By the way, I've always been curious about how they come up with the eagle count, so I emailed the Army Corps of Engineers and got this response:
There is a consistent procedure for the weekly eagle counts done at the dams on the Mississippi. The counts are done every Wednesday in the wintertime from 12/2/2015 to 2/24/2016. The count time is in the morning and needs to be done between the hours of 0830-0930 for consistency. 1 person is the dedicated counter for the season. When that person counts they go to whatever spot on the dam offers them the best view for the season. For example for LD 15 in Rock Island we go to the lower end of the auxiliary lock wall where it meets the dam to do the counts. When counting the person basically makes a 360 degree turn and marks down what they see. What is put on the website is the total number of adults and juvenile eagle that were counted that day. When we count, additional information is reported such as: was the eagle flying, perching (on ice, on a branch?), or feeding. We also make note of weather conditions and an estimate of ice coverage on the river. Also if anything else of note is present such as fisherman, tows, or other types of birds it is marked down. The amount of time spent counting really depends on how many birds are present, and the counters do their best not to double count flying eagles. This is submitted to someone in the Rock Island District headquarters where data is calculated and a totals report is distributed back out to Corps projects where it eventually ends up on the project website. If count is not done for whatever reason, it is just marked down as "no report".