Pei-Fen Lee

Uniform genetic diversity, low differentiation, and neutral evolution characterize contemporary refuge populations of Taiwan fir (Abies kawakamii, Pinaceae)

Based on fossil pollen, the distribution range of Taiwan fir [Abies kawakamii (Hay.) Ito] (Pinaceae) is smaller than it was 50 000 years ago. To characterize the present refuge populations of A. kawakamii, which survive only in subalpine forests in Taiwan, we surveyed nuclear genes and chloroplast intergenic spacers to assess the genetic diversity of Taiwan fir. Populations maintain high genetic diversity and contain similar numbers of haplotypes for the GapC (cytosolic glyceraldehyde 3-phosphate dehydrogenase) fragment. Haplotypes for GapC are generally widespread, and population-specific haplotypes accounted for 2.5% of the total. Differentiation among populations is very low (G(ST) = 0.01). Only three haplotypes were detected for the cpDNA marker, and every population had one or two haplotypes. In a neutrality test, the variation in nucleotides did not deviate from that expected with neutral evolution for either marker. A retreat route to higher elevations was not evident from either the GapC or cpDNA markers. Hsuehshan was the site of the most divergent population in Taiwan. We concluded that uniform genetic diversity, low differentiation, low numbers of population-specific haplotypes, and neutral evolution characterize contemporary refuge populations of Taiwan fir.

GROUP-SIZE EFFECTS AND PARENTAL INVESTMENT STRATEGIES DURING INCUBATION IN JOINT-NESTING TAIWAN YUHINAS (YUHINA BRUNNEICEPS)

Abstract We investigated the effect of group size on incubation effort in Taiwan Yuhinas (Yuhina brunneiceps) at the Highlands Experimental Farm of National Taiwan University at Meifeng, Nantou County, central Taiwan, during 2000 and 2001. The Taiwan Yuhina is a joint-nesting, cooperatively breeding species endemic to Taiwan. We compared differences in parental investment among individuals of different sexes and status, explored the effect of group size on group incubation effort, and investigated whether individuals show compensatory reductions in care with respect to the number of females laying. Constancy of incubation increased as group size increased. Alpha females exhibited a significantly greater incubation effort than other individuals, but effort was similar among other group members. Both alpha males and females decreased their relative and absolute incubation effort as group size increased (i.e., there was a compensatory reduction in parental effort). However, beta pairs maintained a consistent but low incubation effort when either gamma pairs or an extra individual joined the group. Our study also demonstrated a new potential group-size benefit for cooperatively breeding birds—an increase in the constancy of incubation.

Reassessment of the conservation status and protected area coverage of Taiwanese birds: How distribution modelling can help species conservation

Summary Taiwan has 145 breeding bird species, but so far no comprehensive attempt has been made to model their distributions. For the first time, we bring together various datasets to model the distributions of the 116 bird species with sufficient sampling coverage. We improved on previous limited modelling efforts by using ensemble modelling, based on five well-performing modelling approaches: multiple discriminant analysis, logistic regression, genetic algorithm for rule-set production, ecological niche factor analysis and maximum-entropy. We then used these ensemble models to improve our knowledge of the status of each bird species by (1) calculating each species’s coverage of Taiwan, (2) calculating each species’s coverage by Taiwan’s protected area network, and (3) comparing these two conservation-relevant measures with already established measures to highlight those species whose status may need to be reassessed. We categorised each species’s coverage of the entire study area as measured by their modelled distributions into four quartiles, thus establishing a new measure of rarity called ‘range quartile’ which we used to highlight the 22 species with a limited distribution on mainland Taiwan. We also calculated that overall, 29.8% of the distribution ranges of the 116 modelled species are covered by Taiwanese protected areas. We then identified those species whose status may need to be reassessed because of possible conflicts between the respective conservation-relevant measures. Thus we identified 10 species which are first-quartile species < 5% of whose distributions are protected, of which only five are considered threatened. We also identified another 12 species with limited distributions, 30 species with limited protection and 19 species whose status may need to be reassessed for various reasons. We recommend that range quartile and protected area coverage be incorporated into future assessments of the conservation status and protected area coverage of Taiwanese birds.

Hotspot analysis of Taiwanese breeding birds to determine gaps in the protected area network

BackgroundAlthough Taiwan is an important hotspot of avian endemism, efforts to use available distributional information for conservation analyses are so far incomplete. For the first time, we present a hotspot analysis of Taiwanese breeding birds with sufficient sampling coverage for distribution modeling. Furthermore, we improved previous modeling efforts by combining several of the most reliable modeling techniques to build an ensemble model for each species. These species maps were added together to generate hotspot maps using the following criteria: total species richness, endemic species richness, threatened species richness, and rare species richness. We then proceeded to use these hotspot maps to determine the 5% most species-rich grid cells (1) within the entire island of Taiwan and (2) within the entire island of Taiwan but outside of protected areas.ResultsAlmost all of the species richness and hotspot analyses revealed that mountainous regions of Taiwan hold most of Taiwans avian biodiversity. The only substantial unprotected region which was consistently highlighted as an important avian hotspot is a large area of unprotected mountains in Taiwans northeast (mountain regions around Nan-ao) which should become a high priority for future fieldwork and conservation efforts. In contrast, other unprotected areas of high conservation value were just spatial extensions of areas already protected in the central and southern mountains. To combine the results of our four hotspot criteria, we assessed which grid cells were the most valuable according to all four criteria. Again, we found the Nan-ao mountain regions to be important. We also showed that different hotspot criteria only partially overlapped and sometimes barely at all.ConclusionsTherefore, to protect areas based on only one hotspot criterion (total species richness) would not protect areas based on other hotspot criteria (endemic species richness, threatened species richness, or rare species richness) in Taiwan.

A sequential collective action game and its applications to cooperative parental care in a songbird

Collective action problems arise when two or more individuals can free ride on one anothers efforts when investing jointly in a common good. Many collective action tasks in nature, such as parental care, require multiple stages of investments to complete a task, but how the costs of consecutive periods of investment and the excludability and diminishability of a collective good influence investment strategy remains poorly understood. Here, we first developed an evolutionary game-theoretical model to explore the theoretical consequences of sequential investment strategies in collective good problems. We then investigated cooperative parental care during both incubation and provisioning stages in the joint-nesting Taiwan yuhina, Yuhina brunneiceps, to test the key theoretical predictions of the model. We found that yuhina females that laid eggs earlier than other females invested more than they did in incubation (the first stage in the collective action problem). Intriguingly, but as predicted by our model, females that laid eggs earlier brought less food to nestlings in the joint brood during the nestling provisioning stage (the second stage in the collective action problem). This seemingly puzzling pattern can be explained by the fact that females that laid eggs earlier started incubation earlier and continued incubating eggs, which led to their offspring hatching earlier and being competitively superior (obtaining more food) at the nestling provisioning stage. Our study highlights the importance of understanding the complex nature of investment strategies parsed over different development stages in collective action problems.

Population Density, Home Range, and Habitat Use of Crested Serpent-Eagles (Spilornis cheela hoya) in Southern Taiwan: Using Distance-Based Analysis and Compositional Analysis at Different Spatial Scales

Abstract For many tropical raptors, studies of population density and habitat use are still lacking. We used radio-tracking to study population density, home-range size, and habitat use of the Formosan Crested Serpent-Eagle (Spilornis cheela hoya) in Kenting National Park, southern Taiwan, during 1995–1997 and 1998–2007. Over two years, we documented a minimum population density of 2.69 individuals/km2, which is one of the highest ever reported. Home ranges calculated using minimum convex polygons and 95% fixed kernel areas averaged 12.34 km2 and 2.86 km2 (n  =  18), respectively. Core areas represented by the 50% fixed kernel areas averaged 0.41 km2. We used distance-based analysis and compositional analysis to compare habitat use within the entire study area and the home ranges. Both methods indicated the overwhelming use (>90%) of somewhat degraded and semi-open mixed forests, followed by the use of Acacia confusa forests and grasslands to a much lesser degree. Habitat use was nonrandom both within the study area and the home range, as mixed forests covered only 24.4% of the study area. Many perch sites were near the primary monsoon forest, which was, however, almost never used for hunting. As many other species of serpent-eagles are threatened by habitat loss and human persecution, our study provides valuable information for their future monitoring and management. DENSIDAD POBLACIONAL, ÁMBITO DE HOGAR Y USO DE HÁBITAT DE SPILORNIS CHEELA HOYA EN EL SUR DE TAIWÁN: UTILIZANDO ANÁLISIS BASADOS EN DISTANCIAS Y ANÁLISIS DE COMPOSICIÓN A DIFERENTES ESCALAS ESPACIALES Todavía faltan estudios de densidad poblacional y uso de hábitat para muchas rapaces tropicales. Utilizamos radio transmisores para estudiar la densidad poblacional, el tamaño del ámbito de hogar y el uso de hábitat de Spilornis cheela hoya en el Parque Nacional Kenting, sur de Taiwán, durante 1995–1997 y 1998–2007. A lo largo de dos años documentamos una densidad poblacional mínima de 2.69 individuos/km2, la cual es una de las más altas jamás reportadas. Los ámbitos de hogar calculados utilizando polígonos convexos mínimos y las áreas de kernel fijo de 95% promediaron 12.34 km2 y 2.86 km2 (n  =  18), respectivamente. Las áreas núcleo representadas por el 50% de las áreas de kernel fijo promediaron 0.41 km2. Utilizamos análisis basados en las distancias y análisis composicionales para comparar el uso del hábitat dentro de toda el área de estudio y de los ámbitos de hogar. Ambos métodos indicaron el abrumador uso (>90%) de los bosques mixtos algo degradados y semi-abiertos, seguidos en un grado mucho menor por el uso de bosques de Acacia confusa y pastizales. El uso del hábitat no fue al azar tanto dentro del área de estudio como en el ámbito de hogar, a la vez que los bosques mixtos cubrieron sólo el 24.4% del área de estudio. Muchos sitios de percha se ubicaron cerca del bosque monzónico primario, el cual sin embargo, nunca fue utilizado para cazar. Debido a que muchas especies de Spilornis están amenazadas por pérdida de hábitat y persecución humana, nuestro estudio provee información valiosa para su futuro manejo y monitoreo.