In ‘Beyond Words’ at Central Square, friendship is the thing with feathers

But that proves to be a distinction without much of a difference in “Beyond Words,” thanks in significant part to the expressive powers of Jon Vellante.

Playing Alex in the premiere of Laura Maria Censabella’s play at Central Square Theater, Vellante delivers an absolute gem of a performance. It’s a textbook lesson in how to conjure a rich character out of a role that requires you to spend most of your time onstage observing the actions of others.

Under the inventive direction of Cassie Chapados, “Beyond Words” tracks the real-life 30-year relationship — it’s nothing less than that — between Alex and Dr. Irene M. Pepperberg, played by Stephanie Clayman.

Transitioning swiftly among different modes and moods, Chapados gives the eye plenty to do, not just the ear, as she maximizes the theatrical possibilities of Censabella’s script.

The first words we hear in “Beyond Words” are “I love you,” spoken by Alex to Pepperberg. Their connection goes deeper than that between scientist and subject. There are aspects of mother and child, and also of friendship, and perhaps even of partnership, an alliance against a skeptical world.

As Alex, Vellante performs barefoot, often on tiptoe. A piece of crimson fabric dangling over his rear end (the costume design is by Sandra Zhihan Jia) suggests a tail. The rest is a matter of voice, facial expression, and body language, all of which Vellante deploys with skill and an artful calibration of the difference between poignant and cloying, between humor and hamminess.

At Sunday’s matinee, Clayman’s performance as Pepperberg felt underpowered and tentative at times, in need of more intensity to drive home how arduous and demoralizing her years of struggle were, and to communicate the joy of discovery. When Pepperberg experiences a shattering loss, however, Clayman makes us feel the full depth of her devastation.

Rounding out the cast are Karina Beleno Carney as Dr. Lourdes Acevedo, Pepperberg’s best friend and confidant, along with Matthew Zahnzinger, Kandyce Whittingham, and Ken Yotsukura in multiple roles.

Currently a research professor at Boston University, Pepperberg is a Harvard researcher when we first get to know her in “Beyond Words.” Convinced that the birds are capable of abstract reasoning, she sets out to ascertain the cognitive and communicative capacities of grey parrots, with Alex as her subject. As Alex learns colors and categories, Pepperberg homes in on how he learns.

She has to weather the derision of male colleagues eager to heap ridicule on her research. In one memorable scene, a group of male scientists determined to squelch Pepperberg literally go ape, beating their chests and jumping about.

“Beyond Words” also traces the uphill fight Pepperberg had to wage to get her research taken seriously: the failed attempts at getting funding; the rejections by scientific journals; the increasingly strained marriage to Rick Pepperberg, played by Bill Mootos. The ever-reliable Mootos doubles as a condescending scientist out to undermine Irene Pepperberg. He’s an odious fellow in whom Mootos finds the stuff of satire, playing him as a kind of lounge lizard who has wandered into the groves of academe.

Censabella has written a multifaceted play, though “Beyond Words” is exposition-heavy at times. Possibly that’s a response by Censabella to the lengthy timespan of her play, which ranges from 1976 to 2007. Or it’s a reflection of an occupational hazard for any playwright who’s trying to capture a very specialized world — in this case, avian research — while maintaining a level of understanding for all those English majors in the house. Either way, “Beyond Words” would benefit from some streamlining.

No theater company in the Boston area presents more plays set in a laboratory than Central Square Theater. Scenic designer Qingan Zhang has devised a spacious and versatile environment that provides a visual reminder — without being obtrusive — of Pepperberg’s devotion to her research.

In being written by, directed by, and focusing on a woman, “Beyond Words” is another chapter in the theater’s mission to showcase science-themed plays, often by and about women, such as Anna Ziegler’s “Photograph 51,” about British scientist Rosalind Franklin’s insufficiently recognized contributions to the discovery of the double-helix structure of DNA; Lauren Gunderson’s “Ada and the Engine,” about Ada Lovelace, the 19th-century British mathematician (and daughter of Lord Byron) who has been called the first computer programmer; and Joyce Van Dyke’s “The Women Who Mapped the Stars,” about early female astronomers.

“Beyond Words” is a worthy addition to that roster. “Polly want a cracker?” Polly wants much more than that.

BEYOND WORDS

Play by Laura Maria Censabella. Directed by Cassie Chapados. A Catalyst Collaborative@MIT production. Presented by Central Square Theater, Cambridge. Through April 14. Tickets begin at $25. At CentralSquareTheater.org or 617-576-9278 x1

Don Aucoin can be reached at donald.aucoin@globe.com. Follow him @GlobeAucoin.