It was interesting to follow up with another variable ratio reinforcement schedule trial run today. I saw high motivation and had the time to fly the birds a lot and wanted to see how they would do on thinner reinforcement ratios. For the first 2/3 of the session, Kili & Truman flew thinner ratios then they have in the past. However, they were starting to get extremely fatigued and motivation was plummeting so I gave them a break by switching to continuous reinforcement for a little while. You have to realize that eating a pellet is also time consuming and provides greater rest than continuous back to back flying sessions. On a future trial, I would like to use a timer to guarantee a certain rest interval to take fatigue out of the VR equation as it pertains to food. I believe I could have had similar response on this session with less food reinforcement if it weren't for severe fatigue setting in (particularly for Truman who was panting at times).
Motivation was so high that the birds flew to their physical limits. The high pace of the training session got their body temperature to rise noticeably and for rapid breathing. The session lasted 45 minutes and aside from 2x 3 minute breaks, the birds flew continuously in alternating fashion. While one bird flew a recall, the other rested but had to be prepared to go as soon as the other returned.
Kili did not miss a single recall on the first call until the 31st flight recall, and not another until the 49th. After that point she had more missed flights I suspect due to fatigue rather than lack of motivation. Given a chance to rest she would start flying eagerly again. Both birds flew immediately on the first call during the 10 back to back continuous reinforcement trials near the end. Both continued to fly well on a VR schedule after the continuous reinforcement none the less.
I would say that the body condition of both birds is inferior to the condition they were in during the last trial. During the last trial both birds were receiving frequent outdoor flying sessions as well as indoor. Now they have been couped up in winter and only get the flying they can manage at home. Still, they both exceeded a mile of flying and both had flown over a quarter mile during the morning session. They reliably fly a mile indoors on most days in several sessions and play time. Their weights are also higher than they were on previous sessions but motivation was still excellent.
Here are the results of Saturday January 25, 2014 for Kili (Female Senegal Parrot Age 5) and Truman (Male Cape Parrot Age 3):
Truman - Cape Parrot
65 recall flights, 26 treats, 313g, motivation 4/5, pellets
59/65 1st attempt recall 91%
6/65 recall not on first call 9%
VR5 used for first 30
FR1 used for 31-40
VR3 used for 41-65
Total number of recalls - 65
Total number of flights - 130
Total distance flown - 6,500feet (1.2 miles)
Kili - Senegal Parrot
100 recall flights, 21 treats, 114g, motivation 5/5, pellets
90/100 1st attempt recall 90%
10/100 recall not on first call 10%
VR3 used throughout
Total number of recalls - 100
Total number of flights - 200
Total distance flown - 10,000feet (1.9 miles)
What is unbelievable is that the accuracy of response (coming on the first call) is pretty much identical across sessions. Truman has exactly 91% first recall attempt reliability like the previous session. Kili's response rate actually improved a bit and both maintain over 90%. If counting only the first 50 flights for both birds their response rates would be 96% for Kili and 92% for Truman. Their response rate begins to diminish as tiredness kicks in. In other words, for a few flights these birds are extremely reliable and most of the less reliable flights are the result of pushing them to fly more than usual with little resting time. Another interesting coincidence is that the number of pellet rewards received is similar to last time. This just happens to be the amount that they need to consume to make up the energy used for the flying and the rest for 12 hours of living.
Kili works out to be on an average VR5 for the entire session and Truman on VR2.5. This is fairly consistent with past trials. My next trial should include greater periods of mandatory rest to compare the role fatigue plays against food reward based motivation.