Spatial Biodiversity Patterns of Madagascar's Amphibians and Reptiles

Madagascar has become a model region for testing hypotheses of species diversification and biogeography, and many studies have focused on its diverse and highly endemic herpetofauna. Here we combine species distribution models of a near-complete set of species of reptiles and amphibians known from the island with body size data and a tabulation of herpetofaunal communities from field surveys, compiled up to 2008. Though taxonomic revisions and novel distributional records arose since compilation, we are confident that the data are appropriate for inferring and comparing biogeographic patterns among these groups of organisms. We observed species richness of both amphibians and reptiles was highest in the humid rainforest biome of eastern Madagascar, but reptiles also show areas of high richness in the dry and subarid western biomes. In several amphibian subclades, especially within the Mantellidae, species richness peaks in the central eastern geographic regions while in reptiles different subclades differ distinctly in their richness centers. A high proportion of clades and subclades of both amphibians and reptiles have a peak of local endemism in the topographically and bioclimatically diverse northern geographic regions. This northern area is roughly delimited by a diagonal spanning from 15.5°S on the east coast to ca. 15.0°S on the west coast. Amphibian diversity is highest at altitudes between 800–1200 m above sea-level whereas reptiles have their highest richness at low elevations, probably reflecting the comparatively large number of species specialized to the extended low-elevation areas in the dry and subarid biomes. We found that the range sizes of both amphibians and reptiles strongly correlated with body size, and differences between the two groups are explained by the larger body sizes of reptiles. However, snakes have larger range sizes than lizards which cannot be readily explained by their larger body sizes alone. Range filling, i.e., the amount of suitable habitat occupied by a species, is less expressed in amphibians than in reptiles, possibly reflecting their lower dispersal capacity. Taxonomic composition of communities assessed by field surveys is largely explained by bioclimatic regions, with communities from the dry and especially subarid biomes distinctly differing from humid and subhumid biomes.     

Species turnover of amphibians and reptiles in eastern China: disentangling the relative effects of geographic distance and environmental difference

Spatial turnover of species lies at the heart of macroecology and conservation biogeography. However, our knowledge of the causes of species turnover remains poor, particularly for herpetofaunas including amphibians and reptiles. Here, using regression, variance partitioning, and hierarchical partitioning analyses, we examine the relationships of species turnover in herpetofaunas among provinces in eastern China with respect to geographic distance and environmental difference. We found that species turnover in herpetofaunas is moderately to strongly correlated with geographic distance and difference in most environmental variables examined between provinces. Geographic distance and environmental difference together explain 87.1 and 89.9% of the variance of species turnover for amphibians and reptiles, respectively. Variance partitioning analysis indicated that most variance in species turnover is explained by the joint effect of geographic distance and environmental difference. Beyond this shared variance, environmental difference is a stronger predictor of species turnover than geographic distance, particularly for reptiles. Hierarchical partitioning analysis showed that energy-related variables explained more variance in species turnover for both amphibians and reptiles, compared with water-related variables. The independent effects of water-related variables are slightly higher for amphibians than for reptiles whereas the independent effects of energy-related variables are slightly higher for reptiles than amphibians. These patterns are consistent with different ecophysiological requirements of the two taxa. Our results have important implications for predicting changes in biodiversity of herpetofaunas under climate change scenarios. Global warming will affect the immigration and local extinction of both amphibians and reptiles, and precipitation change may affect amphibians more strongly, compared with its effect on reptiles.     

甘肃白水江国家级自然保护区两栖爬行动物资源调查及保护对策

2006年7～8月对甘肃白水江两栖爬行动物资源进行了野外调查。本次调查共采得两栖爬行动物标本49种,隶属于13科4目。结合文献资料,该保护区现已知有两栖爬行动物65种,其中两栖动物28种,隶属于8科2目;爬行动物37种,隶属于11科3目。其区系组成东洋界种类明显占优势,占总物种数的79．63％,古北界成分占14．28％。特有种所占比例较高。根据资源特点,提出了保护区两栖爬行动物可持续保护的对策。     

湖北星斗山国家级自然保护区两栖爬行动物资源调查

2002年6～9月对湖北星斗山国家级自然保护区的两栖、爬行动物资源进行了调查,结合文献资料,该保护区现已知有两栖、爬行动物80种,其中两栖动物38种,隶属2目9科22属;爬行动物42种,隶属2目11科31属.国家Ⅱ级重点保护野生动物大鲵Andrias davidianus、虎纹蛙Hoplobatrachus rugulosus 2种;湖北省重点保护动物35种,占湖北省重点保护两栖爬行动物的75%.被列入<中国濒危动物红皮书>的两栖、爬行动物有21种(极危物种1种,濒危物种6种,易危物种11种,依赖保护物种1种,需予关注物种2种).对两栖爬行动物的种类组成和区系进行了分析,并提出了保护措施.     

南宁吴圩国际机场两栖爬行动物初步调查

通过南宁吴圩国际机场对机场飞行区4类生境中两栖爬行类的调杏,记录到3目11科22种.较为丰富的两栖爬行动物种类和数量成为机场鸟类重要的食物源之一,吸引了捕食性鸟类前来栖息和觅食.分析了解两栖爬行动物情况,对于全面了解亚热带和北热带地区的机场鸟类的食物源和活动规律具有十分重要的意义.并提出建议在今后对于鸟撞防治研究应当开展对两栖爬行类作为鸟类食物源这方面的调查研究工作.     

Interseasonal variation in the circadian rhythms of locomotor activity and temperature selection in sleepy lizards, <Emphasis Type="Italic">Tiliqua rugosa</Emphasis>

Few studies in non-mammalian vertebrates have examined how various effectors of the circadian system interact. To determine if the daily locomotor and behavioural thermoregulatory rhythms of Tiliqua rugosa are both controlled by the circadian system in different seasons, lizards were tested in laboratory thermal gradients in four seasons and in constant darkness. Circadian rhythmicity for both rhythms was present in each season, being most pronounced in spring and summer and least evident in autumn. Most lizards displayed a unimodal locomotor activity pattern across all seasons. However, some individuals presented a bimodal locomotor activity pattern in spring and summer. Seasonal variations in the phase relationships of both rhythms to the light:dark (LD) cycle were demonstrated. No seasonal differences in the free-running period lengths of either rhythm were detected, raising the possibility that a single circadian pacemaker drives both rhythms in this species. Our present results demonstrate that both rhythms are similarly controlled by the circadian system in each season. Although seasonal variations in the thermal preferences of reptiles both in the field and laboratory have previously been well documented, this study is the first to demonstrate circadian rhythms of temperature selection in a reptile species in each season.     

Development and relationships of locomotor, feeding, and oxygen consumption rhythms in house crickets

ABSTRACT. Locomotor, feeding, drinking, and oxygen consumption rhythms in adult virgin Acheta domesticus L. all appear to peak in the first half of the scotophase, be entrained cophasically by a LD 14:10 h cycle, have a lights-off Zeitgeber and persist in LL with a π c. 25 h for the locomotor rhythm and c. 23 h for the oxygen consumption rhythm. There is no evidence of these rhythms in last instar larvae. The onset of the locomotor rhythm requires 3 days at 30°C but 5–7 days at 25–28°C after the final ecdysis in virgins, indicating a temperature related development of the locomotor rhythm. Oxygen consumption rhythms are lacking in 2-day-old virgins but present in 8-day-old virgins. Feeding rhythms can be recorded in virgins as young as 2 days (before locomotor rhythm developed). Both oxygen consumption and locomotor rhythms persist during starvation. The results suggest that a central brain oscillator drives both feeding and locomotor rhythms independently, but that the oxygen consumption rhythm is derived from the metabolic demands associated with the other rhythms.     

神农架大九湖湿地公园及周边区域两栖动物和爬行动物概况

神农架大九湖湿地公园独具特色的高山湿地生态系统孕育了独具特色的动植物资源,但其两栖动物和爬行动物物种多样性尚未报道.为此,2016至2018年对该区域的两栖动物和爬行动物进行了调查.共记录两栖动物21种,隶属于2目8科.其中,东洋种17种,古北种1种,广布种3种;湖北省级保护动物12种;IUCN收录21种,其中棘腹蛙(...     

Environmental determinants of amphibian and reptile species richness in China

Understanding the factors that regulate geographical variation in species richness has been one of the fundamental questions in ecology for decades, but our knowledge of the cause of geographical variation in species richness remains poor. This is particularly true for herpetofaunas (including amphibians and reptiles). Here, using correlation and regression analyses, we examine the relationship of herpetofaunal species richness in 245 localities across China with 30 environmental factors, which include nearly all major environmental factors that are considered to explain broad-scale species richness gradients in such theories as ambient energy, water–energy dynamics, productivity, habitat heterogeneity, and climatic stability. We found that the species richness of amphibians and reptiles is moderately to strongly correlated with most of the environmental variables examined, and that the best fit models, which include explanatory variables of temperature, precipitation, net primary productivity, minimum elevation, and range in elevation, explain ca 70% the variance in species richness for both amphibians and reptiles after accounting for sample area. Although water and temperature are important explanatory variables to both amphibians and reptiles, water variables explain more variance in amphibian species richness than in reptile species richness whereas temperature variables explain more variance in reptile species richness than in amphibian species richness, which is consistent with different physiological requirements of the two groups of organisms.     

内蒙古赛罕乌拉国家级自然保护区两栖爬行动物调查

2007年8月～2008年6月,对内蒙古赛罕乌拉国家级自然保护区内两栖爬行动物多样性进行调查,结合以往采集标本,保护区内共有两栖爬行动物11种,其中,两栖类1目2科3种,爬行类1目3科8种.中国林蛙和中介蝮分别为两栖类和爬行类的优势种,但分布较集中.中介蝮常见于村落溪流附近,可能成为局部有害动物,建议保护区采取一定措施防止其对生态旅游产生负面影响.     

An identification of invariants in life history traits of amphibians and reptiles

While many morphological, physiological, and ecological characteristics of organisms scale with body size, some do not change under size transformation. They are called invariant. A recent study recommended five criteria for identifying invariant traits. These are based on that a trait exhibits a unimodal central tendency and varies over a limited range with body mass (type I), or that it does not vary systematically with body mass (type II). We methodologically improved these criteria and then applied them to life history traits of amphibians, Anura, Caudata (eleven traits), and reptiles (eight traits). The numbers of invariant traits identified by criteria differed across amphibian orders and between amphibians and reptiles. Reproductive output (maximum number of reproductive events per year), incubation time, length of larval period, and metamorphosis size were type I and II invariant across amphibians. In both amphibian orders, reproductive output and metamorphosis size were type I and II invariant. In Anura, incubation time and length of larval period and in Caudata, incubation time were further type II invariant. In reptiles, however, only number of clutches per year was invariant (type II). All these differences could reflect that in reptiles body size and in amphibians, Anura, and Caudata metamorphosis (neotenic species go not through it) and the trend toward independence of egg and larval development from water additionally constrained life history evolution. We further demonstrate that all invariance criteria worked for amphibian and reptilian life history traits, although we corroborated some known and identified new limitations to their application.     

Aging-related changes on social synchronization of circadian activity rhythm in a diurnal primate (Callithrix jacchus)

ABSTRACT

The input of environmental time cues and expression of circadian activity rhythms may change with aging. Among nonphotic zeitgebers, social cues from conspecific vocalizations may contribute to the stability and survival of individuals of social species, such as nonhuman primates. We evaluated aging-related changes on social synchronization of the circadian activity rhythm (CAR) in a social diurnal primate, the common marmoset. The activity of 18 male marmosets was recorded by actiwatches in two conditions. (1) Experimental – 4 young adult (5 ± 2 yrs of age) and 4 older (10 ± 2 yrs of age) animals maintained under LD 12/12 h and LL in a room with full insulation for light but only partial insulation for sound from vocalizations of conspecifics maintained outdoors in the colony; and (2) Control – 10 young adult animals maintained outdoors in the colony (5 animals as a control per age group). In LL, the CAR of young adults showed more stable synchronization with controls. Among the aged marmosets, two free-ran with τ > 24 h, whereas the other two showed relative coordination during the first 30 days in LL, but free-ran thereafter. These differences were reflected in the “social” phase angles (ψ_on and ψ_off ) between rhythms of experimental and control animal groups. Moreover, the activity patterns of aged animals showed lower social synchrony with controls compared to young adults, with the time lags of the time series between each experimental group and control group being negative in aged and positive in young adult animals (t-test, p < 0.05). The index of stability of the CAR showed no differences according to age, while the intradaily variability of the CAR was higher in the aged animals during LD-resynchronization, who took additional days to resynchronize. Thus, the social modulation on CAR may vary with age in marmosets. In the aged group, there was a lower effect of social synchronization, which may be associated with aging-related changes in the synchronization and generation of the CAR as well as in system outputs.     

四川美姑大风顶自然保护区两栖爬行动物资源调查

20 0 2年 8月 1日～ 17日对四川美姑大风顶自然保护区的两栖爬行动物进行了调查。结合前人的工作 ,该保护区共有两栖爬行动物 2 2种 ,其中两栖动物 11种 ,隶属于 9属 7科 2目 ,爬行动物 11种 ,隶属于 9属 4科 2亚目 1目。区系特点为 :(1)物种组成较丰富 ;(2 )都属于东洋界物种 ,没有古北界的成分 ;(3)区系组成较简单 ,以喜马控雅 -横断山区型和南中国型为主 ;(4 )特有种所占比例高。 (5 )既古老又具年轻的特点。美姑县新纪录 6种 ,大凉疣螈为国家Ⅱ级重点保护野生动物 ,横斑锦蛇为四川省重点保护野生动物。美姑大风顶自然保护区两栖爬行动物物种多样性和生境多样性较高 ,对于生物多样性保护和研究横断山脉两栖爬行动物物种组成及区系特征具有一定意义。     

Recovery of Amphibian and Reptile Assemblages During Old‐Field Succession of Tropical Rain Forests

Conversion of tropical forests to agriculture affects vertebrate assemblages, but we do not know how fast or to what extent these assemblages recover after field abandonment. We addressed this question by examining amphibians and reptiles in secondary forests in southeastern Mexico. We used chronosequence data (12 secondary forests fallow for 1–23 yr and 3 old‐growth forest sites) to analyze successional trajectories and estimate recovery times of assemblage attributes for amphibians and reptiles. We conducted 6 surveys at each site over 14 mo (1200 person‐hours) and recorded 1552 individuals, including 25 species of amphibians and 36 of reptiles, representing 96 and 74 percent of the expected regional number of species, respectively. Abundance, species richness, and species diversity of amphibians increased rapidly with successional age, approaching old‐growth forest values in < 30 yr. Species richness and species diversity of reptiles reached old‐growth forest values in < 20 yr. By contrast, the abundance of reptiles and the assemblage composition of amphibians and reptiles recovered more slowly. Along the chronosequence, we observed more species replacement in reptile assemblages than in amphibian assemblages. Several species in the old‐growth forest were absent from secondary forests. Dispersal limitation and harsh conditions prevailing in open sites and early successional environments appear to preclude colonization by old‐growth forest species. Furthermore, short fallow periods and isolation of forest remnants lead to the formation of new assemblages dominated by species favored by human disturbances.     

Effects of Geomorphology and Primary Productivity on Amazonian Leaf Litter Herpetofauna

The Amazon Basin, representing the largest expanse of intact tropical rain forest on the planet, harbors the largest diversity of amphibians and reptiles in the world. Limited elevation and climate differences across the Basin belie one major division of upland forests – geomorphological soil age and induced nutrient levels. We hypothesized that secondary consumers in the leaf litter herpetofauna community on ancient soils of Central Amazonia would exhibit reduced biomass compared with those found on younger soils of Western Amazonia, and that population densities on ancient soils could be driven below viable thresholds, reducing species richness. We found overall herpetofauna abundance, biomass and richness on young soils in Ecuador were significantly greater than those on ancient soils in the Brazilian Amazon. Separately, amphibians were only slightly more abundant, but their biomass on younger soils was twice that on ancient soils. Even more impressive was the variation exhibited by lizards: abundance was not significantly different, but biomass was five times greater on younger soils. Diversity of both taxa was greater on young soils. The most important driver of differences in herpetofauna biomass, abundance and possibly diversity across Amazonia may be the underlying geomorphologic differences. Reduced primary productivity on ancient soils appears to reverberate up the food chain, leaving fewer resources for higher trophic levels. We suggest that conservation initiatives must compensate for reduced biomass on ancient soils through increased reserve size, especially as forest fragmentation escalates. This study highlights the importance of including biomass as a standard measure in herpetofauna sampling.     

基于贝叶斯权重估计方法估计浙江省古田山国家级自然保护区两栖爬行动物多样性

传统的两栖爬行动物多样性调查方法在进行野外实验时,常遇到抽样限制的问题,一些稀有物种可能无法在个体样本中被发现,由于存在相对较大的物种缺失,导致不同的研究结果差距较大,较难反映真实的物种多样性.因此,基于有限的调查和监测数据尽可能准确地估计生物多样性极其重要.本文于2017—2020年的每年秋季,采用视觉遇见法调查了4...     

河北衡水湖两栖爬行动物的多样性及保护

衡水湖保护区有两栖爬行动物22种,其中,两栖动物2目4科4属7种,爬行动物2目5科10属15种。对两栖爬行动物资源的保护进行了探讨。     

Field observation of predation on a horsehair worm (Gordioida: Chordodidae) by a diving beetle larva Cybister brevis Aubé (Coleoptera: Dytiscidae)

Diving beetles (Coleoptera: Dytiscidae) are carnivorous in both the larval and adult stages; larvae are exclusively predatory, whereas adults also scavenge for food. They are known to prey on zooplankton, insects, gastropods, fish, amphibians and reptiles. However, there have been no previous reports detailing direct predation on adult Gordioida by Dytiscidae in the field. This study represents the first observation of a diving beetle larva, Cybister brevis Aubé (Coleoptera: Dytiscidae), predating on an adult horsehair worm (Gordioida: Chordodidae). This might be the first report of predation on horsehair worms by insects.     

Red List of amphibians and reptiles of the Wadden Sea area

In the Wadden Sea, in total, 8 species of amphibians and 4 species of reptiles are threatened in at least one subregion. Of these, 7 species of amphibians and all 4 species of reptiles are threatened in the entire area and are therefore placed on the trilateral Red List. 1 species of the listed reptiles is (probably) extinct in the entire Wadden Sea area. The status of 1 species of amphibians is endangered, the status of (probably) 4 species of amphibians and 3 species of reptiles are vulnerable and of 2 species of amphibians susceptible. This list forms part of the Report on the RED LISTS OF BIOTOPES, FLORA AND FAUNA OF THE TRILATERAL WADDEN SEA AREA. For basic information concerning, for example, function of these lists, species taken into account, structure of the lists and abbreviations used, see also the general introduction to the Red Lists.     

Circadian phase-shifting effects of nocturnal exercise in older compared with young adults

Exercise can phase shift the circadian rhythms of young adults if performed at the right time of day. Similar research has not been done in older adults. This study examined the circadian phase-delaying effects of a single 3-h bout of low-intensity nocturnal exercise in older (n = 8; 55-73 yr old) vs. young (n = 8; 20-32 yr old) adults. The exercise occurred at the beginning of each subject's habitual sleep time, and subjects sat in a chair in dim light during the corresponding time in the control condition. The dim-light melatonin onset (DLMO) was used as the circadian phase marker. The DLMO phase delayed more after the exercise than after the control condition. On average, the difference in phase shift between the exercise and control conditions was similar for older and young subjects, demonstrating that the phase-shifting effects of exercise on the circadian system are preserved in older adults. Therefore, exercise may potentially be a useful treatment to help adjust circadian rhythms in older and young adults.