Program Monitor.exe

What does Program MONITOR do? This software estimates the statistical power of ecological monitoring programs.  Because many design variables interact to determine the capacity of a monitoring program to detect change, intuitive answers are elusive for such basic questions as: "How many plots should I monitor?" or "How often should I conduct surveys?" or "For how long should I monitor?" Program MONITOR is essentially a sample size estimator.
Program MONITOR uses simulation procedures to evaluate how each component of a monitoring program influences its power to detect change. The program has been cited in numerous peer-reviewed publications since it first became available in 1995 (see below  for sample of peer-reviewed publications using Program MONITOR).  The specific components of sampling design that the software  integrates are:

  • Number of plots monitored
  • Frequency of plot re-measurement each season
  • Occasions of plot surveys through time
  • Magnitude of values of measurements on each plot
  • Variation in measurements on each plot: all sources of variation pooled together, or within- ("sampling") and between-season ("process") variation partitioned separately
  • Magnitude of ongoing population change
  • Significance level associated with change detection
  • Number of tails considered in statistical tests of trend significance
  • Data type: Normally/log-normally distributed or presence/absence
  • Pattern of variation in the relationship of magnitude of measurements versus their variance over time (coefficient of variation constant versus proportional to the mean measurement)
  • Whole versus fractional measures (rounding)
  • Measurement truncation
Program MONITOR uses regression, ANOVA or nonparametric tests of trend as appropriate.   Most users will apply Program MONITOR to design population monitoring programs but the software  is applicable to any designing research programs for which an index is measured over time and space.  Program MONITOR has an optimization routine that can be used to find the least-cost sampling design once you have declared desired power levels and maximum sampling effort you are willing to undertake.  The software is a useful tool for teaching students about change  detection and sampling design.

Program MONITOR does not at present integrate temporal or spatial autocorrelation into the estimation procedure...we have algorithms to do so but lack the time and resources to do the programming.  We would like to include these capacities into the program’s next version if support can be found for doing so. 
(v. 11.0.0 MS Windows version, file name “”; program will self-install when you “unzip” it and click on “monsetup.exe”)
Download example input files (.zip file including swallowwort, bear and bittern .mon files)

Download sample MS Excel spreadsheet  for partitioning sampling from process variation given pilot monitoring data (courtesy of Dr.Brian Underwood)

About MONITOR version 11.0.0

March 16, 2010

Copyright 1995-2010 James P. Gibbs and Eduard Ene

This is a freeware application - do not distribute it in any commercial form.

Please credit the authors in any published work that makes use of the software, using the following citation:

Gibbs, J. P., and Eduard Ene. 2010. Program Monitor: Estimating the statistical power of ecological monitoring programs. Version 11.0.0.

Background: The program was first developed in 1995 (as a DOS application written in Turbo Pascal 7.0). This is its first major renovation, prompted in large part by the need for a Windows-based version and a critique of the program by Hatch (2003, Biological Conservation 111:317-329). The current version of the software was programmed in C++.

Acknowledgments: The software benefited greatly from the technical comments of Sam Droege, Tim Gerrodette, Scott A. Hatch, and Clinton T. Moore and the technical advice and encouragement and assistance of Pablo Ramirez, Greg Hood, Scott Melvin, Greg Shriver, Brian Underwood, Jim Hines, and Einar Mencle. Many users have also provided us with valuable feedback.

Suggestions: Send them to Note that we are unable to provide consultation on use of the software - it is provided for your use on an "as is" basis.

Software created by James P. Gibbs and Eduard Ene, State University of New York, College of Forestry and Environmental Science, Syracuse, NY 13210 USA

A sampling of publications citing Program MONITOR:
  • Flesch AD, Steidl RJ Population trends and implications for monitoring cactus ferruginous pygmy owls in Northern Mexico JOURNAL OF WILDLIFE MANAGEMENT 70 (3): 867-871 JUN 2006
  • Lewis KP Statistical power, sample sizes, and the software to calculate them easily BIOSCIENCE 56 (7): 607-612 JUL 2006
  • Pollock JF Detecting population declines over large areas with presence-absence, time-to-encounter, and count survey methods CONSERVATION BIOLOGY 20 (3): 882-892 JUN 2006
  • Freilich JE, Camp RJ, Duda JJ, et al. Problems with sampling desert tortoises: A simulation analysis based on field data JOURNAL OF WILDLIFE MANAGEMENT 69 (1): 45-56 JAN 2005
  • Woodsmith RD, Noel JR, Dilger ML An approach to effectiveness monitoring of floodplain channel aquatic habitat: channel condition assessment LANDSCAPE AND URBAN PLANNING 72 (1-3): 177-204 APR 30 2005
  • Corser JD, Dodd CK Fluctuations in a metapopulation of nesting four-toed salamanders, Hemidactylium scutatum, in the Great Smoky Mountains National Park, USA, 1999-2003 NATURAL AREAS JOURNAL 24 (2): 135-140 APR 2004
  • Newmark WD, Senzota RBM Power to detect trends in ecological indicators in the East Usambara Mountains, Tanzania AFRICAN JOURNAL OF ECOLOGY 41 (4): 294-298 DEC 2003
  • Salvidio S, Delaugerre M Population dynamics of the European leaf-toed gecko (Euleptes europaea) in NW Italy: Implications for conservation HERPETOLOGICAL JOURNAL 13 (2): 81-88 APR 2003
  • Hebert CE, Weseloh DVC Assessing temporal trends in contaminants from long-term avian monitoring programs: The influence of sampling frequency ECOTOXICOLOGY 12 (1-4): 141-151 FEB-AUG 2003
  • Storfer A Amphibian declines: future directions DIVERSITY AND DISTRIBUTIONS 9 (2): 151-163 MAR 2003
  • Hayward GD, Miquelle DG, Smirnov EV, et al. Monitoring Amur tiger populations: characteristics of track surveys in snow WILDLIFE SOCIETY BULLETIN 30 (4): 1150-1159 WIN 2002
  • Lor S, Malecki RA Call-response surveys to monitor marsh bird population trends WILDLIFE SOCIETY BULLETIN 30 (4): 1195-1201 WIN 2002
  • Acosta CA, Perry SA Spatio-temporal variation in crayfish production in disturbed marl prairie marshes of the Florida Everglades JOURNAL OF FRESHWATER ECOLOGY 17 (4): 641-650 DEC 2002
  • Galimberti F Power analysis of population trends: An application to elephant seals of the Falklands MARINE MAMMAL SCIENCE 18 (2): 557-566 APR 2002
  • Marsh DM Fluctuations in amphibian populations: a meta-analysis BIOLOGICAL CONSERVATION 101 (3): 327-335 OCT 2001
  • Cooper BA, Raphael MG, Mack DE Radar-based monitoring of marbled murrelets CONDOR 103 (2): 219-229 MAY 2001
  • Johnson CM, Krohn WB The importance of survey timing in monitoring breeding seabird numbers WATERBIRDS 24 (1): 22-33 2001
  • Bishop MA, Meyers PM, McNeley PF A method to estimate migrant shorebird numbers on the Copper River Delta, Alaska JOURNAL OF FIELD ORNITHOLOGY 71 (4): 627-637 FAL 2000
  • Smith CK, Petranka JW Monitoring terrestrial salamanders: Repeatability and validity of area-constrained cover object searches JOURNAL OF HERPETOLOGY 34 (4): 547-557 DEC 2000
  • Corser JD Decline of disjunct green salamander (Aneides aeneus) populations in the southern Appalachians BIOLOGICAL CONSERVATION 97 (1): 119-126 JAN 2001
  • Lewis SA, Gould WR Survey effort effects on power to detect trends in raptor migration counts WILDLIFE SOCIETY BULLETIN 28 (2): 317-329 SUM 2000
  • Warnock N, Haig SM, Oring LW Monitoring species richness and abundance of shorebirds in the western Great Basin CONDOR 100 (4): 589-600 NOV 1998
  • Nelson SM, Epstein ME Butterflies (Lepidoptera : Papilionoidea and Hesperioidea) of Roxborough State Park, Colorado, USA: Baseline inventory, community attributes, and monitoring plan ENVIRONMENTAL MANAGEMENT 22 (2): 287-295 MAR-APR 1998
  • Becker BH, Beissinger SR, Carter HR At-sea density monitoring of marbled Murrelets in central California: Methodological considerations CONDOR 99 (3): 743-755 AUG 1997