numbering in the thousands

[keannu]

Does " numbering in the thousands" mean "its number was thousands"? But I feel "numbering thousands" is sufficient, so "in the" seems redundant, what is it for?

go33-37 ex)The snowy plover is one of the hardest birds to spot on the beach. Once numbering in the thousands, the species is listed as endangered in several states now. Beige and white, snowy plovers blend perfectly in the white sand. They eat tiny flies that live on the sand or mud flats. Their nests usually contain three tiny eggs, which look like sand and are barely visible to even the most well­trained eye. Mothers incubate the nests during the day and fathers at night. Chicks can get out of their nest within three hours of hatching. They walk, run, and swim well but still require their parents’ care after hatching.

[Tdol]

It emphasises that there used to be thousands and thousands of this species.

[BobK]

In that context, 'numbering thousands' would suggest that there weren't really very many. I don't know anything about snowy plovers' range, but I imagine it's several thousand square miles; 'thousands and thousands' is a good way of emphasizing how numerous they are.

'<numbers> and <numbers>' is a common set of idioms: 'dozens and dozens', 'hundreds and hundreds', 'millions and millions' ... They all emphasize 'countlessness'. Another option, like 'numbering in the ...' is 'numbering in their ...'

b