The primary goal of the breeding atlas was to obtain a list of all birds breeding in each block. This required both identifying as many species as possible, and obtaining the strongest evidence for breeding as possible. In reality, it is unlikely that every species was found in most cases, but the resulting block lists should be fairly comprehensive. To ensure that as many species as possible were found, we asked volunteers to aim for 20 hours of breeding-season survey work in each block. Results from other atlas projects suggest that this level of effort is likely to capture most species.

Spreading the 20 hours over multiple years was typical, and we encouraged people to distribute their survey effort over the course of the breeding season, as the timing of nesting varies among species. In particular, we emphasized the value of visits during the latter half of the summer when evidence of confirmed breeding – especially adults carrying food and recently fledged young – would be most likely to be seen. We encouraged observers to do the bulk of their surveys during the morning, to prioritize times when most birds are most active, but also asked them to make at least one trip in the evening or at night to listen for owls and other nocturnal species.

Time spent during dedicated atlas surveys was reported by volunteers along with their survey checklists, and was summed across all checklists submitted for a block. These numbers will often underestimate the total time spent in a block because incidental observations were generally submitted without time estimates. Quantifying time spent gathering incidental observations is effectively impossible without requiring people to track all the time they spend in a block, whether birding or not – which is clearly impractical. Consequently, estimates of survey effort should be viewed as minima, and interpreted judiciously.

[ADD TEXT ON DISTRIBUTION OF TIME EFFORT]

[INSERT MAP SHOWING NUMBER OF HOURS/BLOCK]

[ADD TEXT ON HOW MUCH TIME IS REQUIRED FOR NUMBER OF SPECIES/CONFIRMATIONS TO ASYMPTOTE]

[INSECT FIGURE SHOWING SPECIES/CONFIRMATIONS RELATIVE TO HOURS BY BLOCK]

In addition to spreading out search effort over time, we asked volunteers to think about ways to gain good spatial coverage of their block. Although we did not emphasize the need to visit the entire area of the block, especially if the land cover was relatively uniform (e.g., continuous second growth forest, or large developed areas) or dominated by private land with limited access, we did ask volunteers to try to visit every habitat type present, in order to maximize the number of species found.

Data were submitted in a variety of ways. Volunteers were encouraged to submit eBird checklists with their observations and to then share those with an eBird account that was set up for the atlas project. We also provided downloadable data sheets for use by observers who did not want to use eBird. Completed data sheets were then submitted on paper by mail, or electronically by email. A small minority of atlas volunteers submitted data via a variety of other means (excel spreadsheets, email communications, etc.). All datasheets submitted on paper were scanned and added to a digital archive that includes datasheets submitted via email. Paper originals are also archived at the University of Connecticut.

Most of the data that were not submitted directly into eBird by the observers were entered by the atlas team using the atlas eBird account to make the data available for other research uses. For rare cases, where privacy was a concern, we added data directly to the final atlas database without entering it into eBird.

Spatial issues with checklist locations

 

Data augmentation from other sources****

 

Checklists were quickly reviewed as soon as possible after submission to identify

[ADD TEXT ON HOW DATA WERE SUBMITTED AND MANAGED]