Mating system variation and morph fluctuations in a polymorphic lizard

Abstract

In polymorphic male painted dragon lizards (Ctenophorus pictus), red males win staged contests for females over yellow males, and yellow males have greater success in staged sperm competition trials than red males. This predicts different reproductive strategies in the wild with red males being more coercive or better mate guarders than yellow males. Yellow males would be expected to sire more offspring per copulation and have a greater proportion of offspring from clutches with mixed paternity. However, here we show using microsatellites that the frequency of mixed paternity in the wild is low (< 20% on average across years), that all morphs on average have the same number of offspring sired per year, and that mating system variation (polyandry vs. monandry) is strongly correlated with perch density on male territories. Furthermore, a logistic regression on male successful vs. unsuccessful mate acquisition showed that red males were under negative selection when they dominated the population, which suggests ongoing frequency dependent selection on male colouration.

Telomere dynamics in a lizard with morph‐specific reproductive investment and self‐maintenance

“…While not significantly different, the telomere length of the orange males was numerically intermediate to the red and yellow males, suggesting that orange males are heterozygotes of red and yellow alleles. Although previous research indicates that the system of color inheritance is more complex (Olsson, Healey, Wapstra et al, 2007), the life history strategy of orange males may still be some intermediate to that of red and yellow males. Blue males had the shortest telomeres and this may indicate higher levels of ROS (perhaps as a result of lower levels of antioxidants).…”

“…The dragons are ideal models for this research as they are short-lived and age rapidly (surviving ~1 year in the wild, Olsson, Healey, Wapstra et al, 2007), making it more likely that attempts to manipulate telomeres will be detected (Olsson, Tobler, Healey, Perrin, & Wilson, 2012).…”

“…The yellow coloration is carotenoid-based, while the red is likely pteridine-based (Olsson, Healey, Wapstra et al, 2007). Red males emerge earlier post-hibernation (Olsson, Healey, Wapstra et al, 2007), experience a greater increase in testosterone throughout the day than yellow males, and outcompete yellow males in dominance contests Olsson, Healey, & Astheimer, 2007). Conversely, yellow males have larger testes and four times higher reproductive success in sperm competition trials than red males, despite much shorter copulations (Olsson, Schwartz, Uller, & Healey, 2009).…”

“…Most research has focused on the red and yellow morphs, since orange and blue morphs have only started appearing in the population in 1997. The yellow coloration is carotenoid-based, while the red is likely pteridine-based (Olsson, Healey, Wapstra et al, 2007). Red males emerge earlier post-hibernation (Olsson, Healey, Wapstra et al, 2007), experience a greater increase in testosterone throughout the day than yellow males, and outcompete yellow males in dominance contests Olsson, Healey, & Astheimer, 2007).…”

Carotenoid intake does not mediate a relationship between reactive oxygen species and bright colouration: experimental test in a lizard

“…Painted dragons are sexually dimorphic (females are cryptically greyish-brown), and the dazzling colours of the adult males are used for signalling to deter approaching rivals Olsson et al, 2007). Polymorphism is correlated with differences in behavioural traits, such as dominance .…”