I am currently working on the unintentional transport of birds and have come across the possibility that small birds, e.g. sparrows, could be unintentionally transported by aircraft. This could be due to their life in close proximity to humans (including airports), their small size and the fact that House Sparrows in particular regularly fly inside buildings.
I haven't found any reports of this yet, but there have been sightings of sparrows at remote airstrips, far from road access. Are there any documented cases? I think it's unlikely on international passenger flights, but perhaps more likely on less-controlled domestic flights, military or civilian cargo flights.
Many thanks.