spot-winged glider" (Pantala hymenaea) is a new one. It gets its name from the dark spot on the hindwing near the body. Spot-winged gliders are common and widespread througout the NewWorld in North, Central, and South America, and parts of Canada. It's a migratory species flying northward into North America from the tropics in the summer and flying south in the fall. It is believed that, like the monarch butterfly, a different generation of dragonfly migrates south in the fall than the one that flew north in the summer. This dragonfly species requires temporary wetland habitats in which to breed -- flooded areas and pools of water that appear after summer rain showers, for example -- wetlands that do not harbor fish that would devour the dragonfly nymphs. Spot-winged gliders are predators of Anopheles freeborni -- the western malaria mosquito. The dragonfly feeds on the mosquitos mostly at dusk, which is when the mosquitos generally swarm. This spot-winged glider was photographed last weekend somewhere along the Pelican Nature Trail at the San Joaquin River NWR, courtesy of Rick Lewis.

The birds in the family Tyrannidae are known to be precision fliers when it comes to sallying forth from an exposed perch to sn**ch flying insects in midair, but this western kingbird (Tyrannus verticalis) appears to be quite adept at juggling too as it attempts to maneuver what appears to be a large cicada into just the right position for swallowing. The visitor watching this performance said he wasn't sure if it was the same kingbird returning repeatedly to the perch, but at least 8 cicadas were caught and devoured! Photo courtesy of Rick Lewis.

This early morning bull session was captured last week at the San Luis NWR. The tule elk rut or breeding season is just around the corner, typically beginning around the end of July. Perhaps these bulls are sharing opinions and anecdotes of ruts gone past, or formulating strategies for the upcoming season. At any rate, the rut is a great time to visit the San Luis NWR and observe the tule elk. Bulls will be bugling and sparring for the attention of the cows. Plan to visit and do some tule elk watching this August and September. Photo courtesy of Gary R. Zahm.

Alkali heliotrope (Heliotropium curassavicum) is considered a prime butterly nectar plant -- a butterfly magnet. Its tiny flowers produce abundant amounts of nectar and pollen and it has been observed to attract many of species of butterflies. Other pollinators visit the flowers too, including bees. The plant favors sandy alkaline soils, whether along the coast or inland at locations like the San Luis NWR Complex. The flowers open along an uncoiling spike, like a fiddleneck, with the flowers at the bottom of the spike opening first. When the flowers first bloom, they have a yellowish throat that changes to purple as individual flowers age. This alkali heloptrope hosting a foraging skipper butterfly was photographed recently somewhere along the Pelican Nature Trail at the San Joaquin River NWR. Photo courtesy of Rick Lewis.

Join us on Saturday, July 13, to hear naturalist, birder, nature photographer, and frequent refuge visitor, Steve Johnston, share his experiences observing and photographing the flycatchers of the San Luis NWR Complex. From kingbirds to phoebes to wood pewees, flycatchers are masters at swooping out from their perch to pluck flying insects from midair. There are many species of flycatchers that make the refuges of the San Luis Complex their home during at least some part of the year and Steve gets great enjoyment observing them, and sharing that enjoyment with others. For more information about Steve's talk or for directions to the visitor center, call 209-826-3508, ext. 127. This ash-throated flycatcher (Myiarchus cinerascens) was observed and photographed by Steve Johnston a few days ago along the wetland nature trail across from the visitor center at the San Luis NWR. The ash-throated flycatcher is one of the flycatchers in the family Tyrannidae -- the "tyrant" flycatchers.

The ring-necked pheasant (Phasianus colchicus) is a popular species with birders and wildlife-watchers, and is one of the most popular game birds with North American sport hunters. However, the ring-necked pheasant is not a native species in North America. The species is native across Asia including the Black Sea, the Caspian Sea, Korea, Japan, the coast of China, and througout the temperate regions of China. The bird was introduced to North America -- some say as long ago as the 1730s. After multiple releases here, the ring-necked pheasant is now found in 40 states and small areas of southern Canada. It's referred to as a "gallinaceous" species referring to those in the family Galliformes -- birds having heavy rounded bodies, short rounded wings, short bills, and strong legs. Other gallinaceous birds include quail, turkeys, and domestic chickens. The gallinaceous birds are well-adapted for life on the ground. Strong legs and feet are great for walking and scratching. Short rounded wings are adapted for quickly lifting off for short rapid flight and short bills are perfect for pecking about for seeds. This ring-necked pheasant brood was observed a few days ago, foraging on thistle seeds, at the San Luis NWR. The visitor counted 8 young in this particular brood. Photo courtesy of Gary R. Zahm.

Swainson's hawk chicks (Buteo swainsoni) can be heard across the San Luis NWR Complex callling for their parents that are working long hours to keep their growing family supplied with food. A frequent visitor to the wildlife refuges keeps a close eye on raptor nests and was recently checking on this family at the Merced NWR. This Swainson's hawk brood has two chicks. Both can be seen in the nest in one photo -- the head end of one chick and the tail end of the other. The single chick in the other photo is thought to be the older of the two as it is much more active and noticeably larger than its sibling. Depending on when the pair gets started laying eggs, Swainson's eggs hatch between March and July. The chicks fledge about 30 days after hatching. One and a half to 2 weeks later, they take their first flight. Swainson's hawk chicks normally remain with their parents through the summer until fall migration. Youngsters will begin learning how to find their own food by "hunting" for large insects like grasshoppers on the ground. Photos courtesy of Steve Johnston.

Something heard a lot from summer visitors to the San Luis NWR Complex goes something like this, "I know the birds are all gone (referring to the winter migratory waterfowl), but will I see anything if I visit the refuge now?" The answer is, "absolutely!" A frequent wildlife refuge visitor spent a little time on the Pelican Nature trail at the San Joaquin River NWR one morning last week and commented that he was amazed at the abundance he observed just a short distance from the parking area in a brief period of time. The photos here are just a sampling from his morning visit. There is one caveat when it comes to visiting the national wildlife refuges in the summer. Wildlife doesn't like being out in extreme heat and glaring sun any more than we do, so the earlier in the day one visits -- the better. This visitor was there before 8 a.m. and wandered about for just a couple of hours -- wrapping up before the real heat of the day set in. Scroll through the photos to find out more. Photos courtesy of Rick Lewis.

NOTICE for visitors to the Merced National Wildlife Refuge: A portion of the Merced NWR Auto Tour route will be closed due to construction from June 24 to Mid-July -- see the area on the map marked in yellow. During this time, visitors will be able to travel a portion of the Auto Tour route on the east side to access the Bittern Marsh parking area and trailhead. During the construction closure, vehicle traffic along the east side of the auto tour route will be two-way, as indicated by red arrows on the map, so please be alert to possible approaching traffic. During this period, also please be respectful of signs, cones, and other construction barricades. Thank you! For information or to ask questions regarding these temporary changes, please call the visitor center at 209-826-3508, ext. 127.

Excitement outside the San Luis NWRC visitor center today! This morning, an American robin (Turdus migratorius) was observed hopping around near a California wildrose shrub outside the visitor center carrying mouthfuls of food and becoming quite distraught whenever anyone approached too close. After being seen with several different mouthfuls of food, it became apparent -- the bird must have a nest nearby. Later in the morning, at the head of the trail into the pollinator garden, a staff member nearly collided with the robin as it darted out from a shrub right in front of them. Looking down to the right, into a mulefat shrub, sat this juvenile robin, trying to remain quiet and motionless, hoping the intruder would leave so mom could bring back lunch. Further investigation revealed a nest, some distance away, on top of a horizontal wooden beam above the visitor center entrance, with at least two more American robin chicks. Mom was seen later delivering food to them, as well. Apparently, the juvenile in the mulefat was the first to find it's wings and now mom is having to deliver food to two different dining rooms. USFWS photo.

Have you heard the buzz? Today is the beginning of National Pollinator Week 2024. This year Pollinator Week celebrates the critical role pollinators play in Earth's ecosystems, countries' economies, and agriculture world-wide. Pollinators are essential creatures including birds, bats, bees, butterflies & moths, flies, beetles, and wasps. Let's start Pollinator Week by discovering what makes a good pollinator? A good pollinator is highly mobile so it can quickly visit a lot of flowers. The most important pollinators can fly. Good pollinators have lots of hairs, scales, or feathers to which pollen can attach -- they need to be "sticky," so pollen can hang on while being transported to another flower. Good pollinators are adapted to feeding on flowers, nectar, and pollen and they often have specialized structures adapted to gather this food like the long skinny bill and tongue of a hummingbird, for example, or the long proboscis of a butterfly, or the "pollen baskets" of a bee. Finally, from a plant's perspective, it's desirable to have a pollinator that visits just one or a few species of plants. It doesn't do a daisy any good if the pollinator collects its pollen and then doesn't visit another daisy.

This bumble bee foraging on Salvia clevelandii (Cleveland Sage) at the San Luis NWR visitor center is an example of a wonderful pollinator. It can fly. Its body is covered with hair. It has a longer tongue than other bee species and bumblebees have a "super power!" Bumblebees can "buzz pollinate." Bumblebees are large and strong. They can hold onto flower parts and then vibrate their wings, literally shaking the pollen loose from plants that hold on tight to their pollen -- like tomatoes, peppers, and strawberries. Bumblebees can also fly and forage in cooler and windier conditions than other bees. This means, bumblebees can forage for nectar and pollen earlier and later in the season, earlier and later in the day, and during cloudy weather. Photo courtesy of Gary R. Zahm.

Join us on Saturday, July 13, to hear naturalist, birder, nature photographer, and frequent refuge visitor, Steve Johnston, share his experiences observing and photographing the flycatchers of the San Luis NWR Complex. From kingbirds to phoebes to wood peewees, flycatchers are masters at swooping out from their perch to pluck flying insects from midair. There are many species of flycatchers that make the refuges of the San Luis Complex their home during at least some part of the year and Steve gets great enjoyment observing them, and sharing that enjoyment with others. Join Steve at 9 a.m. in the San Luis NWR visitor center, on Saturday, July 13. For more information or directions, call the visitor center at 209-826-3508, ext. 127. This ash-throated flycatcher with its lunch was photographed by Steve Johnston somewhere on the San Luis NWR Complex.

Wildlife like this black-tailed jackrabbit (Lepus californicus) at the San Joaquin River NWR, that live in areas with extremely hot daytime temperatures, stay cool by releasing excess body heat from their gigantic ears. A jackrabbit's ears provide a broad expanse of thin skin exposed to the surrounding air. The skin is loaded with blood vessels, as you can see in this photo. When it's hot outside, the rabbit retreats to an area with a slightly cooler temperature -- like the shade beneath a shrub. The blood vessels in the rabbit's ears expand in a process called vasodilation. That increases the blood flow from the body's core to the ears. Then the ears act like radiators allowing the rabbit's body heat to dissipate into the surrounding, slightly cooler air. This method of cooling based on blood circulation conserves water as opposed to methods like panting or sweating, through which moisture is lost from the body as it evaporates into the surrounding atmosphere. This is important to keep the animal's body from dehydrating, especially in environments where there is little or no surface water. Wildlife like jackrabbits rarely, if ever, take a drink of water. They get all the water they need from the food they eat. It's important they don't lose a drop through activities like panting or sweating. This jackrabbit was photographed last weekend courtesy of Rick Lewis.

Hungry mouths to feed -- this photo shows what appears to be a family of black phoebes (Sayornis nigricans). A parent, flying in at the bottom, is likely bringing food to two hungry youngsters waiting, with their mouths agape, eager for breakfast. Black phoebes are flycatchers in the same family (Tyrannidae) as other 'tyrant' flycatchers of the San Luis NWR Complex like the western kingbird, Say's phoebe, and the ash-throated flycatcher. As such, they eat insects and other arthropods, like spiders, almost exclusively. Black phoebes are closely associated with water because they need a source of mud to build their nests, so wetlands are also a source of food in the form of aquatic insects and even small minnows that the birds are capable of plucking from beneath the water's surface. Hungry growing chicks may even be fed fish -- not something one might think of when it comes to songbirds. This photo was taken last week at the San Luis NWR courtesy of Gary R. Zahm.

If you've ever wondered about the plants you see when visiting the San Luis NWR, here's your chance to learn their identity and some of the ways they benefit wildlife. Join the refuge park ranger on Saturday, June 8, at 9 a.m. for the first in our Summer Speaker Series, as she presents Plants of the San Luis NWR Complex. The presentation will take place in the visitor center multi-purpose room and will last approximately one hour. Attendees will have a chance to ask questions. Afterwards, those who are interested can take a guided walk around the visitor center pollinator garden that has been an ongoing project for several years. One may even catch sight of some bumblebees, hummingbirds, and other pollinators that have begun using the garden. For more information call the visitor center at 209-826-3508, ext. 127. Photo of a native bumblebee foraging Cleveland sage (Salvia clevelandii) at the visitor center was taken about a week ago, courtesy of Gary R. Zahm.