Assessing personality in San Joaquin kit fox in situ: efficacy of field-based experimental methods and implications for conservation management

Utilisation of animal personality has potential benefit for conservation management. Due to logistics of robust behavioural evaluation in situ, the majority of studies on wild animals involve taking animals into captivity for testing, potentially compromising results. Three in situ tests for evaluation of boldness in San Joaquin kit fox (Vulpes macrotis mutica) were developed (ENOT: extended novel object test; RNOT: rapid novel object test; TH: trap/handling test). Each test successfully identified variation in boldness within its target age class(es). The TH test was suitable for use across all age classes. Tests were assessed for in situ suitability and for quantity/quality of data yielded. ENOT was rated as requiring high levels of time, cost and labour with greater likelihood of failure. However, it was rated highly for data quantity/quality. The TH test was rated as requiring little time, labour and cost, but yielding lower quality data. RNOT was rated in the middle. Each test had merit and could be adapted to suit project or species constraints. We recommend field-based evaluation of personality, reducing removal of animals from the wild and facilitating routine incorporation of personality assessment into conservation projects

Female preference for blue in Japan blue guppies (Poecilia reticulata)

Guppies (Poecilia reticulata) are widely used as a model species in mate choice studies. Although native to South America, guppies have been introduced to natural water bodies in disparate regions of the globe. Here, for the first time, we examine guppies from one such introduced population in Japan where males have evolved a predominantly blue color pattern. Previous studies of wild-type guppies have shown blue to play a relatively minor role in the mate choice decisions of females compared to other traits, such as orange, and the importance of blue is not universally supported by all studies. The Japanese population therefore presents an ideal opportunity to re-examine the potential significance of blue as a mate choice cue in guppies. Mate choice experiments, in which female Japan blue guppies were given a choice between pairs of males that differed in their area of blue coloration but were matched for other traits, revealed that females prefer males with proportionately larger amounts of blue in their color patterns. We discuss possible factors, including sexual and ecological selection, which may have led to the evolution of unusually large areas of blue at the expense of other colors in Japan blue guppies. However, further studies are needed to distinguish between these scenarios.Web of Scienc

No Association between Personality and Candidate Gene Polymorphisms in a Wild Bird Population

Consistency of between-individual differences in behaviour or personality is a phenomenon in populations that can have ecological consequences and evolutionary potential. One way that behaviour can evolve is to have a genetic basis. Identifying the molecular genetic basis of personality could therefore provide insight into how and why such variation is maintained, particularly in natural populations. Previously identified candidate genes for personality in birds include the dopamine receptor D4 (DRD4), and serotonin transporter (SERT). Studies of wild bird populations have shown that exploratory and bold behaviours are associated with polymorphisms in both DRD4 and SERT. Here we tested for polymorphisms in DRD4 and SERT in the Seychelles warbler (Acrocephalus sechellensis) population on Cousin Island, Seychelles, and then investigated correlations between personality and polymorphisms in these genes. We found no genetic variation in DRD4, but identified four polymorphisms in SERT that clustered into five haplotypes. There was no correlation between bold or exploratory behaviours and SERT polymorphisms/haplotypes. The null result was not due to lack of power, and indicates that there was no association between these behaviours and variation in the candidate genes tested in this population. These null findings provide important data to facilitate representative future meta-analyses on candidate personality genes

Euthanasia methods, corticosterone and haematocrit levels in <i>Xenopus laevis:</i> evidence for differences in stress?

AbstractAmphibians, like other vertebrates, respond to acute stressors by releasing glucocorticoid steroid hormones that mediate physiological and behavioural responses to stress. Measurement of stress hormones provides a potential means to improve the welfare of laboratory animals. For example, manipulations of laboratory housing and procedures combined with measurement of glucocorticoids may identify which conditions are more stressful to animals. This is important because there is very little experimental evidence to guide best practice for welfare in amphibians and other lower vertebrates. We investigated the effect of different methods of euthanasia on the circulating plasma corticosterone levels in the African clawed frog (Xenopus laevis), a model amphibian organism that is frequently used in laboratories. In particular, we investigated the effect of different concentrations and pH of the anaesthetic tricaine methanesulphonate (MS-222). Low concentration and unbuffered (low pH) solutions of MS-222 caused elevated corticosterone levels, but only after the effect of MS-222 treatment on blood fluid volume had been taken into account. The level of disturbance that animals experienced also affected corticosterone levels. Thus, our data suggest that to minimise stress to X. laevis, animals should be euthanised after minimal disturbance and in a 3 g L−1 MS-222 solution, buffered to pH 7. The potential for the improvement of amphibian welfare using corticosterone measures as a tool is discussed.</jats:p

Light environment and mating behavior in Trinidadian guppies (<i>Poecilia reticulata</i>)

Male guppies, Poecilia reticulata, have color patterns that result from a balance between natural selection for crypsis to avoid predators and sexual selection for bright, complex patterns that attract females. Males use displays to show off these patterns to potential mates, but their conspicuousness also depends on the light environment in which they are viewed. We investigated variation in natural underwater guppy light environments in Trinidad, West Indies, and found that mating behavior is correlated with both the ‘quantity’ (total irradiance) and ‘quality’ (spectral composition) of light: light intensity and the proportion of ultraviolet light were negatively related to display rates. Experimental manipulation of light environment to mimic natural daily changes demonstrated that these relationships are causal and are independent of time of day effects. At lower light levels, when guppies are less detectable by visually hunting predators, females had more opportunity for active mate choice, because males displayed more. However, these light conditions may reduce the ability of females to accurately discriminate between males. Guppy mating behavior is therefore strongly affected by light environment, and this may have important effects on sexual selection