Funded primarily by the Department of Defense, NJ Audubon  Research is involved in a multi-year study to quantify general information on reproductive success of grassland breeding birds on regional airfields, and to determine factors affecting nesting success/failure.   Mowing is of particular interest, as it takes place during the breeding season.

Fieldwork began in 2009 at the Lakehurst Naval Air Engineering Station,  a military airport located within the Pinelands National Reserve.   These 1,700 acres of grassland habitat currently support the largest known breeding population of Upland Sandpiper (Bartramia longicauda)  and the second-largest known population of Grasshopper Sparrow (Ammodramus savannarum) in NJ.  Other sites in the study include Westover Air Reserve Base in Massachusetts, and Patuxent River Naval Air Station in Maryland. 

Some questions being addressed: 

   1). How does human manipulation of grasslands affect the success/failure of nests?  
   2). Does mowing cause sufficient disturbance to result in nest abandonment?  
   3). Does mowing make the nests more visible, and thus more vulnerable to predation?  
   4). How many nests are destroyed by mowers?  

   Answers  will aid in the  development of appropriate management plans to encourage successful populations of grassland birds, while continuing to discourage use of the grasslands near runways by avian species which pose a high strike risk to aircraft. 

 
Results from 2009 have provided important information regarding  microhabitat features of grassland bird nest sites, and overall productivity in these areas.  Thus far, a total of 42 grasshopper sparrow nests (15 at Lakehurst)  and 42 nests of other grassland breeding species (11 at Lakehurst) have been located and monitored.  Altho adult Upland Sandpipers are monitored at Lakehurst, no nests to date have been found. 

Preliminary data concerning the effects of mowing or not mowing during breeding seasons will be supplemented by data from the 2010 breeding season to better quantify significant factors influencing successful nesting on these increasingly important grasslands.