Conservation of grassland birds in an agricultural landscape: The importance of habitat availability and demography

Landscape attributes may influence habitat availability, reproduction, and survival of grassland birds. Landscape effects may be especially important where grassy cover exists as small, isolated patches surrounded by intensive agriculture. Understanding how species use the entire landscape matrix may allow the implementation of efficient conservation strategies. I evaluated how grassland birds respond to new habitat creation and provide empirical data on eastern meadowlark annual fecundity and post-fledging juvenile survival in the context of an agricultural matrix.; Grassland birds colonized new habitats the first year after agricultural production ceased, suggesting that suitable breeding habitat is limited in this landscape. Species composition of new grasslands changed with vegetation succession, as birds that prefer early successional habitats were replaced by species requiring more established grassy cover. Rare and area-sensitive species were also documented breeding on relatively small, created grasslands. Reproductive success of new grasslands was comparable to older adjacent grasslands.; The annual fecundity of 34 radio-collard female eastern meadowlarks was 1.26 female offspring. However, fewer females than expected were double-brooded or persistently renested after nest failures, possibly because meadowlarks trade maximum annual fecundity for increased lifetime productivity. Juvenile survival is lowest the first week post-fledging, primarily due to increased predation related to their lack of mobility. Juvenile survival was estimated to be 53% to 90 days. During the period of study, juveniles rarely moved greater than 5 km from their natal sites, although the use of agriculture was greater than expected.; The results from this study suggest that the creation of small grassland complexes within an agricultural matrix is an effective conservation strategy. Furthermore, the results underscore the importance of understanding how life history traits influence population demography and emphasize the importance of surrounding farmland, especially for post-breeding females and post-fledging juveniles. Additional experimental creation of more isolated grassland tracts would help test the hypothesis that clusters of nearby grasslands are preferable to more isolated tracts.