Anthropogenic causes of Wild Animal Admittance to Rehabilitation Centers

Anthropogenic causes of Wild Animal Admittance to Rehabilitation Centers

Abstract

There are anthropogenic impacts on everyones local wildlife across the country that have been overlooked because the causes have become commonplace. Many patients at Brukner Nature Centers (BNC) wildlife rehabilitation center suffer from anthropogenic reasons of admittance. Twenty-six percent (26%) of patients admitted into BNCs rehabilitation facility from 2006 to 2014 suffered from human caused injuries. Which, that figure may be a low estimate as many patients do not come in with a clear history behind their injuries. In order to analyze what type of an impact humans have on their local ecosystems through BNCs data, nine years of records were filtered through to separate each cause of admittance and to see what anthropogenic cause had the biggest impact on the local wildlife. By tallies alone cat attacks were the leading anthropogenic cause of admittance. Dog attacks were the second leading cause of anthropogenic admittance at 594 cases vs. cat attacks at 743 cases. Patients suffering from a cat attack had a significantly lower chance of survival than dog attack victims (t=2.8, P=0.01). This can be explained by the fact that cats teeth are sharper than a dogs teeth, creating deep puncture wounds that can be easily infected by the plethora of bacteria that reside inside a cats mouth. Actual cat predation counts may be more than three times higher than rates measured by prey that was returned to owners. So the full picture of how many animals are being preyed upon by the feral cat population is still unknown, however one could imagine it is an ever growing, massive problem. There is enough supporting evidence that our domestic pets have become a burden on our government and a hindrance to our local wildlife to thrive. These animals were introduced to our ecosystems by us, and they are now posing a problem, it is our responsibility to clean up our mess. There are a number of solutions to domestic pet overpopulation, many which will be disputed over on ethics and efficacy. But the problem should begin with implementing responsible pet ownership, and holding communities responsible for stray/feral cat populations with proper education on management methods.

IntroductionWhen the topic of the human impact on the environment is discussed it will most likely take form in the light of our oil consumption and the current atmospheric carbon dioxide level. The discussion will go on to include how it attributes to global warming, the rising seas and inevitably the impact on wildlife. However, there are other anthropogenic impacts on everyones local wildlife across the country that have been overlooked because the causes have become commonplace. Brukner Nature Center (BNC) is a privately funded organization promoting the appreciation and understanding of wildlife conservation through presentation, education and rehabilitation. BNC is located in Troy, Ohio and serves the greater Miami Valley area. Through the year BNC takes in over one-thousand injured and orphaned wildlife. BNC admits a wide variety of native mammals, birds, reptiles and amphibians. For a comprehensive list refer to Appendix I. Patients suffer from a range of injuries from impact injuries, entanglement in litter, domestic animal attacks, natural predator attacks to orphaned animals. One of the most startling realizations is how many cases are anthropogenic. Twenty-six percent (26%) of patients admitted into BNCs rehabilitation facility from 2006 to 2014 suffered from human caused injuries (Appendix II). These causes may have been direct or indirect, but human causes nonetheless. The twenty-six percent (26%) is a low estimate of the total anthropogenic cases as thirty-percent (30%) of the total patients that were admitted to the rehabilitation center had unknown causes to their injuries. For example, a couple brings in a litter of eastern gray squirrels who are neonates. The pair explains that they dont know the history behind why the nest was down on the ground, but after failed attempts of reuniting the babies with the mother they decided to bring the neonates in. However, in reality tree trimmers tore down the nest. This would be a case were the patient admittance was marked down as orphaned, but in actuality it was an anthropogenic cause that put the animals into that situation. The first step to solving a problem is realizing that there is a problem. As humans we seem to be unaware of how big of an impact we have on our local ecosystems. This study should serve to be a wake up call for all.

MethodsWildlife rehabilitation at Brukner Nature Center begins with donors bringing an animal into the facility. The patient is then examined and deemed whether or not that patient should be admitted, euthanized, or put back out into the wild. There are a variety of different cases where the animal seems orphaned but can be reunited with the mother, or is in fact old enough to survive on its own. In those cases the animal would not be admitted and the donor would place the animal back where they found it. In certain cases the animals physical state is too critical and to prevent a slow painful death, euthanasia on arrival (EOA) would be chosen. Once a patient is admitted, it is given a thorough medical exam where the injuries are assessed and patient care is determined. BNC works with Troy Animal Hospital for advanced medical advice and procedures. BNC provides supportive care for the animal until it can be released back into the wild. It is also noted how the animal came to be in that situation. The variety of different reasons of admittance are classified into the following thirteen categories: natural predator attack, cat attack, dog attack, entrapment, projectile injury, hit by vehicle, impact injury, captive, orphaned, suspect poison, young/ fledgling, unknown, and other. Comment by : Consider placing this before the medical exam info.The data records of BNCs rehabilitation for 2006-2014 were assessed and were filtered through looking at the reasons of admittance to uncover any patterns over the years. Anthropogenic reasons of admittance were highlighted in this study. Anthropogenic causes of admittance to BNCs rehabilitation center are as follows: cat attacks, dog attacks, projectile injuries, entrapment, impact injury, hit by vehicle, captive and suspect of poison. Each years patient records were separated into reasons of admittance. The reasons were then totaled for each cause of admittance. The success rates, animals released back out into the wild, were then calculated for the anthropogenic causes of admittance. If the animals were eventually transferred to a different facility for rehabilitation their data was not included in this study. If for some reason the data record did not have a reason of admittance associated with the patient, then that data was not included either. Some of the records had multiple reasons of admittance. For example a fledgling bird who is learning how to fly on the ground was attacked by a cat, the record shows the reason of admittance to be cat attack and young/fledgling. That instance was totaled with the cat attacks and not the young/fledgling because the reason that bird was admitted was because of the cat and not because it was abandoned by its parental unit. Any record that had multiple reasons of admittance was judged and totaled with the actual cause. Results

Graph A Comparative representation of patient numbers separated into the anthropogenic causes of admittance at BNC wildlife rehabilitation facility. Natural predator attacks were included to allow one to compare natural predator attacks with domestic animal attacks. Cat and dog attacks were the leading anthropogenic causes of admittance.

Success rates

200620072008200920102011201220132014Avg.

Cat Attacks

Total Patients19.18%20.69%30.14%17.39%19.10%16.00%15.29%10.42%18.56%18.53%

Birds17.65%9.09%10.34%15.38%17.14%17.24%16.13%8.70%20.00%14.63%

Mammals21.05%25.45%44.19%17.95%20.37%15.22%14.81%12.00%17.54%20.95%

Dog Attacks

Total Patients22.22%20.83%48.78%34.04%37.31%33.90%27.59%15.91%25.00%29.51%

Birds8.33%0.00%36.36%22.22%30.00%0.00%30.77%44.44%7.69%19.98%

Mammals29.17%23.26%53.33%35.29%38.60%33.93%27.03%8.57%27.27%30.72%

Table B Success rates for domestic animal attacks and comparative success rates for bird and mammal victims

T-Tests

Cat attack victims had a significantly lower rate of survival vs. dog attack victims (t=2.8, P=0.01).

The number of cat attacks vs. dog attacks was not significantly different. However there was a slight trend of more cat attacks (t=1.7, P=0.1).

DiscussionGraph A shows during the years 2006 to 2014 cat attacks were the leading anthropogenic cause of admittance. Dog attacks were the second leading cause of admittance at 594 cases vs. cat attacks at 743 cases. . Running a t-test on the data showed only a trend of cats having a higher average of victims over dogs (t=1.7, P=0.1). However over time the tally shows that cats did in fact have more of an impact on the greater Miami Valley ecosystems than dogs did from 2006 to 2014. Speculation on why cats have a bigger impact than dogs could be the fact that cat owners, who allow their cats outside, allow the cats to free-roam the neighborhood, unsupervised. Whereas dog owners typically monitor their dogs, or have them enclosed to one area while outside. In a study conducted by the University of Georgia, they attached KittyCams to 60 outdoor house cats near Athens, Georgia. The study found that 30 percent of the sampled cats were successful in capturing and killing prey, and that those cats averaged about one kill for every 17 hours outdoors or 2.1 kills per week (K. Loyd et al., 2013). The study also found that cats only brought 23 percent of their kills back to a residence. The implication that most of the cat attack victims at BNC were brought in by donors, who had their cat bring them the victim, shows that the cat statistics in BNCs study may be only the tip of the iceberg for this growing problem. Actual cat predation counts may be more than three times higher than rates measured by prey that was returned to owners. In addition to BNCs data, most studies researching the ecological impact from cat predation were based on prey returns. This would imply that their results would have been a low estimate of the ecological impact. There is an estimated total of 117157 million free-ranging cats in the United States (N. Dauphnie et al., 2009). Given the large numbers of cats and considering the numbers of avian prey returned to owners, a minimum of one billion birds killed by cats annually in the United States is a conservative estimate, and the actual number is likely much higher, and that is not including mammals, reptiles or amphibians (N. Dauphnie et al., 2009). Reaching consensus on a precise estimate of the number of animals killed annually by cats presents a challenge, but as noted in The Wildlife Societys position statement on feral and free-ranging cats: Extensive popular debate over exact numbers or types of prey taken is not productive. The number of cats is undeniably large. Even if conservative estimates of prey taken are considered, the number of prey animals killed is immense (TWS 2006). The vast amount of animals taken out of our ecosystems not only affects that species population numbers, but also limits the populations of other animals that depend on those animals as prey. Adding cats into an ecosystem creates an imbalance. Because they form a domestic species distinct from their wild ancestral species, domestic cats are considered to be a non-native, species in all environments in which they occur. Because of their ability to overwhelm existing native species and natural ecosystem processes in environments in which they have been introduced, domestic cats are moreover classified as invasive species. It should be emphasized that the invasive species label applies exclusively to outdoor cats, rather than pet cats kept indoors or otherwise kept under control by their owners.Predators in nature tend to be uncommon with respect to prey populations. Wild predators are reliant on their prey, and will naturally decline with a declining prey base. Cat predation of birds is different than that by any native predator, perhaps most notably because outdoor cats are maintained in numbers far above natural carrying capacity. There are also a number of other important ways in which cats are distinct from native predators that may multiply their negative effects on bird and other wildlife populations (Coleman et al. 1997, Brickner 2003). To add insult of injury, patients suffering from a cat attack had a significantly lower chance of survival than dog attack victims (t=2.8, P=0.01). This can be explained by the fact that cats teeth are sharper than a dogs teeth. Their teeth are piercing and make relatively deep puncture wounds. When the bite is on an appendage the wound may easily pierce a joint or the membrane sheath around a tendon. Joints and tendons have closed spaces, and are thus great growing places for bacteria. And the mouths of cats are home to many types of bacteria. One of the first steps BNC takes with cat attack victims is to put the animal on antibiotics to help with reduce the spread of infection, however sometimes the patient has already lost their battle for survival. It is our responsibility to take care of the Earth we call home. Humans impact their local ecology in a number of ways. Many of our negative impacts we didnt realize were an issue. The first step to solving a problem is realizing that there is a problem. There is enough supporting evidence that our domestic pets have become a burden on our government and a hindrance to our local wildlife to thrive. These animals were introduced to our ecosystems by us, and they are now posing a problem, it is our responsibility to clean up our mess. There are a variety of ways to approach removing invasive domestic species from local ecosystems. Many of the methods are often disputed. This paper does not serve to argue one method over the other, but rather to serve as an educational tool. The biggest initiative that should take place is responsible pet ownership. Our companion animals belong indoors/under the control of the owner and should be spayed or neutered. We need a shift in cultural thinking to convince people to keep their pets indoors. This could be enforced by educational materials made available to the public. One way to pave the way for this initiative in the future is to weave this educational material into the school systems. Culture change can begin with a new generation. In addition to keeping our pets indoors, getting pets spayed and neutered should also be a part of the education. Adopt, dont shop. This could be enforced by legislation regulating pet shops to maintain a proportion of their animals to be rescues from a local animal shelter. Comment by : Sterilized?Gaining control over owned pets is not the end of this problem. There are large feral cat colonies that account for the other half of the issue. The solution to this problem is to remove all feral/stray cats. However this is where many begin to dispute the best way to extradite feral cats. Nonlethal methods include frightening devices, exclusion, trapping and live-capture with removal, repellents, habitat modification and fertility control. These methods should be deliberated first because the public largely accepts most and the methods help decrease the feral cat carrying capacity. The number of feral cats that will move into the area also will be reduced. Lethal methods, such as kill trapping, trapping with euthanasia, and shooting should also be considered. These methods offer an immediate decline in the population and may be required when feral cats are over abundant and causing significant negative impacts. People who are very sympathetic to cats will be opposed to capture and removal and lethal methods of control. Controlling feral cat populations should be discussed in community meetings and resolutions should be made based on sound research-based information and public sentiment. A productive first step would begin with education materials being brought to community leaders and requiring communities to begin feral cat management. Without the community seeing the neighborhood cat as a problem, the issue will persist, and our wildlife will suffer.

Special Note from the AuthorI recognize this is a difficult and divisive topic, and some will dispute the ethics and efficacy of feral cat management discussed in this paper. However, it is important to see the bigger picture and realize the fragile balance of our ecosystems is much more important to preserve than the life of the neighborhood cat. This paper provides both lethal and nonlethal options that should serve to inform communities so that they can make an educated choice. Acknowledgments Special thanks belongs to Brukner Nature Center for providing the records and data used in this research. Their rehabilitation center and staff also provided education that contributed to this study.

References

Brickner, I. 2003. The impact of domestic cat (Felis catus) on wildlife welfare and conservation: a literature review with a situation summary from Israel. Tel Aviv University report.

Coleman, J. S., S. A. Temple, S. R. Craven. 1997. Cats and wildlife: A conservation dilemma. University of Wisconsin Cooperative Extension Publications.

N. Dauphnie, R. J. Cooper. 2009. Impacts of Free-ranging Domestic Cats (Felis Catus) on Birds in the United States. Fourth International Partners in Flight Conference p. 205219.

K. Loyd, S. M. Hernandez, J. P. Carroll, K. J. Abernathy. G. J. Marshall, Warnell. 2013. Quantifying free-roaming domestic cat predation using animal-borne video cameras. Biological Conservation 160, p.183189

TWS (THE WILDLIFE SOCIETY). 2006. Final TWS position statement: feral and free-ranging domestic cats. [Online.] Available at: (20 July 2015).Appendix

I.Amalee WebbAnthropogenic causes of Wild Animal Admittance to Rehabilitation Centers

1

Species Admitted to BNC Rehabilitation Center 2006-201

Mammal

Mammal

Beaver

Big Brown Bat

Common Muskrat

Coyote

Eastern Chipmunk

Eastern Cottontail

Eastern Gray Squirrel

Fox Squirrel

Gray Fox

Hoary Bat

Little Brown Bat

Long Tailed Weasel

Mink

Northern Long Eared Bat

Raccoon

Red Bat

Red Fox

Red Squirrel

Southern Flying Squirrel

Striped Skunk

Virginia Opossum

White-Tailed Deer

Woodchuck

Bird

American Bittern

American Coot

American Crow

American Goldfinch

American Kestrel

American Red Start

American Robin

American Tree Sparrow

American Woodcock

Bald Eagle

Baltimore Oriole

Barn Swallow

Barred Owl

Belted Kingfisher

Black & White Warbler

Black Billed Cuckoo

Blue Gray Gnatcatcher

Blue Jay

Broad Wing Hawk

Brown Creeper

Brown Headed Cowbird

Brown Thrasher

Canada Goose

Caroline Chickadee

Cedar Waxwing

Chimney Swift

Chipping Sparrow

Common Grackle

Common Loon

Common Moorhen

Common Nighthawk

Common Yellowthroat

Coopers Hawk

Dark-eyed Junco

Downy Woodpecker

Eastern Bluebird

Eastern Meadowlark

Eastern Phoebe

Eastern Screech Owl

Eastern Wood Peewee

Golden-Crowned Kinglet

Gray Catbird

Great Blue Heron

Great Horned Owl

Green Heron

Hairy Woodpecker

Hermit Thrush

Herring Gull

Horned Grebe

Horned Lark

House Finch

House Wren

Indigo Bunting

Killdeer

Lincoln's Sparrow

Magnolia Warbler

Mallard

Merlin

Mourning Dove

Northern Bobwhite Quail

Northern Cardinal

Northern Flicker

Northern Mockingbird

Northern Saw-Whet

Ovenbird

Piebilled Grebe

Pileated Woodpecker

Purple Finch

Purple Gallinule

Purple Martin

Red Necked Grebe

Red Tailed Hawk

Red Winged Blackbird

Red-bellied Woodpecker

Ring Necked Duck

Ring-Billed Gull

Ring-Necked Pheasant

Rose Breasted Grosbeak

Ruby Throated Hummingbird

Ruddy Duck

Sandhill Crane

Scarlet Tanager

Sharp Shined Hawk

Song Sparrow

Sora

Swainson Thrush

Tennessee Warbler

Tree Swallow

Tufted Titmouse

Turkey Vulture

Virginia Rail

Whip-poor-will

White Breasted Nuthatch

White Crowned Sparrow

Wild Turkey

Willet

Wood Duck

Yellow Bellied Sapsucker

Yellow Billed Cuckoo

Yellow Warbler

Yellow-rumped Warbler

Reptile

Black Rat Snake

Eastern Box Turtle

Eastern Milk Snake

Garter Snake

Map Turtle

Midland Painted Turtle

Musk Turtle

Northern Water Snake

Red Eared Slider

Snapping Turtle

Spiny Softshell Turtle

Spotted Salamander

Amphibian

American Bullfrog

American Toad

Green Frog

Leopard Frog

II.

Reason200620072008200920102011201220132014Total

Other Predator171513111717122323148

Cat Attack728773698975859697743

Dog Attack3648419467598847114594

Entrapment10877125231021103

Projectile Injury34120113015

Hit By Car386831325047486653433

Impact Injury293431203224272543265

Captive26523313520394245266

Orphaned4663024493884034223954425153782

Suspect Poison3001002006

Young/ Fledgling531721301381151141461271421137

Unknown11890149526559716156721

Other121484522612011971117106973

Yearly Totals992881993107110059621008105912159186

Reasons of Admittance to BNCs rehabilitation center 2006-2014