Not only is migration impacted by the wind direction but geography as well. The most intense raptor migration in the world takes place there. 100,000 birds a day is not unusual and as many as 1 million have been recorded in a single day. Geography causes the funneling of over 4.5 million raptors through Veracruz each year. The funneling results from the migratory needs of raptors.
Most raptors are soaring birds, so they depend on thermals to obtain altitude.
Since the open sea doesn't have thermals, they are restricted to the Mexican isthmus as they fly between North and South America. The mountains to the west of Veracruz don't have usable thermals either so the birds have to stay near the coast. As a result, virtually the entire population of some raptors fly through a strip of land just 25 miles wide. In a word, no. Scientists believe that birds know when to migrate because as we approach spring daylight gradually lengthens.