Development and

Assessment of Tools

That Managers

Could use to

Monitor Wild

Horse Populations

By: Francis J. Singer and

Ronald Osborne

Midcontinent Ecological

Science Center, US 

Geological Survey

The tenth in a series of 13,

Session 3

Background

Management will be more

effective with modern,

defensible, rapid, easy to use

techniques for the counting,

demographic analysis, and

removal analysis of wild

horse populations. The

Midcontinent Ecological

Science Center is committed

to assisting in development

of such tools for managers.

We have reviewed a selection

of techniques which could be

developed and applied to

important information

needs relative to wild horses. Several of these techniques have been used in

the Pryor Mountain and

Book Cliffs wild horse

herds by the Bureau of

Land Management and the

Midcontinent Ecological

Science Center, US

Geological Survey.

Discussion

Attempts were made at

complete identification and

enumeration of both herds

through two different techniques. First, a unique marking system was developed,

based on visual markings,

that is computer compatible.

This system is rapid, inexpensive, easy to use and

requires only a PC computer

and a data entry program

such as QPRO, EXCEL,

ACCESS, or DBASE. It is

probably useful only for

herds with excellent access

and easy to observe animals.

Second, a computerized

photo-ID system (WHIMS)

is being developed for greater

accuracy in identification of

animals. It is also only practical for use in herds of <200

animals, that are accessible

and easy to photograph. The

WHIMS system would be

very useful for contraceptive

application where individual

recognition is critical.

Conclusion

Many populations do not

meet the criteria for a complete census of the animals,

and an aerial technique is

required. The technique

should meet the criteria of

defensible, tested, and accurate, yet be relatively easy to

use and not require extensive capture or handling of

animals. Four likely candidates are: (1) mark-resight

using some individually recognizable animals (this

proved to be biased in the

Pryor Mountains), (2) mark

resight of entire herd based

on photos, recognition during a pre-survey prior to the

survey (this was used in one

herd and shows promise), (3)

the Idaho sightability model -

tested and used extensively

on elk in many areas of the

western US, and (4) population reconstruction models.

Several population models

are also available that could

easily be applied to wild

horse herds, including several

that are based on marked animals in the herd (White, G.

C. 1996) or in herds with no

marked animals (Wild Horse

Population Model-University

of Nevada, POPII).

Source

White, G. C. 1996. NOREMARK: population estimation

from mark-resighting surveys.

Wildlife Society Bulletin.

24:50-52.

RESOURCE NOTES

NO. 32 DATE 07/31/00

Range

Wild Horse andBurro Program
Range

Resource Notes are intended to be early

announcements of technical and informational topics for

Bureau of Land Management personnel and some of their customers.

Information in this Resource Note is based on the opinion and

experience of the author and has not been peer-reviewed. Conclusions

and opinions expressed herein do not

necessarily represent those of BLM. Use of trade names does not

imply U.S. Government endorsement of commercial products.

If you have received a copy of or found out about Resource

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NAME, TITLE, MAILING ADDRESS and a list of the two or three

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Thank you for your interest in Resource NoteS.

Contact

Francis Singer, PhD.

Biological Resources Division

USGS Midcontinent

Ecological Science Center,

USGS, and Natural 

Resource Ecology Lab

Colorado State University

4512 McMurray Avenue

Fort Collins, Colorado,

80523-1499

phone 970-491-7056

fax 970-491-1965

email:

francis@nrel.colostate.edu.