The phrase "a time when migrating" is correct and usable in written English.
It can be used to refer to a specific period or occasion during which migration occurs, often in discussions about animals, people, or cultural movements.
Example: "The documentary highlighted a time when migrating birds would travel thousands of miles to find warmer climates."
Alternatives: "a period of migration" or "an era of migration".
These greater performances of sialyltransferase expressing Schwann cell correlated with their sustained expression of polysialylated neural cell adhesion molecule at early times when migrating from the graft to the lesion, and its progressive downregulation at later times during remyelination.
And the animal fossils are further proof that this was a time when species migrated from Asia to North America across a land bridge.
And it comes at a time when developers are migrating from simple 2-dimensional games to richer 3-D ones as production costs for hit mobile games continue to rise.
Timing clearly played a part too - Mr Houston launched the firm at a time when users were migrating towards multiple devices, from netbooks to mobile phones (and later tablets).
Mr. Webber's saw his mission of elevating the urban disadvantaged as a way of strengthening mainline Protestantism at a time when many Protestants were migrating to the suburbs.
Much about the school is unchanged from when Mr. Walcott, who turns 61 on Friday, attended P.S. 36 — a time when black families were migrating to the St. Albans neighborhood from Manhattan and Brooklyn in search of a more suburban life.
Certainly, the "Game of Thrones" connection, and the large youthful audiences it brings in, is a powerful promotional opportunity for "It's Always Sunny" at a time when the series is migrating to a new FX spinoff channel, FXX, that is aimed at younger viewers.
Consistent with this idea, we have shown that the zygotic functions of Scrib and Vangl2 are required for planar polarization of neuroepithelial progenitors and floorplate cells across the anterior-posterior axis of the neural tube at a time when FBM neurons are migrating (see also Borovina et al., 2010).
The trouble is that Lycos Europe has continued to focus on teenage users, with online dating and chat services, at a time when other portals have migrated into more specialized, higher-value information.
