In heterogeneous landscapes, birds may mistime their breeding attempts relative to local food abundance. How birds cope with this challenge has been little studied. In this study, we compared the provisioning behavior and nestling condition of the Green-backed Tit Parus monticolus nesting in a landscape mosaic comprised of native mixed-oak forests and exotic Japanese Cedar Cryptomeria japonica plantations. Parent birds in the larvae-poor plantations time their breeding as they do in the larvae-rich forests and have clutches of similar size. We found that parent birds were flexible in adjusting their criteria for prey choice on the basis of larval abundance. In early spring, in cedar plantations where larval abundance was low, male parents maintained constant nearby feeding trips to the early broods, just as they did in the mixed-oak forests, but reduced their dietary specialization on larvae, while female birds increased their provisioning frequency. Combining both parents' efforts, the early brood nestlings raised in the cedar plantations received food deliveries more frequently and with a higher proportion of non-larval prey than their counterparts did in the mixed-oak forests. In contrast, during late brood rearing, when larvae were abundant, both parents in the plantations foraged heavily on larvae at the expense of other prey, just as they did in the mixed-oak forests. We found that parent birds reared heavier nestlings as the contribution of large larvae to the diet increased. Moreover, the nestlings during early broods in the plantations had lower body weights than their counterparts in the mixed-oak forests. We suggest that the provisioning flexibility of Green-backed Tits helps them gather food for raising nestlings when their breeding attempts are less synchronized with the larval food supply in their habitat. As a result, they can breed successfully in the exotic cedar plantations.

Aims: hyperglycemia impairs pancreatic β-cell function instantly, also known as glucotoxicity. It is unknown whether this insult is temporary or sustained, and little real-world evidence needs to reflect the relationship between hyperglycemic burden, per se, and glycemic durability. Materials and Methods: a retrospective observational cohort study was conducted to recruit newly-diagnosed type 2 diabetes mellitus (T2DM) patients. Durability was defined as the episode from first glycated hemoglobin A1c (HbA1c) below 7.0% to where it exceed 8.0% (with treatment failure) or where study ended (without treatment failure). Glycemic burden was defined with the area above a burden value line (HbA1c = 6.5%) but under the HbA1c curve (AUC), and it was then divided into two compartments with the demarcation timepoint once HbA1c was treated below or equal to 7.0%; the former AUC’ represented the initial insult; the latter AUC” represented the residual part. Multivariable regression models assessed factors associated with durability in whole participants and two distinct subgroups: patients with baseline HbA1c > 7.0% or ≤7.0%. Results: 1048 eligible participants were recruited and analyzed: 291 patients with treatment failure (durability 26.8 ± 21.1 months); 757 patients without treatment failure (durability 45.1 ± 31.8 months). Besides age, glycemic burden was the only constant determinant in the two subgroups. AUC’ or AUC” increased treatment failure, respectively, in baseline HbA1c > 7.0% or ≤7.0% subgroup [per 1%/90 days hazard ratio (95% confidence interval): 1.026 (1.018–1.034) and 1.128 (1.016–1.253)]. Other determinants include baseline HbA1c, initial OAD, and education level. Conclusions: in patients with newly-diagnosed T2DM, glycemic durability was negatively associated with greater glycemic burden.

Abstract Montane birds are vulnerable to climate change. However, the mechanisms by which weather drives demographic processes in montane birds have seldom been investigated. We conducted a long-term study (2009–2019) on the Green-backed Tit (Parus monticolus), an insectivorous passerine, in the montane cloud forest of subtropical Taiwan. We explored the effects of weather variability on the productivity and survival of adult Green-backed Tits. Nest survival was negatively associated with seasonal rainfall during the breeding season (April–July) and was lower in early clutches than in late clutches. Higher typhoon-induced precipitation during the postbreeding period (July–September) was related to reduced adult survival, but neither summer temperature nor winter weather conditions were found to be related to adult bird survival. We developed a stochastic simulation model for Green-backed Tit population dynamics based on empirical data. We compared the simulated time-series and observed population growth rates (λ) and found that 80% (8/10 yr) of the observed λ fell within the 5th and 95th percentiles of the simulated data over the 10-yr period. Moreover, the simulated average (± standard deviation) of the geometric mean of λ over 10 yr (1.05 ± 0.07) was close to that observed from 2009 to 2019 (0.99), which provided confidence that the model effectively simulated the population growth rate of the Green-backed Tit. We conducted a sensitivity analysis for λ and found that juvenile and adult survival influenced by typhoon-induced rainfall were the greatest contributors to the variance in the growth rate of the Green-backed Tit population. With the onset of intensified seasonal precipitation associated with global warming, the population growth and density of Green-backed Tits will decline substantially. Our results suggest that under scenarios of high emissions of greenhouse gas, this local population of Green-backed Tits will not persist in the near future.

Accurate estimation of invertebrate biomass is essential for studies of ecosystem structure and function. To estimate seasonal changes in spider biomass on canopies of two coniferous and three broadleaf tree species in plantation and native forests of subtropical Taiwan, 6,554 spiders were collected from February to August 2015. A part of the collection (n = 887) was weighed and measured to develop appropriate body size-mass equations for subtropical montane forest systems. By comparing different equations, we demonstrate that use of shape-specific equations and incorporation of body width measurements provide the most accurate biomass estimates. Generalized whole-fauna equations produced accurate estimates for the entire pooled sample but caused relatively higher biases than shape-specific equations when applied to spider assemblage subgroups. Applying coefficients derived from the best equations, we describe the seasonal variation in spider biomass on five dominant tree species. Compared to broadleaf trees, Taiwan cedar and Japanese cedar supported higher spider biomass and abundance. Spider biomass on the two conifers declined in early spring, then increased over time, and reached its highest in August. In contrast, spider biomass on caudate-leaved chinkapin and Mori oak formed bell-shaped curves with a high peak in late spring. Spider biomass on deciduous Formosan alder remained at a low level from February to June and increased in August. Moreover, phenological patterns of spider biomass differed from those of abundance on some tree species. We expect that regression parameters from our study are appropriate for biomass estimation of spider assemblage in subtropical montane forest systems.

Trophic interactions between birds and their prey often vary among habitat types, but they are poorly studied in low-latitude regions. We assessed the seasonal effect of larval abundance on the breeding performance of the Green-backed Tit (Parus monticolus), a caterpillar specialist, in broadleaf (mixed-oak forest) and coniferous (conifer plantation) habitats in subtropical Taiwan. We measured the biomass of Lepidoptera and Hymenoptera larvae in five tree species: two evergreen oaks and one deciduous alder in broadleaf habitat and two conifers in coniferous habitat. Alder supported a high larval biomass peak in early spring, dominated by noctuid and sawfly larvae, while the two oaks had later, lower peaks. The diversity of trees in the broadleaf habitat supported a broad food peak, spiking in early spring and gradually declining. In contrast, the coniferous habitat had a comparatively lower larval biomass that increased slightly over the season and included a high percentage of hairy lithosiines. Habitat-specific seasonality in larval abundance affected nestling conditions. Early-brood nestlings in the broadleaf habitat were heavier than those in the coniferous habitat. However, the between-habitat difference disappeared in the late broods because the mass of nestlings in the coniferous habitat increased significantly. We found a linear relationship between nestling condition and the total larval biomass available at demand peaks, but there were no differences in annual breeding density, late-brood frequency, laying date, clutch size, or fledging success between the two habitats. Food availability constrained nestling growth but not survival. Habitat-related trophic interactions are present in these subtropical montane forests.

ABSTRACTObjective: This survey identifies the design factors needed to guide aircraft through continuous descent operation (CDO) procedures.Background: Three possible alternatives for CDO at Taoyuan International Airport (TPE) in Taiwan are presented: (a) open path-radar vectoring-based CDO, (b) open path-time control-based CDO, and (c) open path procedure permitting CDO to downwind.Method: One hundred and twenty surveys were distributed and 61 pilots and 49 controllers responded. Eight pilots and 25 controllers had experience implementing CDOs.Results: All respondents ranked altitude control as the most important design factor. Pilots with CDO experience preferred to reduce the frequency of communication in the procedure, whereas experienced controllers expected to know the approach path as early as possible.Conclusion: Altitude control is the highest priority design factor for improving the current CDO procedure at TPE.

In many passerines, reproductively active females must forage for calcium-rich materials on a daily basis to meet exact calcium demands during egg production. Calcium availability often constrains reproductive output in birds, but is dependent on species-specific foraging traits and local calcium availability, and, thus, land use. Here, we examined whether calcium availability limits the reproductive output of Green-backed Tits Parus monticolus over a four-year period in mid-altitude subtropical forest of Taiwan. We compared soil nutrients and the availability of calcium-rich snails between mixed-oak forest and Japanese cedar Cryptomeria japonica plantation. We also provided supplementary calcium (in the form of snail shells and chicken egg-shells) in the nest boxes of half of all pre-laying pairs breeding in both habitats. The reproductive output of birds across the two treatments and two habitats was recorded. Our results showed that the soil was very acidic in both habitats. Compared to the mixed-oak forest, the litter in the cedar plantation contained marginally significantly more calcium, while the soil had significantly higher pH and exchangeable Ca2 . The cedar plantation supported similar, or even higher, snail abundance than the mixed-oak forest. We found no abnormal eggs with defective shells in either habitat. We also found no significant difference in clutch size, egg mass, egg shape index, egg volume, clutch volume, or hatching success across the two calcium-treatment groups or the two habitats. Calcium availability had a weak effect on the reproductive output of birds in the two habitats, possibly because the study area supported a high abundance of snails. Our results, combined with our calculations of the calcium demand of birds, suggest that calcium is not a limiting micronutrient for egg production by Green-backed Tits in the montane forest of subtropical Taiwan at present.

ABSTRACT Biological processes at low latitudes are often associated with seasonal rainfall, while those at high altitudes are also influenced by low temperature and high humidity. Thus, the breeding phenology of montane species at low latitudes requires clarification. We monitored the timing of nesting for two species of secondary cavity-nesting passerine, the Green-backed Tit (Parus monticolus) and the Rufous-faced Warbler (Abroscopus albogularis), in a montane cloud forest in subtropical Taiwan between 2010 and 2014. To determine the effects of weather and extreme events on nesting success, we used program MARK to model daily nest survival rate as a function of weather variables. The results showed that March temperatures, but not spring (February–March) rainfall, affected the mean laying date of Green-backed Tits. Females shifted their laying dates to lay earlier in response to earlier warm spring weather. The Rufous-faced Warbler exhibited a similar but weaker relationship between March temperature an...