The Effect Of Reproductive Success Rate, Age And Mate Maintenance On The Nest Loyalty Of Ningshan Crested Ibis Reintroduced Into The Population

Nest-site fidelity is one of the fundamental research contents of avian ecology and dispersal biology,and it is also a key factor in the conservation of endangered species and ecological restoration.Although the dispersal ecology of Crested Ibis(Nipponia nippon)(including wild population in Yangxian County and reintroduced population in Ningshan County)has been preliminarily studied,the relationships between individuals's nest-site fidelity and their breeding success,age and mate fidelity of Crested Ibis remain unclear.In order to improve the habitat quality,expand the distribution area and increase the number of wild population,the paper studied the effect factors of nest-site fidelity according to the data on the reintroduced population of Crested Ibis in Ningshan County,Shaanxi province.Until July 2018,44 breeding pairs had been formed in the reintroduced population of Ningshan Crested Ibis.There were 35 pairs(32(?),30(?))participated in reproduction at least two consecutive years.Based on these 35 paired reproductive parameters,this study explored the relationship between nest-site fidelity(dependent variable)and breeding success,age and mate fidelity(independent variable).Firstly,the independent variables were analyzed separately;secondly,the factors affecting nest-site fidelity were analyzed by using Generalized Linear Model(GLM).The main results obtained in this paper were as follows:1.From 2008 to 2018,87 nests and 299 eggs were introduced into Ningshan Crested Ibis population,the average number of nests and eggs was 3.5±0.861(n=87):222 young birds were hatched,the average hatching rate was 72.35%±0.09;1 72 young birds were flied;The average breeding success was 54.84%±0.14;There were 45.16%(28/62)females and 49.18%(30/61)males maintain nest-site fidelity.2.Reproductive performance had no significant effect on nest-site fidelity.In the case of reproductive success,58.70%(27/46)males and 63.00%(29/46)females maintain nest-site fidelity;In the case of reproductive failure,64.29%(9/15)females and 61.54%(8/13)males had breeding dispersal.Therefore,data analysis shows that individuals who failed breeding tend to change nest sites.Although the reproductive parameters(nests with eggs,chicks hatched numbers,chicks fledged numbers,hatching success,fledging success,breeding success)before and after dispersal were improved,but the difference was not significant.3.There was a significant positive correlation between the age and nest-site fidelity.That is to say,the nest-site fidelity increased with age.4.Mate-fidelity had a significant effect on female nest-site fidelity.Poor reproductive performance had a significant impact on female's mate fidelity,but there was no significant difference in male's.However,there was no significant difference between the age of breeding dispersal and the age of maintaining nest-site fidelity among individuals with poor reproductive performance.Although there was no significant difference in the age of breeding individuals before and after changing mate,but the age at which females re-select mate was younger than that of former one.At the same time,the breeding success of reproduction increased after changing mate,but there was no significant difference.Therefore,breeding dispersal due to poor reproductive performance is related to the search for high-quality mate,but not to the age or competitiveness of individuals.5.The GLM model analysis showed that breeding success,age and mate fidelity had certain effects on female nest-site fidelity,just age and mate fidelity had significant effects,but had no effect on male nest-site fidelity.