Observations on breeding behavior of the White-eared Night Heron(Gorsachius magnificus) in northern Guangdong, China

The White-eared Night Heron (Gorsachius magnificus) is a Class II protected species in China. It is difficult to observe in the field and its population is small. The present study reports a new distribution site in Nanxiong County, in northern Guangdong Province, where observations of an active nest were made from 4 May to 14 July 2012, the first time consecutive observations have been made for a period of more than two months. The adults flew away from the nest at night, with a peak at 19:00-20:00 and returned in the mornings with a peak at 04:30-05:30. The peak time for feeding young was at 05:00-05:30, accounting for 26.5%of total feeding activities. No feeding occurred from 10:00 to 16:00. The results of our study of its behavior explain why the White-eared Night Heron is usually observed in the evening just before dark, or in the morning before sunrise, at least during the breeding season. There were about 67 days from hatching to fledging, longer than the fledging time of most heron species. This study is the first to cover the entire period of parental care and fills a gap in previous knowledge.

The White-eared Night Heron(Gorsachius magnificus):from behind the bamboo curtain to the front stage

Once,in 2007,the authors had written:regarding to the endangerment of the White-eared Night Heron (Gorsachius magnificus),it would be evidentially to say that no longer the status of the bird is to meet the Criteria EN C1 but more likely still marginally meet EN C2a(i),and hence the bird might be currently remained amongst those Endangered (EN),with caveats that,if any bird could have been found in an area outside the range of any known subpopulation,it will then warrant a lower threat status.Now,it is time for due consideration.

Memory for location and visual cues in white-eared hummingbirds Hylocharis leucotis

In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to visit, partly as a function of the nectar reward. The uncertainty of these decisions would possibly be reduced if an individual could remember locations or use visual cues to avoid revisiting recently depleted flowers. In the present study, we carried out field experiments with white-eared hummingbirds Hylocharis leucotis, to evaluate their use of locations or visual cues when foraging on natural flowers Penstemon roseus. We evaluated the use of spatial memory by observing birds while they were foraging between two plants and within a single plant. Our results showed that hummingbirds prefer to use location when foraging in two plants, but they also use visual cues to efficiently locate unvisited rewarded flowers when they feed on a single plant. However, in absence of visual cues, in both experiments birds mainly used the location of previously visited flowers to make subsequent visits. Our data suggest that hummingbirds are capable of learning and employing this flexibility depending on the faced environmental conditions and the information acquired in previous visits [Current Zoology 57 （4）： 468-476, 2011].

Intruder familiarity and not duet similarity influences the territory defense in a year-round territorial bird species

To avoid unnecessary energy expenditures in territorial defense,many species(e.g.,insects,amphibians,birds,and mammals)have developed the capability to distinguish between different intruder types using visual,acoustic,and/or chemical signals.Determining the mechanism used for intruder recognition is key to understanding the dynamics of territorial behaviors.In birds that use vocalizations for territorial defense,the frequency and duration of vocalizations or the familiarity with the intruder may be the main mechanism used for intruder recognition.Here,we conducted a playback experiment with territorial White-eared Ground-sparrows(Melozone leucotis),to analyze if territorial pairs recognize intruders using frequency and duration characteristics(a bird’s response is based on how structurally similar the intruders’duets are to their own)or by familiarity with the intruders(neighbors vs.non-neighbors).We focused on duets because this species uses duets exclusively for territorial defense.We broadcasted a duet from a territorial neighbor,two duets from non-neighbors(with different frequency and duration characteristics),and a duet from a control species in 39 territorial pair from three populations.During playback we measured five behavioral responses:latency of the first vocalization,latency of the approach to the speaker,time spent close the speaker(within 5 m),number of individuals that approached the speaker,and the number of vocalizations.We found that territorial White-eared Ground-sparrow pairs responded stronger to neighbors than non-neighbors,and this response is not influenced by duet duration or frequency characteristics.This result suggests that neighbors represent a greater territorial threat for White-eared Ground-sparrows than non-neighbors.Further work is necessary to understand how common this observation is for tropical species that defend small territories year-round.