You have surely heard, if not seen, a Northern Mockingbird in your area. They can be heard serenading at any time of the day and night and can mimic hundreds of noises. This small gray bird with white patches on their wings and long tail feathers, can be found in grasslands, wooded areas, or in your backyard.
By: Dr. Guthrum Purdin, Veterinarian
The animals who are brought to wildlife rehabilitation centers represent a myriad of species, each having unique biological and behavioral needs. Successfully treating an animal who may have been dying when they arrived requires a deep understanding of what that particular individual needs, and how their condition is affected by species-specific variables. Very little medical research has been done on treating wildlife, so rehabilitators need to make themselves keen observers and experts on the animals they handle. Often, new therapies and treatment strategies are created by individuals working in the terra incognita of wild animal care.
Many years ago, when my wife and I were finishing our undergraduate classes prior to attending veterinary school, we were co-directors of animal care here at the California Wildlife Center, just a few years after it first opened. I remember one case from this period that needed us to be especially creative in order to help a female Mallard who arrived in dire condition.
Duck boot – photo credit by Dr. Rebecca Duerr
The Mallard had been seen by a regular dog & cat veterinary office for an injured leg before transfer to CWC. That vet had put a splint on the leg that would have been fine for a dog, but the duck was having a lot of trouble. On arrival, she was tumbling over & over as she tried to stand, failed, fell over, and panicked again and again. We removed the leg wrap and found a bone called the tarsometatarsus (TMT) was broken very close to the foot. This bone is below the hock (the hock is the joint equivalent to a human ankle but looks like a backward facing knee when ducks are waddling around). It’s normal for mammals to include the joints above and below a bone fracture into a splint to stabilize the break. However, with most birds, such wraps make normal walking impossible and wild animals quickly start to panic. Plus, birds will heal fractures quicker, with less risk to surrounding joints, if they can use the leg normally. For a broken TMT, we usually apply stiff padded splints to one or two sides of the bone. This can be enough for a hawk or a songbird. For this duck, it was not enough— she was folding the foot under the leg, standing with her foot upside down. We had to put our thinking caps on for this one! The solution we came up with was to make a “shoe” of stiff material (like the firm closed-cell foam used in certain food packaging) cut in the shape of the foot, padded, and taped on, plus we cut metal paperclips, bending them to match the angle of the TMT where it meets the foot, wrapped them in padding, and taped the whole rig in place. Voila! The first “duck boot” was made. The female Mallard could now put her weight comfortably on the leg, walking easily and confidently—without panicking.
Duck boot splint – photo credit by Dr. Guthrum Purdin
But wait! I didn’t mention she had ducklings with her. A broken leg like hers usually means the bird is “dry docked” for a while, kept out of water so the splint and wrap can stay dry. But with her babies in tow, she would need to be able to get into and out of a shallow pool of water. The answer was using a kind of plastic tape that maintained its stickiness in the water, giving her a waterproof boot. With a good diet, medication for pain and inflammation, plus a quiet, peaceful enclosure to heal in, this Mallard was able to resolve the fracture, take care of her ducklings, and they were all released together back into the wild.
Since then, we’ve used this splint dozens of times, taught its use at rehabilitation conferences and veterinary schools, and it has been included in a couple textbooks. This is not a unique story. Wildlife rehabilitators, from highly trained veterinarians to deeply committed volunteers with no formal education, have come up with many of the crucial treatment modalities used around the world for countless injured, sick, and orphaned wild animals who, without their caregiver’s dedication and determination, would not have survived. These techniques are shared and refined amidst the rehabilitation community and will benefit distressed wild animals for generations to come. Every time I go to a conference, open a journal, or sit down to dinner with a colleague, I never know what new ideas and innovations will be revealed!
Ducklings – photo credit by Dr. Guthrum Purdin
By: Cori Carlson, Administrative Coordinator
Burrowing Owl
Burrowing Owls, as their name implies, mostly live in underground burrows dug by other animals such as ground squirrels or gophers. These small brown and white owls have long legs and yellow eyes. While CWC has admitted eighty owls so far this year, only two have been Burrowing Owls.
In mid-October, a finder brought in an injured Burrowing Owl who was suffering from head trauma. When initially admitted, the owl was lethargic, unresponsive to visual stimuli, moderately dehydrated and had a poor appetite. After three days with fluids, anti-inflammatories and pain medication, the patient began to appear brighter, perching and eating on their own. When the hospital staff performed additional tests, they found the owl was experiencing temporary blindness as a result of the head trauma. Over the next week, the patient’s condition improved with medication and cage rest.
While most owl species hunt at night, the Burrowing Owl hunts during the day and night. They live in open areas with minimal vegetation and are most often found on the ground or on low branches where they do most of their hunting. Their diet includes insects, lizards, small birds and rodents.
After 12 days in care, the patient was moved to an outdoor enclosure and immediately flew to the highest perch. The owl then flew a few laps around the enclosure. This remarkable Burrowing Owl will continue to be monitored outside for about two weeks while they strengthen their flight muscles before returning to the wild.
By Jenn Guess, Hospital Manager
Hatchling Acorn Woodpeckers admitted to CWC after branch was trimmed from tree
Trees are essential to our environment in many ways. They absorb and store carbon dioxide, which helps mitigate climate change by reducing greenhouse gases, and are a primary source of oxygen production. Roots help bind the soil preventing erosion, and some varieties of trees even improve soil by making it more fertile for plant growth. One of the most important aspects of trees is their role in supporting wildlife by providing habitat, food, shelter, and nesting sites for a wide variety of species. For example, Acorn Woodpeckers excavate nesting cavities in trees to raise their young and reuse these nest holes for many years. Western Gray Squirrels build compact ball-shaped nests on sturdy branches high in the trees, typically in the canopy. Hummingbirds are known for their tiny and intricate nests made from plant material and spider webs. These golf ball sized creations can be found in well-concealed spots in trees and shrubs.
At CWC we recommend planting native plants to help support wildlife in your neighborhood. In the wild, vegetation is only limited by resources and each species’ genetics. When trees grow near human development, trimming and maintenance is often needed to keep plants healthy and man made structures safe.
Tree trimming serves several vital purposes, making it an essential aspect of tree care. It removes excessive dead branches, allowing the tree to allocate nutrients towards growth. Trimming also removes diseased limbs, which prevents the spread of infection and promotes overall tree health. Overgrown branches can also pose a significant risk to people and property, but regular trimming ensures that branches do not grow too close to buildings, power lines, or roadways.
Tree squirrel nest in tree
Selecting the appropriate time of year to trim trees is critical for protecting native wildlife. Here at CWC we often see the detrimental aftermath of tree trimming gone wrong. Each spring, summer, and fall we admit hundreds of orphaned animals due to people cutting down and/or destroying nests. Tree trimmers can also permanently scare away bird parents if they disturb or linger around a nest for too long. December is the ideal month to trim because many tree species are dormant, they lack leaves allowing for a clearer view of the tree’s structure, and it is the time of year in which it is least likely to disturb an active nest. Most birds tend to nest between February and August, although some species like hummingbirds, doves, and pigeons have been known to nest year-round in Southern California. Tree squirrels can mate twice a year and usually have active nests between January through April and July through October. Historically these time frames were more consistent but shifts in climate conditions have made these nesting periods slightly unpredictable.
Before starting a tree trimming project, it is always advisable to consult a local wildlife expert, arborist, and/or conservation organization to understand the specific needs of the wildlife in the area. Prior to trimming, inspect the tree carefully for active nests. Young animals will often become quiet and stay still if they feel threatened, so using binoculars to examine each branch for movement or activity can be helpful. Look on the ground below the tree for a collection of fresh bird droppings. This can signal that a nest above might be inhabited. If possible, trim branches by hand so it is easier to see up close what is being removed. Only trim branches that are necessary for safety and tree health and leave as much natural habitat as possible, including cavities and foliage. Dead branches also provide important habitats for a number of insect and bird species. Consider leaving some deadwood on trees if it does not pose a safety risk.
Through responsible tree trimming, it is possible to safely enjoy healthy plants while simultaneously protecting the habitats that so many wild animals need in order to thrive in the wild.
Anna’s Hummingbird nest in a tree
By Executive Director, Jennifer Brent
Acorn Woodpeckers
Once able to eat on their own, the woodpeckers were placed in an outdoor aviary to acclimate to the temperature, develop muscle stamina and strength, and de-habituate from humans. In a special aviary, logs were hung from the ceiling to mimic trees. These logs have been drilled with multiple holes, where we secrete mealworms and other tasty tidbits. In this way, the birds learn that pecking the wood will bear food.
Woodpeckers have special adaptations that allow them to “drill” into trees. Their tongues wrap around their brain—this cushions their heads while drilling into wood and provides a handy space for their very long (5 inches for an adult Acorn Woodpecker) tongues to go. These tongues are barbed, which enables them to scoop out insects or sap from a hole.
Male and female Acorn Woodpeckers look virtually the same, both sporting the distinctive red “caps” and black backs and white breasts.
These birds depend on oak forests for survival, as they are specialists in acorns. They may create granaries to prepare for winter and store over 50,000 acorns in a single tree, with each acorn in its own small hole. As specialists, Acorn Woodpeckers are particularly vulnerable to deforestation and loss of habitat.
By Senior Wildlife Technician, Cambria Wells
Upon intake at CWC, baby birds range widely in age, health, and more. A critical task within their first few hours of admission is identifying their species, to begin to provide them with the appropriate care. Los Angeles is home to 518 species of native birds, many of which are especially similar in appearance while in their juvenile feathers. Even more are nearly identical in the first couple weeks of life; their featherless skin and underdeveloped bodies at this age may look very different from how we see them as young adults in our yards and parks.
Black Phoebe Nestling
Most important to very young birds are their housing and dietary needs. Many flycatchers make “cup” nests which we mimic in our hospital; crocheted nests made and donated to CWC are placed into incubators for the youngest birds or those needing a little extra heat support. Older birds are housed in front of sunny windows in small enclosures with appropriate perching and leafy cover for their comfort. They are then hand fed whole insects at thirty- or forty-five-minute intervals by the OCU’s dedicated team of volunteers. How we achieve good nutrition depends on species; for some birds there is a commercial formula which we can use to suit their needs. Some require a homemade mix or blended formula of whole food items and vitamins. For birds on formula, this diet includes all their nutritional needs. For insectivores like our Pacific-slope Flycatchers, who receive a whole prey diet, we give special vitamins by mouth daily and pay close attention to the balance of their diet. Even the insects we feed them are carefully prepared by “gut-loading” with nutritious foods. This ensures our patients build strong bones, smooth well-structured feathers, and the appropriate colors to appear indistinguishable from their wild-raised cousins.
Pacific Slope Flycatcher Fledglings
Though complex, raising baby birds and witnessing their growth into strong, independent, and unique patients is the greatest reward of working in our Orphan Care Unit. Volunteers and staff often remark that they never noticed a species near their home or when hiking until getting to know them at CWC; then, they see and hear them everywhere! Growing our skills in identifying and observing these birds in the wild and at CWC builds an incredibly rewarding relationship. It’s always good to get to know your neighbors.
Birds live by their feathers. They need them to keep warm, to stay dry in the rain and most of all, they need them to fly. There’s a rhythm to molts during which old feathers are shed and new ones grow. If a feather breaks or is damaged, the bird is stuck with it until its next molt. When multiple flight feathers are broken, flight may be impossible. For these birds, unable to find food or escape predators in the wild, life is at an end.
Greater White-fronted Goose
By Dr. Guthrum Purdin, DVM
Avian influenza is a disease that has been infecting birds for over 150 years. The first documentation of the virus dates to 1878 in northern Italy, where it was described as a contagious disease affecting poultry. Historically avian influenza has had minimal impact on wild birds, but the most recent strain of the virus has had a detrimental effect on wildlife across the Americas. The disease is effectively 100% fatal for birds, and it has already caused the death of over 53 million wild and domestic animals in the United States alone.
The current strain of highly pathogenic avian influenza (HPAI) first arrived in North America late in 2021, appearing in eastern Canada. It was likely carried to Newfoundland from Eurasia by migratory waterbirds. Through 2022 it slowly made its way across the continent and the first west coast cases were found in Washington State late April/early May: a pair of Snow Geese and a Bald Eagle. By summer the contagion had reached the San Francisco Bay. Hundreds of wild birds are known to have died in the Bay Area, but fortunately for Southern California the southward advance of the disease was stalled there for the rest of the summer. HPAI does not tolerate hot, dry conditions well and last summer’s heat may have helped protect our local birds.
Although many domestic poultry flocks have been affected, an unusual aspect of this particular H5N1 variant of HPAI is that it particularly affects a wide range of wild birds. Some species can carry it without showing symptoms while others get infected and die quickly. In Washington State, for example, one lake experienced the deaths of hundreds of geese. Even worse, along the coast of Peru, which until now had been free of HPAI, over 22,000 pelicans and other seabirds were lost to the contagion in December. Other animals too can be affected, including harbor seals, bobcats, foxes, even a black bear recently tested positive in the Pacific Northwest.
The staff at the California Wildlife Center had been closely monitoring the inexorable advance of HPAI as it came relentlessly closer to Los Angeles. We learned everything we could from the experiences of other wildlife rehabilitation groups in affected areas of the US, as well as those in Africa and Europe who have been dealing with both this H5N1 strain and multiple other variants of HPAI for many years. Working with hospital staff, as veterinarian I put together a comprehensive set of protocols for how to respond, knowing that HPAI’s arrival in SoCal was inevitable. Of great importance was ensuring that HPAI positive animals not enter the general population of patients. If that happens, there is a high risk of it spreading through a busy wildlife hospital.
Now, when members of the public call about animal’s they’ve found, they’re asked a variety of questions to help identify possible HPAI patients. When they arrive on site, they’re met by volunteers and staff wearing protective gear who bring the new patient to a specially designated screening room separate from the rest of the hospital where they are carefully checked for signs of avian influenza. After initial HPAI screening, patients free of overt clinical signs get a follow-up exam in our ICU to determine what injuries or non-influenza illness led to being rescued and a course of treatment is determined. During this, they are again evaluated for HPAI, since sometimes symptoms that are not immediately obvious can be caught on this second intake exam, especially subtle signs like milky looking eyes or a tendency to act “switched off’, like they’re awake and standing but otherwise totally unresponsive to stimuli. After that they spend a day or two in strict quarantine and then a few days in isolation. HPAI is so virulent, that susceptible species usually present symptoms right away—however, in rare cases they may not show signs until later in care, hence the orderly set of exams and quarantine/isolation housing areas. This way we have a strong sense of a negative HPAI status before new admits are housed around patients already in care. Each area has disinfectant foot baths and appropriate levels of personal protective gear. Special foot coverings are worn when entering and leaving outdoor aviaries and caging to be extra careful, since animals housed outside could potentially be infected by HPAI positive birds flying overhead.
In September, the inevitable happened, and CWC got its first positive HPAI patient, a Canada Goose with the severe neurological and visual deficits that are classic for HPAI birds. The disease was identified during physical exam and this goose was humanely euthanized to alleviate their suffering. The diagnosis of HPAI H5N1 was definitively confirmed with the assistance of the California Department of Fish and Wildlife’s Wildlife Investigation Lab.
Throughout the greater SoCal area numerous other cases have been identified among migratory birds, especially geese and raptors. So far, the horrifying mortality events seen in Europe, Peru and the Pacific north coast have not occurred here and winter cases have tapered off.
CWC awaits the spring migration with trepidation, as birds already stressed by their far travels may be carrying HPAI back into our area. However, our hospital’s thorough and decisive biosecurity protocols, as well as the keen vigilance of the treatment crew, have served well in protecting the hospital from an onsite outbreak. Another hot, dry summer after the winter rains would, in this case, be an added boon.
What can you do to help prevent the spread of this disease?
Townsend’s Solitaire
By Denys Hemen, Hospital Manager
Having a yard is a privilege in the city. If you are fortunate enough to enjoy one at your home, it only takes a few minutes to put down your phone, be very still, and enjoy the nature around you. You may see tiny birds hiding in a bush, a squirrel high up in a tree, a soaring hawk or a gliding crow may pass overhead. Just going outside can bring you closer to nature. Nature is all around us and as humans develop lands farther and farther into open spaces, we are going to share our space more often with the creatures that live among us. One group of animals feeling the negative effects of human encroachment a little more than others are small songbirds. Most populations are on the decline and could use some help. Here are some easy ways to make your yard bird friendly and lend a hand to our feathered friends.
If you choose to have a bird feeder or waterer in your yard, please keep it clean. Take feeders down and discard leftover seed at least every two weeks, scrub with soapy water then rinse well. Make a solution of 9 parts water and 1 part bleach in a clean spray bottle and spray all parts. Leave the feeder sitting for ten minutes then rinse. Allow all items to air dry before refilling. If you provide water for wild birds the water should be changed daily, and the waterer should be sanitized in the same manner as the feeders every two weeks. If you ever see sick birds at your feeder, especially those with what looks like eye infections, take your feeder down, discard the seed, clean, sanitize, and leave it down for a week or two. Many bird diseases are easily transmitted through feeders and waterers.
Hummingbird feeders should be cleaned and sanitized every time they are refilled, which should be every 3-5 days to prevent mold from growing. Do not use detergent to clean, only use boiling water and a bottle brush. Sanitize the same way as previously described. The only formula that should be fed to hummingbirds is 4 parts water to 1-part white granulated sugar. Boil the water until the sugar is dissolved, then let the formula come to room temperature before refilling.
Planting native plants is a fun way to attract more birds to your yard. In Southern California, the fall and early winter are prime times to get native plants into the ground. Choosing which plants birds like best can be tricky on your own. At calscape.org, you can find plants that are native to your specific zip code. Descriptions are included of what each plant will attract- from bees to bugs, butterflies to birds!
If you have trees in or around your yard, try to “leave the leaves” as much as possible. Leaves provide cover for tiny insects that birds such as towhees and Northern Mockingbirds love to scratch around and hunt for. Fallen leaves also make excellent mulch for your native plants.
In the spring and summertime, quickly walk your yard to look for fledgling birds on the ground before letting your dog out. Many bird species have young that leave the nest before they can fly. These fledglings spend a few days on the ground before they build the strength to fly and are very vulnerable.
If you have windows that birds repeatedly fly into there are many ways to fix this issue. A great resource for remedies is abcbirds.org. Here you can find dozens of ways to “bird proof” your windows. From iridescent bird tape to streamers, all the items suggested by this non-profit organization have been tested and rated.
The last and most important way to make your yard bird friendly is to always keep your cats inside and never feed strays around your home. Outdoor cats kill over a billion birds in the US each year. Cats are the number one cause of the decline of native songbird populations.
If you ever find an injured bird, place the bird in a cardboard box that has air holes and is lined with a paper towel. Then take a picture for species ID by our staff later. Give our hospital a call at 310-458-WILD and we will be happy to help you.
By Denys Hemen, Hospital Manager
Bewick’s Wren on fly trap
There are dozens of home pest control items available for purchase today at various home improvement retailers. From sprays to traps to zappers, humans have developed many creative ways to keep unwanted insects and rodents out of our homes. It is understandable for people to strive to keep the inside of homes free of unwanted creatures. Unfortunately, when these products move from indoor pest control isles to the outdoor gardening section in retail settings, this becomes a misguided and irresponsible action. Native and beneficial wildlife often become the unintended victims of these products. The worst items to place outdoors are poisons, glue traps, and snap traps.
When poisons are moved outside of the home, the number of non-target species that are affected increases exponentially. Poisoning rats and mice outside may lead to predator species like coyotes, bobcats, and raptors eating these sick and debilitated rodents that are easy to catch. Many health problems may arise, such as raptors losing the clotting ability of their blood and damage to the immune systems of coyotes and bobcats which may lead to severe break outs of mange. Such problems are seen inside of the hospital at CWC many times a year.
Glue traps, including sticky fly traps, used outside of the home draw in even more non-targeted animals. Sticky traps are a double whammy because the target species gets trapped in the goo and predators will go after it, entangling themselves in the sticky mess. The intention of the glue trap is to keep prey in place so that they slowly die of dehydration and starvation. Also, animals may accidentally get stuck while going about their natural ground or arial foraging routines. We have seen all types of animals stuck in these traps. Snakes, ground dwelling birds like towhees and wrens, mockingbirds, warblers, desert cottontails, and many other species have passed through the doors of our exam room with feathers, scales, or fur entangled in a sticky trap.
A very wide variety of domestic and wild animals are harmed by snap traps left outside. A rat snap trap has the potential to cause great injury to a curious cat or dog that may sniff around the bait. Wild animals fare even worse. Just last month we received an American Crow that had its beak shattered by a snap trap as well as a Barn Owl with a trap on its leg. Unfortunately, neither patient survived their injuries. An earlier snap trap victim, a Striped Skunk, was able to be treated and released with 51 days of medical care after getting his foot caught in a rat snap trap.
Coyote pup with mange