Rediscovering the King of Woodpeckers: Exploring the Implications

The Ivory-billed Woodpecker has long held a special place in the psyche of North American conservation, eliciting unusually colorful prose, even from scientists, as an icon of the wild. The reverence in which it was held did little to slow the habitat loss that led to its apparent extinction 60 years ago. A consequence of the emotion and attention associated with the amazing rediscovery of this species is that conservation biologists will be under considerable pressure to make good on this “second chance.” This poses a challenge to conservation paradigms that has important political consequences. First, the decline of the species is due to habitat loss, recovery from which has been much more seldom achieved than recovery from declines due to impacts on vital rates. This challenge is exacerbated by the enormous area requirements of the species. Second, the species at best exists as a critically small population. It will be difficult to make the case that a viable population can be established without undermining the small population paradigm that underlies conservation strategies for many other species. This has already resulted in some political backlash. Conservation of this species is best based on the one point of clear scientific consensus, that habitat is limiting, but this may result in additional political backlash because of conflicts with other land uses.

The Influence of Body Condition on the Stopover Ecology of Least Sandpipers in the Lower Mississippi Alluvial Valley during Fall Migration

Many shorebirds are long-distance migrants and depend on the energy gained at stopover sites to complete migration. Competing hypotheses have described strategies used by migrating birds; the energy-selection hypothesis predicts that shorebirds attempt to maximize energy gained at stopover sites, whereas the time-selection hypothesis predicts that shorebirds attempt to minimize time spent at stopover sites. The energy- and time-selection hypotheses both predict that birds in better condition will depart sites sooner. However, numerous studies of stopover duration have found little support for this prediction, leading to the suggestion that migrating birds operate under energy and time constraints for only a small portion of the migratory season. During fall migration 2002, we tested the prediction that birds in better condition depart stopover sites sooner by examining the relationship between stopover duration and body condition for migrating Least Sandpipers (Calidris minutilla) at three stopover sites in the Lower Mississippi Alluvial Valley. We also tested the assumption made by the Lower Mississippi Alluvial Valley Migratory Bird Science Team that shorebirds stay in the Mississippi Valley for 10 d. The assumption of 10 d was used to estimate the amount of habitat required by shorebirds in the Mississippi Valley during fall migration; a period longer than 10 d would increase the estimate of the amount habitat required. We used multiple-day constancy models of apparent survival and program MARK to estimate stopover duration for 293 individually color-marked and resighted Least Sandpipers. We found that a four-day constancy interval and a site x quadratic time trend interaction term best modeled apparent survival. We found only weak support for body condition as a factor explaining length of stopover duration, which is consistent with findings from similar work. Stopover duration estimates were 4.1 d (95% CI = 2.8–6.1) for adult Least Sandpipers at Bald Knob National Wildlife Refuge, Arkansas, 6.5 d (95% CI = 4.9–8.7) for adult and 6.1 d (95% CI =4.2–9.1) for juvenile Least Sandpipers at Yazoo National Wildlife Refuge, Mississippi, and 6.9 d (95% CI = 5.5–8.7) for juvenile Least Sandpipers at Morgan Brake National Wildlife Refuge, Mississippi. Based on our estimates of stopover duration and the assumption made by the Lower Mississippi Alluvial Valley Migratory Bird Science Team, there is sufficient habitat in the lower Mississippi Valley to support shorebirds during fall migration.