Virgil's Migrating Birds

Extract

In this famous picture of the migrating birds, what precisely had Virgil in mind? In his note on the passage Conington writes: ‘the birds are apparently supposed to have accomplished their voyage over the sea, and to be just alighting in a mass in the warmer clime that is to receive them.’ Conington was evidently dissatisfied with this explanation, and so was Long, whom he quotes as remarking that ‘the flocking together of the birds before departure would be a fitter and more natural comparison’. There is further awkwardness involved if we take both terram and terris as referring to the same place.