The National Aviary in Pittsburgh recently held birthday parties for two of its sloths - Vivien turned 3 and Wookiee turned 20.

Birthday parties for the Linnaeus two-toed sloths are usually popular affairs with a standing-room-only crowd. But, the coronavirus pandemic put a slight damper on the festivities with only a small group of staff attending and others watching on Facebook Live.

According to the National Aviary, Vivien enjoyed her cake made of corn, zucchini and yellow squash with a sweet potato “icing” and a sweet potato carved into the number 3 on top along with a hard boiled egg and hibiscus flower.

Wookiee climbed down from a tree in the Tropical Rainforest and “celebrated his 20th birthday at a leisurely pace.”

The National Aviary also is home to a third sloth, Valentino.

Vivien and Valentino are species ambassadors. Now through Aug. 23 you can book a sloth encounter with a 30-percent discount.

“During a Sloth Encounter, participants have the chance to hand feed Vivien or Valentino their favorite foods, touch their soft fur, and get to know the species better with the help of a National Aviary expert.

Enhanced safety protocols are in place for all Animal Encounters, with group size limited to allow for a personal experience and for ample spacing between participants. Encounters can be pre-booked online at aviary.org using the promo code ‘SLOTHBDAY.‘”

According to the National Aviary, “A rainforest-dwelling species, sloths spend almost every moment of their lives upside-down and most of their time sleeping, and move very, very slowly.

The Linnaeus’s Two-toed Sloth is native to rainforest habitats in South America. Many species depending on these rainforest habitats are vulnerable to deforestation and habitat loss. Small actions like choosing sustainably harvested chocolate and coffee can protect rainforests."

Christa Gaus, manager of visitor experiences and training, said, “People have an emotional connection to sloths — they bring a smile to your face, which is something we can all use right now. Seeing a sloth in person inspires visitors to think about how they can take action, and it deepens their connection.”

The National Aviary is open 9 a.m. to 5 p.m. daily with timed ticketing and other safety protocols in place to prevent the spread of the coronavirus.

New outdoor activities including with admission are Kids Flamingo Yoga and penguin feedings.