PMC:6403350 / 7362-10343
Annnotations
{"target":"http://pubannotation.org/docs/sourcedb/PMC/sourceid/6403350","sourcedb":"PMC","sourceid":"6403350","source_url":"https://www.ncbi.nlm.nih.gov/pmc/6403350","text":"Experimental design\nThe test pen was situated outdoors within the research compound and comprised of three chambers: left, middle, and right, covered by a fine mesh rendering them escape proof (Fig. 1). The left and right chambers had bark chip flooring and plywood covering the roof to reduce moonlight as a confounding variable. A wooden nest box (51 × 32 × 30 cm high) containing fresh bedding material and water was available in the right and left chambers (Fig. 1).\nFigure 1 Configuration of the test pen showing how the middle chamber incorporated a ‘U maze’ with a wooden divider and contained a seed tray placed under three LED lights, which enabled the level of illumination to be adjusted (high: c. 1000 lux; low: \u003c1 lux).\nThe middle chamber also had bark chip flooring but both ceiling and walls were plywood. A wooden divider (150 × 80 cm high) ran two thirds of the way through the centre of the chamber, creating a ‘U maze’ between the entry tunnels from the left and right chambers into the middle chamber; a seed tray was positioned opposite the divider (Fig. 1). The entry tunnels were also fashioned from plywood (31 × 10 × 10 cm high) and were the only points of entry to the middle chamber. Within the middle chamber, three LED lights (one above the seed tray measuring 75 × 7 × 6 cm high, 19 watts, 220–240 volts; and two over the arms of the ‘U’ maze measuring 135 × 7 × 6 cm high, 41 watts, 220–240 volts; Planox Eco, Rudolf Zimmermann, Bamburg, Germany) were suspended from the ceiling (150 cm above the seed tray surface and 88 cm above the surface of each arm) so that light projected at an intensity of c. 1000 lux onto the floor of the middle chamber.\nTwo infra-red cameras (Techview QV3034 system, 3.6 mm lens; Jaycar Electronics, Auckland) were angled to capture the floor of the middle chamber, giving a bird’s eye view of any rodent activity that occurred within the U maze and seed tray. The seed tray (20 × 16 × 8 cm high) contained 1150 g of sand (c. 4 cm deep) mixed with 100 unhusked sunflower seeds (total weight \u003c3 g) and was used to determine how motivated rats were to obtain a reward under two conditions: light (= high predation risk) and dark (= low predation risk). Counting the number of food items remaining in a foraging patch (Giving-Up Density or GUD)46 is commonly done to investigate the impact of predation risk on the foraging behaviour of small mammals9,13 and can be used as a ‘behavioural indicator’ of patch use47. During the two evenings directly preceding a test, subjects were presented with a clean seed tray in their housing cage that also contained 100 unhusked sunflower seeds, to familiarise them with the feeding apparatus. Seeds were counted the following day to establish that seeds were being removed regularly from the tray; if no seeds were taken, peanut butter was smeared along the side of the tray using a gloved finger until rats foraged within the seed tray for two nights without the peanut butter bait.","divisions":[{"label":"title","span":{"begin":0,"end":19}},{"label":"p","span":{"begin":20,"end":732}},{"label":"figure","span":{"begin":471,"end":732}},{"label":"label","span":{"begin":471,"end":479}},{"label":"caption","span":{"begin":480,"end":732}},{"label":"p","span":{"begin":480,"end":732}},{"label":"p","span":{"begin":733,"end":1679}}],"tracks":[{"project":"2_test","denotations":[{"id":"30842448-26760039-136704296","span":{"begin":2407,"end":2408},"obj":"26760039"}],"attributes":[{"subj":"30842448-26760039-136704296","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#ecc093","default":true}]}]}}