Why census counts matter
A deer census serves two purposes: wildlife exemption compliance and actual land management. Knowing roughly how many deer are on your property — and the buck-to-doe ratio — tells you whether you're overpopulated, underpopulated, or balanced. That drives harvest decisions, stocking rate adjustments, and how aggressively you feed.
For wildlife exemption compliance, you don't need a formal scientific survey. Your county appraisal district wants to see that you're actively monitoring your wildlife population. Dated game camera photos, a spotlight log, or a written observation record all satisfy that requirement.
Method 1: Game camera survey
This is what I use and what most private landowners use. It's passive, continuous, and produces photographic documentation that's easy to organize and share if your CAD asks.
How to run a camera survey
- Camera density. The standard recommendation is one camera per 100–200 acres. On smaller properties you can get by with fewer — on my 83 acres I run cameras at both protein feeders and one additional trail location.
- Survey timing. Run a dedicated survey in late summer (August–September) when bucks are still in velvet and identifiable, and again post-season (February–March) for an accurate count after harvest. Year-round cameras give you ongoing data.
- Survey duration. A minimum 7–14 day continuous run at each camera location gives a meaningful sample. Longer is better.
- What to record. Count individual deer — bucks, does, and fawns separately. Note distinguishing characteristics on bucks (frame, tine count, any unique points) to avoid double-counting the same deer across photos.
- Calculate buck-to-doe ratio. Divide total doe observations by total buck observations. A healthy ratio is 1:1 to 1.5:1 (does to bucks). Heavily skewed ratios (3:1 or worse) indicate overharvesting of bucks or underharvesting of does.
Camera survey — pros and cons
Method 2: Spotlight count
A spotlight count (also called a spotlight survey) involves driving established routes across your property at night, counting deer spotted with a high-powered spotlight. It's the traditional method used by TPWD biologists and wildlife managers for decades.
How to run a spotlight survey
- Route. Establish a fixed route — roads, senderos, or cleared lanes — and drive the same route every survey. Consistency matters more than perfection. Record total distance.
- Timing. 1–3 hours after dark, ideally on a clear night with low wind. Deer are most active in the first few hours of darkness.
- Count. Record every deer observed — location, sex if identifiable, and number of fawns. Two observers work better than one (driver and spotter).
- Frequency. Run at least 2–3 surveys per year for a meaningful trend. Most wildlife managers do late summer and late winter.
- Results. Calculate deer per mile of transect. Over multiple years this gives you a population trend — going up, stable, or declining.
Spotlight count — pros and cons
Method 3: Thermal drone survey
Thermal drone surveys are the newest and most accurate method available to private landowners — and the one generating the most questions about legality. Here's what you need to know.
A thermal-equipped drone flown at night can detect deer by body heat, even through light brush cover. A single flight over a few hundred acres can count deer quickly and with high accuracy. Professional wildlife management companies offer this service, and some landowners are running their own drones.
Legality in Texas — read carefully: Texas Parks & Wildlife Code prohibits using drones to locate game animals for the purpose of hunting. Using a thermal drone strictly for population census or wildlife management surveys — not for scouting before a hunt — is a legal gray area that TPWD has not definitively ruled on as of this writing. Professional wildlife biologists do use thermal surveys on private land for management purposes. If you use a drone survey, keep it clearly documented as a management activity separate from any hunting, and consult TPWD or a licensed wildlife biologist before proceeding. Do not use a drone survey to locate deer and then hunt the same property in the same season without getting clear legal guidance first.
Thermal drone survey — pros and cons
What counts for wildlife exemption compliance
Any of these methods satisfies the census count requirement for your wildlife management plan — as long as you document it. Here's what to keep:
- Camera surveys: Keep photos organized by date and location. A simple folder on your phone or computer labeled by month and year is enough.
- Spotlight counts: Keep a written log with date, route, weather conditions, and count by sex and age class. One page per survey.
- Thermal drone: Keep the video footage and any count report provided by the service.
Your CAD doesn't expect a scientific report. They want to see that you're actively monitoring your wildlife. Consistent, dated records over multiple years tell that story clearly.
Which method should you use?
For most landowners: game cameras year-round, supplemented by a spotlight count once or twice a year. It's the lowest-cost, lowest-effort combination that produces solid data and strong compliance documentation.
If you want the most accurate snapshot of your herd — especially on larger properties or after several years of management — a thermal drone survey run by a professional wildlife management company is worth the investment every few years.
The most important thing is consistency. Run the same method, in the same locations, at the same time each year. Trend data — population going up or down — is often more valuable than any single count.