|Abstract: The beaches of Long Island, New York act as important breeding grounds for the Piping Plover(Charadrius melodus), yet human development of these beaches poses a considerable threat to the conservation of this listed species. Conservation management efforts must take into account the reproductive ecology of the species. We investigate how reproductive success and fecundity of the breeding population changes over the course of the breeding season. Data collected during breeding seasons starting from 1999 through 2008 by The Nature Conservancy on Long Island provide evidence that initial nesting attempts (first nests) exhibit the same fecundity and likelihood of success as attempts to replace a lost nest (renests); there were no significant differences between the two in terms of average clutch size (P = 0.55), hatching success (P = 0.58), or fledging success (P = 0.46). The data also suggest that nests that hatch earlier tend to feature a larger clutch size (P < 0.001) and hatch more eggs (P < 0.001). However, the number of chicks fledged from a nest was not associated with hatch date (P = 0.07). Research on other sites has suggested that more young fledge from nests that are laid earlier in the season. If so, we suggest that this may be more attributable to higher hatching success than to higher fledging success from amongst the chick population. Because of this intraseasonal decline in breeding capacity, likely due to greater challenges from human development and life history demands, the early part of the season is critical for breeding success and should be a priority for conservation management.||
Electrophoretic Variation of Malate Dehydrogenase in Lysimachia fraseri.
May 4, 2009
Mentor: Dr. Jeff Holmes
Abstract: Lysimachia fraseri (Fraser’s Yellow Loosestife) is a rare plant belonging to the Primulaceae (Primrose) family, endemic to the central and southeastern United States. North Carolina is home to the majority of the 86 confirmed extant populations nationwide. The cause of this species imperilment is unknown, but an understanding of the genetic variation among and between subpopulations of L.fraseri is essential for conservation. Using starch gel electrophoresis, the metabolic enzyme malate dehydrogenase (MDH), was analyzed for polymorphism among and between individuals from two groups of L. fraseri residing on the Warren Wilson College Campus. The enzymatic activity in leaf tissue from eighteen individuals from each of the potential sub populations was assayed. Results indicate that MDH is expressed from a minimum of two loci, one of which is polymorphic. Additionally, one of the two plots sampled expressed a unique phenotype, indicating the presence of greater genetic diversity within that plot. This suggests that the two groups of L. fraseri may have emerged as separate subpopulations of a larger metapopulation and may have been reproductively isolated for some time.