Did you ever wonder how wildlife officials come up with a number for doe tags per WMU? It’s not an easy task, and complicated because it’s not just about doe numbers.

When biologists are working on numbers, they are looking at the total overall population number per WMU, bucks and does. But when calculating how many doe tags to make available, they also have to consider specifics about the number, such as the ratio of bucks to does, and also the age of the population.

One early method was called the Change in Ratio method, starting around 1940. First, game officials got a sample from a spotlight survey, recording the ratio of antlered to antlerless deer. Then they would have a hunting season, on antlered deer only. Next, after the hunting season, they would have another spotlight survey and again check the number of antlered and antlerless.

That all sounds fairly straightforward but there was a lot more to it. There are other equations and calculations that went into that method. All that arithmetic might be mind-numbing to most of us, but all deer population estimates are just that – estimates. The estimates are based on known facts, that are used to make assumptions.

But there were glitches in the Change in Ratio method. What about births or deaths (not as a result of hunting) that occurred? Was the sex ratio in the harvest, comparing the number of bucks to the number of does, indicative of the adult sex ratio in the population? What about the number of yearlings taken in the harvest – how did that effect the population? How can populations be estimated, given the wide disparity in deer populations in various parts of the state?

In 1978, a Pennsylvania Game Commission deer biologist named William K. Shope, came up with a variation of the Change-in-Ratio technique, based on harvest data. He added a set of assumptions:

• That 1 and ½ year old males and females have the same survival rate from birth.

• That by using age distribution of harvest to estimate survival rates, a life table can be created.

• Add the age structure of the harvested males, which can be known, based on number of points.

Antler point restrictions greatly changed estimation techniques – the Change in Ratio method was no longer the best source of figuring. With the antler restrictions, more than half of yearling males are protected. No model for estimating deer populations will be perfect, but with the antler restrictions game officials got a reliable indication of population trends.

Population models are driven by harvest, reproduction, and natural mortality. A big key to the population model is us. In order for this deer population estimating plan to work, the PGC needs us. Yes, they can check numbers at butcher shops but many hunters butcher their own deer.

We have to send in those little report cards. Truth be told, I kind of like sending in my cards. I’m proud to do it. A biologist told me a few years ago that the PGC estimates that only one doe is harvested from every 8 to 10 tags issued – BUT that’s only an estimate because the PGC believes that the majority of successful hunters don’t send in the tags.

As I was, I bet you were happy to see that pink envelope in the mail. Now make somebody happy by sending in your report this year!