Deer Monitoring

Why are we capturing deer?

There are two reasons to tag and radio-collar deer on the study areas:

  1. Estimate annual harvest rates
  2. Monitor changes in deer populations over time

Capturing and tracking deer

Deer are captured using Clover traps and rocket nets. Six adult does and four adult bucks will be fitted with satellite GPS Collars on each study area. Deer not fitted with radio-collars will receive ear tags with a $100 reward for hunters to report the harvest of the deer. No rewards are paid for harvesting radio-collared deer. Trapping will be conducted each winter (January–April) of the study.

The GPS collars collect 5 locations per day. Locations are transmitted via email and uploaded to a database so field technicians can monitor movements and recover the radio-collar if necessary. 

Figure 1.  Movements of a female deer on the Rothrock State Forest documenting the proportion of the time the deer spent on the study area.  This deer was the first deer captured on the project but was later killed by a vehicle.

Monitoring Deer Movement

Estimating harvest rates

Applying ear tagRadio-collared deer allow us to estimate the proportion of deer that survive from the time of capture to the hunting season. This information, in combination with data on the ear-tagged deer that are harvested, provides the means for estimating the proportion of deer harvested on the study area. This methodology was developed as part of a M.S. Thesis by Frances Buderman at Penn State University under the direction of Dr. Duane Diefenbach. (figure 2 [right], applying ear tag)

Monitoring deer populations over time

Deer populations will be monitored over the course of the study using state-of-the-art genetics techniques.

Deer droppingsEach April, hundreds of transects across the study areas will be walked and deer pellets collected. These deer pellets can be analyzed using genetic techniques to individually identify deer.  Tissue samples also are collected from captured deer. By knowing how many deer are identified in both tissue and deer pellet samples we can estimate deer abundance.

However, this deer abundance estimate reflects the number of deer that spend at least some of their time on the study area. To accurately estimate deer populations we need to know what proportion of time, on average, deer spend on the study area. Some deer may spend 100% of their time on the study area whereas others may only spend 5%. This is why the satellite GPS collars are important by providing information on deer movements on and off the study area (see Figure 1 opposite page).

This innovative technique will allow us to estimate deer populations annually and monitor changes over time.