Study On Reproductive Strategies Of Yellow-rumped Flycatcher

The study on reproductive strategies of Yellow-rumped Flycatcher (Ficedula zanthopygia) was conducted at ZuoJia Nature Reserve, Jilin province from March to July in2010and2011. We observed the behaviors of parental bird outside the artificial nest-box, and used videos for analyzing its behaviors inside the nest-box. Different reproductive strategies of Yellow-rumped Flycatcher had been preliminarily discussed in this paper. The results showed that parental birds can use diverse strategies according to different breeding period. In order to improve nestling fledging success and achieve the maximal reproductive success, parental birds adopted relevant strategies from nest-building to the nestlings’fledging.The females and males Yellow-rumped Flycatcher were captured and measured. The average body length of female was113.87±5.98mm, and average tarsus length was19.10±1.02mm; the average body length of male was116.46±4.57mm, and average tarsus length was19.44±0.89mm. No difference was found between females and males body condition. Correlation analysis showed that weight of nest materials and clutch size had no significant correlation with female body condition; male body size had no significant correlation with clutch size and the weight of nest materials, but the tarsus length had significant correlation with clutch size (r=0.804, P=0.000). Females and males built the nest together, generally5±1.21days. During2010and2011, the birds used95nests with laying eggs. The mean weight of nest materials was29.80±10.55g; no notable difference was detected between the two years’weight of nest materials, but there existed significant difference in nest materials weight among different reproductive individuals (t=24.958, P=0.000); nest materials weight had no significant correlation with nest-building period, clutch size, incubation period, nestling period and fledging success, but the hatching success (r=0.258, P=0.035). The average reproductive success was74.55%, the average clutch size was5.74±1.01, the average egg mass was1.59±0.16g, the average egg size was17.31±0.82mm×13.12±0.47mm, and the peak time of laying eggs was at the end of May. There was significant negative correlation between clutch size and egg mass (r=-0.189, P=0.000), so was the clutch size and the egg size (long diameter and short diameter)(r=-0.196, P=0.000; r=-0.144, P=0.005). The egg mass was significant difference in different clutch size (F=6.199, P=0.000). There existed significant positive correlation between egg mass with long diameter or short diameter (r=0.728, P=0.000; r=0.882, P=0.000), and it was the same correlation between clutch size and hatching success (r=0.480, P=0.000) and with fledging success (r=0.379, P=0.002).The results also showed that there was no significant difference between clutch size and incubation period or nestling period, and the average incubation period was13.07±1.39days, the average nestling period was13.60±1.96days.By observation and analysis of all-day videos via DVR of female bird in incubation period, we found that incubation behavior was the main behavior, which accounted for58.36%of the times, and the second behavior was leaving the nest, which accounted for30.82%. Incubation behavior, alert behaviors, turning eggs behaviors, and preening behaviors were not significant difference during incubation period at different time intervals of a day. The average incubation time of female was621.45±541.81s per time, and leaving nests340.57±342.84s per time. Results showed that there was no significant difference in the daily rhythm of brooding. There existed significant difference in females and male mean brooding times (t=2.552, P=0.017), and females mean brooding times were significant difference with nestling age changes (F=6.210, P=0.001), but males not. In addition, brood size was positive correlation with brooding times (r=0.895, P=0.016). The ability of food provision between females and males was not significant difference, but the times of dispose nestling faeces was significant difference (F=9.332, P=0.007), the approach was not significant.