MVZ researchers are expected to deposit their field notes (specimen catalogs, journals, data sheets, etc.) in the Archives when their project is complete or before they leave the MVZ. Curation of specimens and other types of data (e.g., observations) depends upon complete, accurate, and clearly written field notes. Data on specimens and observations should minimally contain information on “who, what, where, when, and how” for each record.

WhatScientific name of species
WhereComplete locality data (see guidelines below)
WhenDate collected/observed
HowMistnet, shotgun, trap, salvage, etc.

“Data are of high quality if they are fit for their intended use” (Juran, 1964). As a collector, you may have an intended use for the data you collect. In the museum, the data you collect have the potential to be used in unforeseen ways; therefore, the value of your data is directly related to the fitness of those data for variety of uses.

Higher quality locality data can be achieved by following the guidelines given in the MVZ Guide for Recording Localities in Field Notes (PDF), the justifications for which are elaborated below.

Provide a descriptive locality, even if you have geographic coordinates. Write the description from specific to general, including a specific locality, offset(s) from a reference point, and administrative units such as county, state, and country. The locality should be as specific, succinct, unambiguous, complete, and accurate as possible, leaving no room for uncertainty in interpretation. Hint: The most specific localities are those described by a) a distance and heading along a path from a nearby and well-defined intersection, or b) two cardinal offset distances from a single nearby feature of small extent.

One purpose behind a specific locality description is to allow the validation of coordinates, in which errors are otherwise difficult to detect. The extent to which validation can occur depends on how well the locality description and its spatial counterpart describe the same place. The highest quality locality description is one with as few sources of uncertainty as possible. By describing a place in terms of a distance along a path, or by two orthogonal distances from a place, one removes uncertainty due to imprecise headings. By choosing a reference point of small extent, one reduces the uncertainty due to the size of the reference point. By choosing a nearby reference point, one reduces the potential for error in the offset distances. To make it easy to validate a locality, try to use reference points that are easy to find on maps or in gazetteers. At all costs, avoid using vague terms such as “near” and “center of”. In any locality that contains a named place that can be confused with another named place of a different type, specify the feature type in parentheses following the feature name.

Locality example using distance and heading along a path:
E shore Bolinas Lagoon, 3.1 mi NW (via Hwy. 1) intersection of Hwy. 1 and Calle del Arroyo in Stinson Beach (town), Marin Co., Calif.

Locality example using two cardinal offset distances from a reference point:
ice field below Cerro El Plomo, 0.5 km S and 0.2 km W of summit, Region Metropolitana, Chile

See examples of good and bad locality data below.

Supplement the locality description with elevation obtained from a GPS that has a barometric altimeter. Elevations also can be obtained by plotting coordinates on a topographic map (e.g., or by using a web service (e.g., Advanced Converter). Specify the source for how the elevation was obtained.

Under normal conditions, GPS devices are much less accurate for elevation than for horizontal distances, and they do not report the altitudinal accuracy. If elevation is a defining part of the locality description, be sure to use a reliable source for this measurement (barometric altimeter, or a trustworthy map).


Coordinates are a convenient way to define a locality that is not only more specific than is otherwise possible with a description, but that is also readily usable in GIS applications. Provide the coordinates of the location where collections or observations actually occurred. If reading coordinates from a map, use the same coordinate system as the map. Always include as many decimals of precision as given by the coordinate source. A measurement in decimal degrees given to five decimal places is more precise than a measurement in degrees minutes seconds, and more precise than a measurement in degrees decimal minutes given to three decimal places. Set your GPS to report locations in decimal degrees rather than make a conversion from another coordinate system.

The datum is an essential part of a coordinate description; it provides the frame of reference. Except under special circumstances (the poles, for example), coordinates without a datum do not uniquely specify a location. Confusion about the datum can result in positional errors of hundreds of meters. When using both maps and a GPS in the field, set the GPS datum to be the same as the map datum so that your GPS coordinates will match those on the map. If you are not basing your locality description on a map, set your GPS to report coordinates using the WGS84 (World Geodetic Datum 1984) datum. Always record the datum with the coordinates.

Most GPS devices are able to report a theoretical horizontal accuracy based on local conditions at the time of reading. For highly specific localities, it may be possible for the potential error in the GPS reading to be on the same order of magnitude as the extent of the locality. In these cases, the GPS accuracy can make a non-trivial contribution to the overall uncertainty in the position given by the coordinates. Record the accuracy as reported by the GPS whenever you take coordinates. Most GPS devices do not record accuracy with the waypoint data, but provide it in the interface showing current satellite conditions. By habitually recording the GPS accuracy, you will not have to worry about whether this is the case, and your data will be of the highest possible quality.

The extent is a measure of the size of the area within which collecting or observations occurred for a given locality – the distance from the point described by the locality and coordinates to the furthest point where collecting or observations occurred in that locality. For example, coordinates taken in the center of a 1 km linear trap line have an extent of 0.5 km. Without a measure of the potential deviation from the point provided, a user of the data usually has no way to know how specific the locality actually is. The extent is a simple way to alert the user that, for example, all of the specimens recorded for a set of coordinates were actually collected up to 0.5 miles from that point. It can be quite helpful at times to include in your field notes a large-scale map of the local vicinity for each locality, marking the area in which the collecting and observations occurred.

Record the sources of all measurements. Minimally, include map name, GPS model, and the source for elevation data.

Modoc National Wildlife Refuge, 2.8 mi S and 1.2 mi E junction of Hwy. 299 and Hwy. 395 in Alturas, Modoc Co., Calif.
Lat/Long/Datum: 41.45063 N, 120.50763 W (WGS84)
Elevation: 1330 ft
GPS Accuracy: 24 ft
Extent: 150 ft
References: Garmin Etrex Summit GPS for coordinates and accuracy, barometric altimeter for elevation.

Examples of Good & Bad Locality Data

VAGUE LOCALITIES – Localities that give a large area without more specific detail:

BAD: Sacramento River Delta – an extremely large geographic area
BETTER: Locke, Sacramento River Delta, Sacramento Co., California – names a town within the Delta

BAD: 3 mi W of San Jose/Cartago border – without additional details, this would mean anywhere 3 mi W of the border
GOOD: 3 mi W of San Jose/Cartago border on Highway 2, San Jose Province, Costa Rica

BAD: Pond along Chattahoochee River, Fulton Co., Georgia – there are millions of ponds along the Chattahoochee River
GOOD: Pond, 0.43 mi SW of intersection of Nancy and Ridgewood Roads, Chattahoochee River National Recreation Area, Fulton Co., Georgia

Due to the nature of the georeferencing guidelines, localities that are simply given as a city name are georeferenced as the center of the city. If the specimen is collected on the outskirts of the city, then it must be noted as such. Specifying an exact intersection is best.


BAD: Highway 9, Alajuela Province, Costa Rica
GOOD: Intersection of Hwy 9 and Rio Cariblanco, Cariblanco (town), Alajuela Province, Costa Rica

Directions given with no distances, road or air miles noted:
BAD: S Berkeley, Alameda County, California
GOOD: Oakland, 1 mi S Berkeley on Telegraph Ave. (1 mi S of intersection of 66th St and Telegraph Ave), Alameda Co., California


For many countries, especially Spanish-speaking ones, there are oftentimes several cities with the same name in the same province
BAD: San Marcos, Intibuca Province, Honduras – There are at least five San Marcos in Intibuca Province
BETTER: San Marcos, ca 7.5 km south of Los Chaguites, Intibuca Province, Honduras

If there is both a city and a geographic feature that share the same name, then note which locality (city, mountain, creek, lake) you meant
BAD: Battle Mountain, Lander Co., Nevada
BETTER: Battle Mountain (city), Lander Co., Nevada

Highway mi/km markers are very difficult to georeference retrospectively unless additional information is given
BAD: Km 58 Pan American Highway
GOOD:Km 58 Pan American Highway, 6 km S of Cartago on Pan American Highway, Cartago Province, Costa Rica

Crossing County/State/Country lines while collecting – make sure to use the correct names and specify clearly if using a town in a different county/state for an offset, e.g., 10 mi below Ehrenberg (La Paz Co, Arizona) on the Colorado River, Imperial Co, California

Spelling of Foreign Localities – while a misplaced letter in a familiar name is easily corrected, for example “Berkely” instead of “Berkeley,” a misspelling in any other language can cause confusion. e.g. Turrubares instead of Turrucares, Barra Blanca instead of Vara Blanca

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