Message from Trustee Lemons: Deer Immunocontraception Study 2016 Report
Posted on: January 18, 2017 - 11:29pm
Fellow Residents,
We have completed our third year of the immunocontraception study and a full report is now available on the Village website (Here or go to http://www.hastingsgov.org/deer-issues ). You are encouraged to read it so you can gain a full sense of what the project is about and what has been accomplished so far.
As you are well aware, deer numbers in the Village of Hastings-on-Hudson have increased dramatically over the past fifteen years, and that rise has resulted in losses that are estimated to be in the hundreds of thousands of dollars annually. In 2014 the Village launched a five-year research project to evaluate PZP immunocontraception as way of reducing deer impact. That method was chosen after all the other major population control methods were considered and deemed to be either unworkable or too expensive. Our partners in this project, who have provided the personnel and expertise to carry it out, are the Humane Society of the US and the Cummings School of Veterinary Medicine at Tufts University. Many village residents have volunteered their time to assist the study. The study was approved and is monitored by the New York State Department of Environmental Conservation (DEC). The study’s key outcome indicators are fawning rates, deer population size, the rate of monitored habitat destruction and the annual number of deer-vehicle collisions (DVCs). An intermediate study output is the number of immunized does as a percentage of the total estimated doe population. The study design does not anticipate sufficient data for final analysis until near the end of the five-year period in 2018. The Village’s 2016 report presents the intermediate results. While the data after three years are promising, they are not yet sufficient to judge whether the project results will support an ongoing, long-term program of immunocontraception. Any effective management program will have to be sustained long into the future if it is to be successful.
There were three phases of study activity in 2016: 1) During the Pre-capture Phase, two weeks before beginning deer immunization, the Deer Team came for a few days to set up feeding stations around the village. The stations were intended to draw deer predictably to locations where they could be found and darted more easily. During this time residents were also asked for permission to dart does found on their property. 2) During the four-week Capture and Treatment Phase in March the Deer Team began darting and treating deer at the feeding stations and then elsewhere in the community as opportunities arose. 3) During the Re-treatment Phase in September before the mating season, does who were immunized in 2014 were re-immunized, as they will need to be every other year throughout their reproductive lives if they are to remain infertile. Re-treating did not require capture and was done with auto-injecting darts.
In 2016 the Deer Team immunized and tagged twenty additional does, bringing the project total to 48 treated does. Of these, three does are known to have died as of December 2016, two from hunting and one from a non-vehicle-related accident. As a result, the current total number of immunized live does is believed to be 45. Camera trapping data from 2014 and 2015, resident web reporting and field observations, taken together lead to the conclusion that the observed fawning rate of immunized does is 8% or less, which is dramatically lower than the almost 95% pregnancy rate found for animals prior to PZP treatment. Population estimates based on camera trapping and sightings of tagged and untagged females suggest that close to 60% of the does in the village have been immunized and tagged. In September, five of seven does first treated in 2014 received vaccine re-treatments. The study cost to the Village to date is $53,495, some of which was non-recurring cost for equipment.
A fourth capture, immunization and re-treatment season will take place this coming March and September.
If you have any questions, please reach out at the email below.
Sincerely,
Trustee Daniel Lemons