Why Portland Rat Control Can Actually Be Green

by | Mar 21, 2021 | Pest

Eco-friendly Rat Control Portland

In Portland, rat control is incredibly important. We have a multitude of gardens, aging garages and old homes that are totally vulnerable to city rats. This article will describe why ignoring rats can create more problems for the environment, and what we can do to help.

Portland Rats as Invasive Species

It’s important to recognize that rats, particularly Norway and roof rats, did not choose to be here. Humans unintentionally introduced Norway rats and roof rats across the globe. They exist because we exist. First, let’s imagine a pre settler colonist time. Before either Norway or roof rats were introduced, native rats lived here.

Portland Native Rats & Mice

What adorable varmint species originally scurried through native bunchgrass prairies and oak savannas of the land occupied called Portland? Native rats include bushy tailed woodrat (Neotoma cinerea) and dusky footed woodrat (Neotoma fuscipes). Willamette Valley native mice are deer mouse (Peromyscus maniculatus), Pacific jumping mouse (Zapus trinotatus), and Townsend’s vole (Microtus townsendii).

The red tree vole (Phenacomys longicaudus) lived in conifer forests and nibbled almost exclusively on Douglas fir needles. They are now relatively rare but can be seen in this amazing video.

For the most part all these small rodent species are long gone from the land we call Portland. Now the only rodents common in Portland are invasive “pests”. Particularly, Rattus norvegicus (Norway rat aka brown rat), Rattus rattus (roof rat aka black rat) and Mus musculus (house mouse).

Portland skyline downtown showing Morrison bridge

Rat Control “At The Table”

Norway rats & house mice are stereotypical “commensal” pest species. Commensal means “at the table,” and refers to rats and mice’s dependence on humans for basic survival. Rats rose to this status of notoriety over thousands of years by self-domesticating for the food and habitat that we unknowingly and unthinkingly provide. Another term for species that live alongside humans is “synanthropic”.

Norway rats are no doubt a nuisance. They contaminate food storage with feces and urine and chew wires in parked vehicles. Rats can start electrical fires. They foul up and make unsettling noises in our wall voids, attics, basements and crawl spaces at night. Also they make large unsightly burrow holes in our gardens and backyards.

Rat Pest Control Challenges

When discussing invasive species we should recognize that humans ourselves are the greatest. Indeed we’re the premier contributor to habitat degradation and biodiversity loss. Undoubtedly there’s major issues today. So while we blame Norway rats and house mice for habitat degradation, it’d be poor taste not to note our role in creating big sticky ecological messes.

Commensal rodents’ ability to so precisely adapt to the crevices of human habitats, gleaning our food scraps is an incredible evolutionary strategy for survival.

Rat Pest Control to Conserve Native Rodents

But ecologically Norway rats, roof rats and house mice are also invasive species. Norway rats likely originated from northeast Asia, roof rats from southeast Asia and house mice from the Indian subcontinent. They’re not just problems for humans, they harm the ecosystem too. By being more aggressive, invasive rat species have mostly overtaken our native rat, mouse and vole species.

Invasive rats and human actives supplanted dusky footed wood rat. This endemic rat species builds towering wooden nests up to three feet high which are critical habitat for smaller critters when abandoned. Sometimes dusky footed wood rats even line their nests with bits bay laurel to keep pathogenic insects and mites away. These native rats do their own pest control!

Choosing to Control Portland Rats

There are many issues with pests and pesticides today. Many Portland homeowners choose not to control rats with rodenticides for this reason. However the fact of the matter is, private landowners are mostly responsible for Portland rat control. If we value reducing pesticide usage, we should be sure we are not worsening an ecological issue.

Eco-friendly Portland Rat Control

For the greenest Portland rat control, remember to remove any exterior food sources. Limit nesting habitat by removing vegetation within one foot of the ground, fence lines, and sides of buildings. If you’ve tried a few things and need help creating a custom Integrated Pest Management (IPM) strategy for Portland rat control, feel free to call.

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