Are our camera surveys accurate?

By Grant Woods,

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← Grant's AnswersDeer Biology
Question
Hi Grant,
I have a few questions on how you use your trail camera surveys to make management decisions.
I have attached a file of our surveys that we did on our 220 acre lease in south central PA. On this sheet are the numbers for 2012 and 2013 where we did the traditional survey with corn bait and 2014 and 2015 where we did the survey using cameras set on food plots and trails, because our lease is in the CWD management zone so we cannot use bait to do our survey. In 2014 we had 5 cameras and ran the survey for 3 weeks and in 2015 we had 10 cameras and ran the survey for 2 weeks. The cameras are set to a 1 second delay.

As you can see on the 2015 survey we had 31 unique buck on camera in a two week period in the last part of August! This would put our deer per sq. mile at 400, almost double what our survey showed in 2014! These numbers are without adding the 10% that QDMA recommends.

How are these numbers useful to us in managing our property?

Are these number even accurate enough to be useful?

Has anyone done research on doing a survey without bait? Are does going to be photographed more then bucks?

Some additional info about the property is: We have harvested as many does as possible in the past 3 years (about 8 to 10 does and 1 to 2 buck per year) and the numbers just keep climbing. The habitat is not in good condition, it is over grown with bush honeysuckle and autumn olive. But our lease does not allow us to do any timer cuts or invasive species control. The only thing that we can do is plant food plots and we plant about 6 acres of those in a mix of clover, soybeans (soybeans cannot be grown without a fence) and Broadside.

Thank you for any info you can give and God bless.

Winston,

I’m thrilled you are doing camera surveys and tracking data year to year. Year to year comparisons (or trends) are often very useful!

Do you see more deer and/or more deer sign on the lease compared to during 2012?

There are several factors that could explain the trend of an increasing population.

1.  I noticed the fawn recruitment rate increased significantly even during 2012 and 2013 (both years when corn was used as an attractant).  Increasing fawn recruitment rates will allow for deer populations to increase rapidly!

2.  If the neighbors fed and stopped feeding (due to new regulations) deer may be much more attracted to your food plots, at least during certain times of the  year. This could easily explain the increase in number of deer.

3.  I never use a deer population correction factor .  The correction factor won’t solve error. It will simply be same amount of error from year to year.  If the survey yields erroneous data, the data will simply have a 10% larger error if the correction factor is used.  Remember – it’s the trend that’s important – not the actual number of deer. 

4.  If you know you have more deer than quality forage produced on the lease it will be necessary to harvest more does compared to past years.

5.  Have you initiated a predator control program?  My biggest question based on your data is why the fawn recruitment rate has increased so significantly.

Enjoy creation,

grant