Category: Insects

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Birds and West Nile Virus

Birds and West Nile Virus: Bald Eagle, Haliaeetus leucocephalus
Bald Eagle
Haliaeetus leucocephalus
Courtesy US FWS
It’s that time of year again when we encounter a barrage of public health messages alerting us to take precautions during cold and flu season. However, a different disease outbreak has been making headlines this winter in Utah: West Nile virus.

Though West Nile virus is not a new name to most of us, our familiarity with it typically comes from summer time outbreaks amongst human populations. Yet this particular flare up has gained attention for causing the deaths of over 50 Bald Eagles and it happened during winter.

West Nile virus is maintained in nature by a transmission cycle between mosquitoes and birds. In this cycle, birds simply act as pathogen reservoirs, while the mosquitoes act as pathogen vectors passing the virus on to their eggs and infecting humans and animals through bites. Historically, in the locations of its origin – Africa, Europe, Asia, and the Middle East – this pathogen is rarely fatal to its avian hosts. In fact, antibodies to West Nile virus have been found in the blood of birds native to this region.

It wasn’t until 1997, when a stronger strain of West Nile virus emerged and caused fatalities in a wide range of avian species, that the infection started to be considered pathogenic to birds. When the disease first reached the United States in 1999 it proved to be highly virulent in North American bird populations. The American crow was particularly susceptible. Within 4 months of detection in New York, nearly 5,500 crows died from the infection. Since this first outbreak, West Nile virus spread across the United States and has been isolated in over 250 species of birds, including Bald Eagles.

While wintertime infection amongst human populations is rare, infection during this season is not so uncommon for birds. This is because birds can contract the disease by a variety of routes other than mosquito bites and direct contact. This is especially the case amongst opportunistic scavengers like raptors. If a raptor consumes the carcass of a bird killed by West Nile virus it can contract the virus orally, as the Bald Eagles did after consuming the remains of infected Eared Grebes. Luckily, while bird-to-bird transmission does occur amongst birds that exhibit roosting and group behaviors, the likelihood of a Bald Eagle, which is typically a solitary bird, directly passing the disease to another Bald Eagle is quite low. Meaning that once the last of the infected food source is gone, hopefully no further infections will occur.

For Wild About Utah, I’m Anna Bengtson.

Credits:
Image: Courtesy US FWS
Text: Anna Bengston

Sources & Additional Reading:

West Nile Virus, World Health Organization, https://www.who.int/mediacentre/factsheets/fs354/en/

DWR Learns What Killed Bald Eagles, Wildlife News, Utah Division of Wildlife Resources, https://wildlife.utah.gov/wildlife-news/1330-utah-dwr-learns-what-killed-bald-eagles.html

Koenig, W.D., Hochachka, W. M., Zuckerberg, B., and Dickinson, J.L. 2010. Ecological Determinants of American Crow Mortality Due to West Nile Virus During its North American Sweep. Oecologia, 163: 903-909. https://www.nbb.cornell.edu/wkoenig/K156TA_10.pdf

Powell, Hugh, Counting Crows: The Impact of the West Nile Virus, All About Birds, Cornell Lab of Ornithology, October 15, 2010. https://www.allaboutbirds.org/Page.aspx?pid=1956

Rappole, J.H., Derrickson, S.R., and Hubálek, Z. 2000. Perspectives: Migratory Birds and Spread of West Nile Virus in the Western Hemisphere. Emerging Infectious Diseases, Vol. 6, No. 4, July-August 2000, pp. 319-328. https://wwwnc.cdc.gov/eid/article/6/4/pdfs/00-0401.pdf

Reisen, William K. 2013. Ecology of West Nile Virus in North America. Viruses, Vol. 5, Issue 9, pp. 2079-2105. https://www.mdpi.com/1999-4915/5/9/2079

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Nature’s Recyclers

Courtesy and copyright Andrea Liberatore, Stokes Nature Center, https://logannature.org/
Fungi Decomposing Fall
Leaves Outside the
Stokes Nature Center
Courtesy & © 2011 Andrea Liberatore
Stokes Nature Center 

Courtesy and copyright Andrea Liberatore, Stokes Nature Center, https://logannature.org/Redworms Eisenia fetida
from Stokes Nature Center’s
vermicomposting system
Courtesy & © 2011 Andrea Liberatore
Stokes Nature Center

On November 15th, our nation celebrates America Recycles Day. While the day itself tends to focus on human recycling activity, I thought we should also give a nod to nature’s recyclers. Worms, maggots, fungi, beetles, and bacteria – it sounds like a list of leftover Halloween horrors. But in reality, we should be more afraid of what our world would look like without these creepy-crawlies, for these are nature’s recyclers. Scientists call these organisms saprophytes, and as important as their role in life is, they are more likely to evoke a shudder than any feeling of gratitude.

What decomposers actually do is break dead things down into smaller and smaller pieces, until all that is left are the basic molecular components that make up all living things such as nitrogen, phosphorous, carbon, and potassium. Once broken down, this material is then free to be taken up again by plants and animals that use them to live and grow. This cycle of nutrients is vital to life on Earth, and our saprophytic friends make it all possible.

While decomposition would occur even without the help of the decomposers, it would take much, much longer. In some landfills, newspapers have been unearthed that are more than 20 years old, and still quite readable. This is because landfills often create anaerobic environments, where oxygen-loving insects, fungi, and bacteria cannot live and therefore cannot aid decomposition. If without decomposers, a newspaper can last 20 years, what would happen to much larger and hardier items such as tree trunks and roadkill? I shudder to think about it.

Did you know that the U.S. throws more than 33 million tons of food waste into landfills each year? This organic material goes to waste there – taking up valuable space and taking longer than normal break down. So this year, celebrate America Recycles Day by employing some of nature’s recyclers in your yard. Consider starting a compost pile where your fall leaves and food scraps can get broken down into nutrient-rich all-natural fertilizer for next year’s garden.

For composting tips and more information about nature’s recyclers, visit Wild About Utah online at www.wildaboututah.org. Thank you to the Rocky Mountain Power Foundation for the research and development of this Wild About Utah topic. For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.

Credits:

Photos: Courtesy & © 2011 Andrea Liberatore, https://logannature.org/
Text:    Andrea Liberatore, Stokes Nature Center, logannature.org

Composting Tips & Information:

Farrell-Poe, K. and Koenig, R. (2010) Backyard Composting in Utah. Utah State University Cooperative Extension. https://extension.usu.edu/files/publications/factsheet/HG-Compost-01.pdf

U.S. Environmental Protection Agency: Composting. https://www.epa.gov/epawaste/conserve/rrr/composting/index.htm

Additional Reading:

Fogel, R. (2002) Waste Not, Want Not: Fungi as Decomposers. Utah State University Herbarium. https://utahpests.usu.edu/ipm/ornamental-pest-guide/diseases/wood-decay-fungi

Hoff, M. (2009) Young Naturalists: Nature’s Recyclers. Minnesota Conservation Volunteer Newsletter. July-August 2009. https://files.dnr.state.mn.us/publications/volunteer/young_naturalists/natures_recyclers/natures_recyclers.pdf

U.S. Environmental Protection Agency (2011) Basic Information About Food Waste. https://www.epa.gov/osw/conserve/materials/organics/food/fd-basic.htm

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Shrikes

Loggerhead Shrike
Loggerhead Shrike
Lanius ludovicianus
Copyright 2013 Linda Kervin

Northern Shrike Courtesy US FWS, Dave Menke, Photographer Northern Shrike
Lanius borealis
Courtesy US FWS, Dave Menke, Photographer

The name songbird conjures up an image of a colorful singing warbler. But one family of songbirds, the shrikes, are fierce little predators. No bigger than a robin, shrikes mainly eat insects, especially grasshoppers and crickets, but they also prey on rodents, small birds, lizards, snakes and frogs.

Utah has 2 species of Shrike: the Loggerhead which resides here year round and the Northern which breeds in tundra and visits Utah in the winter. Shrikes prefer semi-open country that has some trees, shrubs or fenceposts where they perch to watch for prey and then swoop to kill with their thick hooked bill.

Shrikes are sometimes called butcher birds Continue reading “Shrikes”

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Cricket or Cootie?

Jerusalem Cricket
Jerusalem Cricket
Orthoptera: Stenopelmatidae
Copyright 2013 Holly Strand

Hi, I’m Holly Strand from the Quinney College of Natural Resources at Utah State University.

It’s almost Halloween so I’d like to tell you about an unusual creature that has given many people a fright. It has a shiny oversized body with long spiny appendages. Dark eyes stare disturbingly from a smooth, bald head. It eats both living and dead matter. And sometimes it engages in cannibalism.

It’s a zombie you may be thinking! But no; Continue reading “Cricket or Cootie?”