eBird Map Quiz #6

Map quiz 6

Another one for all years and all seasons. A tough one! The record off the Canadian Maritimes is probably erroneous (we'll check it out!).

Map quiz 5

Map quiz #5 was pretty straight-forward. It seems as though we're looking at a high arctic breeder of primarily western distribution. It is highly coastal, and shows relatively low frequency along the West Coast and a few scattered vagrants in the East. The dead give-away on this one is the high frequency in Hawaii. So what species breeds in Alaska, winters in Hawaii and migrates along the Pacific Coast with just a few eastern vagrant records? Pacific Golden-Plover of course.

Map quiz 4

Map quiz #4 showed a pretty distinctive range. This bird was restricted to the USA and Canada (actually one of the eBird records is from northernmost Baja California and represents the first and only Mexican record) with its range centered in the Northwest. It seems to follow the Rocky Mountains, extending north to Alaska at high frequency. There is a light scattering of records for the Midwest, and a dense area of occurrence in the Northeast. High frequencies in the Canadian Maritime Provinces suggest that it occurs there with some regularity. So...what bird is common in British Columbia, nw. Wyoming, Washington, and Alaska, but also occurs in Atlantic Canada?
 
A couple Northwestern specialties might spring to mind. Rufous Hummingbird would be far more common nationwide and since this is an all-year map would show its area of regular winter occurrence on the Gulf coast (as well as Mexican records). Varied Thrush might be closer, but the frequency in Colorado and especially eastern Canada preclude that species.
 
The map in fact is for Barrow's Goldeneye. This makes sense, since there are two disjunct breeding populations: one in eastern Canada and one throughout much of the Rocky Mountains and Northwest. Once we realize it is Barrow's, it makes sense that there is high frequency in the Parker Dam region of the Colorado River (the dark spot in Arizona) and at a couple Colorado locations where the species winter regularly. In New England Barrow's used to be more regular, but is now found annually at locations south only to New York, and it is a great rarity south of there.

Map quiz 3 - Answer

OK, so this is a western species, clearly. Occurs from southern British Columbia (the only place in Canada to find it, so Canadians might get this one more easily!). It also extends south into NW Baja California, the so called "California District" with lots of species (e.g., Wrentit, Acorn Woodpecker) typical of coastal California. This is a bird that appears to be absent from the desert southwest of e. California and sw. Arizona and extends about as far west in Texas as many "western" birds like Hutton;s vireo, Western Scrub-Jay etc. Actually Western Scrub-Jay would be a great guess here, as their distribution is pretty similar. But that species has eBird records from the central Baja California Peninsula, and does not occur south to Guatemala.

The Guatemala distribution combined with the isolated population in southernmost Baja California Sur may be the two keys to this one. Band-tailed Pigeon and Acorn Woodpecker might come to mind, as those both have isloated populations in southernmost Baja. But both of those extend farther south than Guatemala and can even be found in western Panama.

The answer on this one is Bushtit. A non-migratory bird with essentially no records out-of-range (although the w. Kansas record in eBird is a "vagrant"). That was a pretty tough one!

Map Quiz 2 - Answer

This is clearly a widespread Tropical species. Even with relatively little data in South America, this species is showing up from almost all the areas that we have data. Other than Chile, which has lots of data but no records of this species, this is a species that has been reported from every South American country. In Middle America, this species is numerous too, although it appears to be mostly absent from the highlands of Mexico and the Central Mexican Plateau. The United States distribution is telling. This bird occurs in reasonably high frequencies in south Texas and Southeast Arizona, but has scattered records from almost the entire Pacific Coast, as well as scattered birds elsewhere in the United States as far northeast as Massachusetts!

Many birds that reach the USA in South Texas are widespread in the tropics (such as Ferruginous Pygmy-Owl and Tropical Parula), but many of these are also non-migratory and do not occur as far-flung vagrants.

Tropical Kingbird in fact ends up being the only species that makes sense. This is a bird that is regular in southeast Arizona and colonized south Texas in 1991, but has now become regular and locally common there. It has increasingly been detected as a far-flung vagrant, and is annual in small numbers along the California coast and accidental as far north as southern Alaska! On the East Coast there are a number of records, and careful attention to yellow-bellied kingbirds there in recent years has produced records for the Carolinas, Maryland, Connecticut, and Massachusetts. Just recently, Delaware got its first; see photos here.

Click on the map below to enlarge. Good luck!

Map Quiz 1 - Answer

The map below is the full western hemisphere map for our quiz bird. Note the observations in Argentina. Since this is a year-round view of the species it could either be a widespread resident bird, or a long-distance migrant that breeds in North America and winters as far south as Argentina. Our quiz bird is heavily encountered in the western United States and the Canadian Prairie Provences. We can learn a bit more by looking at this species' range at its western edge. In California for example, it seems heavily represented in the Central Valley, yet not on the coast. It occurs widely in eastern Oregon and Washington but again seems largely absent from coastal areas. There also appears to be a scattering of vagrant records from the eastern seaboard, Great Lakes, and Florida. The higher frequency at the very southern tip of Florida suggests wintering. Looking further south we see a clear line of distribution through Central America south to Panama. In South America, however, our data are sparse, and more difficult to interpret. What we do see is that there are a few observations in Argentina, but not much to the north. Could these be vagrants?  Unlikely, but a more plausible scenario is that this species reaches Argentina in winter.

Given the patterns observed on these maps we can make the following deductions. Our quiz bird is a widespread breeder in the Great Plains and then occurs in mainly agricultural and riparian areas west of the Rockies, being absent from the highest mountain regions. It appears to be a clear long-distance migrant, as evidenced by its occurrence on the Atlantic Coast, and its apparent southbound migration through Central America to Argentina. It possible winters in extreme south Florida.

There are only a few species that show this kind of pattern. Some of the high arctic breeding shorebirds like Baird's Sandpiper might be similar, but are more widespread in the East and along the Pacific Coast, and we see no evidence here of a high arctic breeding distribution. The few records for the Yukon and the Northwest Territory could be vagrants.

Our bird is one of the longest-distance migrant raptors on earth. The Swainson's Hawk undertakes an annual migration that carries it from breeding areas as far north as the Canadian prairies, across Mexico and then Panama en masse, to winter in the Pampas of Argentina. When we begin to collect more data from South America, we'll be able to connect the dots a bit better between Panama and Argentina, and begin to understand how these birds cross the high peaks of the Andes on their way south!

Click on the map below to enlarge.

About the eBird Map Quiz

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% 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.