How do I know when a block is complete?

By Julie Hart 17 Jul 2023
Piping Plover Charadrius melodus

Updated January 2023

As we enter the last couple years of data collection, it’s important that we focus on “completing” as many blocks as possible.

A block is “complete” when it meets the following block completion guidelines:

  • Visited at 3+ times of year (e.g., April, June, July)
  • All accessible habitat types in a block are visited
  • 20+ hours of daytime birding
  • 55-95+ species reported (highly variable throughout the state)
  • 45 species or 67% of reported species marked as ‘Probable’ or ‘Confirmed’
  • 2+ hours of nocturnal birding (strongly recommended)

Some of these guidelines are easy to assess, while others take a little more effort.

When you think a block meets these guidelines, please email your Regional Coordinator and they will evaluate the block for completion.


A block is “Complete” if you can answer “YES” to each of the following questions

Below we look at the West Davenport NW block (data as of July 15, 2020) as an example.

1. Are there checklists from three different months?

On the “Recent Visits” tab, verify there are checklists from multiple dates. For most blocks (those with fewer than 100 checklists) this will show you all the visits to a block. If you are in a highly trafficked block, you may need to look at the data for the different locations that have been visited. Click on the link to take you to a checklist for the location of interest (e.g., Robert V Riddell SP) and look at the dates. You want to aim for one visit in April to capture early breeders, one in early June to compile a good species list, and then a couple of visits in late June and July to confirm breeding.

2. Are species from multiple habitat types represented?

On the “Recent Visits” tab, verify there are checklists from multiple locations. Then look at a satellite map of the block to identify the main habitat types in the block. For each habitat, check that birds commonly found in each habitat type are documented (use the default “Overview” tab).

  • Residential – House Wren, House Finch, House Sparrow
  • Deciduous forest – Scarlet Tanager, Red-eyed Vireo, Downy Woodpecker
  • Coniferous forest – Red-breasted Nuthatch, Dark-eyed Junco, Blue-headed Vireo
  • Mixed forest – American Robin, Black-capped Chickadee, Blue Jay
  • Shrubland and early successional habitat – Song Sparrow, Gray Catbird, Common Yellowthroat
  • Grassland – Bobolink, Eastern Meadowlark, Field Sparrow
  • Wetland, lake, riparian – Canada Goose, Swamp Sparrow, Red-winged Blackbird
  • Coastal beach – Willet, Clapper Rail, Swamp Sparrow, Yellow Warbler
  • Montane or boreal – Blackpoll Warbler, Yellow-bellied Flycatcher, Gray Jay

Note that not all habitats are accessible. If a particular habitat cannot be surveyed legally, do not trespass.

Where to look at on the block summary page to determine if a block is complete.

3. Have at least 20 hours been spent atlasing in the block?

Look at the Effort Hours on the top of the “Overview” tab and make sure there are at least 20 daytime hours. Then check that the hours spent were effective. Not all checklists are comprehensive and some birds are overlooked by beginner atlasers. To help assess how thoroughly a block was surveyed, check that a variety of breeding codes were used. If there are a lot of H’s and no M’s or S7’s, there’s a good chance a number of species could be bumped up to Probable breeding. On the “Overview” tab, sort by the different breeding evidence codes by clicking on the column label. Then scan down through the species and see if common species are listed as at least Probable, if not Confirmed. American Robin, for example, should be confirmed in nearly every block.

4. Is the number of coded species in the right range for that region?

Blocks should have 55-95 species with a breeding code, depending on habitat diversity and accessibility. On the “Overview” tab, look at the Total species. Then compare that number of species to neighboring blocks. You can also look at the county summary in which a block lies. Go to “Explore Atlas Regions” and type in the County. Alternatively, click on the county link below the block name at the top of the page. On the “Overview” tab, look at the list of species confirmed. There should be a lot of overlap between this list and the list of species for any block in that county. Also check that common birds are listed and confirmed (e.g., American Robin, Blue Jay, Gray Catbird, etc.).

5. Are 45 species or 67% of coded species marked as Probable or Confirmed?

First take a look at the stats on the “Overview” tab and add up the number of Probable and Confirmed codes. If the sum is more than 45, this guideline is met. If you are in a block with few species (less than 70 species coded), use the 67% threshold. Divide the total coded by the number of (Probable + Confirmed) to see if it is greater than 67%.

6. Are nocturnal and crepuscular species recorded?

Even though we no longer require 2 hours of nocturnal effort (as of 1/1/2023), we still want to document nocturnal and crepuscular species. Check the species list for owls, nightjars, rails, bitterns, cuckoos, snipe, and woodcock. If none of these birds are reported, please plan some dawn or dusk surveys.


I think this block is complete, now what?

If you believe a block is complete, please let your regional coordinator know. They will review the block data and forward it to the Project Coordinator if everything looks good. Completed blocks will show up on the Atlas Effort Map as black squares and the status on the block page will indicate that the block is complete. While you are waiting for a determination on block status, the best use of your time is to visit other priority blocks.

When a block is considered complete, we ask that you divert your attention to other incomplete priority blocks. New sightings will still be accepted for completed blocks, and you should still submit such sightings if you notice them, but your time is more valuable if you contribute to other priority blocks.