Variable ecological effects of hurricanes: The importance of seasonal timing for survival of lizards on Bahamian islands

Abstract

Two recent hurricanes passed directly over the northern Bahamas 2 years apart, allowing a comparison of their effects on lizard populations inhabiting exactly the same islands. The hurricanes differed in two ways: one struck during the reproductive season and was relatively severe; the other struck after most reproduction had taken place and was milder. The late-season hurricane produced a significant relation between population reduction and lowness of the island that lasted at least through two seasons; the earlier hurricane produced no such relationship. The late-season hurricane wiped out populations of lizards on two islands (two of the three lowest) that the earlier hurricane failed to exterminate even though it was stronger. We relate these effects to the fact that the study lizards regenerated from the earlier hurricane only via the egg stage, whereas eggs were unavailable when the later storm struck and regeneration was via hatched lizards. We discriminate and illustrate four kinds of hurricanes, cross-classified by two contrasts: earlier vs. later and stronger vs. weaker. A later, stronger hurricane completely exterminated lizard populations at a second Bahamian site, whereas an earlier, weaker hurricane had no detectable effect at a third Bahamian site. We suggest that, in addition to severity, the timing of a hurricane as it coincides with reproductive scheduling or other phenological aspects may determine the magnitude of its effect on a variety of organisms.

Nonsynchronous recovery of community characteristics in island spiders after a catastrophic hurricane

“…3). Michelle was a Category I hurricane, and its storm surge was not nearly as high [Ϸ1 m at our site (29), as compared to 3 m during Floyd]. A 1-m increase in sea level would have completely submerged or nearly (high water level Ͼ90% of the total altitude) submerged only 18 of the 41 islands in the present study; of course, the lower parts of even the highest islands would have been covered as well.…”

“…The dramatic increase in hurricanes over the past decade means that such data are becoming increasingly common (e.g., refs. 12,18,29,32,33,[42][43][44]. This increase could continue if the elevated North Atlantic sea-surface temperatures were to be resulting, in part, from long-term climate change (ref.…”

“…Variation in lizard numbers was not, of course, the only kind of variation induced by the hurricane's effect on lizards: The number of lizard islands also dropped substantially, from 25 to 28 before the hurricane to 11 to 16 after the hurricane (the maximum was reached just before Michelle, which was a very late-season hurricane that exterminated some lizard populations surviving Floyd, probably because it struck after the hurricane-resistant egg stage was no longer being produced; ref. 29). This change in state of island from one year to the next could have varying influences on the relative recovery of the lizard effect.…”

Herbivore-initiated interaction cascades and their modulation by productivity in an African savanna

“…Within each exclosure and control plot, we randomly selected four 25 ϫ 25 m study quadrats without replacement. We censused lizards within these quadrats (the first two quadrats per plot during June-September 2004 and the other two during June-September 2005), using the mark-resight procedure and analysis described by Heckel and Roughgarden (43), with the modifications incorporated by Schoener et al (44). These censuses were randomly ordered within each field season to prevent any short-term temporal biases.…”

Inter-locus antagonistic coevolution as an engine of speciation: Assessment with hemiclonal analysis

“…By comparison, ecologists have gained important insights into the extinction and colonization process by studying very small island populations of vertebrates in nature, despite the fact that these ''islands'' are little more than large protruding rocks, 1-16 m on a side (see, for example, ref. 41).…”