DURHAM, N.H. — Scientists with the New Hampshire Agricultural Experiment Station at the University of New Hampshire have developed a method to estimate the abundance of New England cottontail populations. The noninvasive method provides an important tool in the effort to conserve this region’s only native rabbit.
“The New England cottontail is a species of greatest conservation need throughout the Northeast and state-endangered species in Maine and New Hampshire. Tremendous conservation efforts have been ongoing on behalf of the species, primarily in the form of the creation and restoration of thousands of acres of shrubland habitat over the last decade,” said experiment station researcher Dr. Adrienne Kovach, assistant professor of natural resources and the environment.
“To conserve a species, it is essential to know its population status and to able to monitor it to detect trends over time, especially trends that reveal how the species is responding to the management actions. Abundance is the most fundamental piece of information about population status. Our work provides the methodology to measure abundance and therefore an approach for monitoring trends and response to management in the future,” said Kovach, who collaborated with Dr. Thea Kristensen, who is the first author on the paper and worked on the project as an experiment station supported postdoctoral researcher. She now teaches at Amherst College.
According to Kovach and experiment station researchers who have been studying the New England cottontail, there has been an 86 percent decline in the distribution of the New England cottontail over the last several decades. In addition, the New England cottontail has lost more than 80 percent of its habitat over the last 50 years as people have developed the landscape and as areas of shrubs and young trees have grown up to become mature woods that don’t offer enough ground-level vegetation for cottontails to find food and hide from predators, according to The New England Cottontail Conservation Initiative, of which UNH is a part.
“The loss of young forest and shrubland habitats has implications not just for New England cottontail, but also for other species that depend on these habitats, including shrubland birds and pollinators. Many of these specialist species are on decline,” she said.
Kovach and Kristensen developed a method to estimate the abundance of New England cottontails on habitat patches using a noninvasive genetic monitoring approach. They used the DNA obtained from cottontail fecal pellets collected during winter surveys to identify unique individual rabbits. They then constructed histories of the “captures” of these individuals and used that in a mark-recapture framework to estimate the abundance of cottontails.
“New England cottontails are a rare and secretive species. They are exceedingly difficult to monitor. Observations or trapping are not practical, and noninvasive genetic methods tied to fecal pellet sampling is the most effective way to monitor them. Here we developed an efficient and effective survey design for sampling cottontail pellets in conjunction with the analytical framework for population estimation. Specifically, we determined the level of survey effort needed by field biologists to collect sufficient data for precise and accurate population estimates,” Kovach said.
Going forward, this new estimation method will be integrated into ongoing conservation and monitoring activities for the New England cottontail. Specifically, this method can be used to assess cottontail population status and measure the response to habitat management and restoration.
“This is an area of uncertainty in New England cottontail conservation. Despite a tremendous habitat restoration effort has been underway for the last decade and continues, we do not know how effective this management is for helping the species. This method now provides a way to directly measure and quantify the effectiveness of management on the cottontail populations. We are currently implementing this method on 30 managed sites across the species range to estimate population sizes and measure the response to management,” Kovach said.
This research will be published today in the journal Ecosphere in the article “Spatially explicit abundance estimation of a rare habitat specialist: implications for SECR study design.” (DOI: 10.1002/ecs2.2217) Portions of this work and its extension for cottontail monitoring and management was presented in a New England cottontail symposium at the Northeast Fish and Wildlife Conference in Burlington, VT, in April 2018, and the Wildlife Society Annual Meeting in September 2017 in Albuquerque, NM.
This material is based upon work supported by the NH Agricultural Experiment Station, through joint funding of the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 225575, and the state of New Hampshire. Funding also was provided by the U.S. Fish and Wildlife Service (Region 5, Division of Natural Resources, National Wildlife Refuge System), the Maine Department of Inland Fisheries & Wildlife, and the Connecticut Department of Energy & Environmental Protection.
Founded in 1887, the NH Agricultural Experiment Station at the UNH College of Life Sciences and Agriculture is UNH’s original research center and an elemental component of New Hampshire’s land-grant university heritage and mission. We steward federal and state funding, including support from the USDA National Institute of Food and Agriculture, to provide unbiased and objective research concerning diverse aspects of sustainable agriculture and foods, aquaculture, forest management, and related wildlife, natural resources and rural community topics. We maintain the Woodman and Kingman agronomy and horticultural research farms, the Macfarlane Research Greenhouses, the Fairchild Dairy Teaching and Research Center, and the Organic Dairy Research Farm. Additional properties also provide forage, forests and woodlands in direct support to research, teaching, and outreach.
The University of New Hampshire is a flagship research university that inspires innovation and transforms lives in our state, nation and world. More than 16,000 students from all 50 states and 71 countries engage with an award-winning faculty in top ranked programs in business, engineering, law, liberal arts and the sciences across more than 200 programs of study. UNH’s research portfolio includes partnerships with NASA, NOAA, NSF and NIH, receiving more than $100 million in competitive external funding every year to further explore and define the frontiers of land, sea and space.
–UNH College of Life Sciences and Agriculture
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