Social Reinforcement Delays in Free-Flying Honey Bees (<em>Apis mellifera</em> L.)

<div><p>Free-flying honey bees (<em>Apis mellifera</em> L.) reactions were observed when presented with varying schedules of post-reinforcement delays of 0 s, 300 s, or 600 s. We measured inter-visit-interval, response length, inter-response-time, and response rate. Honey bees exposed to these post-reinforcement delay intervals exhibit one of several patterns compared to groups not encountering delays, and had longer inter-visit-intervals. We observed no group differences in inter-response time. Honey bees with higher response rates tended to not finish the experiment. The removal of the delay intervals increased response rates for those subjects that completed the trials.</p> </div

Percentage of Drop-Out Bees with Higher Response Rates.

<p>Percentage of Drop-Out Bees with Higher Response Rates.</p

Response Rate Pattern Matching of Individual Bees.

<p>Response Rate Pattern Matching of Individual Bees.</p

Average response rate.

<p>The condition averages of group response rates are presented. The average of the control 0-0-0-0 group displays a subtle rise across conditions while the experimental groups do not display this increase during the second and third conditions. The removal of the delay intervals for the experimental groups induces a rise in response rate. The average of the baseline for the 0-10-10-0 group differs from the other groups due to one powerful “outlier” which dropped out mid-way through the second condition (visible in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046729#pone.0046729.s018" target="_blank">Figure S18</a>).</p

Percentage of Adjunctive Responses Which Are Smaller Than Crop-Filling Responses.

*<p>subjects did not make additional responses.</p

Inter-Visit-Interval Individual Results of Ordinal Analysis.

<p>Inter-Visit-Interval Individual Results of Ordinal Analysis.</p

IRT Pattern Matching of Individual Bees.

<p>IRT Pattern Matching of Individual Bees.</p

Percentage of Larger First Responses Following an Adjunctive Response.

*<p>subjects either did not make an additional response or did not return after an additional response.</p

Averaged inter-visit-interval.

<p>The averaged cumulative curves of group inte<i>r-visit-interv</i>als are pr<i>esented. All g</i>roup’s baselines are very similar during <i>the first condition of the experiment. The aver</i>aged control 0-0-0-0 group maintains this increase for the remaining conditions and trials while the averaged 0-5-5-0, 0-10-10-0, and 0-10-5-0 experimental groups begin differing from the control group after about 3 visits of the second condition. The averaged 0-5-5-0, 0-10-10-0, and 0-10-5-0 experimental groups’ curves continue to increase (roughly resembling exponential curves when not presented as a cumulative curve) until the final condition change removing the delay intervals. Curiously, the averaged 0-5-10-0 group (which for the second condition is no different from the averaged 0-5-5-0 group) does not differ from the control group until the third condition (when the delay interval increases to 600 s), but then quickly increases similarly to the remaining experimental groups until the final conditional change removing the delay intervals. Most striking is the immediate near-return to baseline for all four experimental groups’ averages once there are no delay intervals. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046729#pone-0046729-t002" target="_blank">Table 2</a> displays average slope values for each condition and group for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046729#pone-0046729-g001" target="_blank">Figure 1</a>. Individual bee’s cumulative curves can be observed in Figures S1,S2,S3,S4,S5.</p