Range maps should be used with the understanding that they
provide only a general indication of typical distributions.
Ranges are highly variable for many species and are very
dynamic. Range maps are static and usually several years behind
the birds. These are some of the complications that present
themselves when developing range maps. Summer or winter range
information may hide migration pathways. Ranges of some species
can vary from year to year. Warmer winters are changing
historical ranges. As an example, the White-winged Dove, common
in south Texas but once very rare in North Texas, is now common
at many feeders on a year-round basis in North Texas. Red-
bellied Woodpeckers are spending their winters much further
north than in the past. Populations of some species can be high
in a specific area one year and totally absent the next
(irruptive behavior). Ranges of some species are expanding very
rapidly. The Eurasian Collared-Dove is an introduced species
that has quickly moved from its initial introductio