Red-Shouldered Hawk with Anticoagulant Rodenticide Toxicosis

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By Dr. Stephany Lewis, Veterinarian

This winter, CWC admitted an adult male Red-Shouldered

Red-Shouldered Hawk
Photo by Johanna Molina

Hawk after he was found on the ground in Santa Monica, too weak to fly. On physical examination, his only injury was a very small laceration on his toe, only about 5 mm in length, yet his feathers were completely soaked with blood and the laceration was actively bleeding. The mucous membranes in his mouth were pale white, and he was so weak that he couldn’t stand, wouldn’t open his eyes, and was barely responsive to external stimuli. A small amount of blood was collected from the bird for some basic bloodwork. He was found to be severely anemic, with 5 times less red blood cells than normal.

Sadly, those of us working in wildlife rehabilitation know that there is only one thing that could cause these clinical signs in a bird of prey. This bird was suffering from anticoagulant rodenticide toxicosis. Anticoagulant rodenticides are rat poisons that cause death to rodents by preventing their ability to clot their blood. Non-target species, such as Hawks, Owls, Bobcats, Coyotes, and Mountain Lions are exposed to these compounds by ingesting the rodents that have eaten these poisons. The poisons do not kill the rodents immediately, but rather slowly weaken them and make them easier prey. Some of these compounds, such as brodifacoum, difethialone, and bromadiolone, are known as “second generation anticoagulant rodenticides”. These compounds were invented in the 1970s in response to rodents becoming resistant to the “first generation” compounds, such as warfarin. One of the differences between the first and second generation rodenticides is also what makes the second generation compounds so much more dangerous for wildlife; they last for a very long time in the body. This means that non-target wildlife species can ingest multiple small doses over long periods of time until they build up levels high enough that they are no longer able to clot their blood. This has disastrous consequences. Animals can bleed into their lungs, causing severe distress, as well as into their brains, eyes, joints, and muscles, causing severe pain and permanent disabilities. Or, like our Red-Shouldered Hawk patient, they can lose all of their blood through what should be an inconsequential wound. Additionally, Bobcats and Mountain Lions are believed to suffer deleterious impact on their immune systems due to chronic exposure to these poisons, making them more susceptible to illness and death from infectious diseases such as mange.

Luckily for our Red-Shouldered Hawk patient, there is an antidote to these poisons, and it is just a simple vitamin, vitamin K. This treatment needs to be given daily for four weeks. Additionally, he received fluid therapy for the first week (a blood transfusion would be the preferred treatment but is unfortunately not an option for our unique patients). This bird actually had a catheter placed into a bone in his wing to quickly replenish blood volume and blood pressure after such drastic blood loss.

Forty-three days after he arrived, our Red-Shouldered Hawk had normal bloodwork, was well-conditioned, flying beautifully in one of our flight pens, and ready to be released! This was a wonderful outcome for this patient, but sadly most of the rodenticide victims who come to us are not as lucky. Because they arrive very late in the course of their illness, the majority of them pass away in the first 24 hours, before our vitamin K therapy has had time to work. Every patient who passes away due to rat poison is submitted for examination by biologists at the California Department of Fish and Wildlife to confirm the cause of death and aid research proving how damaging these poisons are to our native wildlife. The exposure frequency of wildlife to these compounds continues to be astounding, despite previous legislation made to limit their use. Scientists continue to detect these compounds in anywhere from 79 to 100% of animals tested, and in many cases, 3 – 6 different compounds are detected in the same individual.

Anticoagulant rodenticides pose a substantial and far-reaching threat to wildlife and ecosystem health. A California bill, AB1788, has reached the State Senate, and if passed will greatly restrict use of these poisons in our state. CWC is so grateful for everyone who has been working tirelessly to get this bill passed, and we hope you join us in urging your senator to pass this important legislation! Our wildlife deserves poison-free food!

CWC Cares for Its First Fawn of the Year

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By Cori Carlson, Administrative Assistant

First Mule Deer Patient of the Year
Photo by Cambria Wells

California Wildlife Center took in its first Mule Deer fawn of the year on May 2. As of writing this, we’re caring for two. That timing is fairly typical since Mule Deer are born from April to June. They are nursed by their mothers throughout the summer and weaned in the fall.

CWC is the only facility authorized to care for orphaned or abandoned fawns in Los Angeles County. Last year, we admitted 11.

Native to California, this Deer got their name because of their large ears that look a bit like they belong on a mule. They can be found throughout the western United States. When they’re first born, their backs are dotted with white spots, a bit of camouflage to help protect the newborns.

When they first come to us, the young fawns are kept in a heated room with a hay-covered floor and are bottle-fed a specialized formula containing goat milk. We greatly limit the number of people who come into contact with Deer in our care. Only our veterinarian, wildlife technicians, and trained interns and volunteers care for our fawns. The young Deer can habituate to humans very easily, so it’s important they don’t get too exposed to us while they’re here. For this reason, we have installed cameras in the Deer enclosures to monitor them and limit our face-to-face interactions. There is nothing like seeing an adorable wobbly young fawn.

As they gain weight and grow, they move into a small outdoor enclosure and learn to eat on their own. Mule Deer are herbivores and eat a variety of fresh green leaves, twigs, shrubs, various grasses, and berries. Toward the end of their stay, they move into a large field-like enclosure until they are ready to be released, which typically happens in the fall.

In the wild, fawns may appear to spend a lot of time on their own.  But that’s one of the ways their mothers try to keep them safe. Fawns are often left alone, allowing them to hide until they’re big enough to outrun predators. Their mothers usually are close by and will come back to nurse them but are keeping their distance to protect their fawns.

If you find a fawn that appears abandoned, sick, injured or in distress, please call your local wildlife rehabilitator or CWC at (310) 458-9453 before you approach.

Oh Deer! CWC Helps a Deer Impacted by Plastic Waste

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By Dr. Stephany Lewis, Veterinarian

This Mule Deer buck had a plastic pipe stuck on his leg. Photo by Heather Henderson

This fall the California Wildlife Center was given a unique opportunity to help a Mule Deer buck who had gotten PVC piping entrapped on one of his legs. A caring citizen named Brenda Robinson contacted our hospital manager, Denys Hemen, regarding this buck in need of help. The buck spent much of his time with a herd at the Getty Villa, and a few days prior Brenda had noticed that the animal had gotten a piece of white PVC piping trapped just above his hoof. He was licking at the area and had begun to limp on the leg.  Brenda was worried that this animal was in pain and would eventually be weakened to the point that he could fall prey to coyotes or mountain lions known to be in the area.

After learning of the situation, Denys and I visited with Brenda at the Getty Villa to observe the Deer and see if it would be feasible for us to help the animal. Brenda knew exactly where the herd would be throughout the morning, and he was so accustomed to her presence that we were able to observe him from a reasonable distance. We were excited to be able to potentially help this animal, and after organizing with biologist Amelia Viera at the California Fish and Wildlife Service, we were scheduled to return on the morning of October 30th to sedate the Deer and remove the plastic pipe from his leg.

The morning of October 30th, the group of us involved in the procedure as well as grounds crew at the Getty Villa, met just before sunrise to discuss the plan of action. Immobilizing an adult Deer in the field requires quite a bit of preparation, and it’s extremely important that everyone involved knows each step in the procedure, what to expect, what could go wrong, and what their responsibilities are.

The deer was sedated so the pipe could be removed. Photo by Heather Henderson

The grounds crew quickly located the buck for us, and I was able to get into a position to successfully dart the animal. Our dart gun at CWC is a simple carbon dioxide-powered rifle (sort of a glorified blowpipe), and the darts are pressurized with air so that when the needle enters an animal’s skin, a rubber sleeve is pushed off small holes on the side of the needle, and the drugs are quickly injected right after impact. The Deer was darted in the hindquarters with a combination of sedatives, half of which were reversible, and the other half were short-acting. He trotted off a few meters after darting, but we were easily able to watch him as the sedation was taking effect. His close-knit herd stayed by his side the entire time until I approached. About 15 minutes after darting, the buck laid down, and we were able to safely approach him. We protected his eyes with lubrication, blindfolded him and placed cotton in his ears to decrease stress and make him less reactive. He was held in a safe position and his vital signs were monitored by Denys and Maria Jose Lopez Jara, a visiting veterinarian from Chile.

Staff was able to remove the restrictive pipe from the Deer’s leg. Photo by Stephany Lewis

The PVC pipe was quite tight around the Deer’s leg, around the pastern area, which is just above the hoof and below the fetlock joint. It has caused several large wounds on the leg around its entire circumference, but none so severe that we did not think he could recover once it was removed. Heather Henderson, our marine mammal stranding coordinator, removed the pipe with a coping saw, starting between the pipe and the leg and sawing outward to avoid causing further trauma. The wounds were clipped of dirty hair, cleaned, flushed, and an antiseptic ointment was applied. The buck then received an injection of a long-acting antibiotic, a pain medication, and reversal of the sedation.

It took just over a half hour after reversing the sedation for the buck to start to stand and walk on his own. While he was recovering, one of his herd-mates, a little doe, came to check on him! He spent most of the rest of the day relaxing with his herd, but has since been up and about, no longer in pain. We are still receiving updates from Brenda, and the buck is doing fabulously! We are so thrilled to have been able to help this animal, and hope this serves a reminder to everyone to please be neat and remove your trash!

Orphan Care Unit Update

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By Jennifer Guess, Senior Wildlife Technician

Orphaned Fox Squirrels need to be fed frequently
Photo by Anne Slattery

It’s finally spring and the Orphan Care Unit (OCU) at California Wildlife Center is up and running! The doors officially opened for the season on March 15th. Of course, nature had its own plans.The first orphaned patient California Wildlife Center received in 2018 was a nestling Band-Tailed Pigeon on January 25th. Between then and March 15th, CWC received 95 orphaned animals who were treated in the Intensive Care Unit until OCU opened for the season. Forty-six of those young patients were Eastern Fox Squirrels being cared for under the supervision of our home care rehabber Glenn Ellis. Besides orphaned Eastern Fox Squirrels, CWC received 22 Mourning Doves, 13 Band-Tailed Pigeons, nine Virginia Opossums, and five Hummingbirds.

Fledgling birds like this Northern Mockingbird learn to fly from the ground up
Photo by Jamie Pelayo

As of this writing, the OCU has taken in over 275 young patients. Our dedicated team of volunteers, staff, and our Homecare Network have been looking after more than 105 Eastern Fox Squirrels, 75 Virginia Opossums, and 90 baby birds including House Finches, Lesser Goldfinches, Northern Mockingbirds, Hummingbirds, Mourning Doves, and Band-Tailed Pigeons. As time progresses, the mammals in OCU will slowly transition into outdoor enclosures preparing for release. We will see a major influx of injured and orphaned baby birds.

If you find a young animal the first thing you will want to do is look from afar to see if it has any obvious injuries. If you notice an injury, prepare a box with an absorbant towel at the bottom, and gently contain the injured animal. Contact the hospital at (310) 458-9453 to get further instructions. If you find a young uninjured animal you believe might be orphaned, contact the hospital as soon as possible to get instructions on whether the animal should be contained and brought into our Orphan Care Unit. It is very common for many species of birds to spend anywhere from 3-7 days on the ground learning how to fly. This is called the fledgling stage. Many people mistake these fledgling birds for orphans, but in reality the parent is still caring for them while they are on the ground. Unfortunately a lot of young animal are orphaned from tree trimming incidents. The best way you can help young animals is to wait until December to trim your trees!

Rabbit Rescued from Fire Returns to the Wild

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by Heather Patrice Brown, Development Coordinator

Exam of the burnt tissue on the rabbit’s ears, Photo by Alyssa Schlange

Rabbit after surgery, Photo by Jamie Pelayo

This fall, when terrible wildfires ravaged the Southern California landscape, there came a spark of hope.  A video went viral of a young man rescuing a wild rabbit from the flames of the Thomas Fire. The rabbit was initially brought to a local animal hospital and was then transferred to California Wildlife Center for care on December 6th.

The rabbit had suffered serious burns to her ears and toes, minor burns to her lips and singed fur all over her body. She was given pain relief and a quiet place to recover from shock. At first, she was not very active. There were concerns that she might have internal injuries from the fire as well as the obvious burns.

Rabbit returns to wild, Photo by Heather Patrice Brown

After two days, she began to perk up and eat again. The burn areas on her feet began to scab over, which was a sign of healing, but the burned tissue on her ears began to die. Dr. Duane Tom surgically removed the dead tissue from her ears. The overall shape of her ears did not change, so her hearing was not impacted. Dr. Tom also removed some dead tissue from her outside toes and she was still able to hop and get around.

The rabbit continued to recover and was transferred to a larger enclosure at the house of home care volunteer, Julie Gluck, for rehabilitation. Her appetite and activity level continued to increase.  Her wounds healed well, and she was given a clean bill of health for release. On January 17th, she was released in Ventura. While she couldn’t be returned to her exact location because of the fire’s deforestation, she was released in a nearby area that had plenty of food, water and shelter. After a moment’s hesitation, the rabbit leapt out of the cage and quickly made her way to the cover of nearby bushes. The rabbit’s recovery from her horrible ordeal was a bright spot of hope amid the devastation of the fires.

Orphan Care Unit 2017 Wrap Up

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By Jennifer Guess, Senior Wildlife Technician

Eastern Fox Squirrel
By Anne Slattery

November marks the end of baby season at California Wildlife Center (CWC).  It was another year full of energetic squirrels, curious crows, grumpy mockingbirds, and aggressive woodpeckers.  This year we had quite a busy season.  CWC took in over 275 Eastern Fox Squirrels and over 85 Virginia Opossums between the spring and fall months.  Throughout the height of summer we saw over 200 American Crows, Common Ravens and Western Scrub-jays, over 300 Mourning Doves and Band-tailed Pigeons, and 135 Northern Mockingbirds.  We also had a few unique patients come through our doors.  Many volunteers working in our Orphan Care Unit have fond memories of feeding our one and only Pacific-slope Flycatcher or a few of our Western Bluebirds.  Even more volunteers will remember building up the courage to feed our lively Acorn Woodpeckers.

Nestling Northern Mockingbirds
By Alyssa Schlange

We’d like to thank all our fantastic Orphan Care volunteers for their tireless work and dedication in helping us feed and care for the almost 1,500 young patients that came through our doors for this season.  We’d also like to thank our wonderful transport team who helped bring almost 300 young patients from shelters across the Los Angeles area.  We are so fortunate to have an amazing group of people committed to helping injured, sick and orphaned wildlife.

I’m sure we are all looking forward to taking a deep breath and relaxing a little during the relatively calm winter months.  But, don’t get too comfortable; spring will be here before you know it!

Garbage Impacts All Kinds of Animals

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By Heather Patrice Brown, Development Coordinator

Photo By Jaana Shellock
This poor skunk had a plastic cup in his head that CWC staff was able to remove.

In April, California Wildlife Center was surprised to receive a skunk with a plastic cup stuck over his head.  Volunteer Jaana Shellock first noticed the skunk and with guidance from CWC staff, was able to capture it.  CWC supporter Rick Gunderson was kind enough to drive it to CWC for treatment.  Dr. Duane Tom, California Wildlife Center’s Director of Animal Care, restrained the skunk and cut the cup off his head.  Luckily, the cup had not caused any additional injuries, and the skunk was able to be released to where it had been found that same day.

This skunk was very lucky someone noticed him and was able to bring him to CWC for help.  Unfortunately, CWC staff routinely sees wildlife that have been injured or impacted by garbage.  While most of these animals are tend to be marine mammals, land animals are affected too.  Animals investigate food trash and get entangled in or ingest the paper or plastic.  It is important to be conscientious about how garbage is disposed of and make sure trash cans are securely closed so that we can peacefully coexist with our wild neighbors.

 

Opossums: More Friend Than Foe

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By Anna Noble, Administrative Assistant

Virginia Opossum

Young Virginia Opossum
Photo by Kim Barker

California Wildlife Center admits an average of 250 opossums yearly.  Of this number, 40-50 are adults, while the remainder are orphans.  Most adult opossums who are admitted have experienced bodily injury due to trapping, predation, gun shots, or encounters with vehicles on roadways.  Joeys (the word for baby opossums) that are seven inches or longer should be left if found alone unless they show obvious sign of injury.  Smaller joeys should come to CWC for treatment.

While the opossum is sometimes perceived as a “nuisance” animal, they serve a pivotal role in the ecosystem.  Opossums act as nature’s double-duty pest control and sanitation.  They eat mice, rats, snakes, worms, slugs and insects, rotting fruits and vegetables, and even garbage.  As they have an unusually high need for calcium, they often eat the skeletons of rodents and road kill for a boost.

Opossums are incorrectly perceived as unclean and disease-ridden animals.  In fact, they bathe and groom themselves nearly as often as house cats.  They also have very powerful immune systems which fend off many diseases.  Opossums almost never have rabies, as their low body temperature makes it difficult for the virus to survive.  They are even immune to the venoms of snakes, scorpions and bees, as well as to ricin and botulinum toxin!  Despite having some similar physical traits, opossums are not related to rodents and are actually the only marsupial found in North America.

Despite their tendency to appear vicious when showing their fifty teeth, opossums are rarely looking for trouble.  They are very docile animals, and when threatened their first instinct is to simply run away.  If danger persists, they will show their teeth and make a hissing sound.  And when neither of these options prevail, they fall into a comatose state in which their bodies temporarily freeze, causing them to appear lifeless.  This defense mechanism is known as “playing possum.”

Coyotes Released

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By Staff Veterinarian Dr. Lorraine Barbosa

Coyotes peer out of their transport crate while on their way to their release location. Photo by Aileen Martinez

Coyotes peer out of their transport crate while on their way to their release location. Photo by Aileen Martinez

This year, California Wildlife Center took in seven orphaned coyote pups, which came to us from various locations in Topanga, Los Angeles, and Hollywood, at only a few months old. After treating them for a GI parasites, giving them their vaccinations, and providing them with nutrition and supportive care, they spent several months rehabilitating in our outdoor coyote enclosure with minimal human contact. Our goal is for them to form a pack so that when they are released, they will be able to find a defend a territory together.

In the wild, coyotes are born into a pack led by a monogamous male-female pair.  Some youngsters will stay with their own packs while others will leave either to live on their own or in pairs, or to join another pack.  Coyotes defend their territories together but rarely hunt together unless they need to bring down large prey. The size of their territory is dependent on the on the size of the pack and the food sources available. Coyotes often use natural and man-made structures as territory boundaries, which is why you may see lone coyotes walking along roadsides – they are keeping to the edge of a pack’s territory.

When releasing our coyotes, we try to find a location that has the natural resources they’ll need to survive, including free space, prey, and a water source.  Without much human interaction over the past several months, these animals had grown very skittish of our presence, therefore, catching them up for transportation to their release location was a difficult task.

Peering in through the small opening of one enclosure, I could see only a jumble of ears, paws and noses protruding from a dense furred pile, each coyote looking away from me as if thinking, “if I can’t see you, you can’t see me.” With my Kevlar gloves on and a towel under my arm, I squatted down and began to crawl in, slowly and quietly, one small step at a time.  I knew that if I could cover their faces, they would calm and I would be able to work with them more easily.  While one coyote leaped repeatedly at a corner of the enclosure, another squeezed past me through the small enclosure door. I managed to cover two of the remaining coyotes with towels, keeping them quieted while Dr. Tom gathered the one that managed to sneak through, and then I wrestled with the coyote leaping at the enclosure corner.  Once all were covered and stilled, moving them the several feet from the enclosure into their kennels was a whole other task. It seemed simple enough, but coyotes have an unparalleled ability to enhance normal gravitational forces, pressing themselves so hard into the ground that one would think they weighed ten times what they do. It took all of my strength to move a 26-pound coyote one foot forward at a time toward and then into the kennel. One by one, with a great deal of coordination, composure and effort, we were eventually able to get all seven coyotes into their kennels, injury-free. We drove the short distance to our release site, walked the kennels down the trail a ways, then opened the doors and watched them run off up and over the hill and out of sight.

 

A Squirrel for All Seasons

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Spring and fall are busiest times for baby squirrels
Eastern fox squirrels are one of the most common species of animals admitted to California Wildlife Center. CWC's Baby Care Unit also cares for large numbers of orphaned song-birds, opossums, hummingbirds, and crows.

Eastern fox squirrels are one of the most common species of animals admitted to California Wildlife Center. CWC’s Baby Care Unit also cares for large numbers of orphaned song-birds, opossums, hummingbirds, and crows.

By Executive Director Jennifer Brent

Last year, California Wildlife Center received 486 Eastern Fox Squirrels and so far this year, we have received 414.  They are the species that we see the most at CWC (second most common is the Mallard).

Why so many?  Some have had negative contacts with people – shot by a BB gun, struck by a vehicle or caught by a pet.  However, the vast majority we receive are babies (called kittens) and have fallen from trees of have otherwise been separated from their mothers. This may occur if a tree is trimmed during squirrel nesting season (February-April and August-October) or if the baby falls from a nest and it’s too dangerous for the mother to go down and retrieve him.

When baby squirrels are found on the ground, they should be observed from afar (as long as they are not in direct danger) to make sure that the mother picks him up.  If, after 3 hours, there are no signs of a mother coming, the squirrel can be picked up and put into a dark, quiet box with a small towel or blanket for warmth and brought to CWC.

Baby squirrels are fed a warmed species appropriate formula that mimics mother’s milk.  When very young, they are fed four times a day. Once they are old enough to be fed just three times a day, they are put together into social groups of four to seven squirrels who will act as surrogate siblings and eventually be released together.  A diet of nuts, berries and vegetables are introduced and, over time, this combination completely replaces the milk formula.  As with all rodents, squirrel’s front teeth grow continually so at CWC, they are given appropriate material such as pine cones and branches to keep them healthy.

Eventually the squirrels are self-feeding and are transferred from CWC’s Baby Care Unit to outdoor enclosures.  These allow them to move more freely and decreases any habituation that the squirrels developed while constantly being around people in the Baby Care Unit.  After about a month in the outdoor enclosures, they are released in their same social unit back into the wilderness. The average length of stay for a baby squirrel is three months at CWC.