Capture Techniques

Note: Community involvement is essential for this project to succeed.  Permission for access by property owners must be granted before any of the baiting and trapping can begin. 

Establishing Bait Sites
Biologists will contact landowners and locate potential bait sites for catching deer and conducting camera surveys.  Whole apples, or apple mash will be used as bait.  The trap site will then be baited prior trap setup so the deer get accustomed to apples being at the site.  Bait sites for deer capture are best in areas with high deer density to maximize captures per setup.  Also, areas with blocks of woody cover provide security and travel lanes for deer herds.

Capturing Deer
Once bait sites have been established and deer are visiting the sites, biologists will set up netted cages (Clover traps), drop nets, rocket nets, or dart rifles.  As more deer experience Clover traps, the more reluctant they are to go into them.  The drop and rocket nets offer a less intimidating trap set because all the sides are open for escape if necessary.  Having three trap options increases our chances for capturing unmarked females. However, trapping is becoming more time-consuming, with many previously tagged and sterilized  animals still using the bait piles.  Recapture of previously-tagged deer is undesirable with the potential for losing ear tags and possible capture stress.  

Clover Traps:
These netted cages can easily be set up in the backyards of cooperating landowners. This system worked very well for capturing and marking deer in other studies. Traps will be tied open during the day so deer can freely enter and leave. During late afternoon, traps will be set so that deer can be captured during the night. Shortly after sunrise each morning, traps will be checked so that captured animals can be removed as soon as possible. Deer will not be caught and handled during the day.

Deer are hardy animals and can easily spend the night outdoors in a trap with snow and cold temperatures. It is not unusual for deer to bleat and struggle in the cage when first captured. However after a few minutes, the deer usually become calm and will often bed down in the trap. In an emergency (deer in a trap harassed by dogs, or 2 deer caught at the same time), immediately contact Mike Ashdown, Dr. Jay Boulanger, or Dr. Paul Curtis. It is important for people and pets to stay away from the cage, or the deer may become excited and sustain an injury inside the trap. We usually handle deer from about 7 am in the morning until 9 pm at night, so please limit calls to these hours except in case of an emergency.

Drop Nets:
Drop nets are used in a different manner.  Rigging a drop net requires two stout trees about 50 feet apart, with strong limbs about 30 feet above the ground.  A support rope is stretched tightly over the limbs and has a pulley centered over the bait pile.  The drop net is then suspended by a second rope  that goes through the pulley, into a sight hole in the blind, and is tied off to a post or tree behind the blind.  The corners of the net are pulled away from the center and secured with a release connection.  When the net is dropped over a deer, the corners are freed, and the net will move with the deer wrapping them up in the process.  Bait is added daily to keep the deer going under the suspended net.  When the weather forecast is suitable, and staff are available, the biologists will put bait under the net and sit in the blind to wait for the deer.  Family groups of deer with untagged females can be selectively captured under the net and released.

 Rocket Nets:
Rocket nets are similar to the drop nets, as they are triggered by biologists from a blind. However, rocket nets are large (60 feet X 40 feet) and use 4 blackpowder-charged rockets to lift the net off the ground and carry it over deer at the bait pile.   Note, the rocket charges are never left in the rockets without staff on site.   As one might expect, firing the rocket net can alarm the neighborhood with the loud bang.  Consequently, we contact the Village Police Department and close neighbors prior to firing the rockets.  Because of the loud noise, and only a few areas in the community large enough to fire the rocket net safely, this is the capture method of last resort for re-capturing tagged deer that are trap-shy. 

Dart Rifle:
Dart rifles may be used to anaesthetize deer during times when Clover traps and nets are ineffective.  Research staff discharge darts from motor vehicles or while on foot when deer are 30 yards or closer.  Once darted, deer are monitored and recovered once anaesthetized (usually less than 15 minutes).

Tranquilizing
Captured deer are tranquilized, and blind folded (a cut off old sock is put over its eyes), in order to minimize stress to the animals.  Once the deer is sedated, it is removed from the trap or net, and its feet are tied together.  Tying the feet protects the biologist from getting kicked by the deer, protects the deer from getting hurt, and keeps the deer from running off before tagging procedures are completed.

Marking and Tracking Deer
All the captured females are marked with sequentially numbered ear tags and randomly numbered collars to allow individual identification. In addition, newly-captured adults are fitted with radio collars so movements and home ranges can be monitored.  The deer fitted with the radio collars will be checked weekly throughout the year.  These marked deer will help us estimate the total population size and determine core activity areas. Research staff with vehicles, radio antennas and receivers, and other field equipment will be seen frequently during day and night in the community. We welcome discussion of the research with Cayuga Heights residents and would be glad to schedule presentations about the project, or deer management in general, for interested community groups. 

Recovery
Once deer are released, they typically remain groggy for a period of about 40 minutes.  Occasionally, deer may remain groggy for several hours. Deer usually will lay down and rest until the tranquilizer wears off.  However, sometimes a deer will attempt to move about, and may be seen stumbling or acting oddly. If you see a deer that is acting strangely for more than a 2-hour period, please contact us.