Last updated: February 4, 2025
Article
Surprises in Scat: Studying the Eastern Coyote population within Cape Cod National Seashore
Written by Katy Perrault, NPS
Science doesn’t exist in a vacuum – it was amazing to see and contribute to science informing management decisions within the park.
If you’ve been on Cape Cod, chances are you’ve seen or heard a coyote. They seem to be everywhere - running across the dunes, howling down neighborhood roads, looking to cross Route 6. If that’s ever made you wonder exactly how many there are, you’re not alone: scientists at Cape Cod National Seashore were wondering the same thing.
Koryna Boudinot
Coyote History on Cape Cod
Hundreds of years ago, the Cape was occupied by a different canid – wolves – which were pushed off by European settlers. This left an empty ecological niche (an opening in resources and competition suitable for a certain species) that provided the perfect opportunity for coyotes to move in during the 1970’s.
In the 1900’s, America was becoming increasingly agricultural. Changes from forested to agricultural land led coyotes to undergo a massive range expansion from the west and midwest – the fastest of any carnivore in the last 70 years, sped along by their opportunistic and behaviorally flexible nature. As they made their way to the eastern United States, they hybridized with wolves and dogs, producing the Eastern Coyote species we see on Cape Cod today. The new kid on the block ecologically-speaking, coyotes have been extremely successful on the Cape but their population within the Seashore has also been less extensively studied.
Koryna Boudinot
Population Study – How many coyotes are there?
The first thing scientists were curious about was the health of the population. They wanted to understand more about how many coyotes there were on the Cape (their abundance), what land spaces the coyotes were occupying and in what proportions (their spatial distribution and density), and if Cape coyotes were mating only with each other (their genetic diversity and inbreeding).
University of Vermont Master’s student Koryna Boudinot and Professor Jed Murdoch worked in collaboration with park staff to answer these questions. To do this, these scientists hiked 360 kilometers (over 223 miles) throughout Cape Cod National Seashore! Throughout their hikes, they located and collected 215 scat (animal droppings) samples. By sampling scat, Koryna was able to avoid invasive sampling or physical capture and use something coyotes naturally leave behind! She sent the scat samples out for genetic analysis, which determined how many of the samples were from coyotes, how many unique individuals were sampled, and how many of each sex were present in the samples.
To make sense of this genetic information and develop an understanding about the population, Koryna used statistical models that helped her estimate the abundance of coyotes in the Seashore, including a newer technique that involves creating a bunch of family trees.
Jed Murdoch
Abundance within the Seashore
Biologically, every mammal offspring has a father and a mother. Using genetic information provided by the scat, researchers were able to estimate missing (unsampled) family members.If a male and its offspring were both sampled, for example, but not the mother, then scientists could estimate that there is at least one more unsampled Cape coyote. By reconstructing family trees, accounting for inferred and invisible coyotes, the model produces an estimate of total (sampled and unsampled) coyotes.
Using pedigree reconstruction and statistical models, Koryna and her collaborators estimated that there are between 70 and 90 coyotes who call Cape Cod's National Seashore home! This density is similar to the rest of mainland Massachusetts and higher than other areas.
Genetic Diversity
Another thing Koryna’s study helped natural resource managers to understand was the health of the population. In this case, that health refers not to things like disease prevalence or physical health of individual coyotes, but to the genetic diversity and prevalence of inbreeding in the population, which can indicate whether that population will be successful for generations to come.
The genetic analysis of the scat samples showed high genetic diversity and indicated that the coyote population on Cape Cod is experiencing sufficient gene flow, little to no inbreeding, and a measure of genetic diversity consistent with other Eastern Coyote populations. This indicates that coyotes may be taking vacations and traveling too – they may be temporarily leaving the Cape to follow resources and traveling between the Seashore and the mainlaind.
Koryna Boudinot
Space and Land Use
Data from the scat samples was also used to determine what type of landscapes coyotes were most associated with within the Seashore - where are they hanging out most? Using the locations where Koryna and her research assistant, Jessica Pollack, collected the coyote scat samples in another model, they were able to see if there was a positive association with certain land types, such as barren land (dunes and beaches), forested land, or developed land (houses, businesses, and towns).
Their analysis revealed a positive association with both barren and forested land as well as distance from developed land, showing that coyotes prefer the beach and forested areas over places in town. Even so, you may have seen coyotes in your neighborhoods – that likely has more to do with food scavenging than land use preference.
They also discovered that the coyotes are likely occupying all available habitat, indicating a healthy population. This means that there are probably close to the maximum number of coyotes living within the Cape’s Seashore as can be supported by available resources, indicating success of the population.
NPS / Katy Perrault
Diet Study – What are coyotes eating?
After learning more about the coyote population and its health, scientists at the University of Vermont and natural resource managers at the Seashore were curious about their diet. They suspected a large range of foods may be on coyote dinner plates, given their opportunistic and flexible feeding patterns – coyotes have been known to eat everything from rodents to deer to birds to plants!In addition to coyotes, the piping plover (a small shorebird) calls the Cape home and has been the focus of protective management plans given its status as federally threatened under the Endangered Species Act. As omnivorous predators, the possibility that coyotes are consuming plovers and other threatened shorebirds was an important question for Seashore Natural Resource Managers.
To learn more about what coyotes are eating, Carolyn Hanrahan – another Master’s student at the University of Vermont - used a genetic analysis technique called metabarcoding on many of the scat samples analyzed by Koryna along with 213 scats collected the next summer. Metabarcoding detects the genetic material (DNA) present in a scat sample from different species, which tells scientists all the foods coyotes consumed before they produced the scat.
Human Food
Apparently, coyotes are eating the same things we are sometimes. The metabarcoding revealed that coyote diet on the Seashore included human food, deer, rabbit, small mammals, bird, fish, larger marine mammals, and amphibian species.
Human food sources, like chicken and beef (which are not present enough agriculturally on the Cape to indicate direct consumption) were the most commonly found food source, followed by deer. Human food isn’t good for the coyote’s microbiome, however, and can cause negative health effects.Coyotes eating human food is not good for them or for humans, as it indicates reliance on and habituation to humans. This can lead to negative interactions between humans and coyotes that can cause harm to both. Admire these canids from a distance, but please don’t share your chicken tenders!
USFWS / Amanda Boyd
Threatened Species
Besides human food, two other important findings were the lack of threatened shorebird and the presence of a species of greatest conservation need in Massachusetts, the New England Cottontail, within the diet of the sampled coyotes.The fact that there was not any piping plover or least tern (a Massachusetts state protected species) found in the sampled scat is particularly interesting. Shorebird biologists know that coyotes predate on shorebird nests – these results suggest that perhaps shorebirds make up much less of a coyote’s diet than biologists originally thought. More study is needed to better understand the relationship between beach-nesting shorebirds and coyote diet. In the summer, for instance, piping plover nests are often fenced off by Seashore staff and may not calorically be worth the extra effort, and not all coyotes living on the Seashore were sampled.
On the flip side, the presence of the New England Cottontail was an unexpected surprise. This finding was exciting to Seashore scientists because it showed something previous studies had not been able to – that the New England Cottontail is present within the Cape’s Seashore. Much like the piping plover finding, this indicates that further study of coyote – Cottontail interactions may provide more information about both the Cottontail population and considerations for potential protection plans.
The Scientists Behind the Studies
Koryna Boudinot
Koryna Boudinot
The coyote population study was Koryna’s thesis research for her Master’s in Natural Resources under Professor Jed Murdoch. Koryna’s work with the Seashore did not start there, though: she was part of the shorebird monitoring program for two years, which gave her first-hand experience monitoring sensitive species. The potential shorebird management implications of the study were what initially interested her, but it ended up leading her to continue studying canids. Koryna has since graduated from her Master's and started a PhD in 2024 studying wolves in the Northern Rockies!
Carolyn Hanrahan
Carolyn Hanrahan
Carolyn’s coyote diet study was also her thesis research for her Master’s degree in Natural Resources. Continuing on with applications of genetics and bioinformatics following her graduation, Carolyn joined the US Forest Service in a research fellowship! A native Cape Codder, she had completed coastal research on the Cape before and was excited about the opportunity to get more terrestrial experience here studying coyotes. The genetics, data analysis, and GIS skills she learned during this study not only provided valuable information to Seashore staff but also laid a foundation for her career!
For more information, questions about their research, or to read their theses, you can email Koryna or email Carolyn.