A “Purrfect” Partnership: Collaborative efforts create ideal situations for tiger breeding

Staff with The Detroit Zoo have been working together to monitor Ameliya, an Amur tiger. Photo credit: Jennifer Harte

Authored by Emily Bovee, CZAAWE lab assistant

A little teamwork can go a long way — especially when it comes to caring for the animals who call the Detroit Zoo home. Center for Zoo and Aquarium Animal Welfare and Ethics (CZAAWE) staff recently teamed up with fellow Zoo employees to ensure two of the Zoo’s feline residents have the best possible opportunity to bring a litter of cubs into the world. 

Amur tigers (Panthera tigris tigris) were the first species to be part of an Association of Zoos and Aquariums (AZA) Species Survival Plan, a program aimed at supporting the conservation of endangered species by maintaining the genetic diversity of AZA populations. Breeding animals in zoos can be surprisingly challenging, even for the most amorous of Amur tigers! As a solitary species, wild adult Amur tigers generally live alone. Females and males will only meet briefly to mate before parting ways. Tigers living in AZA-accredited zoos are often housed separately, thus the timing of breeding introductions is extremely important. The successful birth of healthy cubs requires some coordination and planning from experts in the field. The last time efforts were made to breed tigers at the Detroit Zoo was in 2003 when healthy cubs were born. 

Team members have been monitoring how Ameliya and Nikolai interact with each other.

Collaborations between different departments at the Detroit Zoo provide staff opportunities to examine the welfare of the animals from new and diverse perspectives. Recently, CZAAWE staff started working with mammal supervisor Melissa Thueme and animal care specialist Sarah Semegen to assist with tiger breeding efforts. The two resident Amur tigers, male Nikolai and female Ameliya, rotate through the public enclosure and a second outdoor tiger yard behind the scenes. 

CZAAWE uses an on-campus endocrinology lab to non-invasively measure indicators of physiological welfare such as hormones — a fancy way of saying we analyze a lot of poop! With the amount of poop collected from animals big and small throughout the Zoo, CZAAWE depends on the intrepid lab volunteers who spend hours crushing samples to prepare them for lab testing. This can include hormones that may indicate changes in reproductive states such as testosterone, estradiol and progesterone. 

Hormone data, along with behavioral observations, can help track Ameliya’s cycles.

Using fecal samples collected by animal care staff from Ameliya, CZAAWE first monitored estradiol, an estrogen hormone involved in the regulation of the estrous cycle. This allowed us to assess if Ameliya had an active cycle and determine the timing of her cycles. The hormone data supplements and confirms animal care staff behavioral observations, which can also be used to track reproductive cycles. Indicators of her estrous cycle included behaviors such as chuffing (an affectionate throaty vocalization!), rubbing on walls and mesh, rolling on the ground, and being friendly toward Nikolai and animal care staff. In only a few days, she can switch from snarling and swatting at Nikolai to chuffing and cheek rubbing! Using a combination of hormonal monitoring and behavioral cues, animal care staff can determine the ideal time for facilitating interactions between Ameliya and Nikolai that are more likely to result in a successful breeding attempt. 

After a potentially successful breeding introduction, the CZAAWE lab staff can shift to monitoring Ameliya’s progesterone levels. Progesterone is a hormone that maintains pregnancy and gets the body ready for and supports a developing fetus. Examining her progesterone levels will allow us to non-invasively detect a possible pregnancy and make sure our care protocols provide excellent support for the mother-to-be. While we are not yet listening for the pitter-patter of tiny tiger paws, we are hopeful that the continued collaboration between animal care staff and CZAAWE will mean healthy tiger cubs in the future.

The collaboration between Zoo departments will help Ameliya and Nikolai be in the ideal situation for potential breeding.

Fundraising Gala Highlights New Habitats that Promote Great Animal Welfare

Whenever we design and construct a new animal habitat, our focus is on ensuring it is expansive, naturalistic and meets the animals’ specific needs. These spaces should provide the animals with opportunities to do the things that are important to them – be it climbing trees, swimming, wallowing in the mud, and interacting with social partners (or avoiding social partners if that’s what they want at any given time).

Attendees of the Detroit Zoological Society’s (DZS’s) annual fundraising gala, Sunset at the Zoo, on Friday, June 7, will have the opportunity to observe two newly renovated and expanded spaces in the Detroit Zoo’s Asian Forest that succeed in doing just that.

A few months ago, red pandas Ash, Ravi and Ta-shi moved into the Holtzman Wildlife Foundation Red Panda Forest. DZS staff immediately began making observations to determine the effect of the new space on the well-being of the animals. We call this a “post-occupancy evaluation” – in this case, it consisted of behavioral observations on each individual as they explored their home. We spent eight weeks monitoring where they chose to spend their time and how their behavior varied based on a number of different factors, including noise levels and if guests were present in a new way the habitat provides. A 70-foot long canopy walkway extends through the trees of the space, allowing visitors to have a red panda’s-eye view.

 

Through these observations, we learned exactly what we hoped for – the red pandas demonstrated diverse “activity budgets”, which means they engaged in different behaviors throughout the day. We were really pleased to see that Ash and Ravi explored and scent-marked their space, both signs that it is stimulating for them. Ta-shi spent a bit more time inactive than the others, which is not surprising given that she is older.

The red pandas made use of most of their space, but did have some preferences, including spending time high up in the trees. This is a natural tendency for the species, and we were glad to see them use the elevated features. Having visitors present on the bridge did not seem to change their preferred resting locations, although Ash occasionally stayed inside the holding building when the habitat first opened. In order to allow the red pandas to acclimate to their new surroundings, we provided them with the choice to go inside their respective buildings. Enabling animals to choose where to spend their time is an important factor in ensuring positive welfare. This ability to retreat was also helpful when noise levels rose, primarily due to the construction happening at the Devereaux Tiger Forest close by. We were thrilled to see that Ash, Ravi and Ta-shi found their home to be a great place to live, letting us know that all of the planning that went into this habitat expansion was successful.

 

Our next post-occupancy evaluation will focus on the Devereaux Tiger Forest. The tiger forest will significantly increase the amount of space for tigers. Naturalistic features, including caves, trees, elevated areas, a waterfall and pool, have been incorporated in order to promote species-appropriate behaviors. We look forward to assessing how the new habitat impacts the well-being of the tigers when the habitat opens this summer.

This year’s Sunset at the Zoo celebrates the Asian Forest, which includes both the tigers’ and red pandas’ new digs. On the evening of Friday, June 7, guests will have the opportunity to explore the Holtzman Wildlife Foundation Red Panda Forest and take a sneak peek at the new Devereaux Tiger Forest. Just as the red panda habitat includes an exciting new experience for guests with the canopy walkway, the tiger habitat has a thrilling element of its own. In addition to expansive acrylic viewing windows, an SUV will be positioned half in the habitat and half out, allowing visitors to sit in the driver’s seat – and a tiger might just lounge on the hood.

Proceeds for Sunset at the Zoo benefit the Detroit Zoological Society’s mission of Celebrating and Saving Wildlife.

– 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.