- Acid rain for many decades has led to severe acidification of waters in southern Norway. Acidic water can be fatal to gill-breathing vertebrates (i.e. fish and larval amphibians). Great crested newt Triturus cristatus (GCN) - seems to be less tolerant of acidic water than other Norwegian amphibians. Not until 2015 was GCN recorded in Agder, the southernmost county in Norway, when the larvae of this species were found in two ponds. The aim of our investigation, in late spring and summer 2021, was to find out whether GCN was still present in these two ponds and ten others in the same area, which are surrounded by peat bogs and forest. Since this is a marginal and acidic area with probably low numbers of individuals and low detectability, we used three survey methods in combination (funnel traps, nets, and eDNA) and also measured water conductivity and pH. At the same time, the occurrence of other amphibians in the area were investigated; the smooth newt Lissotriton vulgaris, the common toad Bufo bufo, the common frog Rana temporaria and the moor frog Rana arvalis. Using traps and nets, GCN was found in four ponds but in only two of these ponds by eDNA. However, GCN eDNA was detected in three other ponds, showing that a combination of methods gave the most complete result. eDNA of the common toad and the common frog were detected in (almost) all samples but there were few records from traps or nets. Smooth newts were detected in almost all ponds by traps, nets and eDNA, while none of the methods detected the moor frog. Especially when a species is rare at a location, eDNA analysis may be the most efficient method of detection. However, only trapping and netting can give information about breeding. Water pH in late spring and early summer varied from 4.7 to 5.6 (median pH 5.1), which makes this area marginal for amphibian reproduction.
The clouded monitor lizard (Varanus nebulosus), is a semi arboreal lizard widely distributed throughout much of South and Southeast Asia. Despite its wide distribution there is almost nothing known about the ecology of this species. During the course of an 11-month radio telemetry study, in a reserve with a tropical savannah climate (Köppen Aw), we made the first records of brumation in this monitor lizard. This contrasts with earlier reports of the same species in a tropical monsoon climate (Köppen Am) where no brumation was recorded. We successfully tracked 10 individuals throughout their inactive period and found that seven of the monitors selected tree hollows within the endangered Shorea henryana tree. All tree hollows selected faced between the east and south cardinal points (90 °-180 °). The average brumation period was 100 days (range 86-113 days, standard deviation - 10.7), beginning in November at a time of falling temperatures and humidities and ending in early March when these variables had been restored. Eight of the 10 monitors basked partially or completely out of their shelters on multiple occasions. Of those eight monitors, two individuals moved between shelters during brumation after an extended period in one location. Our observations provide insight into the relationship between V. nebulosus and the tree S.henryana, in the dry evergreen forests of north-eastern Thailand. Future research should investigate how this tree will be affected by climate change in the coming decades and what that could mean for the future persistence of the clouded monitors that appear to rely on it.
- Bothrops species are known to have a wide range of defensive behaviours against potential threats. Herein we show a frequently observed, but to date undocumented, behaviour in male and female Bothrops spp of varying sizes in newly arrived specimens from the wild, short-or long-term captives as well as in captive born individuals. The behaviour consists of irregular, synchronous or asynchronous muscular twitches in segments of the body flanks in otherwise motionless snakes. We named this ‘Segmental Muscle Twitching Behaviour’ (SMTB). We observed fifteen Bothrops spp from six species groups for incidence of this behaviour and made videos of snakes during the ‘alertness’ and ‘threatening’ phases of response to human approach. We found the behaviour in only five species, these belong to the monophyletic Bothrops jararacussu and Bothrops atrox species groups, suggesting a single evolutionary origin of this behaviour. Macroscopically, SMTB varied in the number of segments involved and the twitches had uneven intensities. Although recurrent and often replicable in similar situations during human approach, the behaviour was not displayed consistently. In addition, SMTB can be interrupted, stay inactive for quite some time and then restart. Hypotheses to explain this behaviour are suggested.
Vehicles running over vertebrates has been an increasing challenge to the local conservation of some herpetofauna. The Amphisbaenidae are fossorial reptiles which are poorly known ecologically. Biological and natural history data were obtained from three specimens of Amphisbaenia alba that were found dead along 8320 km survey of highways. The rarity of road kill and the importance of the species conservation are discussed.
This paper summarises observations carried out in nature on populations of Salamandrina terdigltata in Southern Latium, where the species is widely distributed, if localized, in the hilly and mountainous areas. The laying period studied was notably wide: laying females were observed in nature at the end of October and larvae at the first stage of growth in the first days of November. This species, in the Mediterranean habitat and in the locations where the danger of late spring-summer drought is greater, uses different reproductive strategies: it begins egg-laying early in the autumn (starting from the first days of October) and winter months, which is the time in the study area of maximum rainfall (generally highest in November). Furthermore, observations in nature and in the laboratory confirmed the relationship between water temperature and the duration of embryo growth.
The diet of Elachistocleis ovalis was studied based on material from the Serra Geral in the Brazilian state of Rio Grande do Sul. Stomachs of 16 frogs captured in their natural environment were flushed. Elachistocleis ovalis had an insectivorous diet composed exclusively of Hymenoptera and Isoptera. Ants of the subfamilies Myrmicinae, Dolichoderinae, Ponerinae and Ecitoninae were the most common prey items. Feeding experiments in the laboratory showed that E. ovalis has a defensive reaction which consists of crouching and attempting to burrow its head into the ground when offered ants of the subfamily Formicinae.
To describe the life history traits of the northern ring-necked snake (Diadophis punctatus edwardsii), we examined 187 museum specimens collected in West Virginia during 1926-2000. This facilitated geographical comparisons across the species range and will serve as a baseline to detect future changes in life history traits that could result from climate change. Our findings revealed a unimodal distribution of captures during January-October. Such a distribution could arise from unequal sampling effort, nevertheless such a distribution is typical of those species in the mid-Atlantic and north-eastern region of the United States. The male gonadal cycle conformed to the temperate pattern, whereas that of females tended towards a tropical pattern. Females oviposit during April-July, which began earlier than those of surrounding northern states; however, the June peak in captures of gravid females was similar to that found elsewhere in its geographic range. Mean clutch size (4.3 eggs) was similar to those reported from elsewhere in the eastern USA, and mean adult body size of males (26.4 cm SVL) and females (28.9 cm SVL) typified those of northern populations. Age at sexual maturity was similar to that of conspecifics from Pennsylvania. For many females, first clutches occurred at an older age than those in Florida. Our findings corroborated the relative stability of some life history traits as well as geographic variation in other traits. These may be subject to change in response to contemporary and future region-wide changes in climate.