0.84) and handle (mean insertions to resolve 3, GLM [intercept] estimate four.72, SE 0.05, z
0.84) and manage (imply insertions to resolve three, GLM [intercept] estimate four.72, SE 0.05, z 86.86, p 0.00) groups didn’t differ in the number of insertions (Fig. three; ESM Table S).EXPERIMENT two: TWOCHOICE COLOUR DISCRIMINATION TASKMaterialsThis setup consisted of two plastic cupsone black and one white (diameter six cm, height 4.five cm). Cups were spaced 30 cm PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/22479161 apart on a wooden board (50 cm five cm). Every single cup was attached to its own metal rod so they could move up and down independently,Miller et al. (206), PeerJ, DOI 0.777peerj.Figure 2 Experiment : objectdropping test trials for observer and control groups. Imply latency to 1st touch on the apparatus or object per trial for Observer (white boxplot) and Manage (hatched boxplot) groups.Figure three Experiment : number of object insertions to resolve. Total quantity of object insertions to resolve the objectdropping activity per group.Miller et al. (206), PeerJ, DOI 0.777peerj.2Figure 4 Experiment two setup. Twochoice colour discrimination activity where observers only saw a JW74 web demonstrator obtain meals under the white cup. Photo: Sarah Jelbert.but they have been prevented from becoming removed totally in the rod by a bolt. Cups could possibly be lifted upwards to reveal a hidden reward (Fig. four). Two live mealworms have been placed underneath each and every cup.ProcedureDemonstrator coaching 1 bird acted as a demonstratorHomerthe similar demonstrator as in Experiment . In visual isolation from the observer group, Homer received four sessions (50 min per session) of 0 trials per session, exactly where only 1 cupthe white cupwas baited (`demonstrated’ cup) plus the other cupthe black cupwas locked down making use of the bolt so it couldn’t be lifted. To pass demonstrator education, Homer had to regularly lift only the demonstrated cup in all 0 consecutive trials inside a session and not touch or attempt to lift the other cup ahead of he could move on for the demonstrations for observers. Homer touched both cups in session one particular and two, but passed criterion in session three. He was given four coaching sessions in total to make sure comparability together with the number of demonstrator training sessions employed for the carrion crows and ravens in Miller, Schwab Bugnyar (in press). Homer chose the white cup 00 of your time in the course of demonstrators for observers; therefore observers did not see any incorrect possibilities. Demonstrations for observers The observer group consisted of seven birds (four females and three males) in an effort to be comparable using the sample size in Miller and colleagues (206). These individuals also participated in Experiment : 3 in the educated group, three in the observer group, and a single in the control group. In an adjacent compartment with visual access for the observers, the demonstrator lifted the demonstrated cup (white) and obtained the reward in 4 sessions, with 0 trials per session. Each cups have been baited and could potentially be lifted, even though the demonstrator only lifted the demonstrated cup. The demonstratedMiller et al. (206), PeerJ, DOI 0.777peerj.3cup place (left or correct) was counterbalanced across trials. Every single observer watched 1 session per day.Testing observers After observers had observed Homer lifting the demonstrated cup 40 times, they were tested in visual isolation in the group. Each observer was presented using the cups, each cups have been baited outofsight with the observer and we recorded which cup they touched very first. They were offered a single test trial, which lasted as much as 3 minutes (all subjects interacted together with the cups inside 3 m.