Atlas Blocks

Atlas projects typically use a block design to distribute effort systematically across the area of interest. We will be using USGS Topo Quadrangle boundaries, split into 6 equal-sized blocks roughly 3 miles by 3 miles each. You should make sure that your birding path (transects or tracks in eBird) does not cross over into other blocks so we know in which block you surveyed.

Priority Blocks
Interactive Mapper / Block Sign-up
Block Maps / Staying Within a Block
Determining Adequate Coverage

Priority Blocks

Of the 5710 blocks in New York, we selected a subset of priority blocks that are evenly distributed across the state to ensure broad coverage. To complete the atlas, we need to adequately survey every priority block. Sightings from every block will count towards our understanding of birds of the state, but priority blocks are where the focus should be. If your backyard or favorite birding destination does not fall within a priority block, you can and are encouraged to submit your breeding observations for those areas, too.

Within each topo quad, the center-east (blocks ending in “_CE”) and northwest (ending in “_NW”) blocks are priority blocks. There are a few exceptions for blocks that are mostly water or fall in another state. Priority blocks are indicated on the block maps and on the interactive mapper.

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Interactive Mapper / Block Sign-up

Use the interactive mapper to search for priority blocks near you, download block maps, and identify block names for naming your eBird checklists. This is also where you will be able to sign up for blocks starting January 1, 2020. (Note: The app performs best on Chrome or Safari. If you use Firefox and the map doesn’t display correctly at first, try toggling any of the options and refreshing the page.)

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Block Maps / Staying Within a Block

It’s important that we survey blocks thoroughly. In order to do that, we want to visit all the major habitat types in a block. Often times, some great habitat will lie on the edge of a block. So how do you know if you are about to cross over a block boundary?

While we work with eBird to add the block boundaries to the mobile app (hopefully these will be in place by the end of 2020), there are a few strategies you can use. One option is to take a map of the block(s) you plan to survey with you in the field. You can download such maps below and print them out or add them to a mobile device and refer to them while in the field. This option will be sufficient for most people. However, if you are more technically inclined, you can download digital versions of the block boundaries. KMZ files are provided below that can be imported to Google Earth and other GPS apps. A shapefile of the block boundaries is also provided if you want to make your own map or convert the layer to another file type. We realize that none of these options are perfect, so just do you your best.

PDF Maps

Static PDF maps of each block can be downloaded through the block sign-up tool. These maps can be printed out or saved to a mobile device for reference in the field. Two versions of each block map are available, one with the background “terrain” map offered by Google and a “hybrid” map that shows satellite imagery combined with roads. Maps also include open access lands (where known) and indigenous areas.

If you already know the block(s) you are interested in, you can download maps directly from Google Drive at the link below. (Tip: log in to your Google account to download individual files instead of entire folders.) If you do not know the block you are interested in, use the Interactive Block Mapper to download maps for the block(s) you are interested in.

To see what data have already been observed in a block, follow the link printed just above the map.

All the PDF maps are georeferenced and can be imported into mapping apps on your mobile device (e.g., Avenza Maps) to keep track of your location in the field.

Digital Maps

Use these files to add the block boundaries to a GPS, GIS, or mapping app. A good free option (if you have a smartphone) is to install the Google Earth app and load the kmz files of the block boundaries and labels. Once you add the layers to Google Earth, make sure you know how to show your current location so you see where you are in relation to block boundaries when you are in the field.

Land Ownership & Access

Always make sure that you have permission to access the area you want to survey. There is no single map layer that covers all of New York and indicates public access. However, there are a few tools that will help you determine what lands are public and for which lands you need to request permission. If you know of another helpful resource, please let us know!

  • Open Access Lands kmz (large file, 11MB) [A compilation of open-access state and federal lands, land trust properties, and other protected areas. Some sites require a permit or fee.]
  • NYS Parcel Map (tax maps; incomplete coverage) [Additional tax parcel maps can be found by googling your county, accessing the maps either online or at a town hall, and then contacting the landowner via the yellow pages or by knocking on their door.]
  • DECinfo Locator (interactive map of state lands and trails)
  • OnX (paid app with property boundaries)
  • Avenza Maps (free app offering offline maps)
  • AllTrails (website and app for public hiking trails)

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Determining Adequate Coverage

At some point, you will stop finding new species in your block and it will become challenging to find additional breeding evidence. It is at this point that you should stop surveying in that block and switch to another one. Although the variability of atlas blocks makes it difficult to come up with rules that work in every situation, the following guidelines suggest when a block is complete. When you feel you’ve achieved the below Block Guidelines in a block for the 5-year atlas period, please let us know and we’ll evaluate the block for completion. Blocks will be flagged as complete in eBird when they reach these guidelines.

Block 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
  • 2+ hours of nocturnal birding
  • 55-95+ species reported (highly variable throughout the state)
  • 50% of reported species marked as ‘Confirmed’

Note that these metrics apply to the cumulative effort of yourself and others in a block. A running total of species and effort within your block can be found on the eBird portal.

Details on Block Guidelines

Visited at 3+ times of year – Aim to survey each block at different times of the breeding season (e.g., April, June, July) to capture species that breed at different times of the year. While most birds in New York breed in June and July, some groups of birds breed earlier (e.g., owls, nightjars, resident birds) and others later (e.g., waxwings and goldfinches).

All accessible habitat types in a block are visited – All of the major habitat types in a block should be visited to ensure that we record the full diversity of species breeding per block. Major habitat types include deciduous, coniferous, and mixed forests; shrubland and early successional habitat; grassland; wetlands; coastal beaches; and montane areas. If a significant habitat type does not lie on public land, please use the landowner letters to request access. Access will be denied in some areas, but we do ask for a concerted effort to gain permission. You can also ask your regional coordinator for assistance in gaining access.

20 hours of daytime birding – Studies based on other atlas projects indicate that 20 hours is the average time it takes to adequately survey a block. Some of the factors that influence how long it will take to finish a block are observer skill, access, and habitat diversity. Experienced birders are able to identify species by ear and are familiar with the local habitat requirements of species so it may take them less time on average to atlas a block. If the land is difficult to access, either with little public land or few roads and trails, it will take longer to atlas the block. Some blocks contain fairly uniform habitat and it will take longer to increase the species count.

2 hours of nocturnal birding – Nocturnal surveys are important to capture crepuscular and nocturnal species like nightjars, owls, and rails. eBird defines a nocturnal checklist as starting more than 20 minutes after sunset and ending 40 minutes before sunrise. We recommend making at least two nocturnal visits per block, once in March or April to capture owls and again in May or June for nightjars and rails.

55-95+ species reported – The number of species breeding in a block is highly variable depending on geographic location and local habitat diversity. Areas like Long Island and the Adirondacks support fewer species than central New York. To gauge how many species you should target in your block, use the atlas effort map on eBird to see how many species have been documented in neighboring blocks. You can also refer to the second atlas results to see how many species were reported in the same general area.

50% of reported species marked as ‘Confirmed’ – At least half of the species reported in a block should be documented with a ‘Confirmed’ breeding code. Refer to the breeding code section of this handbook for a list of Confirmed codes. To determine how many species have been reported as Confirmed, go to the atlas effort map, click on your block, and follow the “View all block data” link. Alternatively, from the PDF of the block map, click on the link just above the map. The top of the detailed block data page shows the total number of species reported according to three breeding categories: Possible, Probable, or Confirmed. Divide the Total by 2 to determine how many species should be Confirmed and compare the result to the Confirmed count.

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