GFP Harvest Survey Program
The South Dakota Department of Game, Fish and Parks has conducted harvest surveys for many years. There have been some changes to the structure and style of these surveys, but for the past twenty years the form and content of the surveys has remained consistent.
Still, quetions often arise concerning the nature of the surveys and their importance to the Department's wildlife management. The surveys are vital, so it is important that we try to answer as many of your questions as possible in hopes it will help you understand why the short time you spend filling out these questionnaires is so worth while.
Why is it necessary to do harvest survey analysis?
Game populations are a limited resource. Hunting has an impact on that resource. The question is, how much. It is not possible to watch over every hunter's shoulder to see if they harvested game. We must therefore interview or survey the hunters to find out how successful they were. Game, Fish and Parks' biologists can use the harvest information with population census to determine what impact hunting is having and what limits must be set to maintain future hunting for a particular species.
How long has this survey business been going on?
The necessity of harvest surveys has been recognized from the earliest hunting seasons. They have been done with some structure in South Dakota for over 50 years. The earliest surveys would have been a random check of hunters stopped on the road and asked, "So, how'd you do?" Rough harvest projections were estimated from this information. Today we still ask the same basic question, "So, how'd you do?" The difference is a scientific approach that gives us close to 100% confidence in the accuracy of our findings.
What is your "scientific approach"?
For many years South Dakota sent surveys to every big game hunter. A report card was inserted with each license package with instructions for the hunter to complete the card at the conclusion of his or her hunt and return it to GF&P. However, the return rate on these cards was often only 50% and seldom better than 65%. Statisticians doing similar surveys around the country found there was significant errors in data when so many people were not responding. Overall, a survey such as East River Deer might have fairly accurate harvest data. But, when you looked at the individual units with the smaller sampling base, the errors could be huge. In 1984 GF&P tested the sub-sampling survey method on the Black Hills Buck deer season. Satisfied with those initial results, the sub-sampling method was expanded in 1986 to include 10 West River Deer, 15 East River Deer and 8 Sand Lake Refuge Deer units. Surveys were mailed to coincide with the conclusion of the respective seasons. In 10 days a second mailing was sent to those who had not responded. The results went very well and the information proved accurate. The method was timelier than the previous method, provided more reliable information, and was less work-intensive. Gradually most seasons have been worked into this framework.
How can you get accurate information from only a small portion of the people who hunt?
The individuals chosen to receive harvest surveys are randomly selected from each hunting unit. Years of research have proven that a random portion of hunters can accurately reflect results for everyone hunting that unit. Units with a very large number of licenses will have a smaller percentage of individuals drawn for surveys. For example, a unit with 700 licenses available may have only 25% of the hunters selected to receive harvest survey cards. Conversely, units with only a limited number of licenses may have all the hunters in that unit selected to receive a harvest survey card. There are defined rules to follow in selecting percentage of hunters to sample based on the number of licenses sold in each unit.
How many seasons are surveyed?
In 2009 GF&P will conduct over 30 sub-sampling surveys on hunting seasons. Initial mailings for surveys will total approximately 90,000 surveys, but to get the accurate 90% return rate we will probably have to send an additional 100,000 pieces of mail. In all, approximately 70,000 survey cards will be returned along with several hundred undeliverable pieces of mail.
Wouldn't you save some of that cost if you cut down on the number of people sampled for each unit?
That would not only cut down on cost, but on the accuracy of the survey information as well. In order to get accurate harvest projections, we must insure we can get a cross-section of hunters in our survey. If we have only 10 licenses sold in a unit and sample only half of them, we will be getting information too biased for accurate use. There will be bias in 25% sub-sampling 700 license holders in a unit, but the bias is so small it will not adversely affect the harvest projections.
Well then, wouldn't you cut down your mailing cost if you didn't send out so many mailings? I received three mailings of the same survey. What a waste!
Yes it is a waste and yes we would significantly reduce the cost of our mailings if we only had to send out one or two mailings. However, the key to the success of this sub-sampling is to get a response rate above 85%. The goal of GF&P is 90% to maximize the accuracy of our data. On a typical first mailing, we can expect to get about a 50% return of surveys. On the second mailing, we usually are close to 70%. Getting results from the last 10-20% percent takes a third and sometimes even a fourth mailing. We continue to work with the hunting public to stress the importance of this survey information and the time and costs savings of sending back a survey card as soon as they receive it. This not only saves us the cost of sending out a second and third mailing, it also insures that the survey information is fresh in the mind of the hunter and the most accurate information is provided.
I already complete survey information when I send in my tooth envelope. Why not use that information?
Some of the information is duplicated, but some isn't. The fact is, these are two incredibly important functions in South Dakota's big game management that serve two completely different purposes. The tooth envelope information provides our biologists with data on age and health of the deer population. But, since it only involves those who are successful, it does not give us a report from those who were unsuccessful or did not hunt. That information is also valuable. In addition, the tooth envelope survey is a one-shot deal. You have one chance to remove the teeth from your deer and return the card. There can be no follow-up mailings to improve the response because the deer has been disposed of. We have looked at ways to combine these surveys, but have come up with no working solution. In fact, we have checked methods used around the country for harvest survey analysis and we think we are blessed with one if the most cost efficient and accurate surveys anywhere. To get the data that is required for our big game management we must have you do both the tooth envelope and harvest survey forms.
If these surveys are random, why do I always get one?
In the world of random chance, there is a chance that a hunter will get pulled for a certain survey, or multiple surveys, on a regular basis. This is less likely in units with a large number of licenses where we are drawing only a small percentage. If an individual hunts in a unit with only a very small number of licenses available, odds are very good he or she will receive a survey card on a regular basis. Also, hunters who purchase more than one license in a season may receive more than one survey. Hunters who participate in different seasons also have a chance of being randomly drawn for surveys in different seasons. The selection of names is completely random. We do not target any one person to receive a hunter survey any more than we delete specific individuals from getting a survey.
Should I even bother to fill out the survey? I wasn't successful in my hunt.
The fact that an individual receives a harvest survey makes them a vital link to the final analysis. That fact that someone was unsuccessful in their hunt is every bit as important as their success. Unsuccessful hunters represent a cross-section of all hunters and GF&P needs to know that information. In fact, it is every bit as important that you provide information on whether or not you even hunted. Each survey has a question to determine how many days you hunted. If the answer is "zero", that is valuable information to the Department. We ask that you fill that information in on your survey and return it to us.
What type of information do you seek on the surveys?
The surveys are kept very basic. We try to limit the number of questions on a survey to five or fewer. The basic questions we ask are: How many days did you hunt, what and/or how many did you harvest, where you hunted, and how satisfied were you with your hunt. There are variations on some survey cards, and as research goals and needs change there could be some change in questions asked. Needless to say, there are a hundred more questions that could be asked, but this makes the process very cumbersome and guarantees a poor return of our sub-sampling. We can expand our questions on more detailed Human Dimension surveys.
What becomes of all this survey information and who is it available to?
The survey information is compiled into harvest projections for each of the hunting seasons. The limited sample taken is expanded in proportion to the number of licenses actually sold for that unit. The information is complied into the "Game Report" for big game seasons. The small game and migratory bird harvest information is found in a separate report. These reports are used by GF&P biologists to prepare proposals for licenses available, bag limits, season dates and so forth. The compiled reports are available here.
Again, these harvest surveys are a very important part of wildlife management in South Dakota. You are the link between what happened during the hunting season and how that will translate into next year's hunting season. This information is so vital to how wildlife is managed, rules are in place to make the return of both the harvest survey card mandatory.
You are to be congratulated for your faithful and accurate efforts on behalf of South Dakota's wildlife management. Best of luck in your hunting and fishing efforts, and always remember to fill out and return those surveys as soon as you get them.