Breeding Behaviors And Response To Human Disturbance Of Common Coot Fulica Atra

A scientific research on behavioral ecology of Common Coot was made in Anbanghe Nature Reserve and Daqing Longfeng Nature Reserve since April to November of 2008 and 2009. Research contents included territory behavior, conspecific brood parasitism, habitat selection, as well as coots' behavioral response to human disturbance.Territory and territorial behavior of Common Coot were observed in both sites in breeding season, territory were formed after paired, and both sexes display the rights and protected it through calls, patrolling and "display platform" construction. Both individuals of coots and other species were drove out when they approached the boundary. Territory activities became severe since May to June, the territorility level was highest in the nest building period and weaker since then. As territory owners engage in territorial fights and contests of their neighbors, and avoid the potential costs of escalated fights was reasonable to interprate the weaker of territory activities; more energy were turned into breeding after egg laying was the other reason for interpreting the weaker of territory activities. After the young was independent, territory behaviors disappeared, and the coots gathered again. Territory size differed from 1 333 m2 to above 5 000 m2. Wintering population was observed in Poyang Lake of Jiangxi province; the coots gathered in the open water and did not present territory behaviors in wintering sites.Similar to the American coot (Fulica americana), each pair of Common Coot, build 2-7 display platforms in their territory during the breeding season, besides the nest. The functionality of display platforms of the coots and figure differences of them with nests has been discussed; nests were more refined and significantly higher than the platforms. Display platforms were used primarily for roosting, preening, and mating in reproduction periods, and the use ration of platforms decreased with the development of reproduction stages, contrarily, time spend on nests increased. Besides these, the platforms might play an important role in confirming and recognizing the territory boundaries. Besides these, for the platforms, use ration (time of every present, day present times and day total present time) of the male was higher than the female in different breeding stages, for the nest, the result was contrary. Platforms construction was most active in nest building period, and weaker in next stages. However, the coots would add new platforms near conflict points when they were incubation. It seems that the construction of platforms was a result of neighbor conflicts, so I inferred the platforms were a kind of territory display, and they might be used as a reference of territory boundary reorganization.Conspecific brood parasitism of Common Coot was observed in both study sites. Similar as American Coot, egg rejection was used for parasitism defence; parasites' eggs were buried, driven out and pecked by the hosts. Besides these manners, territory behaviors and the construction of display platforms might play an important role in defending parasitism In species driven by the coots, Common Parchard was observed most, and they occupied the coots' structures, as inter-specific nest parasitism of Common Parchard had been reported, and ducks were detected in the list of parasites of other coots, so I inferred the severe territory behaviors of coots to Common Parchard might be caused by brood parasitism.Effects of human activity on the behavior of waterbirds were checked using focal-animal sampling method in two study sites from April to June of 2008 and 2009. The results showed that the responding distances of the Common Coots to human walking and motor vehicles were similar, however, the tolerance degrees were different, tolerance distance of the coots to motor vehicles were larger than human walking, and the percentage of responses to disturbance was higher in Anbanghe wetland where the main disturbance type was tourists' walking, which indicated that the coots and other swimming birds were more tolerant to motor vehicles compared with walking. In Anbanghe wetland, the responding distance of the coots to boating disturbance was much larger than walking; it means the coots were less tolerant to invading activities.Fixed line transect method and sample plot method were used combined to investigate the amount and distribution of coots and other species in disturbance area (tourist area) and core area of Anbanghe wetland. Results indicated that the amount of coots in disturbance area were similar as the core area and even higher in disturbance area in October as more coots gathered in the open water of the lake in the disturbance area. Water depth and open water area were more important to coots compared with recreation disturbance. The species abundance and distribution were not significant influenced by recreation disturbance in Anbanghe wetland.Though the coots shows little response to human disturbance on behaviors, amount and distribution, human disturbance combined with habitat quality might delay the breeding date of the coots.Principal component analysis and stepwise discriminate analysis were used associated with observation to investigate the nest-site selection of coots in breeding season. Results showed that:(1) coots favored to nest in area with middle vegetation coverage and height, moderate water level, near to open water and thin reeds and cattails; (2) impact of human disturbance on nest site selection was weaker, intra and inter species attractions and competition were more influential factors for coots' nest site selection. (3) territoriality played important roles in habitat selection of the coots.On the basis of the aforesaid results, the coots adopted breeding tactics as followed:(1) More energy were paid on territory activities before egg laying, and territory was important in occupying resources, mate-guarding and defending parasitism; after egg laying, more energy was turned into breeding offsprings, neighbors tended to adopt behaviors less energy cost in territory activities.(2) High proportion of conspecific brood parasitism existed in coots, and parasitism was cost for the hosts as fitness reduction, so defense mechanism was important for the species with CBP, besides egg rejection based on egg recognization, the coots adopted territory guarding and platforms construction to reduce the parasite opportunities by other females.(3) Coots tend to chose high quality habitat for nesting, which wound be advantages for reproduction, however, territory competition and resource availability will made some pairs unable to obtain these areas, they might chose to delay the breeding date until habitat changes better.(4) Coots response to human disturbance less sensitively compared with ducks, and avoidance degree was lower, pairs distributed in the edge were disturbed more frequently than the central ones, they adopted less energy cost response to the disturbance, such as swim away which was more used by the edge pairs compared with flush and run.