Fig 1.
Schematic illustrating where physical measures were taken of hens’ wings.
A. The length of the folded wing (FW) was obtained by placing the ruler over the wing and measuring from the carpal joint to the tip of the longest primary flight feather. B. Measures of manually extended wings were taken by placing a long wooden ruler against the ventral (underside) of the bird’s wing. First, the wing was gently extended at a right angle from the body. Then, the end of the ruler was placed against the hen’s body under the wing, where the wing joined the body. Distances were measured from the body to distal end of the phalanges (Ph), marking the extent of skeletal structure of the wing, and from the body to the end of the longest primary flight feather (Pr), marking the extent of the feathers of the wing.
Fig 2.
Schematics of the experimental set up.
A. Side view of test pen with a hen. The depth camera was centered directly above the test pen, 250 cm above the surface of the black-painted plywood floor. The orange line represents the threshold applied for depth video analyses, which was 5 cm above the floor of the pen. B. Top-down view of the test pen. The blue rectangles labelled 1-4 represent the small carriers that hens were placed in prior to testing; these carriers faced the test pen allowing hens to see other hens during holding and testing. An RGB video camera on a tripod recorded the hen from the side to confirm wing flapping and likely time of maximum vertical extension.
Fig 3.
Examples of images used to measure vertical height reached by wing flapping hens while in the test pen.
A. Image taken from the depth video file. The binary mask removed pixels (yellow) which were below the 245 cm threshold and were not included in depth analysis. The red dot indicates the part of the wing flapping hen’s body that was the highest vertical point in this frame. B. Image from the RGB camera placed beside the test pen corresponding to the example images captured by the depth camera.
Fig 4.
Descriptive statistics for vertical height reached by 28 Hy-Line W36 hens while wing flapping along with physical measures of weight and wing dimensions.
A. Maximum vertical height reached by the hens while wing flapping (cm) as recorded with a depth camera. B. Body weight (kg) of hens in the study. C. Length of the folded wing as measured from carpal joint to distal tip of the longest primary feather (cm). D. Length of the extended wing measured from where the wing joins the body to the distal tip of the longest primary feather (cm). E. Length of the extended wing measured from where the wing joins the body to the distal tip of the phalange (cm). All wing measurements were taken from the hen’s left wing. Bold horizontal line = median. X = mean. Vertical lines extending from the box plots = standard deviations.
Table 1.
Spearman rank correlations between physical measurements taken from hens.