Table 1 in A comparison of image and observer based aerial surveys of narwhal

<p><i>Table 1.</i> Summary of survey effort in the four strata during aerial surveys conducted in Melville Bay from 25 to 30 August 2014.</p><table><tbody><tr><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th>Aerial observers</th></tr></tbody><tbody><tr><th></th><td></td><td></td><td></td><td></td><td></td><td>Image</td><td></td><td>Aerial observers</td><td>(truncated 500 m)</td></tr><tr><th></th><td></td><td>Planned/</td><td>Length of</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><th></th><td>Area</td><td>completed</td><td>surveyed</td><td>Analyzed</td><td>No. of</td><td>No.</td><td>Ave. group</td><td>No. of</td><td>No.</td><td>Ave. group</td><td>No. of</td><td>No.</td><td>Ave. group</td></tr><tr><th>Stratum</th><td>(km2)</td><td>transects (no.)</td><td>transects (km)</td><td>images a</td><td>sightings</td><td>of ind.b</td><td>size <i>n</i> (CV)</td><td>sightings</td><td>of ind.</td><td>size <i>n</i> (CV)</td><td>sightings</td><td>of ind.</td><td>size <i>n</i> (CV)</td></tr><tr><th>NW</th><td>6,376</td><td>5 / 4</td><td>226</td><td>2,066</td><td>0</td><td>0</td><td>0 (0)</td><td>0</td><td>0</td><td>0 (0)</td><td>0</td><td>0</td><td>0 (0)</td></tr><tr><th>NE</th><td>2,076</td><td>11 / 12</td><td>468</td><td>6,572</td><td>23</td><td>49</td><td>2.1 (0.95)</td><td>15</td><td>39</td><td>2.6 (0.77)</td><td>13</td><td>32.5</td><td>2.5 (0.76)</td></tr><tr><th>C</th><td>2,621</td><td>9 / 18</td><td>663</td><td>8,193</td><td>39</td><td>86</td><td>2.2 (0.73)</td><td>48</td><td>188</td><td>3.9 (0.69)</td><td>23</td><td>93.5</td><td>4.1 (0.61)</td></tr><tr><th>S</th><td>3,748</td><td>13 / 10</td><td>575</td><td>4,105</td><td>0</td><td>0</td><td>0 (0)</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><th>All strata</th><td>14,821</td><td>38 / 44</td><td>1,932</td><td>20,936</td><td>62</td><td>135</td><td>2.2 (0.77)</td><td>63</td><td>227</td><td>3.6 (0.72)</td><td>36</td><td>126</td><td>3.5 (0.69)</td></tr></tbody></table><p>^a Including 180 off-effort images that were not used in the analysis. ^b Ind. = individuals.</p>