Sea otter (Enhydra lutris nereis) sighting data can be selected to dynamically generate a graph based on the criteria you select. You can either graph the data using monthly sightings over the course of a single year, or you can graph yearly sightings for two or more years.
When viewing monthly sightings, the number of sea otters sighted are plotted for each age class (i.e. adults, adults with pups, large pups, and/or small pups) you selected for every month, from January to December. At the top of each bar on the graph is the actual number of sightings. Bars are color-coded by sea otter age class. Below the graph are four summary statistics based on the set of data you selected for each age class over the whole year: 1) total sea otter sightings, 2) monthly mean number of sea otter sightings, 3) standard deviation for the monthly mean number of sea otter sightings, and 4) the standard error of the mean.
When viewing yearly sightings, the number of sea otters sighted are plotted for each age class (i.e. adults, adults with pups, large pups, and/or small pups) for every year you selected. Each bar on the graph can include 1 or more of the four color-coded age classes, depending on how many you selected. Below the graph are four summary statistics based on the set of data you selected for each age class over the range of years you selected: 1) total sea otter sightings, 2) annual mean number of sea otter sightings, 3) standard deviation for the annual mean number of sea otter sightings, and 4) the standard error of the mean.
Remember that these data are for sightings, and they do not represent unique observations. Many of the same sea otters are spotted each month and counted again.