Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species.

Testes size was compared among 19 species of Japanese anurans in relation to their breeding systems. Although the mean body mass of the species examined varied markedly between 1.8 and 116 g, the mean proportion of testes mass to body mass was fairly constant at 0.2 to 0.4% across all species except the rhacophorid species. Foam-nest building rhacophorids had relatively large testes constituting more than 1% of their body mass. Among them, Rhacophorus arboreus had the largest, exceeding 5% of the body mass. Multi-male breeding, where a female is grasped by two or more males during spawning, occurs frequently in these rhacophorids, especially in R. arboreus. This close association between large testes size and multi-male breeding strongly suggests that sperm competition is an important factor affecting the evolution of relative testes size in Japanese anurans.

Summary The postmetamorphic growth and survival of the salamander Hynobius nebulosus tokyoentisTago were surveyed in the study site located in Habu village of Hinodemachi, a suburb of Tokyo City, during 1975–1981. A laboratory experiment on the growth rate of juveniles was conducted in parallel with the field survey. The result indicated that this salamander grew at the rate of 8,mm in s.v.l. per year during the juvenile stage, but its growth rate decreased markedly as low as 1.8 mm for males and 1.1 mm for females, once it had attained sexual maturity. According to the “capture‐recapture” procedure the annual survival rate after metamorphosis was found to be quite high; that is, approximately 0.7. By using the growth rate of juveniles and the difference between the sizes at metamorphosis and sexual maturity, the age at first reproduction was estimated to be 4 year for males and 5 year for females. From the data obtained in this study, the intrinsic rates of increase (r) were calculated for various values of age at first reproduction under different survival schedules, and the relationship between the age at first reproduction and fitness as measured by r was examined. The result indicated that an optimal age maximizing fitness always existed under respective survival schedules, and the observed age at first reproduction of this salamandei was found to coincide well with the predicted optimal age.

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. This content downloaded from 130.179.16.201 on Sat, 20 Jun 2015 20:59:09 UTC All use subject to JSTOR Terms and Conditions SHORTER COMMUNICATIONS SHORTER COMMUNICATIONSother undesirable stimulus such as contact from the investigator. Such an avoidance response would be consistent with a ranid frog's normal behavioral pattern of remaining immobile to avoid aversive stimuli such as predators (Gregory, 1979; Licht, 1986). Therefore, learning to inhibit the righting response through passive-avoidance might be an ecologically relevant response for ranid frogs. However, it is also possible that the frogs were simply habituating to being repeatedly overturned by remaining on their backs until they were righted by the investigator, thus perceiving being overturned as a neutral stimulus. It might be ecologically relevant for ranids to have behavioral mechanisms that allow them to rapidly habituate to neutral stimuli. Such responses would allow them to save energy, which would be a valuable adaptation given the high fatigue rate of this taxa as compared to bufonids (Bennet and Licht, 1974; Carey, 1979). Regardless of whether this inhibition of the righting response is derived from a passive-avoidance response or through simple habituation, it represents an example of learned behavior in postlarval ranid frogs. There are few studies that clearly demonstrate learning in postlarval ranids (see review, Suboski, 1992). Therefore, our experiments add to the knowledge concerning patterns and the capacity for learned behavior in these species. Furthermore, this study provides a useful assessment of learning abilities in ranids since our methods for producing the inhibitory response were easy to perform and did not require application of painful stimuli to the animals. Such an assay might be used to examine learning and retention of learned responses in a variety of anuran species. Anurans are capable of retaining this learned response (Harvey et al., 1976), and some species display better learning abilities than others when tested for righting response inhibition (Harvey et al., 1981). Our procedures might also be used to rapidly assess the learning abilities of ranid frogs which have been exposed to neurotoxins. We are particularly interested in using this procedure to determine the effects of lead exposure on learning in postlarval ranids. Previous research has shown that exposure to lead has profound effects on the learning abilities of larval ranids (Strickler-Shaw and Taylor, 1990Taylor, , 1991), but no studies thus far have examined the subsequent effects of lead exposure in the postlarval stages. Acknowledgments.-We thank D. Groggel for assistance with the statistical analyses, and S. Stric...

Body size and age structures of two breeding populations of Rana tagoi tagoi were studied in southwestern Kanto. The mean snout-vent length of males and females was 42.2 and 44.2mm in Kanagawa, and 41.7 and 42.2mm in Tokyo, respectively. The populations studied exhibited almost no sexual dimorphism in body size. Rana. t. tagoi was successfully aged by skeletochronology using phalanges. The breeding adults were 2-4 yr old and the age at first reproduction was estimated to be 2-3 yr. Their lifetime growth schedule was also estimated, based on the relationship between body size and age.