Temporal patterns of three sympatric pheasant species in the Nanling Mountains: N-mixture modeling applied to detect abundance

Background:The reliability of long-term population estimates is crucial for conservation and management purposes.Most previous studies assume that count indices are proportionally related to abundance;however,this assumption may not hold when detection varies spatially and temporally.We examined seasonal variations in abundance of three bird species(Cabot’s Tragopan Tragopan caboti,Silver Pheasant Lophura nycthemera,and Whitenecklaced Partridge Arborophila gingica) along an elevational gradient,using N-mixture models that take into account imperfect detection in our bird data.Methods:Camera-trapping was used to monitor temporal activity patterns of these species at Guangdong Nanling National Nature Reserve from December 2013 to November 2017(4 seasons per year).For abundance analysis(N-mixture modeling),we divided a year into 4 seasons,i.e.3 months per season,and performed the analysis by season.Elevation was incorporated into the N-mixture model as a covariate that may affect abundance.We compared the N-mixture model with a null model(no covariate model) and selected the better model based on AIC values to make an inference.Results:From 24 sampling sites,we obtained 6786 photographs of 8482 individuals of 44 bird species and 26 mammal species.Silver Pheasant was photographed much more frequently and showed higher temporal activity frequency than White-necklaced Partridge or Cabot’s Tragopan.Silver Pheasant was camera-captured most frequently in summer,and other two species in winters.All three species had two daytime activity peaks:between 6:00 a.m.and 10:00 a.m.,and between 5:00 p.m.and 7:00 p.m.,respectively.Our estimated abundance and detection probability from the N-mixture model were variable by season.In particular,all three species showed greater abundance in summer than in winter,and estimated abundance patterns of all three species were more similar with observed cameratrapping counts in summers.Moreover,in winter,elevation had a positive impact on abundance of Silver Pheasant and Cabot’s Tragopan,but not on White-necklaced Partridge.Conclusions:Our results demonstrate that the N-mixture model performed well in the estimation of temporal popu lation abundance at local fixed permanent plots in mountain habitat in southern China,based on the modeling of repeated camera-trapping counts.The seasonal differences in abundance of the three endemic bird species and the strong effect of elevation on abundance of two species in winter were only indicative of variations in spatio-tempora distribution within species and between species.In identifying suitable habitat for endemic pheasants,the positive elevational effect also suggests that more attention should be paid to conservation of areas with higher elevation in the Nanling Mountains.

Do non-target species visit feeders and water troughs targeting small game?A study from farmland Spain using camera-trapping

Provision of food and water is a widespread tool implemented around the world for the benefit of game and other wildlife,but factors affecting the use of food and water by non-target species are poorly known.We evaluated visits to feeders and water troughs by non-game species using camera-traps in two separate areas of Spain.Feeders and water troughs were either“protected”(when surrounded by more than 50%of shrubs/forest)or“open”(in the opposite case).A total of 18948 photos from 5344 camera-trapping days depicted animals,and 75 species were identified.Feeders and water troughs were visited by target species(partridges and lagomorphs,55.3%of visits)and non-target species(44.7%of visits).Among the latter,corvids were themost common(46.1%of visits),followed by rodents(26.8%),other birds(23.6%,mainly passerines),columbids(1.9%),and other species at minor percentages.The highest proportion of visiting days to feeders and water troughs was from corvids(0.173)followed by otherbirds(0.109)and rodents(0.083);the lowest proportion was recorded for columbids(0.016).Use intensity and visit frequency of water troughs tripled that recorded in feeders,and visits to open feeders/troughs were approximately twice those to protected ones.In summary:feeders and water troughs targeting small game species are also used regularly by non-target ones;they should be set close to cover to optimize their use by non-target species that are not competitors of target species(though corvids may visit them);water availability should be prioritized where drought periods are expected.

Productivity constraints on Citron-crested Cockatoos in a rich community of large hole-nesting birds

Knowledge of breeding success and its limiting factors is crucial in assessing species’conservation needs.As cavity-nesters,parrots are particularly influenced by the availability of suitable cavities and low breeding output,whether due to natural processes or trapping.On the island of Sumba,Indonesia,the Critically Endangered Citron-crested Cockatoo(Cacatua citrinocristata)has the added problem of co-existing with an unusually rich hole-nesting bird community in a forested environment much constrained by habitat loss.We monitored 95 nesting cavities of cockatoos and their competitors and potential nest-predators,over one to four breeding seasons,using a combination of camera-traps,direct checks on nest contents,and observations from the ground.Competition for suitable cavities was intense among three large parrot species,two owls and a hornbill.Visitation rates by potential competitors were higher at unoccupied cavities than at those containing active nests,reflecting the guarding behaviour of the occupants.The Endangered Sumba Hornbill(Rhyticeros everetti)dominated observed direct confrontations and was the most frequent visitor to active parrot nests,suggesting a further role as a potential nest-predator.Cockatoos prospected many cavities but rarely then attempted to nest:instead the sites were usually occupied by other cavity-nesters,or by bees.At the few cavities where cockatoos did breed,predation pressure was likely low,and observed success rate high(10 successful of 15 nests),although the low number of nests found early in the breeding cycle suggests that some may have failed before detection.Intense competition for cavities suggests a shortage of suitable nest-sites,the need for preservation of old hole-bearing trees and a role for nestboxes.Accessible,known,safe artificial nest-sites would also provide opportunities to assess the scale of nest-site shortage,allow camera placements to study productivity,exclude some competitors and predators,and prevent illegal trapping.Especially given continued trapping pressure,the species would benefit from targeted local awareness-raising and law enforcement,with the whole endeavour backed up by longer-term forest restoration.

Free-ranging livestock altered the spatiotemporal behavior of the endangered North Chinese leopard (Panthera pardus japonensis) and its prey and intensified human–leopard conflicts

Widespread distribution of livestock in the natural habitats of large carnivores may negatively impact carnivore populations by reducing wild prey availability and increasing human–carnivore conflicts.In this study,we used camera-trapping data collected in the temperate forests of the Taihang Mountains in North China during 2016–2019 to examine whether and how free-ranging cattle affected habitat use and Diel activity patterns of the endangered North Chinese leopard(Panthera pardus japonensis)and its 2 wild prey species,Siberian roe deer(Capreolus pygargus),and wild boar(Sus scrofa).Residents were also interviewed to record livestock depredation events by leopards during 2015–2019.We found that roe deer spatially avoided sites frequented by cattle,but wild boar did not.In the growing seasons,leopards shared habitats with cattle and tended to increase their diurnal activities where cattle were present.All 3 study species exhibitedfine-scale spatial-temporal segregation to cattle.Leopards selectively preyed on calves over adult cattle and livestock depredation frequency was positively correlated with the detection rates of cattle and wild prey,but not that of leopard.Thesefindings not only show that through behavioral adaption large carnivores and their ungulate prey may persist under livestock disturbance,but also highlight how important proper livestock management is for conserving North Chinese leopards in this region.To enhance livestock management and mitigate human–leopard conflicts,we recommend specific actions,such as better guarding of free-ranging cattle or adoption of a captive farming system.

Ecology and local knowledge of the Baird’s tapir (Tapirella bairdii) in the Sierra Madre de Oaxaca, Mexico

As well as being of global cultural importance(from local tribal folklore to being an iconic species for conser­vation),the tapir plays an important role in its ecosystem as a herbivore and seed disperser.However,the ecol­ogy and ethnozoology of the endangered Baird’s tapir in the north of Oaxaca,Mexico is poorly understood.We used camera traps to estimate its relative abundance and density and to describe the activity patterns of the northernmost population of Baird’s tapir in the Sierra Madre de Oaxaca.Local knowledge concerning the ta­pir was also documented,along with the conservation strategies undertaken by the 2 indigenous communi­ties that own the land where the study site is located.Only adult tapirs were photographed,and these were ac­tive 14 h per day,but were mainly nocturnal and crepuscular.The estimated relative abundance(12.99±2.24 events/1000 camera days)and density values(0.07-0.24 individuals/km2)were both similar to those found in another site in Mexico located within a protected area.Semi-structured interviews revealed that people have a basic understanding of the eating habits,activity and main predators of the tapir.There were reports of hunt­ing,although not among those respondents who regularly consume bush meat.Thus,the relative abundance and density estimates of tapir at the study site could be related to the favorable condition of the forest and the ab­sence of hunting and consumption of tapir meat.Fortunately,the local people are conducting initiatives promot­ing the conservation of this ungulate and its habitat that combine to constitute a regional trend of habitat and wildlife protection.