Gopher Traps

The Short Answer

A blunt broom handle, and the patience to find the main tunnel with it before you set anything.

That is not a way of avoiding the question. Every extension source we read makes trap success conditional on placement: UC IPM states that setting a trap in the lateral tunnel is not as successful as in the main burrow, and New Mexico State Extension says greater success will usually be achieved by trapping in the main runway. Texas A&M AgriLife Extension notes that a probe can be made from a bluntly pointed broom or shovel handle. The trap you buy matters less than the hole you put it in.

We have set the page out in that order: the tunnel, then the mechanisms, then the one trial that compared models, then the traps themselves. A ranking of brands is not included, because the evidence supports a description and not a league table.

Find the Main Tunnel First

Gophers push soil out of short lateral tunnels, so the mound is not above the tunnel that matters. The main runway is off to one side.

• Work from a fresh mound. Texas A&M describes the mound as horseshoe shaped, roughly 8 to 24 inches across, with the hole plugged and set to one side.
• Probe beside it. Texas A&M gives 6 to 8 inches from the mound, on the side where the horseshoe-shaped depression is.
• Feel for the drop. UC IPM describes it as a sudden, noticeable drop of about 2 inches as the probe breaks through into the tunnel.
• Set two traps, not one. Texas A&M says to place two traps, one in each direction from the hole. UC IPM gives the same instruction as setting traps in tunnels in pairs facing each other.
• Know the depth you are looking for. UC IPM puts feeding burrows 6 to 12 inches below ground; Utah State University gives the main tunnel as 4 to 18 inches below the surface.

One thing you can stop worrying about: UC IPM states there is no impact of human scent on trapping success. Gloves are for your hands, not for the gopher.

Trap Mechanisms Compared

As on our other trap pages, the rows are mechanisms rather than brands. The last column says what is actually known about each, including the rows where the answer is that nothing has been measured.

What One Trial Measured

There is one comparative trial we could source, and it is worth reading carefully because it is narrower than its headline sounds.

Utah State University Extension published it in October 2016, authored by S. Nicole Frey and Mark Nelson (as of 2016). In the authors’ own words: in 2015, they compared the effectiveness and efficiency of several types of kill traps — Macabee, DK-1, and Cinch. The study was conducted in Beaver County, Utah, and they had a sample of four fields, each located outside Beaver.

What it reported, with each figure attached to the claim it belongs to:

• Time efficiency. Macabee traps were more time efficient than the DK-1 or Cinch traps, based on animals trapped per minute spent in the field (KW X2 = 10.2, df=2, P = 0.006).
• Effectiveness per visit. Macabee traps were more effective — animals caught per animal visit to the trap — than the other trap types (KW X2 = 7.12, df= 2, P = 0.03).
• The trade-off. The same traps were also tripped or plugged statistically more than the other two (KW X2 = 6.05, df = 2, P = 0.048). A trap that attracts more attention gets set off without a catch more often too.

And the limits, which the authors state themselves. Because their sample size was small they used a Kruskal-Wallace Rank Sum Test, and treated comparisons as statistically different at a probability of 0.05 or below. Four fields, six weeks from the first week of April, one county, one crop, and Thomomys bottae in alfalfa — not a lawn.

Set against that, UC IPM states that the Gophinator trap can be more effective than the Macabee in catching larger, mature gophers. Two extension sources, two different measures, no contradiction between them, and we are not going to crown one. That is the honest state of the evidence, and it is why the sections below are grouped by how a trap works rather than ordered first to last.

Fencing Instead of Trapping

Exclusion is the non-lethal option and every source that describes it also describes where it stops.

• For a single plant. UC IPM specifies wire baskets of light-gauge, non-galvanized steel wire, installed when the plant goes in.
• For a bed. Utah State University describes a buried mesh fence, but states that excluding pocket gophers can be very costly and is usually impractical.
• The limit, stated by the sources themselves. UC IPM says underground fencing is not perfect because persistent gophers can burrow below the wire. Washington Department of Fish and Wildlife is blunter: a below-ground barrier only slows them, and sooner or later the barrier will be breached.

Read that as scope rather than as failure. A basket around a young tree is a reasonable thing to install. A fence around a yard is a large bill for a delay.

What Does Not Work

This section exists because the shelf next to the traps is full of things the extension literature has already tested.

• Repellents. UC IPM: no repellents have proven effective. New Mexico State Extension: no registered repellents.
• Vibrating stakes, ultrasonic devices and pinwheels. UC IPM’s reasoning is that these rodents don’t frighten easily. New Mexico State says noise-making devices and plants reported to repel pocket gophers have not been proven effective.
• Bait placed behind the trap. UC IPM reports that UC Davis researchers have observed no such benefit.
• Gas cartridges. Utah State University states that because of their higher cost and inconsistent effectiveness, gas cartridges are not recommended.

The Legal Position

Yours may differ and this is not legal advice.

California. Fish and Game Code § 4152 provides that nongame mammals found to be injuring growing crops or other property “may be taken at any time or in any manner in accordance with this code and regulations adopted pursuant to this code by the owner or tenant of the premises”. The qualifying words are part of the sentence: the permission is expressly subject to the regulations adopted under the code. UC IPM, an extension source rather than the statute, adds that a trapping license is not required for gopher removal. California also restricts body-gripping traps, but the restriction is written by purpose: the code makes it unlawful to trap for the purposes of recreation or commerce in fur with such a trap, and it expressly provides that cage and box traps, nets, suitcase-type live beaver traps, and common rat and mouse traps shall not be considered body-gripping traps. Whether any particular trap design falls inside the statutory definition is a legal question the code does not answer for you.

Washington. The Department of Fish and Wildlife states pocket gophers are unclassified and may be trapped or killed, but that a special trapping permit is required for the use of all traps other than live traps. It also states that it is unlawful to release a pocket gopher anywhere within the state other than on the property where it was legally trapped, without a permit. The same source states that the Mazama pocket gopher of four counties is state threatened, and that people are not permitted to use lethal control in these areas.

On that Washington statement, moving a live-caught gopher off the property where it was trapped is the step that needs a permit there. That is one state, and it is the opposite of what many people assume is the kind option. It is not a general rule, and this page has checked two states.

Pincer Traps

UC IPM describes these as 2-pronged pincer traps, and says the gopher triggers one when it pushes against a flat, vertical pan or metal wire. This is the mechanism named first in the extension literature and the one two of the three trial models belong to.

The traps below are the two-pronged pincer type described above, named because that is the mechanism the extension literature names first.

Cinch-Style Traps

The other mechanism sits in the tunnel and closes across it. UC IPM names the choker-style box trap as the other common type, and notes box traps require more surface excavation to install than pincer traps — which matters in a lawn. The Cinch was the third model in the Utah trial.

What we checked and did not include. Five further listings were fetched while writing this page and none is named here. Four were dead pages and one was marked currently unavailable. A trap you cannot buy is not an option.

Questions

Sources