Getting on in Years: Caring for Older Animals

Time passes for us all. Whether you have just lost a baby tooth or have discovered your joints twinge more often these days, we humans are all aging. At the Aquarium, Animal Care staff see variations of time's progression in the animals they care for each day. Eggs hatch, young are born ... before long, babies have grown into juveniles, then adults. Aging isn't uniform, though. Some species experience a lull in adulthood where quickly changing age markers slow but never fully stop. Meanwhile, other species grow at such a measured pace that it seems they're hardly aging at all.

Regardless of the path aging takes, Animal Care and Welfare staff are always on the lookout for signs that animals are entering the later stages of their lives. The high quality of care staff provides never ends, but an animal's advancing age sometimes requires making changes to better meet their needs. Staff rely on daily observations, routine medical exams and the established relationships with animals in their care to find the best path forward, whether that means adjusting diets, switching routines or making larger accommodations.

"Our team's deep understanding of the individuals in their care allows them to spot subtle changes quickly. This not only benefits the animals at the Aquarium but also adds to shared knowledge of their species." - SVP and Chief Animal Welfare Officer Stephanie Allard

Diversity in Aging

From salmon and their rapid decline after spawning to Greenland sharks slowly maturing over 150 years, fish run the gamut in terms of aging. But figuring out the age of a fish by looking at it is typically very hard. Most prey species in their natural habitats don't show signs that they're getting old since it could make them vulnerable to predators. It's no different for many of the fish in Aquarium exhibits. So, staff must pay close attention to physical exam results, trends in eating habits and other behaviors.

The lengths, weights and growth rates of the sand tiger sharks in Shark Alley allow aquarists to estimate their approximate age ranges, and routine exams help staff track changes over time. For sharks that have resided at the Aquarium for many years, veterinary staff use ultrasound to look for abnormal masses or digestive tract changes that affect nutrient uptake. They also scan for calcification of the kidneys, a hardening of tissue. Scientists have occasionally noted calcification in different fishes, but the root causes are not always clear and may or may not be age-related. The data collected on these sharks helps fill the gaps so future aquarists, vet staff and researchers have a more complete picture.

Seeing and interacting with these animals daily helps staff keep tabs on any changes. Aquarist Tiffany Burkard feeds the redtail catfish, nicknamed Mr. Whiskers, by hand. She gets a good look at him this way and can also better track his food intake. Under human care, redtail catfish typically reach 15 years of age. Mr. Whiskers arrived at the National Aquarium in 1999 and is thought to have hatched in 1995, which would put him approaching 30 years old.

Redtail catfish tend to be more active at night and relatively sedate during the day. Mr. Whiskers remains active in the early morning around his feeding time; afterward, he seeks shelter under the submerged tree trunks in his habitat to rest.

Like Tiffany, Herpetologist Alex Marinich routinely observes two animals in his care when bringing them their breakfast of leafy greens. Nicknamed Judy and Maggie, these two yellow-footed tortoises can be found in Upland Tropical Rain Forest. Tortoises are iconic among species for their long lifespans, with this species expected to live 50 to 60 years. Judy is Maggie's mother and, while it may be hard for guests to see the family resemblance, their shells offer clues about which one is the older of the two.

Providing excellent care for Aquarium animals occasionally turns Animal Care teams into pioneers—especially when staff are among the first to witness, handle and document age-related changes in certain species. This is where their eye for detail, creativity and thorough knowledge of the animals in their care can have lasting impacts on the field of animal husbandry and beyond.

Handling the Unknown

The poison dart frogs residing in the Hidden Life section of the Upland Tropical Rain Forest are prime examples of animals teaching staff about the subtleties of aging. The Aquarium established a poison dart frog breeding program in the mid-1980s to reduce impacts on native populations in Central and South America. Breeding any animal requires excellent care, which means staff, like Herpetologist Kacie Fitzhugh, often have the chance to document the full lifespans of these animals. Currently, little research exists on the typical lifespans of poison dart frogs, so any data on their longevity is valuable. One might expect small frogs like these to have shorter lives. However, with plenty of food and lack of predators, some of the Aquarium's frogs have reached ages on par with, or even beyond, those of the average domestic cat or dog!

A frog's body condition—or the way fat and muscle are spread over the animal's frame—helps Animal Care staff spot health-related issues. As staff observed older frogs, they noticed slight differences in how the frogs carried the weight on their bodies, even if the animals weighed as much as younger individuals. Spotting these differences and drawing body condition charts to include age-related changes is important. Not only might other zoos and aquariums use this to care for their animals, but field herpetologists and other biologists can use these resources, too.

Accommodating and Engaging These Elders

Our Animal Care and Welfare staff's priority is the wellbeing of animals at all stages of their lives. This can mean emphasizing an aging animal's choice in daily routines and modifying enrichment activities where necessary. It can also mean making accommodations for older animals' comfort and safety.

Maintaining an animal's high quality of life sometimes requires Animal Care staff to make larger adjustments. Some modifications are things a guest might see, while others largely go unnoticed by the public.

Sea Cliffs—home to Atlantic puffins, guillemots and razorbills—is a habitat where Animal Care staff have installed visible accommodation. A few of the birds in the colony are now 20 to 25 years old and are not as agile as they once were. This can make entering and exiting the water difficult. To assist the older birds, staff gradually introduced them to a soft, foam-like mat before placing it at the water's edge where it effectively acts as a ramp.

Building relationships with animals requires dedication and time, but these bonds allow staff to notice age-related changes. The rapport Aviculturist Ellie Yaunke has built with the birds in her care allows her to take older individuals in hand to feel and examine their body condition.

Of all Aquarium animals, one has likely had more dedicated staff than any other—for the simple reason that this yellow-headed Amazon parrot, nicknamed Uncoco, has been at the National Aquarium since we opened in 1981. She and her companion, Coco, are the Aquarium's oldest residents, estimated to be around 58 and 47, respectively.

Their energetic shrieks and whistles as staff bring them into Upland Tropical Rain Forest each morning seem at odds with their age. However, the fact that they no longer stay in the habitat overnight indicates that they have grown old. It's one of a few changes to their daily routine.

While the parrots once had perches over pools and streams in the exhibit, staff moved their current perch further away from the water. If one of them were to slip off accidentally, they would land on a cushion of dirt and mulch beneath their perch instead.

Besides relocating the perch, staff also made sure the parrots could easily maneuver around the branches. Instead of a perch with steep inclines and parts that could be harder to grasp firmly, their new setup has shallow slopes with tapered and widened sections that allow them to stand comfortably.

Staff caring for the parrots look for ways to keep them engaged and mentally sharp. Aside from their transport behavior, staff can also work on behaviors that allow the birds to participate in their own health care. After they've had a bath, Aviculturist Jack Eibel presents Uncoco and Coco with a stick dipped in a bird-safe moisturizing cream. They have learned to grasp the end with their feet, transferring the salve onto their toes and claws. This helps prevent their skin from becoming too dry and is also an excellent workout for their feet.

Older, But Still Thriving

In the end, aging is inevitable. But regardless of how quickly or slowly it occurs, all animals at the Aquarium have dedicated staff at their back watching for it. Whether an animal's eyes start getting cloudy with cataracts or their joints start to stiffen with arthritis, staff monitor and assist where they can, learning valuable lessons along the way.

Maintaining an older animal's quality of life can be challenging, but that they've reached an advanced age is a testament to all the care that came before. They may be transitioning into later stages of life, but at the Aquarium, that simply means these older individuals will thrive in a different way.