Breeding Ecology Of Cinereous Tits:A Comparison Of Geographic Populations In China

The ecological patterns such as the diversity of species and species?eco-evo adaption in line with the latitudinal variation are fundamentally appealing in ecologists and naturalists.In particular,the breeding ecology with which key life-history traits of secondary cavity bird species in tropical area remains largely unexplored.Ornithologists have mostly studied the breeding ecology of birds within one population at a given study site,with relatively few studies focusing on latitudinal variation across different populations.Research into such geographic variation in birds can provide a unique opportunity to test ecological and evolutionary theories.In this study,breeding ecology of the cinereous tit(Parus cinereus)in Hainan,Henan and Hebei populations across China,was investigated by integrating video surveillance with field observations,during the breeding season from March to August in2017-2019.The main results and conclusions are as follows:1.Regarding the nest building time,we found that the shortest population was Henan(3-7 d,5.33±2.08 d);and the longest population was Hainan(4-12 d,8.75±2.82 d).In addition,we found that mosses were the commonest material for the nest of this species across three populations.This special nest material appeared in 89.5%of nests in the Hainan population(n=60),100%of nest in the Henan population(n=67)and 98.2%of nest in the Hebei population(n=58),respectively.However,there was difference in terms of the other commonly nest material among these three populations:in the Hainan population was plant fibres(65.6%,n=60),while in both of the populations Henan and Hebei was animal hairs(77.6%,n=67 and 100%,n=58,respectively).Finally,we found the mass of the nest from the population of Hainan was the highest(31.9±13.3 g,n=58)while this variable was the lowest in the population of Hebei(12.3±6.1 g,n=54).2.For the egg laying pattern and egg measurements of cinereous tits,we found that the population of Hainan was the earliest population regarding the first egg laying date;and the population of Hebei was the last one.However,the laying time during the day in the Hainan population(7:18±1:59 a.m.,n=19)was much later compared with the Hebei population(4:53±0:24 a.m.,n=22).We also found that,most of the time(83%),the parental bird stayed overnight in the nest before the egg laying day.For the clutch size,we found that the population from Hainan(5.5±1.0,n=31)was the smallest compared with the populations Henan(7.3±1.5,n=59)and Hebei(7.7±1.8,n=48).The pattern kept the same in terms of the egg mass:the Hainan population was the lightest(1.26±0.10 g,n=48)compared with the populations from Henan(1.38±0.12g,n=35)and Hebei(1.41±0.16 g,n=56);and egg volume as well:the Hainan population was the smallest(1234.92±80.72 mm~3,n=27)compared with the populations from Henan(1409.08±114.37 mm~3,n=35)and Hebei(1459.61±104.21 mm~3,n=40).3.For the incubation pattern,there was no significant difference between the population Hainan(12.04±1.72 d,n=23)and Hebei(11.76±0.90 d,n=17)in terms of incubation period.During the days of incubation,we found that parents from the Hebei population left much earlier than the parents from the Hainan population.However,the time of back to the nest during the days of incubation was not different to each other in these two populations.Moreover,there was no difference between these two populations in terms of?the times of leaving the nest of the incubating parental bird?and?the feeding times to the incubating parental bird from the partner?.Yet,interestingly,we found that the level of activity during the incubation days was much higher in the Hainan population while the time of incubation was much shorter in this population.4.For the nestling period and the nestling measurements,we found that the nestling period in population of Hainan(18.4±1.1 d,n=43)was longer than the population of Hebei(15.1±6.39,n=19).As the body measurements,the chick body mass from the population of Hainan was lighter than the population of Hebei;as well as the tarsus length.5.We found that hatching success,nesting success and reproductive success of cinereous tits differentiated significantly among these three populations.However,there was no great variation within a population across different years.Particularly,the nesting and reproductive success of the two higher latitude populations(Hebei and Henan)were higher than those of the tropical population(Hainan).