Effects Of Increasing Expected Predation Risk(Photographic Behavior) On Bird Reproduction In North Tropical Limestone Forests

Predation risk is a very important factor affecting the bird's life-history strategy in natural selection and one of the main reasons for the reproductive success of birds.It has shown great importance for shaping the bird evolution and life-history strategy.Human activities are one of the most important factors affecting nest predation of birds.Some studies have shown that human activities could lead to increased nest predation,while others have shown that human activities did not affect nest predation.In recent years,more and more photographers have taken pictures of nests,adding to the expected risk of nest predation.The purpose of this study was to explore the effects of photographic behavior on the nest predation,feeding,and reproduction of birds in Longzhou County,Guangxi,China.This study analyzed the influencing factors of nest predation of breeding birds by comparing the difference of breeding characteristics between photography and natural nest between May and August2020,in order to provide a theoretical basis of the relationship between ecological tourism and biodiversity conservation.The main results of this study were as follow:1)A total of 277 nests(83 photographic nests and 194 natural nests)belonging to 42 species,29 families,and 9 orders were observed in this study.2)Among the 83 photographic nests and 194 natural nests,11 and 122 nests were preyed on,and the nest predation rates were 13.25% and 62.89%,respectively.It was shown that the predation rate of the natural nests was significantly higher than the photographic nests whether at incubation or fledgling stages.3)The predation rate of the open nest was higher than the closed nest,and the non-cave nest was higher than the cave nest at two stages of reproduction(incubation and fledgling).During the whole breeding stage,the predation rate of natural nests was higher than the photographic nests,with the same nest position(tree,shrub,ground,and soil cave).4)Increasing the expected predation risk(photographic behavior),the daily predation rate of natural nests was significantly higher than that of photographic nests at the breeding stage.Among all photographic nests,the successful fledgling number reached 74.70%,while the natural nests were 26.94%.5)Five species of birds,including White-browed Piculet(Sasia ochracea),Great Barbet(Psilopogon virens),Indochinese Green Magpie(Cissa hypoleuca),Yellow-eyed Babbler(Chrysomma sinense),and Black-naped Monarch Flycatcher(Hypothymis azurea),had a slightly higher feeding frequency under the natural conditions than those under the photographic behavior conditions,but the difference was not significant.6)Among the analyzed factors,only disturbance(photographic and natural)had significant effects on nest predation,while other factors such as species,nest type and nest height had no significant effects.In summary,in this study we found that increasing the expected predation risk(photographic behavior)on bird reproduction in north tropical limestone forests does not always negatively affect bird reproduction,but instead reduces nest predation rates and has no significant effect on bird feeding frequency.Therefore,this result could be related to the vulnerability of local nest predators to human disturbance,or it could be due to the increased reproductive success of the local population by consciously protecting the photographed birds.