In June, biologists from Rachel Carson National Wildlife Refuge, Biodiversity Research Institute and University of New Hampshire captured and placed radio transmitters on 15 female saltmarsh sharp-tailed sparrows.  The birds were caught using mist nets, with teams of people forming semi-circles and driving the birds towards the nets.  When captured, both male and female sparrows were banded, measured, weighed, and a blood sample taken.  The blood samples were taken for methyl mercury analysis.  Previous studies have indicated these sparrows can serve as indicators of mercury contamination in the marsh.

            Radio transmitters were placed on females to assist with assessing nest success.  Saltmarsh sharp-tailed sparrows are a species of high conservation concern throughout their range.  Their nests are difficult to find, as they are hidden under tufts of salt marsh grass on the marsh surface.  Because of the difficulty of locating saltmarsh sparrow nests, refuge staff used telemetry to follow birds to their nests and then searched the area for nests.  However, we found that extensive, well timed nest searches found more nests than telemetry.     Telemetry did allow us to measure nest attentiveness, in addition to matching females where blood was taken, to nests.  This enabled us to measure mercury levels in relation to nest success without trapping the female directly off the nest.  Approximately 89 nests were located.  All nests were observed for nest success and nest attentiveness.

            Nest attentiveness was observed by a staff member sitting 15-20 m from the nest for approximately an hour, recording the departures and arrivals of the female.  We discovered that the females would occasionally walk on or off the nest, remaining out of sight of the observer, making telemetry necessary to track their movements and measure nest attentiveness.  The transmitters were intended to be deployed for five weeks (the predicted battery life); however, several of the transmitters fell off of the birds.  Three of these fell off early enough in the study that they could be redeployed.  These three were put on birds that were captured at previously discovered nests.

            Over the course of the study, much was learned about sparrow behavior, and also about the use of telemetry in studying these birds.  This project increased our knowledge of salt marsh sparrows and will enable us to do more effective nest searches and tracking of these birds in the future.