Use of satellite telemetry data , GIS , and H T M L to create an interactive display of caribou movements

Caribou from the Teshekpuk Herd i n northern Alaska are an important subsistence resource for a number of native villages, and much of the herd range is w i t h i n the National Petroleum Reserve—Alaska ( N P R A ) . Because interest i n oil and gas development w i t h i n N P R A has recently increased, a cooperative study was undertaken to gain a greater understanding of herd distribution and movements. It is often difficult to get an intuitive feel for the temporal aspect of caribou movements using maps depicting a series of caribou locations. In an effort to make caribou movement data more accessible to the general public, we used satellite telemetry data collected over a 10-year period from female caribou of the Teshekpuk Herd to create interactive animations of caribou movements. Here we present a method to create an interactive display using only basic knowl¬ edge of Geographic Information Systems (GIS) soft¬ ware and web page production.


Introduction
Caribou from the Teshekpuk Herd in northern Alaska are an important subsistence resource for a number of native villages, and much of the herd range is within the National Petroleum Reserve-Alaska (NPRA).Because interest in oil and gas development within NPRA has recently increased, a cooperative study was undertaken to gain a greater understanding of herd distribution and movements.
It is often difficult to get an intuitive feel for the temporal aspect of caribou movements using maps depicting a series of caribou locations.In an effort to make caribou movement data more accessible to the general public, we used satellite telemetry data collected over a 10-year period from female caribou of the Teshekpuk Herd to create interactive animations of caribou movements.Here we present a method to create an interactive display using only basic knowl¬ edge of Geographic Information Systems (GIS) soft¬ ware and web page production.

Methods
Satellite data were collected from 27 different cari¬ bou of the Teshekpuk Herd for varying lengths of time during the period 1990-1999 as part of a coop-erative study by the North Slope Borough, Alaska Department of Fish and Game, and U.S. Bureau of Land Management.Data were screened and one location of the highest quality rating score (provided by Argos, Landover, MD) was selected per duty cycle (generally one location per 48 hours).
Geographic Information Systems (GIS) are used to compile spatial data as a series of computer "layers" that allow the user to make detailed maps and explore spatial relationships among layers.We used this technology to create a series of maps that could be combined to form animations of caribou move¬ ments.Using ArcView GIS 3.2a (ESRI Inc., Redlands, CA), we developed a series of animations depicting caribou movements over this 10-year period.These animations were created with GIS and compiled in Hyper Text Markup Language (HTML) with text and figures to create an interactive com¬ puter display that could be used by anyone with basic knowledge of web browsers.Different anima¬ tions were created for the entire 10-year period, annual movements, seasonal movements (winter, spring migration, calving and post-calving, insect season, late summer, and fall migration and rut), a sample of individual animals, and for movements near subsistence hunting areas.A total of 16 anima¬ tions were included in the final display.

Software
We created image files (JPEG format) in ArcView GIS 3.2a using ArcView Tracking Analyst Extension.Image files were then converted to Windows Media™ Format files (extension .WMV) files using ImageN (http://www.pixoid.com)and Windows Media Encoder v.8 software.Windows Media™ Format files, text, and image files were combined in an HTML framework using Netscape Composer to create a graph¬ ical user interface viewable on computers with upto-date web browsers and Windows Media Player or other software capable of playing WMV files.
The ArcView Tracking Analyst Extension allows the user to change symbols based on the location or the value of a data field, specify the speed of move¬ ments, the length of time symbols remain on the screen, and colors of symbols and arrows.Users cre¬ ate the background using standard GIS layers.

Conclusions
The use of animation clearly reveals the large annual variation in wintering areas and large differences in daily movement rates for this herd.This interactive display can be adapted for school groups, subsistence hunters, the general public, or scientists.Animat¬ ions are effective for quickly portraying a large quan¬ tity of data to any audience, and they should be use¬ ful for educating the public and user groups about herd range, seasonal movements, and annual varia¬ tion in distribution.Caribou movement animations also provide biologists with another tool to under¬ stand range use and identify important habitat and range areas.This method is easy to use and presenta¬ tions with single or multiple animals can be made with basic skills in GIS and HTML.