USGS - science for a changing world

Upper Midwest Environmental Sciences Center

Wildlife Toxicology

Great Lakes Restoration Initiative (GLRI) Project 80

Swallows as indicators

 

Tree swallows nest across the northern half of the U.S. and because they nest in artificial nest boxes can be attracted to specific areas of interest. Tree swallows are very numerous so they are not as difficult to find and study as other avian species.

Swallow range

Because you can see them, you know where they are feeding and hence are accumulating the contaminants present in their tissues.

 

 
Swallows will nest in more diverse aquatic habitats within their breeding range than most other avian species.  
marsh
marshes
lake
lakes and ponds
river
rivers and streams
 

- including highly industrial and urban locations where other species are often rare.

industrial photo

industrial photo  
 

Greater than 85% of swallow’s diet are benthic aquatic insects and they feed within ~ 1 km of their nest box so contamination in their tissues are closely tied to sediment contamination and the cleanup of those sediments. The short, consistent food chain makes data interpretation easier and more direct. 

dragonflyinsectmayfly
       

The level of clean-up achieved can be readily quantified by the swallows.
They integrate over appropriate time and spatial scales.

 
Dredging Sorting and processing dredged material  

Tree swallows are relatively easy and efficient to study. Because they nest in boxes, swallows can be attracted to almost any area where data are needed. By putting up many (20 – 50) nest boxes adequate sample sizes can be generated which results in strong statistical power to detect trends through time and to quantify adverse effects.

Field work Field work
             

swallow

While much better looking  “ . . . tree swallows deserve equal standing beside fruit flies, nematodes, and mice as one of the classical model organisms in biology.”
(J.Jones 2003 Auk 120:591-599).

swallow

   
 

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey

URL: http://www.umesc.usgs.gov/wildlife_toxicology/why_swallows.html
Page Contact Information: Contacting the Upper Midwest Environmental Sciences Center
Page Last Modified: August 5, 2011