Laserfiche WebLink
<br />intensive individual field studies are undertaken, it may be <br />beneficial to coordinate surveys of potential sites with natural <br />resource employees or local birders to determine if interior <br />least terns are stopping en route to wintering sites. <br />13. Assess status and distribution durinE the winter. <br />Interior least terns spend 6-7 months at wintering sites. Most <br />field research, however, has been carried out on breeding birds. <br />Factors limiting non-breeding birds may be as severe or worse <br />than threats encountered during other times of the year. Field <br />studies should begin to at ,least locate wintering sites. <br />131. Survev beaches and other suitable habitat to determine <br />winter distribution. <br />Biologists familiar with the avifauna of Atlantic and <br />Caribbean coastal Latin America should be contacted to <br />assist in determining the winter distribution of least <br />terns. A survey of the north coast of South America should <br />be carried out to identify those habitat types used by least <br />terns. However, the surveys may be difficult. <br />Accessibility of coastal areas along central America and the <br />northern coast of South America may be problematic for <br />geographical and political reasons. Color-banded <br />individuals would provide the means to distinguish interior <br />least terns from other races or populations. <br />132. ~ensus known winterinE areas. <br />Once winter sites are known, censuses of important areas <br />will provide an indication of their continuing importance <br />and status as post-breeding sites. <br />133. Monitor movement of birds between winterinE sites and assess <br />mixinE of DODulations. <br />It is not known if post-breeding interior least terns mix <br />with coastal least terns at wintering sites. Once the <br />habitat types of interior, least terns are known, habitat <br />protection can begin. Monitoring movements of birds between <br />different sites will provide this information, as well as <br />indicate the degree to which individuals from various <br />breeding populations mix during the winter. <br />134. A~sess mortalitv on winterinE areas. <br />The extent and cause of mortality to post-breeding interior <br />least terns has not been addressed. It is not clear if <br />adults and juveniles suffer differential mortality, or if <br />post-breeding birds face greater threats than do breeding <br />birds. Any information leading to further delineation of <br />threats to the species during this time will be important. <br /> <br />35 <br />