The Global Decline of Reptiles, Déjà Vu Amphibians

Abstract

A s a group [reptiles] are nei t h er ‘good ’n or ‘b ad ,’ but ia re intere s ting and unu su a l , a l t h o u gh of m i n or i m port a n ce . If t h ey should all disappe a r, it wo u l d not make mu ch differen ce one way or the other ”( Zim and Smith 1953, p. 9 ) . Fortu n a tely, this op i n i on from the Golden Gu i de Series does not persist tod ay; most people have com e to recogn i ze the va lue of both reptiles and amph i bians as an i n tegral part of n a tu ral eco s ys tems and as heralds of envi ron m ental qu a l i ty (Gibbons and Stangel 1999). In recent ye a rs , as overa ll envi ron m ental aw a reness among the p u blic has incre a s ed , con cerns have come to inclu de intere s t in the eco l ogical state of reptile and amph i bian spec i e s t h em s elves and of t h eir habi t a t s . In c re a s ed aw a reness may s tem from bet ter edu c a ti on abo ut threats to bi od ivers i ty in gen era l , and to reptiles and amph i bians in parti c u l a r, a n d po s s i bly even from an innate attracti on to these taxa ( Kell ert and Wi l s on 1993). From the perspective of many nonscientists, the two vertebrate classes comprising reptiles and amphibians, collectively referred to as the herpetofauna, are interchangeable. For example,the Boy Scout merit badge pamphlet for herpetology was called simply Reptile Study from 1926 to 1993 (Conant 1972, Gibbons 1993), and major zoos (e.g., National Zoo in Washington, DC; Zoo Atlanta; and San Diego Zoo) use only the name “reptile” to refer to the facility that houses both amphibians and reptiles. Thus, public attitudes about the need for conservation of reptiles are probably linked to concern about amphibian declines and deformities (Alford and Richards 1999, Johnson et al. 1999, Sessions et al. 1999), which have been the subject of numerous, well-documented scientific studies. Because amphibians are distributed worldwide, but herpetologists who document amphibian declines are not, it is difficult to accurately assess what portion of amphibian populations are experiencing significant declines or have already disappeared. Furthermore, the means of determining a species’ conservation status is a rigorous and time-intensive process, and therefore counts of “officially” recognized endangered and threatened species are likely to grossly underestimate the actual number of imperiled s pecies (Ta ble 1). The worl dwi de amph i bian decl i n e probl em , as it has come to be known, has garnered significant attention not only among scientists but also in the popular media and in political circles.