Life-history costs of reproductive behaviors in a wetland-breeding amphibian

Abstract

Studies examining the association between life-history strategies and behavior can help inform our understanding of the fitness consequences of reproductive behaviors. Breeding migrations are common in numerous taxa and often represent an important reproductive cost. We examined body mass changes of spotted salamanders (Ambystoma maculatum) during their seasonal breeding migrations to determine the influence of breeding behaviors on reproductive costs. We sampled salamanders entering and exiting a 0.92-ha ephemeral wetland in the North Carolina Piedmont using a 400-m drift fence completely encircling the wetland. Traps were checked daily during annual breeding migrations in mid-January to early March of 2013 and 2014. The relationship between body mass changes and explanatory factors including sex, duration of stay at wetland, and distance between site entrance and exit were examined using a set of candidate linear mixed models selected a priori and compared using Akaike's information criterion. Female salamanders lost a greater percentage of body mass during the time in the wetland than males as a result of oviposition. Model selection identified duration of stay as the most important predictor of female body mass change with greater duration of stay associated with lower mass loss. In males, percentage mass loss was most closely associated with site entranceÀexit correspondence with greater distance between entrance and exit sites associated with greater mass loss. These data demonstrate both the importance of wetland entranceÀexit sites and duration of stay at the wetland in determining mass change during spotted salamander reproduction and also that these relationships can differ as a function of sex. Taken together, our findings provide a potential link between behavior, life-history cycles, and costs experienced during reproduction.

Climate‐associated decline of body condition in a fossorial salamander

“…The negative relationship between body condition and ice-on (winter) duration can be reasonably attributed to extended fasting in years of late ice-off. Similarly, later spring capture dates resulted in reduced body condition of females and males, a result corroborated in similar salamander field studies (Homan et al, 2018;Strickland et al, 2015), and likely related to their non-feeding status and energy expenditure throughout winter (Figure 6b) and during early spring migration and breeding. Although we did not forecast how changes in ice-on duration may affect body condition (largely due to the lack of any projection available), it seems likely that warmer fall temperatures will be associated with decreases in winter duration in future climates, and hence relatively warm temperatures in the overwintering environment (Figure 6a), which may partly offset the energetic benefit of a shortened winter duration.…”

Multistate model to estimate sex‐specific dispersal rates and distances for a wetland‐breeding amphibian population

“…Unfortunately, we were unable to estimate intra‐annual breeding dispersal distances of females due to low recapture rates within breeding seasons. However, it is likely that the high physiological and ecological costs associated with breeding (Strickland et al, 2015) prohibit female movement between wetlands, particularly those located in different clusters, within a breeding season. Of the 339 females we recaptured over the study period, we only observed 10 within‐year movement events.…”

The effects of conspecifics on burrow selection in juvenile spotted salamanders (Ambystoma maculatum)

“…The wetland is surrounded by deciduous and pine forest and is dominated by tall grassy vegetation (Pittman et al 2008). Every day at approximately 1000 hours, we sampled 38 pitfall traps (13-L plastic buckets) placed every 10 m on the inside of a 400-m drift fence completely encircling the wetland (Strickland et al 2014). Two 61 9 122-cm wooden cover boards were placed on the inside of the drift fence.…”