Bobcat Isotope Analysis
In the fall of 2017, Furbearer Conservation founder Jeff Traynor was approached by local independent biologists in search of data; in particular, isotope characteristics. Isotopes are chemical signatures incorporated into all growing tissues proportionately to the signature of whatever an animal eats. In the case of bobcats (Lynx rufus) particularly, all prey items will have slightly different isotope ratios based on their diet.
An example would be hares eating mostly grasses and herbaceous plants will have different ratios than beavers eating mostly bark and cambium, and both will be different from grouse eating mast such as acorns and berries. By collecting isotopes of bobcat prey, scientists can piece together how important each prey species is in a bobcat's diet.
Between 2017 and 2018, Jeff extracted and set aside hair samples from each furbearing species taken during the regular New Hampshire trapping season to assist with this continued research. Samples were robust - including tissue samples from weasels, beavers, muskrats, coyotes, raccoons, and others. These samples would help gleam integral insight into what, exactly, composes much of a bobcat’s diet. Another prime example of NH's trappers giving back to conservation of wildlife.
Dr. Rory Caroll utilized the submitted tissue as part of a dissertation seeking to compare genetic structure, diversity, effective population size, and gene flow between historic and contemporary bobcat populations. The study can be reviewed in its entirety below.
Hair samples from Jeff's harvested furbearers are collected and sent to UNH biologists. (Photo | Jeff Traynor, Furbearer Conservation™)
From University of NH:
"Scientists theorize bobcats have rebounded, in part, because they have shifted their diet to different prey, such as turkeys and squirrels that hang out beneath bird feeders during the winter. To test their hypothesis, they will compare the stable isotope signatures – different forms of chemical elements such as nitrogen and carbon -- in possible prey animals with those in bobcat hair. The idea behind the analysis is that isotope signatures in a top predator are a reflection of foods consumed at different ecological levels.
They also want to understand if bobcats that live in more developed areas are subjected to higher levels of stress. To do this, scientists will compare levels of a stress hormone called cortisol in hairs from individuals living in developed areas with those from individuals in more rural areas."