Maybe we overuse “unique.” But in the entire Washington region, who denies that the National Zoo’s panda cub is unique? It is our one and only. And on Friday, the rare and cherished creature was 8 weeks old.

It still lacks a name, but it has developed in ways that seem likely to help it thrive and pursue panda happiness amid the events of this eventful time, or any other.

It is not just that it has begun crawling, which can be taken as an obviously good sign.

In a bulletin issued Thursday by the zoo, assistant curator of pandas Laurie Thompson reported the development of other vital faculties.

Both of the little fellow’s eyes are open, Thompson said. That does not occur at birth, but finally happened a little more than a week ago.

Not only that, the cub’s ears are also open. Signs of auditory sensitivity arrived this week. When keepers entered his den to fetch him for another brief exam, Thompson said, the sound of the door prompted him to vocalize.

As the cub was being looked over, Thompson said, it turned its black-and-white head on the examining table, indicating an effort to find the source of the voices it heard.

In what keepers took to be a sign of the absence of panda passivity, it barked as it was being measured.

And so it grows. In the seven days between Oct. 7 and Wednesday, it added a pound. Its girth has also grown, from 13.7 inches, to 15.9 inches.

That’s only 2.2 inches, not a great deal perhaps. But we can also regard it as 16 percent in a single week. A step along the road to giant panda rotundity.

The young panda, seemingly one of a kind in the mammalian population of the Washington region, has been described by zoo staff as a miracle cub.

In doing so, they cited the age of its mother, Mei Xiang, 22, suggesting she had reached the limits of her cub-bearing years.