Demilitarized zones may aid in the protection of endangered wildlife. We compared relative abunda... more Demilitarized zones may aid in the protection of endangered wildlife. We compared relative abundance of the endangered Chinese Pond Turtle (Mauremys reevesii) among water bodies on the Kinmen Islands, a recently demilitarized zone between Taiwan and China. Vegetation and wildlife on the two islands, located 2 km from the Chinese coastline, were degraded by bombardment and military occupation between 1958 and early 2000s. However, natural habitats gradually recovered after military forces withdrew. More than 100 ponds, mostly produced during the occupation to provide freshwater for the soldiers, are now abandoned and provide habitat for aquatic turtles. We sampled 41 ponds and found that presence of M. reevesii was tightly associated with vegetation coverage around the pond, whereas its relative abundance was associated with aquatic vegetation and distance from roads. Comprehensive protection and management of this species should consider both vegetation coverage and road effects in certain vulnerable areas where establishment of a natural reserve might be considered.
Capsule A Crested Goshawk population recently colonizing an urban area of Taiwan is characterized... more Capsule A Crested Goshawk population recently colonizing an urban area of Taiwan is characterized by earlier egg-laying dates, a higher ratio of mixed-age pairs and higher nesting success. Aims To compare breeding time, productivity and pairing pattern of Crested Goshawk populations between urban and rural areas. Methods A total of 117 nests, comprising 49 rural and 68 urban ones, were monitored in Taichung, central Taiwan over six years. Age of parents, egg-laying date, clutch size and number of fledglings were recorded from each nest. Results The urban Crested Goshawk bred 34 days earlier on average than the rural population with a significantly higher nesting success. Mixed-age pairs occurred in a higher frequency in urban (30.9%) than in rural (14.3%) areas. Predation (55.6%) and inclement weather (27.8%) were the two main factors causing nesting failures in rural areas, whereas neither occurred in the urban area. Conclusion We conclude that the urban Crested Goshawk population benefits from high food supply and low predation risk. The year-round abundance of prey might increase the breeding success of young adults and advance their breeding schedule, which coincidently shifts the brooding period away from the heavy rainy season.
Heterozygosity-fitness correlations (HFCs) provide insights into the genetic bases of individual ... more Heterozygosity-fitness correlations (HFCs) provide insights into the genetic bases of individual fitness variation in natural populations. However, despite decades of study, the biological significance of HFCs is still under debate. In this study, we investigated HFCs in a large population of the sexually dimorphic lizard Takydromus viridipunctatus (Lacertidae). Because of the high prevalence of parasitism from trombiculid mites in this lizard, we expect individual fitness (i.e., survival) to decrease with increasing parasite load. Furthermore, because morphological asymmetry is likely to influence individuals' mobility (i.e., limb asymmetry) and male biting ability during copulation (i.e., head asymmetry) in this species, we also hypothesize that individual fitness should decrease with increasing morphological asymmetry. Although we did not formally test the relationship between morphological asymmetry and fitness in this lizard, we demonstrated that survival decreased with increasing parasite load using a capture-mark-recapture data set. We used a separate sample of 140 lizards to test the correlations between individual heterozygosity (i.e., standardized mean d 2 and HL based on 10 microsatellite loci) and the two fitness traits (i.e., parasite load and morphological asymmetry). We also evaluated and excluded the possibility that single-locus effects produced spurious HFCs. Our results suggest male-only, negative correlations between individual heterozygosity and parasite load and between individual heterozygosity and asymmetry, suggesting sex-specific, positive HFCs. Male T. viridipunctatus with higher heterozygosity tend to have lower parasite loads (i.e., higher survival) and lower asymmetry, providing a rare example of HFC in reptiles.
Background: The effects of parasitism on host survival and reproduction can be highly complex dep... more Background: The effects of parasitism on host survival and reproduction can be highly complex depending on the type of parasites, host sex and life-history characteristics, and ecological conditions. In this study, we tested sex-biased parasitism from Trombiculid mites (Acarina: Trombiculidae) and their sex-specific effects on host reproduction and survival, in a natural population of the Taiwan field mouse (Apodemus semotus). We performed surveys of A. semotus and their Trombiculid mites between April 2010 and August 2011 and again between June and September 2012 in a subtropical evergreen forest in Taiwan. Results: Contrary to the commonly reported male-biased parasitism in mammals, we did not find sex-biased parasitism in A. semotus. We found that mite abundance was negatively associated with A. semotus reproduction and survival in both males and females. The mite abundance and rodent reproduction fluctuated seasonally, and the peak reproductive season coincided with the time period of relatively low mite abundance.
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Papers by Jhan-Wei Lin