Several recent studies demonstrate that wild birds are actively transporting ticks and their associated diseases during migration. In addition, a number of bird species are able to contract Borrelia burgdorferi (the bacterial causal agent of Lyme Disease infection) and transmit it to uninfected ticks that parasitize the birds for a blood meal. Since ground-feeding species such as Northern Cardinals, Gray Catbirds, Song Sparrows (pictured) and American Robins spend a significant amount of time foraging for food at the optimal height for ticks, they are excellent hosts and have all demonstrated the ability to infect larval ticks with Borrelia burgdorferi upon their first blood meal. (Look carefully at the Song Sparrow’s neck and you will find a tick.)
The return of song sparrows and their energetic songs tells us spring has definitely arrived. The males sing a sequence of notes, including clear whistles and buzzy sounds. According to nature recordist Lang Elliott, each male has about ten songs in its repertoire and tends to repeat one pattern for several minutes before changing to another. Although other birds may produce more musical songs, you’d have to search far and wide for more enthusiastic outbursts than those of a song sparrow.