Sex-specific parental care strategies via nestling age: females pay more attention to nestling demands than males do in the horned lark, Eremophila alpestris.

In many species, nestling demands vary continuously during early development and both parents have different parental care strategies at each nestling age. Sexual conflict arises when each parent expects its partner investing more in parental care. It is largely unknown how the two parents respond to the dynamics of nestling demands and resolve the sexual conflict during nestling period, especially on Qinghai-Tibetan Plateau. To address this question, we monitored parental care behaviors of horned larks (Eremophila alpestris) using video-recording systems. We found that male horned larks invested less in parental care, but had a larger body size than females, which is consistent with the parental investment hypothesis. Only the female brooded nestlings, but both parents contributed to feeding efforts. Feeding rates of males and females were negatively correlated, indicating that they used evolutionarily stable strategies. Strategies of parental care via nestling age were sex-specific. Females continuously adjusted care behaviors to follow the dynamics of nestling demands as nestling age increased, such as decreasing brood attentiveness and increasing feeding rate. By contrast, male feeding rate showed no significant correlation with nestling age, but increased with the synchrony feeding rate. We suggest the synchrony feeding behavior may act as a control measure for females to promote and assess the males' contribution. We consider low mating opportunities drive males to act as assistants for females, and correspondingly cause males to pay less attention to nestling demands than females.

[Phylogeny and genetic diversity of Phrynocephalus przewalskii].

Phrynocephalus przewalskii is one kind of lizards inhabiting inclusively in the desert that has controversial viewpoints on its phylogeny. Based on mitochondrial ND2 gene of 119 samples from 12 geographic populations, we analyzed the effects of environmental factors on the variation of genetic diversity, as well as its relationship to P. versicolor. The results showed that these populations clustered into three major lineages, with P. versicolor embedded within one lineage. The twelve populations had great genetic diversity variation, which was tightly linked with local altitude, annual precipitation, and variation of annual precipitation. High latitudes, increased annual precipitation and great variation in annual precipitations may all have resulted in the decrease of genetic diversity. It thus assumed that altitude can change the genetic diversity of different geographic populations of P. przewalskii resulting from the effects of different local annual precipitation.