P.D. Skaar's Monunj Bird Distribution is revised and updated approximately every 5 years. Each 

 update is cumulative, adding new bird records to those documented historicaliv. This sixth edition of 

 this publication is one of Dr. Skaar's ongoing legacies. Future editions will continue as a direct result of 

 his inspirational and forward-thinking efforts. 



About the Montana Bird Distribution Database 



The Montana Bird Distribution database contains observation records for the birds of Montana 

 submitted by volunteer contributors from across the state. CreatecH in 1991 by entering information 

 contained in the third edition of P.D. Skaar's AlontJna Bird Distribution ( 1985 ) uito database format, 

 the database contained approximately 88,000 records when the maps in this edition were generated on 

 1 January 2003. Of these, 13,000 represent latilong values from the third edition, 14,000 are records 

 entered for the fourth edition (records received from 1985 through 1991 ), 22,000 are records for the 

 fiftJi edition (records received from 1992 through 1995), and 39,000 are new records entered for this 

 sixth edition (records received from 1 January 1996 through 31 December 2002). 



Entries into the database from the third edition were entered directly from the publication, and 

 not from specific observation reports. These records, therefore, do not include the source (observer) or 

 date, and do not represent a known number of actual observations. In contrast, since 1991, all records 

 added to the database include information on the observer, species, location, and date the observation 

 was made. The database is housed at the Montana Natural Heritage Program in the Montana State 

 Library in Helena and is maintained by Montana Audubon. 



Latilongs and Quarter-latilongs 



The maps in this book are shaped in the general outline of Montana, with a grid pattern overlaying 

 the state in units called latilongs and quarter-latilongs. The back cover of this book illustrates this grid 

 pattern and how the latilong system is positioned across die state. The word "latilong" is a combination 

 of the words "latitude" and "longitude" and represents the areas formed by the intersection of these 

 imaginary mapping lines, thereby delineating rectangulai' sections across the state. Latilong and quarter- 

 latilong units work well in a large, sparsely populated state like Montana and allow for a consistent, 

 systematic method of gathering and displaying distribution information about bird species. Forty-nine 

 latilongs and 185 quarter-latilongs cover Montana. 



More specifically, Latilongs (LL) are mapping units formed by successive lines of latitude and 

 longitude, marked at one-degree inter\als. These lines form a rectangular grid pattern across the state. 

 Each latilong is assigned a number: 1 through 49, starting at the northwest corner of the state. The 

 average dimension of each latilong is 47 miles (76 km) wide and 69 miles (111 km) long, representing 

 an area of approximately 3,200 square miles ( 8,436 sq. km). Because of the earth's curvature, latilongs 

 along the Canadian border are 5.4 percent smaller than those along the Wyoming border. Latilongs 48 

 and 49 cover only small portions of southwestern Montana. 



Quarter-latilongs (QLL) are created by e\enly dividing each latilong unit into four quarters. 

 Each quartcr-latilong is identified by its associated latilong number, with the addition of a letter (A, B, 

 C, or D), ordered left to right (see Figure 1). Thus, latilong 19 is divided into 4 QLLs: 19A, 19B, 19C, 

 and 19D. 



Figure 1. Quarter-latilongs are created by dividing 

 each latilong unit into four quarters. 



