Animal Welfare: Seal of Approval

The Detroit Zoological Society (DZS) is investigating the effect of foraging opportunities on the welfare of the seals who live at the Detroit Zoo. Foraging is a very important behavior category for animals, as it typically involves mentally and physically stimulating behaviors. Wild gray seals may spend up to two-thirds of their time searching for food. Although they do have well-developed hearing and sight, seals often rely on their extremely sensitive whiskers to locate the fish they eat. This is necessary as visual conditions underwater can be poor and swimming fish may not generate much noise as they move. Instead, the fish – and other prey items – create vibration trails in the water and these are the stimuli the seals’ whiskers detect. Research has shown that harbor seals can use their whiskers to distinguish between objects of different sizes and shapes – a skill they can use to select better prey items when hunting.

Seals living in zoos and aquariums don’t need to forage in quite the same way as they would in the wild, and thus may not engage in as many complex feeding behaviors. As part of her residency with the Center for Zoo and Aquarium Animal Welfare and Ethics, Sara Zalewski worked with DZS staff to design a project examining the impact of three different ways to increase foraging behavior in the gray and harbor seals living at the Detroit Zoo. The seals were presented with fish frozen in ice, fish placed on top of a floating disk and sunken tubes the seals needed to manipulate to allow fish to fall out of holes in the tube. All three items were used to increase the amount of the work the seals would have to do to get to the food. As part of this research, Sara found that the seals differed by both species and individual in how they used the items.

The gray seals interacted with the items most when they were first presented with them, and the harbor seals’ level of interaction increased as time went on. The likely explanation for this is that the gray seals were younger and more dominant, and thus were able to use the items more easily. Once they had their fill of the food, they would lose interest and the harbor seals could begin to investigate the items. Dealing with dominance hierarchies can create challenges when providing animals with resources, and is therefore something we have to keep in mind when thinking about the welfare of all of the individuals.

Another challenge was getting the seals to use the items for longer periods of time. It makes sense that less interaction occurs without the motivation of obtaining food, so there is a need for more challenging devices that require the seals to use more of their foraging abilities. One unexpected outcome was that Georgie, one of the female gray seals, would sometimes use a floating disk as a resting place later in the day. However, it could not support her body weight, so she would lay on it on top of something else, such as a ledge in the pool. Other studies have shown that gray seals’ preferred prey, haul out sites, and feeding locations and techniques differ greatly between individuals. Finding ways that items can serve more than one purpose and allow each seal to make use of them as they choose are also goals.

Harbor seals are an especially playful species, including as adults. However, as animals age, play and exploratory behavior tend to decrease, regardless of the species. Additionally, decreases in their sensory abilities may occur. This means that for Sydney, the older male harbor seal, opportunities may be more challenging or potentially less engaging for him.

In order to create more engaging ways for all the seals to forage, Sara worked with DZS staff to refine the items and will observe Georgie and Jersey, the two gray seals, and Sydney, the harbor seal, to see how the modifications affect their behavior. DZS staff members are creating floating devices that the seals can use to rest – as well as interact with for access to fish – and are changing the design of the tubes so that they rest standing up, rather than lying flat on the bottom of the pool. This should make it a bit harder for the fish to fall out, and will be more stimulating for the seals as a result. Finally, Sydney will have some alone time with the items, to ensure the younger and more agile females don’t deplete the food before he has a chance to interact with the foraging devices. During your next visit, you may see these items in the seal pool at Arctic Ring of Life. Although we are only observing the seals at specific times, incorporating these types of behavioral opportunities is part of our daily comprehensive program of ensuring the environments for all the animals at the Detroit Zoo are ever changing and appropriately complex.

– Dr. Stephanie Allard is the director of animal welfare for the Detroit Zoological Society and oversees the Center for Zoo and Aquarium Animal Welfare and Ethics.

Celebrating International Polar Bear Day

Polar bears are iconic animals, known for their incredible ability to survive in one of the harshest environments on Earth. These marine mammals are the most carnivorous member of the bear family, with a diet consisting primarily of seals. They have a thick layer of fat and waterproof fur, providing insulation in the cold Arctic climate in which they live.

Sea ice is imperative for polar bear survival; they spend the majority of their lives on the ice, relying on it to find a mate, build a den and hunt for seals. In the last 30 years, scientists have seen a dramatic shift in ice within the Arctic Ocean. The amount of “old ice” – ice that stays throughout the summer – is significantly smaller than what it was 30 years ago. The seasonal sea ice is forming later in the year – and melting earlier – directly impacting polar bears’ ability to hunt. As a result, many polar bears aren’t able to build up the fat reserves they need for the summer when food sources aren’t plentiful, and they starve to death.

We know the climate is changing. As humans, we are using fossil fuels such as coal and gas to drive cars and use electricity. These fossil fuels release carbon dioxide into the atmosphere, which builds up and creates a blanket effect around the Earth, trapping in heat that would otherwise escape. This trapped heat is causing global climate change and is impacting many species, including polar bears.

On February 26 and 27, the Detroit Zoo will join others around the world in highlighting the challenges that polar bears are facing in the wild. International Polar Bear Day celebrates these majestic creatures while also encouraging the community to not only better understand the impact we have on the environment, but to join us in taking positive action that will help protect vulnerable species.

Each one of us has the power to make a difference. We can change our daily behaviors and use less energy by seasonally adjusting our thermostats, riding our bikes, carpooling with friends or turning off the lights. We can also scale these actions up to our schools or workplaces by encouraging others to join us in this endeavor. Celebrating International Polar Bear Day is a great reason to start, or to take things to the next level.

Our International Polar Bear Day will take place on February 26 and 27 from 11 a.m. to 3 p.m. The events will include zookeeper talks, educational activities and visits with the Zoo’s polar bear mascot. Talini and Nuka, the two polar bears who reside at the Zoo, will receive their usual treats at scheduled times (11:30 a.m., 1 p.m. and 2:30 p.m.) so guests can watch the bears enjoy them. This is not only a great time to visit the Zoo and the more than 2,000 animals living within our 125 acres, but it’s also a chance to learn more about how we can work together to save wildlife and wild places.

– Carla Van Kampen is a curator of education for the Detroit Zoological Society.

Education: Inuit Artwork in the Arctic Ring of Life

The Detroit Zoological Society’s permanent art collection focuses on making people think about their relationship with animals. Throughout history, humans have always been intrinsically linked with animals in many ways. This could be through worshipping animals, hunting them (both as a food source and as a culturally significant event), anthropomorphizing them, and more.

Dancing Walrus - Adamie Alariaq

Dancing Walrus – Adamie Alariaq

The language of art is universal; it is the language that can bind cultures together and can preserve them. It is the language that can strengthen a multi-cultural society without weakening or emboldening any one of its members. The works of art we have in our collection are designed to show the human relationships and interactions with animals in several cultures.

During the upcoming Wild Winter event on Saturday, January 21, we will provide talks on the Inuit art that is displayed in the Arctic Ring of Life at 11:30 a.m. and 12:30 p.m.

The Arctic Ring of Life houses most of our Inuit art collection, which demonstrates many of the different ways and styles that animals can be showcased in art. Art is used for many things in all cultures, including helping to explain the stories of a culture and support understanding of it. In Inuit culture, animals play a vital role, including in significant events and rituals. Due to this, every piece has a distinct, important and personal story that it illustrates.

Sleeping Ptarmigan - Pangnirtung

Sleeping Ptarmigan – Pangnirtung

Come to the Arctic Ring of Life this Saturday to hear more about the Inuit peoples and how art plays into their lives and to hear more detailed information on two pieces we are going to highlight.

– Sioux Trujillo is the curator of fine and performing arts for the Detroit Zoological Society.