ABA Fundamentals

Leaving patches: Effects of travel requirements.

McCarthy et al. (1994) · Journal of the experimental analysis of behavior 1994
★ The Verdict

Travel cost alone keeps pigeons pecking longer—use added response or delay requirements to stretch on-task behavior.

✓ Read this if BCBAs shaping extended work bouts or smoother transitions in clinic or classroom.
✗ Skip if Practitioners focused only on social or token reinforcement without transition hurdles.

01Research in Context

01

What this study did

Pierce et al. (1994) watched pigeons forage in two patches. To reach the second patch birds had to peck a travel key many times or wait several seconds. The team tracked how long birds stayed in the first patch as travel cost rose.

No prey cues changed. Only the work or wait to leave varied. A single-parameter threshold model predicted the stay times.

02

What they found

When travel took more pecks or seconds, pigeons stayed longer in the current patch. Higher cost to leave meant longer persistence, even though food odds never changed inside.

The model fit well. One simple rule—stay until leaving cost outweighs staying value—explained every bird’s choice.

03

How this fits with other research

Dardano (1973) showed pigeons escape hard work by taking self-imposed time-outs. D et al. extend that idea: travel itself is a cost animals weigh, not just ratio requirements.

Howard et al. (1988) used mild shock to mimic predator risk. Birds ate fewer, bigger meals to cut exposure. Both studies use closed-economy chambers to isolate one cost—travel in D, danger in S—and show pigeons reorganize foraging to minimize it.

Fantino (1968) found birds dodge schedules that force rapid responding. D adds distance or delay as another cost class; together they map how pigeons continuously trade effort for reward.

04

Why it matters

Your clients also “stay in the patch” when switching tasks feels hard. If you raise the response cost to leave a low-demand activity—say, adding steps to get toys or a 30-second wait timer—you may see longer engagement with the current task. Test this during transitions: require five helper responses or a short delay before a break and measure if work time stretches.

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→ Action — try this Monday

Before a preferred break, make the client complete five quick sorting responses; track if work time increases across sessions.

02At a glance

Intervention
not applicable
Design
single case other
Sample size
5
Population
not specified
Finding
not reported

03Original abstract

Five pigeons were trained in an analogue foraging procedure in which, by completing a travel requirement, they entered a "patch" in which a reinforcer might be available after an unpredictable time. They also had the opportunity, by emitting a defined response, to exit the patch and travel to another patch. Prey availability in a patch was not signaled. Data were collected on the length of time that subjects stayed in patches before exiting (residence times) as a function of various travel requirements: travel for a fixed time in blackout, fixed-interval schedule traveling, fixed-time traveling with an added response required to terminate traveling, and fixed-ratio traveling. For each of these conditions, the required amount of travel (time or responses) was varied over a wide range. As previously reported, residence times increased with increases in fixed-time traveling, as they did with increasing fixed-interval or fixed-ratio traveling. There was no evidence that adding response or work requirements systematically affected residence time except via increased travel time, although 3 of the 5 birds stayed longer in a patch under higher fixed-ratio values. A "threshold-maximization" model described the data well with a single parameter that was consistent across subjects, procedures, and experiments.

Journal of the experimental analysis of behavior, 1994 · doi:10.1901/jeab.1994.62-185