Research On The Breeding Ecology Of Paradoxornis Heudei On The Coast Of Dafeng, Jiangsu

The breeding ecology of the reed parrotbill(Paradoxornis heudei)was studied at the third core area of Dafeng Milu National Nature Reserve in Jiangsu Province during March to July 2014 and April to July 2015.The home range was estimated by radio-tracking methods and the incubation rhythm,feeding frequency of parents were calculated by infrared video monitoring system.The results are as follows:1.The reed parrotbill flocks had fixed feeding area and night roosting area during the non-breeding period.The flock flied to feeding area at 6:30,and went back to night roosting area at 18:00.The reed parrotbills preferred to select highly covert reeds as their night roosting area,and selected food-abundant habitat as the feeding area,both of them were all near to the water and far away from the human disturbance.The home range size was 12.80 hm2(95%FKE)in non-breeding period,and 4.66 hm2(95%FKE)and 1.76 hm2(95%FKE)in early breeding period and nestling period respectively.2.We measured the nest-site characteristics at microhabitat and territorial patch scale,the results showed that the reed parrotbills preferred to build nest on middle height reeds with both dry and green stems,lower nest visibility,far to the human disturbance and near to the water sources.The principal component analysis indicated that the main factors affecting the nest-site selection of the reed parrotbills including the species of nest vegetation,concealment by vegetation,nest location,and water sources.3.The reed parrotbills were monogamous.The bowl-shaped nests were built by both parents,and main materials were leaves and skins of reeds with some spider silks.The mean inner and outer diameter were 5.64�0.50 cm and 7.75�0.63 cm(n=63)respecetively,the mean inside depth and outside height were 5.90�0.49 cm and 8.52 �0.89 cm(n=63)respectively.Nest height above the ground was 69.60 � 21.34 cm(n=65),and nest weight was 10.06 � 2.61 g(n=1 8).Total of 171 eggs from 35 nests were measured.The mean clutch size was 4.86�0.49(Range=3-6,n=35),the mean egg length and egg breadth were 18.68 � 0.86 mm and 14.44�0.48 mm respectively,mean fresh egg mass was 2.06 � 0.18 g and mean egg volume was 1.99 � 0.17 cm3.4.Usually the female laid one egg per day.Incubation and provisioning of nestlings were carried out both by male and female,which lasting 16.14�0.38 days(n=7)and 12.13 � 0.35 days(n=8)respectively.Incubation behavior occurred only at daytime before the fourth egg was laid,then the female would brood the eggs or nestlings at night until the day before fledging.There were significant difference between male and female activites(P>0.05),including incubation number,incubation time,recess time,feeding numbers,warming numbers,warming time.In contrast,the female had a significantly higher egg-turning frequency than male(P<0.01),but the recess time of female was significantly longer than male(P<0.01).The reproductive investment of femals was larger than that of male during the incubation and nestling periods.The reproductive success was 13.85%(9/65)in the area and nest predation rate was about 67.69%(44/65).The main predator was Elaphe anomala for the reed parrotbills.5.The growth of each body indicators could be well fit the model of logistic which is similar to other passerine birds.The feeding organs grow fast at early stage,such as bill,tarsus and claw,while the flying organs grow slowly at the same time,such as wing and tail.