What’s All This Fuss About Wildlife Habitat?
The Small Stuff You Do Really Does Matter
By Chuck Blair, Wildlife Ecologist
As I explained in my previous blog, What’s All the Fuss About Wildlife Habitat? Part 1, wild animals require four basic habitat components--food, water, cover or shelter, and space. The place where an animal gets all these things is called its habitat. Vegetated landscapes are highly variable with corresponding variability in their value for wildlife. Monocultures such as highly modified and managed farm fields and urban and suburban lawns offer very few habitat components needed by birds and other fauna. And those few components are of very marginal value.
Native landscapes, on the other hand, can provide most or all the habitat requirements for a wide variety of local native and migratory birds and other critters. Generally, natural areas with the lowest levels of disturbance and fragmentation provide the best habitat for the widest variety of species.
It's easy to be overwhelmed by news and research findings about the state of the planet. But there are many things you can do in your yard that can make a positive difference on a local, and even regional or global scale. And, by setting an example, you can often engage your family, friends, and neighbors to also do small, but meaningful, things. If you don’t have a yard, you know people who do, and you can make a difference by sharing this information with them.
Dusky Grouse in native habitat by Louisa Evers
Just Say No to Your Local Pest and Weed Control Company
Habitat diversity and wildlife diversity are both aspects of biodiversity, which is a broad term that encompasses the variety of living organisms on Earth. As I mentioned, manicured lawns are a form of monoculture that offers very little value for birds and other animals. And, to make matters worse, the chemicals used to control insects and weeds can have very bad unintended consequences for wildlife. There’s a lot of solid peer-reviewed literature on these topics.
This spring and early summer my wife and I had five vendors on our doorstep wanting to spray the outside of our house and our yard with chemicals that would kill all the unwanted insects and spiders (bugs) and weeds “lurking” there. And in the process, they would eliminate all those unsightly cobwebs that “detract from the beauty of our home.” We declined these offers because many, though not all, pesticides and herbicides that may be used by these companies or are available at your local big box store have primary or secondary adverse impacts on wildlife.
Pesticides and Their Impacts
Pesticides are substances that are designed to control pests. They include insecticides (substances used to kill insects), rodenticides (substances used to kill rodents, such as rat poison), and herbicides (substances used to kill plants). Although pesticides are designed to kill specific animals, insects or plants, these products commonly impact non-target species through either primary or secondary poisoning.
Primary poisoning occurs when an animal ingests a pesticide directly – for example, a vole eating poison bait. Secondary poisoning occurs when an animal eats another animal that has itself ingested a pesticide – for example, a great horned owl eating a vole that had eaten rat bait. Pesticides can kill wildlife, as well as cause illness which increases an animal’s risk of being preyed upon. The exact effect of both primary and secondary pesticide poisoning on wildlife depends on the species, and on the type and amount of poison consumed.
Secondary poisoning of birds, reptiles, amphibians, and mammals is a serious problem. It can occur when they eat insects or other animals that have been poisoned by pesticides. Examples of secondary poisoning are (1) birds of prey becoming sick after feeding on an animal that is dead or dying from acute exposure to a pesticide, and (2) the accumulation and movement of persistent chemicals in wildlife food chains. Some pesticides that can cause secondary poisoning include neonicotinoids, organophosphates, carbamates, and anticoagulant rodenticides.
Great Horned Owl by Linda Wentz
Pay Attention to Neonicotinoids
Neonicotinoids (aka neonics) are a class of insecticides that can be toxic to bees. They're chemically related to nicotine and are used on farms and in urban areas. The following information is from an extensive review of scientific studies prepared by the Xerces Society (Hopwood, et al. 2016). Neonicotinoids can be absorbed by plants and can be found in their pollen and nectar. They can also dissolve in water and enter waterways through agricultural runoff. Several neonicotinoid formulations are highly toxic to honeybees by contact and ingestion and some breakdown products are as or more toxic than the original compound. And products approved for home and garden use may be applied to plants at rates substantially higher than the maximum label rate approved for agricultural crops. The U.S. Fish and Wildlife Service phased out all use of neonicotinoids on National Wildlife Refuges in 2016. That fact alone should be good enough reason to never use products containing neonicotinoids.
Insecticide Impacts
The intended and immediate impact of spraying insecticides around your house is dead bugs. A secondary impact of killing bugs is that dead bugs don’t reproduce to create more bugs. Both the immediate loss of bugs due to spraying and the ongoing effect of no reproduction translate to a significant loss of important foods for birds. Hummingbird fans should take note that those ‘unsightly cobwebs’ are vital for their nest building.
Bugs, both adults and larvae, are a vital part of many birds' diets, providing them with protein and other nutrients. Insects are a high-quality source of protein, and they also contain other essential elements for growth, such as phosphorus, vitamins, minerals, and non-chitin carbohydrates. Insects are especially important for young birds, helping them grow quickly and gain the energy they need for migration (American Bird Conservancy 2024). An estimated 96 percent of all terrestrial North American bird species rely on insects for at least part of their diets at some point throughout the life cycle.
House Wren by Ceredig Roberts
Another unintended consequence of spraying insecticides and herbicides may be increased mortality of honeybee colonies. The herbicide glyphosate (Roundup) was expected to be innocuous to animals, including bees, because it targets an enzyme only found in plants and microorganisms. However, most bee gut bacteria contain the enzyme targeted by glyphosate, but vary in whether they possess susceptible versions and, correspondingly, in tolerance to glyphosate. Exposing bees to glyphosate alters the bee gut community and increases susceptibility to infection by opportunistic pathogens (Motta et al. 2018). Glyphosate also disrupts honeybee navigation (Xerces Society for Invertebrate Conservation, No date). Xerces maintains a database of summaries of scientific research articles on pesticides and how they impact invertebrates that provides further information about specific studies.
Do you need another reason to Just Say NO? Read on.
Dogs explore their world through their noses. If you are spraying pesticides and herbicides around your yard, then that’s what your dog is inhaling as it checks out the new smells. These chemicals can negatively impact a dog's body and have been linked to several types of cancer, including lymphoma, mammary, bladder, and transitional cell carcinoma. For example, a 2013 study found that Scottish terriers exposed to herbicide-treated lawns had a risk of cancer that was up to seven times higher than Scottish terriers that were not exposed (Glickman 2004). Also, professionally applied pesticides have also been linked to a 70% higher risk of chronic myeloid leukemia in dogs (Takashima-Uebelhoer et al. 2012). Risk was also higher in dogs belonging to people reporting use of self-applied insect growth regulators.
There Are Alternatives
I could write several pages about alternatives to spraying commercial and consumer grade pesticides and herbicides that are not nearly so harmful, but space is limited. Instead, here’s several sources of useful information.
Daily Benefits of Not Spraying Bugs at My House
The window in my office at home looks out at the small front porch. It’s very common to see a Say’s phoebe (Sayornis saya) perched on the back of a chair and looking around for bugs for itself or its nestlings. They often spend 30 minutes or more finding bugs, flying away briefly, and returning to search for more bugs. If I’d sprayed those bugs the phoebe wouldn’t have this great food source and I wouldn’t be able to enjoy the show.
A couple days ago, while writing this blog, I witnessed an intense skirmish between a praying mantis and a house finch (Haemorhous mexicanus). The mantis was on the porch because we don’t spray and have lots of bugs, and the finch was there because it saw a very large potential meal. The much larger finch was trying to subdue the mantis that was fighting back by standing tall, spreading and flapping its wings, and striking at the finch with its claws. It was a standoff and the finch eventually retreated. I had to leave for an appointment, so I don’t know how it ended, but it was quite interesting to watch.
Praying Mantis by Ceredig Roberts
References and Resources
American Bird Conservancy. 2024. What's Good for Insects Is Good for the Birds.
Balbuena, María Sol, Léa Tison, Marie-Luise Hahn, Uwe Greggers, Randolf Menzel, and Walter M Farina 2015. Effects of sublethal doses of glyphosate on honeybee navigation. J Experimental Biology Sep;218(Pt 17):2799-2805.
Freydier, Laurène and Jonathan G Lundgren 2016. Unintended effects of the herbicides 2,4-D and dicamba on lady beetles. Ecotoxicology Aug;25(6):1270-1277.
Glickman, Lawrence T., Malathi Raghavan, Deborah W. Knapp, Patty L. Bonney
and Marcia H. Dawson. 2004. Herbicide Exposure and the Risk of Transitional Cell Carcinoma of the Urinary Bladder in Scottish Terrier Dogs. J Am Vet Med Assoc 2004;24:1290—1297.
Hopwood, Jennifer, Aimee Code, Mace Vaughan, David Beddinger, Mathew Shepard, Scott Hoffman Black, Eric Lee-Mader, and Celeste Mazzacano. 2016. How neonicotinoids can kill bees. The Xerces Society. 84pp. (Available here)
Motta, Erick V.S., Kasie Raymann, and Nancy Morana (2018). Glyphosate perturbs the gut microbiota of honey bees. Proc Natl Acad Sci U S A. 2018 Oct 9; 115(41): 10305–10310. PMCID: PMC6187125
Takashima-Uebelhoer, Biki B., Lisa G. Barber, Sofija E. Zagarins, Elizabeth Procter-Gray, Audra L. Gollenberg, Antony S. Moore, and Elizabeth R. Bertone-Johnson. 2012. Household Chemical Exposures and the Risk of Canine Malignant Lymphoma, a Model for Human Non-Hodgkin’s Lymphoma. Environ Res. 112: 171–176. Published online 2012 Jan 4.
Understanding Pesticides & Their Risks. No date. Xerces Society for Invertebrate Conservation.