Comparing behaviors in wild and captive animals allows us to have additional insights to how we may best care for animals in zoo or aquarium environments. Specifically, an understanding of social behaviors is important to ensure that captive animals have opportunities to exhibit species-typical social interactions as if they were in the wild. I researched whether harbor seal (Phoca vitulina) social behavior in a zoo environment was comparable to harbor seal social behavior in natural settings. This species is an ideal candidate for this study because their social behavior is not entirely understood. I performed this research by comparing observational data collected by a team of divers in the Puget Sound in Washington, and observational data I collected from the captive harbor seals at the Columbus Zoo and Aquarium.
Reagan Jennings
“Observational Comparison of Natural versus Captive Social Behaviors in Harbor Seals (Phoca vitulina) ”
General information about Phoca Vitulina and the Columbus Zoo and Aquarium
Harbor seals (Phoca vitulina), an aquatic mammal species apart of the pinnipedia order, can be found in a wide range of locations. Throughout the northern Atlantic coast, Pacific Ocean, Baltic Sea, and North Sea; this species has the widest habitation range of all the other pinnipeds.
These seals can measure as long as six feet and have a mass of 290lbs. They primarily consume anchovies, herring, cod, and shrimp, but are generalist feeders that can prey on many different organisms. While they are predators harbor seals are also prey. Known predators include killer whales, great white sharks, and Greenland sharks. Their defense against these predators is to quickly escape, swimming at speeds up to 12mph and plunging depths as deep as 1640 feet.
Picture provided by the Delaware Gazette of harbor seal Keaton July 11, 2020
Although, thanks to the Columbus Zoo and Aquarium, four harbor seals and ten California sea lions are safe from predators in their newly built habitat. Adventure Cove opened on July 10th, 2020 and contains over 350,000 gallons of water. The harbor seals, Keaton (three-year-old male), Hillie (five-year-old female), Sloan (three-year-old female), and Farris (three-year-old female) came from SeaWorld Orlando where they had no training or significant human contact before arriving to Columbus.
With three to four training sessions a day the Pinniped team is hoping to provide adequate enrichment to the new residents. Enrichment in zoo and aquarium settings are vital to captive animal health. Proper enrichment stimulates zoo animals to prevent boredom, and this results in the reflection of natural behaviors. My research focuses on the comparison of observed natural versus captive behaviors in harbor seals. The observational data collected from both settings will be compared to determine whether or not the harbor seals in Adventure Cove are receiving quality enrichment.
Natural Behaviors
Harbor seals are known to be naturally solitary creatures that can become aggressive when surrounded by other conspecifics. Even during mating season, their most social time of year, Phoca vitulina keep their distance when hauling out on land and traveling. Overall, little is known about their general social behaviors, especially when underwater where they spend half of their lives. To research these behaviors, I utilized of team of divers, The SpongeBob Crew and a few other independent sources, to dive weekly into the Puget Sound in Washington from February to May 2021. This is a known area for harbor seals to congregate as they are regulars during mating season (late spring through fall). There would be multiple encounters over the next few months, with the following being significant to the overall research results.
Encounter #1
March 21, 2021
A single, small white seal got very up close and personal with a diver in the Puget Sound located in Mukilteo, Washington. This seal was estimated to be three feet long and appeared to be alone for the thirty minutes it followed divers. The seal was originally spotted from far away, hiding behind structures on the sea floor. Eventually the speckled pup made its way until it was right next to the divers. At one point the seal, "swam up as fast as it could and flipped around (traveling the other direction) at the very last second." The action of flipping around was described as "extending its neck all the way back and its body following that same path." After a few more laps around the divers, the seal left and was not seen again for the duration of the dive.
Picture courtesy of Joe Drelling
Encounter #2
April 11th, 2021
A light grey harbor seal was seen from a distance at Redondo Beach in Des Moines, Washington. This seal was estimated to be three feet long and was very interactive with the divers. This seal had no hesitation and quickly approached the group, circling them for 10 minutes. One diver reported the seal was, "very interested in my flipper" as he kept nudging the black and yellow fin. This individual soon after swam away. No other seals were seen for the rest of the dive.
Picture courtesy of Joe Drelling
Encounter #3
May 14, 2021
A large, dark grey harbor seal was seen in the Puget Sound in Edmonds, Washington. This seal was estimated to be five feet long and was not too interested in the foreign group of divers. The team recorded, "the seal swam by us for a passing glance and nothing more". As the seal swam away, it stayed close to the bottom of the ocean floor and was not seen again. There were no other sightings for the rest of this dive.
Picture courtesy of Joe Drelling
While there were many more sightings, the encounters shared above provide the most information relating to harbor seal social behavior. There was never a time when more than one seal was seen, and there was no evidence to suggest there were others nearby. These encounters did, however, provide evidence that seals are generally curious and will interact with humans in their natural habitats. These observations gave us a direct insight to the natural behaviors of harbor seals. Now these behaviors will be compared to those of the same captive species to determine the enrichment efficiency of the seals at the Columbus Zoo.
More Pictures Along the Way
Here are some extra pictures taken of the crew involved, as well as more encounter pictures captured by Joe Drelling during his personal dives.
"The SpongeBob Crew" enjoying a Halloween dive.
"The SpongeBob Crew" heading out on a Sunday dive
A harbor seal exploring the ocean floor
More floor exploring
A harbor seal creeping up on diver Joe Drelling
Captive Behaviors
I spent the last four months visiting Adventure Cove three times a week. During this time, I meticulously observed how the harbor seals behaved socially in an environment where close proximity to conspecifics was inevitable. In addition, the harbor seals also shared their space with California Sea Lions (Zalophus californianus). This, an unnatural pairing, puts two species with drastically different personalities together. Since there were so many visits and a plethora of data observed, I will describe significant behaviors I witnessed consistently.
One of the most repeated behaviors I saw every time I visited was patterned swimming. It always seemed the harbor seals followed the same swimming paths every day. This behavior was especially apparent in Keaton and Hillie who stayed close to the tank floor and enjoyed barrel rolling over the 360° viewing tunnel. When I asked a member of the Pinniped care team, Shane Gorbett (an Ohio Wesleyan alum), he noted these behaviors were, “Certainly repetitious and seem to serve no real purpose.” Each harbor seal follows a patterned swimming path each day when not preoccupied by sunbathing or guests.
On the topic of sunbathing, once the water got warmer this was a common activity for the harbor seals. I observed hauling out (temporarily leaving water to reproduce or rest) behaviors multiple times once the weather started reaching an average of 60° Fahrenheit. The harbor seals would position themselves on the top of the 360° viewing tunnel and lay in the sun, until another seal also hauled out here. Soon after the second seals arrival the first one would leave. This was another common behavior that the seals exhibited when playing with enrichment toys. When one went to play with the toy and another arrived, the first seal left soon after. They did not seem to enjoy conspecific presence at all.
Although, the seals did particularly enjoy interacting with guests. When visitors would peer into the tank, the harbor seals would make the effort to swim up to the individual and flip around right before they hit the glass. During periods of high visitation, the seals would be more interested in swimming up to visitors looking in than sunbathing or patterned swimming. This was especially true for children, as I witnessed the harbor seals swimming in circles and following the hand movements of kids interacting with them. Shane explained to me, “Enrichment comes in many forms for the Pinnipeds, one example being interactions from guests. It stimulates the animals as much as it stimulates the people.” This was clear as I myself had some fun interactions with Hillie throughout my time visiting.
All in all, there were never any significant social interactions I observed between conspecifics or the California Sea Lions. Primarily, based off of captive behaviors, it seems the harbor seals are very solitary even in a populated setting unless interacting with guests.
Flipping around at the glass
Interacting with guests
Hauling out behavior
Hauling out behavior
Hauling Behavior
Enjoying the privacy of the corner
Coming to say Hello
Interacting with guests
Interacting with a guest
Results and Implications
Through my research I found that socially, harbor seals are solitary, independent creatures that rarely interact in either setting. There were many similarities in social behavior between the observed and captive seals which provides evidence the Columbus Zoo and Aquarium is appropriately enriching the Adventure Cove residents.
As stated above, both the wild and captive harbor seals were very interested in people that entered their space. This was seen in the divers’ reports as well as in the interactions with guests at the zoo. The naturally curious and adventurous personality of the harbor seal was viewable in both settings. These behaviors are both represented in different ways, and we can assume that these behaviors are indicative of normal harbor seal behavior. There were also similarities in the way seals interacted with conspecifics. While divers never saw more than one wild seal, the captive seals also rarely interacted with each other. This lack of social interaction indicates that this species tends to behave in a solitary, antisocial manner.
Overall, this research provides an important insight to the comparable behaviors exhibited by both captive and wild animals, and how we can determine adequate care based off of these displayed behaviors. It appears the behaviors exhibited by the Adventure Cove harbor seals are indistinguishable from those exhibited by the wild seals. This evidence shows us that the Columbus Zoo and Aquarium has provided the exceptional care necessary to mimic a natural, stimulating environment for the harbor seals to thrive in.
Acknowledgment
Dr. Shala Hankison
I would like to thank Dr. Shala Hankison for all of her help throughout this semester. Without her invaluable advice, mentorship, and hard work this research would not have been possible.
Shane Gorbett
I would also like to thank Shane Gorbett for his input and willingness to help make my research successful. His knowledge and ideas were the inspiration for this focus topic, and he is a wonderful representation of Ohio Wesleyan University.
The SpongeBob Crew
Another group I would like to express thanks to is The SpongeBob Crew. This crew, that I am lucky enough to call research partners and family, searched constantly throughout the past four months. Without their countless dives and impertinent data this research could not have been conducted.
Joe Drelling
A special thank you to Joe Drelling for sharing your seal encounter stories and incredibly detailed photos.
Small Grant Program, Ohio Wesleyan University
This research was able to be completed due to the support of the Small Grant Program. Thank you for investing in me, my ideas, and my passions.
