Companion Parrots, Outdoor Aviaries, and West Nile Virus

Recently, someone asked me if I remembered the movie about the “boy in the bubble.” I said I didn’t, and the conversation ended there. However, later a vague memory resurfaced.

David Vetter was born in 1971 with Severe Combined Immune Deficiency (SCID). For 12 years, until his death, he lived in “protected environments” to maintain a relatively germ free existence. He was, essentially, “a boy in a bubble.” The media at the time referred to him as “David, the bubble boy.” A television movie drama, produced in 1976 called “The Boy in the Plastic Bubble,” was inspired by his story.

I remembered that brief conversation today and it struck me that David’s existence is similar to the existence of many companion parrots. Many live in “bubbles” of one sort or another, due to fears about how to keep them safe. Admittedly, living with parrots can be an experience fraught with worry. On some level, we seem to understand that there is likely much we do not know about threats that exist to them in our homes.

Perhaps we are all much like David Vetter’s parents – people desperately loving something that we must struggle to protect from not yet entirely identified threats to survival.

Because of this, sometimes we do err on the side of keeping our parrots “in a bubble.” We can’t let them fly because they might hurt themselves. We can’t allow them to have bowls of water because they get the water dirty and then it might have germs. We can’t let them stay up late because they might get tired. We can’t take them to the vet because they might get “stressed.”

And, we can’t have them in outdoor aviaries because they might get West Nile Virus.

Ethics… Again

However, examine for a moment what they evolved to enjoy…and need. Images from the wild carry powerful messages to our collective subconscious. Wild parrots move around frequently at will, using flight as their primary means of locomotion. Fresh air, rain, sunshine, and shade comprise their natural environmental surroundings. They constantly problem-solve, finding and figuring out how to access their food. They enjoy multiple social relationships on a variety of levels. Their lives are rich and complex.

At the time that David Vetter was alive, his parents and doctors struggled with the question of whether it was ethical to keep him alive in his “bubble.” I think that we also must examine the question of whether it is ethical to keep our companion parrots in a bubble – in such a way that they do not get to enjoy their natural birthright activities – exercise, foraging, liberty, and time spent outdoors.

If we decide that it is not, then we must place ourselves courageously in the position of becoming learners in the area of risk management. Currently, one area needing greater scrutiny is that of whether it is safe to maintain outdoor aviaries for our companion parrots, given the risk of West Nile Virus (WNV).

Do the benefits of having our parrots in outdoor aviaries outweigh the risks to them? I believe that they do, in the vast majority of cases. This is a risk that can be managed.  However, I will share with you what I have learned and then allow you to be the judge….

West Nile Virus Facts

West Nile Virus (WNV) has been common in Africa, West Asia, Eastern Europe and the Middle East, but was only discovered in the United States in New York City in the summer of 1999. Since then, it has spread westward across the United States, down into Central America and the Caribbean and up into Canada. (4)

WNV is spread by mosquitoes, pimarily the Culex species. Other species of mosquitoes can also be vectors, but their role in the transmission of the virus is unclear. (11) Thus, not all mosquitoes carry equal threat.

Birds are the natural hosts for WNV. Mosquitoes become infected when they bite an infected bird.  They then transmit the virus to other hosts – other birds, humans, and horses. Not every bird bitten by an infected mosquito becomes fatally ill. Most birds survive. (3) The most susceptible species are raptors, crows, and jays.

When horses and people become infected with WNV, they do not develop high viral loads and thus do not serve as vectors for the disease as the illustration shows. They are known as “dead end” hosts. Thus, the disease is only spread from birds to other birds through mosquito blood meals.

Mosquito Facts

Mosquitos lay their eggs in or near water. They need only one inch of standing water in which to lay their eggs. A curled leaf filled with rain will do.

Once the eggs hatch, the larvae and pupae continue to live in water. Unlike some other mosquitoes that prefer clean, fresh water, Culex sp. mosquitoes prefer stagnant or polluted water. (9)

The adults are attracted to life in forests, marshes, tall grasses and weeds with ground that is wet at least part of the year.  High populations are often found around areas where rice is grown and around salt marshes. Around your home, they prefer dark, humid areas – under patio furniture, under carports, and in garages.

Mosquito populations change from year to year. Many states so far have shown no WNV activity in 2019. You can go to your state map to check statistics for your location.

Some perfumes and lotions seem to attract mosquitoes. So do people drinking beer or eating Limburger cheese. (1)

Adult mosquitoes feed primarily at dawn, dusk, and for several hours into the dark.

Parrots and West Nile Virus

Research performed to date does not agree on the issue of just how susceptible parrots are to this virus. Most sources I found agreed that they appear to be somewhat resistant. However, the disease has been reported in parakeets, cockatoos, conures, rosellas, caiques, lorikeets, and others. (5) Further, there have been parrots who have died.

Avian pathologists agree that companion parrots are susceptible, but according to Dr. Rick Axelson, “Not every healthy person, animal or bird bitten by an infected mosquito will come down with WNV.” (2)

According to Dr. Margaret Wissman, “The chances are very good that a susceptible parrot that has become infected may show no signs of illness at all, as occurs in many indigenous species.” (14)

Juvenile birds are most commonly infected. This makes sense, since the immune system of parrots does not develop fully for several months after hatching. This brings up an important point. Feeding our parrots a diet that supports best health and a strong immune system is one of our most important protections against all disease, including West Nile Virus. 

Mosquitoes don’t have an easy time biting parrots. The skin on their feet and legs have scales and their feathers also offer a good layer of protection. Macaws and others with bare facial patches are perhaps at most risk.

Is There a Vaccine?

There is a vaccine approved for use in horses. Preliminary research indicates that it causes no harm in parrots, but that it may not stimulate the immune system enough to offer complete protection. (2 ) However, it is being used in some outdoor collections of birds living in zoological, falconry, and rehabilitation settings in high risk areas, although it has not yet been proven whether this approach is effective. (11) At this stage, it does not appear practical for the companion parrot living in a home.

Managing the Risk – What Does Work?

Environmental Control – Cleanliness

As with many physically small dangers (viruses, bacteria, insects), practicing excellent hygiene is the answer.

• Eliminate any sources of standing water – empty, turn over, cover or throw out any items that hold water. This includes tires, buckets, planters, toys, flower pots, cisterns, rain barrels, and trash containers.
• Empty and clean bird baths and pet dishes daily.
• Empty unused swimming pools.
• Repair any apparent cracks or gaps in your septic tank.
• Fix leaky outdoor faucets and sprinklers.
• Cover with screening any open vents or plumbing pipes.
• Unclog roof gutters so that standing water does not accumulate in them.
• Keep grass and weeds around your home mowed low.
• Rake up fallen leaves regularly.
• Keep your garage door closed – this is a favorite resting place for mosquitoes.
• Fill in any low-lying areas in your yard that accumulate water with dirt or install a drainage system.

Mosquito Dunks

If you have a pond, use Mosquito Dunks. These are small, beige, donut-shaped discs that float on standing water. They are non-toxic, approved for organic gardening, and can be used in koi ponds. They will not harm household pets, even if eaten. (13)

These use a naturally occurring bacterium that lives in the soil, Bacillus thuringiensis israelensis (Bti). While the disc floats on the water, it releases this bacterium that is toxic only to mosquito larvae and a few other biting insects, like black flies. (13)

Dragonflies

These insects are natural predators for mosquitoes. The larvae feed on mosquito larvae; the adults feed on adult mosquitoes. A simple Google search will produce both sources for ordering dragonfly larvae on-line and information for creating a favorable “habitat” for them in your garden.

Mosquito Fish

If you have a pond that does not connect to other waterways, consider stocking it with the Gambusia fish – a small, hardy, minnow-like freshwater fish. These grow only as large as the size of their water habitat will allow and they eat mosquito eggs and larvae by the hundreds. They can also survive in stagnant water, a favorite habitat for the Culex mosquito. Local mosquito control programs will often provide them free of charge to the homeowner. (These must be confined to perfectly enclosed bodies of water due to their predilection to also feed on native fish.)

Fans

Mosquitoes are weak flyers. If you have a small aviary or screened-in porch, you can significantly reduce risk by installing a large fan at one end and using this when the birds are out.

Mosquito Netting

For areas in which mosquito populations are high and deaths of wild birds due to WNV are documented regularly, mosquito netting can be used to cover aviaries. While there are many sources for this, a brief few moments of a Google search found Mosquito Curtains for larger enclosures.

Know Your Area

You can contact your local mosquito abatement district, if such exists in your area, or call the Technical Advisor of the American Mosquito Control Association to discover which species of mosquitoes are most common in your area. If you do not have large populations of Culex species, then your risks will be lower.

Mosquito populations change from year to year. The Center for Disease Control maintains up-to-date statistics on WNV activity. Statistics for 2019 can be found here.

Mosquito Control – What Doesn’t Work

• Bug-Zappers (black light insect electrocution devises): Mosquitoes make us less than 7% of all insects killed. In addition, these kill a significant number of beneficial insects, such as pollinators, as well as insects that make up a major part of the diet for our songbirds. (1)
• Ultrasonic Devices: Ten studies conducted over the past 15 years have revealed that these offer no protection whatever. (1)
• Bats: It is a myth that bats eat large numbers of mosquitoes. This misinformation was originally spread due to a study in which bats were released into a laboratory room filled with mosquitoes. In this situation, the bats did eat approximately 10 mosquitoes per minute. However, there was no other food source available to them. If given a choice, bats primarily eat beetles, wasps and moths that offer larger amounts of nutrition per item. (1)
• Purple Martins: It has been said as well that these birds feed widely on mosquitoes and many people have set up houses for them for this reason. There are two problems with this. First, purple martins eat few mosquitoes and more often feed upon dragonflies, which are a natural predator for mosquitoes. Second, purple martins typically feed above the flight paths of mosquitoes at dusk when the insects are most active.

Mosquito Control – What Helps “Around the Edges”

• Mosquito Traps – also known as “mosquito magnets.” These devises trick mosquitoes into thinking that they are a warm-blooded animal. They do this by emitting odors similar to those often given off by humans (CO2, lactic acid, sweat, etc). Each different model then uses some sort of method for killing them, such as adhesive strips. These offer limited effectiveness at present and should not be used as a sole method of control. Further, they do require regular maintenance, such as replacing the adhesive strips. (1) However, this technology is evolving and may offer better control in the future.

Conclusions

The risk to our companion parrots from West Nile Virus ranges from minimal to significant, depending upon many different factors – the state in which we live, the geography around our homes, the degree to which we keep our yards clean and mowed, the species of mosquitoes present locally, the existence of bodies of water nearby and how these are managed, and more.

On the other hand, the benefits to our companion parrots of being outdoors to experience the natural world are important and consequential. I will not make this blog post any longer by reiterating them here. I have discussed them in two previous blog posts, Parrots and the Need for Nature and Lighting Needs: Could Your Parrot Be UV Deficient.

Risk management is always a subjective and personal endeavor. Each of us must determine at which point along the spectrum we are comfortable when it comes to weighing the risks of West Nile Virus against the benefits of getting our birds outdoors.

I believe that the measures outlined above under Mosquito Control – What Does Work will, in most cases, be sufficient to ensure safety for companion parrots placed outdoors. In addition, two obvious actions to take are to feed a diet that ensures best health and to only put our parrots outside during the hours when mosquitoes are less likely to bite.

In the less common situations in which mosquito populations of the Culex species are dense and deaths of wild birds occur regularly, mosquito netting may be necessary, in addition to rigorous backyard clean-up. However for the majority of us, using a combination of the other measures will likely be enough.

Lastly, while the focus of this piece has been on the dangers of placing parrots outdoors in aviaries, it must be recognized that equal danger exists from mosquitoes that get into our homes.  Fixing tears in window screens, keeping access doors to the garage closed, and practicing yard hygiene is necessary even if you decide that an outdoor aviary is not in the cards at this moment in time.

References:

1. The American Mosquito Control Association. “Frequently Asked Questions.” https://www.mosquito.org/page/faq#Which%20mosquitoes%20transmit%20WNV?
2. Axelson, R. DVM. 2009. VCA Hospitals. West Nile Virus in Birds. https://vcahospitals.com/know-your-pet/west-nile-virus-in-birds.
3. Centers for Disease Control and Prevention. 2019. “West Nile Virus.” https://www.cdc.gov/westnile/prevention
4. Hayes, E. B., Komar, N., Nasci, R. S., Montgomery, S. P., O’Leary, D. R., & Campbell, G. L. (2005). Epidemiology and transmission dynamics of West Nile virus disease. Emerging infectious diseases, 11(8), 1167–1173. doi:10.3201/eid1108.050289a
5. Hoppes, Sharman M. DVM, ABVP (Avian). 2019. Merck Manual Veterinary Manual. “West Nile Virus.” https://www.merckvetmanual.com/exotic-and-laboratory-animals/pet-birds/viral-diseases-of-pet-birds
6. Insect Cop Website. 2019 “Insectcop Reviews: How effective and Safe are Mosquito Dunks?” https://insectcop.net/mosquito-dunk-review
7. Mayo Clinic Staff. 2019. Mayo Clinic website. “West Nile Virus.” https://www.mayoclinic.org/diseases-conditions/west-nile-virus
8. Mosquito Dunks Fact Sheet: https://www.planetnatural.com/wp-content/uploads/2013/04/mosquito-dunks-faq.pdf
9. Mosquito World: Your Guide to Home Mosquito Control. 2019. http://www.mosquitoworld.net
10. Palmieri, C., Franca, M., Uzal, F., Anderson, M., Barr, B., Woods, L., … Shivaprasad, H. L. 2011. Pathology and Immunohistochemical Findings of West Nile Virus Infection in Psittaciformes. Veterinary Pathology, 48(5), 975–984. https://doi.org/10.1177/0300985810391112
11. Pérez-Ramírez, E., Llorente, F., & Jiménez-Clavero, M. Á. (2014). Experimental infections of wild birds with West Nile virus. Viruses, 6(2), 752–781. doi:10.3390/v6020752
12. Reich, S. DVM. 2018. College of Veterinary Medicine University of Illinois. “What’s the Buzz? Birds, Horses, People Get West Nile Virus.” https://vetmed.illinois.edu/pet_column/birds-horses-people-west-nile-virus. Accessed 7/14/2019.
13. Washington State Department of Health. 2019. “Mosquite Larvicide – Bti”
14. Wissman, M. A., DVM, DABVP. 2006. :West Nile Virus: What You Must Know For Your Bird’s Sake.” https://www.exoticpetvet.net/avian/westnile.html.
15. World Health Organization. 2017. “West Nile Virus.” https://www.who.int/news-room/fact-sheets/detail/west-nile-virus

*All above sources were accessed during the writing of this blog post, between 7/12 and 7/16/2019.

Thank you for reading my blog. I am Pamela Clark, an IAABC Certified Parrot Behavior Consultant. My passion is helping people with parrots by offering behavior consultations and publishing information you can trust. To access free resources, schedule a consultation, or subscribe to my newsletter (which is a different publication from this blog), please visit me at http://www.pamelaclarkonline.com. Until next time!