Life‐history traits and fitness of plateau pika (Ochotona curzoniae) in alpine meadow ecosystem

Abstract

Plateau pika (Ochotona curzoniae) is an endemic mammal living in the alpine meadow ecosystem in Qinghai–Tibet Plateau. We studied life history of plateau pika by mark–recapturing method. The research results showed that fitness of plateau pika to its habitat was lower than those of many other mammal species; plateau pika adopted quick growth strategy; the life‐history features of plateau pika were accorded with Charnov (Evolutionary Ecology Research, 2002, 4, 749)'s formula about life‐history classification, that is, E/α ≈ 1.35, C·E ≈ 1.7, I/m ≈ 0.3, in which E stands for average adult life span; α stands for age at first reproduction; C is reproductive effort; I is the size of an offspring at independence from the parent; m is average adult body mass. There does not exist dimorphism in plateau pikas. The configurations of females and males are similar; the average body mass of males is a little heavier than that of females, but the difference is not significant (F = 1.0854, df = 154, p > .3058). The juveniles exhibit a J‐form growth curve before 30‐day age and grow slower between 30 and 65‐day age and reach body mass equilibrium at about 65 days old. So, 65 days is the maturity age of plateau pika. There are 3 mortality peaks in plateau pika population. The first time is in neonate period, when only one half of juveniles can pass through this period, which implies that juvenile period is influenced strongly by natural selection; the second time is in fecundity peak period, which reflects the cost of reproduction; the third time is in the old age of plateau pika, a significant loss occurs during this period, which is the result of natural selection. The average longevity of females is longer than that of males. A female reaches the maximum life span recorded, that is, 931 days. The average longevity of all individuals is 16.33 months ≈ 490 days. The survival rate of females is higher than that of males, which reflects the cost of reproduction and society role of males. It is the outcome of natural selection. The sex ratio of neonates is 1:1; however, the sex ratio of adults is female: male = 1.31:1, which is caused by higher mortality of males over females in life history. Plateau pikas reproduced two times every year. The average gestation period of females is 18–20 days. The average litter size is 4.57 individual. The average body mass of neonates is 9.28 g. The average litter size of adult female plateau pika does not variate with age. Breeding season is between April and June. The reproductive value and fertility of 15–18 months age females are highest. The reproductive value and fertility increased with age before reproductive value and fertility peak age; however, the reproductive value and fertility decreased with age after peak age. The fitness of plateau pika (r = .1125) was lower than that of American pikas (O. princeps) (r = 2.172). The survival rate was the main factor influencing fitness. The dynamic trend of plateau pika population was coincident with r, that is, the plateau pika population...

Pika disturbance intensity observation system via multidimensional stereoscopic surveying for monitoring alpine meadow

“…38 The multidimensional stereoscopic surveying technology proposed in this study improves the efficiency and reliability of the field work, does not harm the ecosystem, and provides a new way for the investigation and study of plateau pika activities on a large scale. In recent years, scholars have conducted a lot of work on the relationship between plateau pika activities and alpine grassland ecosystems, mainly using the number of pika holes to characterize the disturbance intensity, [39][40][41] and it was found that with the increase of the activities intensity, the vegetation coverage, vegetation height, the proportion of edible grass and aboveground biomass will continue to decrease, and the area of bald spots, weeds and poisonous plants will continue to increase, but the pika holes number will increase first and then decrease. [42][43][44] That is, the vegetation and soil conditions of the pika activities areas reflect the disturbance intensity objectively, and the intensity reflected by a single number of holes is not comprehensive.…”

The role of herbivores in the grassland carbon budget for Three‐Rivers Headwaters region, Qinghai–Tibetan Plateau, China

“…On the one hand, rodents compete with livestock (e.g., yak and Tibetan sheep) for available vegetation (Harris et al, 2015; Yang & Jiang, 2002). Plateau pika, therefore, are considered to play a key role in food chains (Z. Guo et al, 2012; Lai & Smith, 2003; Smith & Foggin, 1999; Y. Zhang et al, 2016), although regarded as a harmful species (Chen et al, 2017; N. Fan et al, 1999; Pang & Guo, 2017; W. Wei et al, 2020), and have an adaptive strategy with a higher mortality and higher regeneration in its population (Nie et al, 2022). On the other hand, alpine creatures have to struggle with environmental and biological stresses through multilevel adaptations in the extreme environmental conditions of lower air temperature and lower atmospheric oxygen concentration (Dahal et al, 2020; Feijó et al, 2020).…”

“…Fan et al, 1999;Pang & Guo, 2017;W. Wei et al, 2020), and have an adaptive strategy with a higher mortality and higher regeneration in its population (Nie et al, 2022). On the other hand, alpine creatures have to struggle with environmental and biological stresses through multilevel adaptations in the extreme environmental conditions of lower air temperature and lower atmospheric oxygen concentration (Dahal et al, 2020;Feijó et al, 2020).…”

Daily and Seasonal Activity Patterns of Plateau Pikas (Ochotona curzoniae) on the Qinghai–Tibet Plateau, China, and Their Relationship with Weather Condition

“…However, this species is regarded as a pest that leads to the degradation of the rangeland ecosystem in the QTP, and it has been largely eliminated by rodenticides [29,30]. Pikas are social mammals that live in groups of adults and their young in a family unit [31]. Within a population, these families consist of a variable number of adult breeding males and females, and individual families may exhibit monogamous, polygynous, or polyandrous mating systems [32].…”