eBird Map Quiz #11

About the eBird Map of the Week

If you are unfamiliar with the eBird maps we encourage you to play with them under 'View and Explore Data'. Below we give some more information on how these maps are generated.

The green shading gives an indication of how often a species is reported in different regions. The darkest shading means that the species is reported on more than 50% of checklists. The palest green shading is used when the species is detected on less than 2 percent of checklists. Gray areas show areas where we have eBird data, but the the species has not been reported.

The beige map background shows areas where no checklists have been submitted to eBird. CAUTION: Note that eBird maps will not resemble your field guide maps in these blank areas, with northern Canada, central Mexico, and Nicaragua being particularly sparse regions. We hope someday to not have any beige space left and we would LOVE to get any checklists from these blank regions.

These maps only can be generated from eBird reports that include complete checklists--checklists that report ALL species detected and identified on that outing. Otherwise, we have no way of knowing whether a species you didn't report actually wasn't there, or you just didn't report it. The one exception to this is that we will shade a box in the lightest color green if we have no other reports from that 100 x 100 km grid cell. This allows us to include some noteworthy historical records where we don't have effort information. We encourage you to report complete checklists of birds and enter them as stationary counts, traveling counts or area searches--we can do a lot more with these kinds of counts.

When the eBird Team gets together, we've had a lot of fun challenging each other with the eBird maps. We hope you will enjoy it as much as we have. Let us know.

If you want to look at the map more carefully, you can download it from the bottom of this page.

Thanks for eBirding,

Team eBird.

Map#10 answer

We departed a bit on map #10 and included only observations made within the last five years, 2004-2008. This combined with the relatively odd distribution may have made this latest quiz the hardest yet!

The first thing that should stand out is that this is a bird that is typically found in the Northeast. The highest rates of detection are along the coast from North Carolina to Nova Scotia and New Brunswick. There are relatively few checklists from Newfoundland and Labrador, but the darkness suggests that this species may be common there. The species is seen somewhat less frequently (but still commonly) in the Great Lakes, Northeast and Midwest. The medium shaded box from the Churchill area of Manitoba and others boxes in southeastern Manitoba, taken with Newfoundland and Labrador checklist suggest that this species may be regular throughout northern Ontario and Quebec where we have no data--remember the gray areas on the map indicate the species wasn't detected. The buff areas indicate no data!

This species appears to be a vagrant in the West with no accepted records entered in eBird during the last five years (outside of the Puget Sound Region of Washington). Certainly not many species fit this pattern! The map looks good for American Black Duck. Recall that this map is limited to the last 5 years when records committees have been particularly reluctant to accept vagrant records of American Black Duck, given the relatively large number of hybrids with Mallards. But what are we to make of these odd records in Washington? A small feral population of American Black Ducks exists in the Washington and British Colombia region, and these records likely reflect these birds. In recent years this population has largely died out. This is the map for American Black Duck.

Map#9 answer

Map 9 was our first map to include data gathered in eBird throughout the Western Hemisphere. The first thing that stands out is that this species appears to be primarily coastal in distribution. The species appears to be most frequently reported from the West Coast of Mexico, the Yucatan Peninsula, much of the Caribbean and the Galapagos Islands. Much of the Gulf of California and the Mexico's West Coast are the darkest shade of green, indicating this species is very common. There certainly are not many species that fit that distribution! One may start thinking about some of the boobies, but none of them have such an expansive range. Other pelagic species are usually seen far from shore, whereas this species is seen most commonly near shore. The scattered pale green dots in the interior of the Lower 48 represent vagrants of this species, Magnificent Frigatebird.