14 April 2007

A shitty way to get dispersed

Andy J. Green, Marta I. Sánchez. 2006. Passive internal dispersal of insect larvae by migratory birds. Biology Letters, 2:55-57. pdf

According to the authors, this is the first published evidence for dispersal of aquatic insects by migratory birds. They collected 6 samples of fresh faeces of black-tailed godwits (Limosa limosa) from soil ~5 m from the edge of water in a marsh in Spain. Three of those samples contained live larvae of the midge Chironomus salinarius.

The authors' conclusion is that the birds had consumed the larvae, which survived passing thru the birds' intestines to be deposited with their faeces. These birds are said to defecate usually over water. Therefore, they may help disperse aquatic insect larvae.

Could the eggs from which the larvae hatched have been laid by midges on the faeces on land? Presumably that is not likely, because these midges deposit their eggs in water.

More info on the Chironomidae is available at the Chironomid Home Page.


Snail said...

This link might be handier. (If it works.)

pascal said...

"Egestion" is actually a large issue with some invasive snails (the Spiny mud snail comes to mind). Perhas it is another mechanism that we have to consider with land snail dispersal. (?)