Habitat selection by Asiatic black bear (Ursus thibetanus) in Siran and Kaghan Valleys, Pakistan

Asiatic black bear is present in variety of habitats like broad-leaves and coniferous forests, extending form sea level to 4300m elevation and change their habitat for food purpose seasonally. The present study was conducted at Kaghan and Siran Valleys, District Mansehra, Khyber Pakhtunkhwa, Pakistan to assess habitat of black bear. Line transect method was used for observation of bear signs. Twelve meter circular radius plots were selected for the concern vegetation’s i.e. (trees, shrubs and herbs) and three to six plots were placed in each transect. At the result of sign survey, thirteen different categories of bear signs were recorded and encounter rate was calculated for each sign. A total of 1858 signs were observed during field surveys. Total (81%) coniferous species were recoded among trees, with the highest appearance of Pinus wallichiana (34.22%) and Spruce spp (27.76%), similarly broad leaves trees (18.56%) were also recoded from habitat plots. Most of the signs were encountered in bushy areas, whereas high number of Viburnum Spp (60.29%) was present. It is indicated that black bear prefers blend of Coniferous Trees, Viburnum and Ferns Species; probably because these plants provide enough food, protection, and meticulous shelter because more than 80% of habitat composed of these three species. Currently habitat destruction and increase in human population are the up-growing issues for wild animals (especially Asiatic black bear), which is highly sensitive to such problems. High levels of conservation efforts are recommended for the protection of black bear habitat and to avoid human interference in their territory.

Role of vegetation characteristics on the distribution of three hornbill species in and around Pakke Tiger Reserve, Arunachal Pradesh, India

The relationship between various vegetation characteristics and the relative abundance of three hornbill species [Great Pied Hornbill (Buceros bicornis), Wreathed Hornbill (Rhyticeros undulatus) and Oriental Pied Hornbill (Anthracoceros albirostris)] was studied in and around Pakke Tiger Reserve, Arunachal Pradesh. We walked transects (n=11; 22 walks) in three study sites to detect hornbills. Vegetation sampling was done using circular plots (n=33; 10 m radius) at every 400m interval along each transect. Encounter rate (1.5/km) of Great Pied Hornbill (Buceros bicornis) was highest in the protected and undisturbed forest area where food and roosting tree density were also high (114/ha). Oriental Pied Hornbill was common in both the sites within Pakke Tiger reserve near riverine forests (0.75/km) and also in the dense undisturbed forest (0.875/km). Multivariate analysis revealed that tree density, presence of fruiting trees (utilized by hornbills), canopy cover, and tree diversity in a particular area are the major factors responsible for the assemblage of more than one species of hornbills. The study shows that protection of the forest patches to keep the diversity and density of the tree species intact is crucial for the survival and distribution of the hornbills in the landscape.

Winter Tick Burdens for Moose Are Positively Associated With Warmer Summers and Higher Predation Rates

Climate change is expected to modify host-parasite interactions which is concerning because parasites are involved in most food-web links, and parasites have important influences on the structure, productivity and stability of communities and ecosystems. However, the impact of climate change on host–parasite interactions and any cascading effects on other ecosystem processes has received relatively little empirical attention. We assessed host-parasite dynamics for moose (Alces alces) and winter ticks (Dermacentor albipictus) in Isle Royale National Park over a 19-year period. Specifically, we monitored annual tick burdens for moose (estimated from hair loss) and assessed how it covaried with several aspects of seasonal climate, and non-climatic factors, such as moose density, predation on hosts by wolves (Canis lupus) and wolf abundance. Summer temperatures explained half the interannual variance in tick burden with tick burden being greater following hotter summers, presumably because warmer temperatures accelerate the development of tick eggs and increase egg survival. That finding is consistent with the general expectation that warmer temperatures may promote higher parasite burdens. However, summer temperatures are warming less rapidly than other seasons across most regions of North America. Therefore, tick burdens seem to be primarily associated with an aspect of climate that is currently exhibiting a lower rate of change. Tick burdens were also positively correlated with predation rate, which could be due to moose exhibiting risk-sensitive habitat selection (in years when predation risk is high) in such a manner as to increases the encounter rate with questing tick larvae in autumn. However, that positive correlation could also arise if high parasite burdens make moose more vulnerable to predators or because of some other density-dependent process (given that predation rate and moose density are highly correlated). Overall, these results provide valuable insights about interrelationships among climate, parasites, host/prey, and predators.

Prevalence of viral frequency-dependent infection in coastal marine prokaryotes revealed using monthly time series virome analysis

Viruses infecting marine prokaryotes have large impacts on the diversity and dynamics of their hosts. Model systems suggest viral infection is frequency-dependent and constrained by the virus-host encounter rate. However, it is unclear whether the frequency-dependent infection is pervasive among the abundant prokaryotic populations with different growth strategies (i.e. r-strategy and K-strategy). To address this question, we performed a comparison of prokaryotic and viral communities using 16S rRNA amplicon and virome sequencing based on samples collected monthly for two years at a Japanese coastal site, Osaka Bay. Concurrent seasonal shifts observed in prokaryotic and viral community dynamics indicated that abundances of viruses correlated with that of their predicted host phyla (or classes). Co-occurrence network analysis between abundant prokaryotes and viruses revealed 6 423 co-occurring pairs, suggesting a tight coupling of host and viral abundances and their 'one to many' correspondence. Although dominant K-strategist like species, such as SAR11, showed few co-occurring viruses, a fast succession of their viruses suggests viruses infecting these populations changed continuously. Our results suggest the frequency-dependent viral infection prevailed in coastal marine prokaryotes regardless of host taxa and growth strategy.

Impact of Fear and Habitat Complexity in a Predator-Prey System with Two Different Shaped Functional Responses: A Comparative Study

Habitat complexity or the structural complexity of habitat reduces the available space for interacting species, and subsequently, the encounter rate between the prey and predator is decreased significantly. Different experimental shreds of evidence validate that the presence of the predator strongly affects the physiological behaviour of prey individuals and dramatically reduces their reproduction rate. In this study, we investigate the interplay between the level of fear and the degree of habitat complexity in a predator-prey model with two different shaped functional responses. We, therefore, develop the functional response using the timescale separation method, and the shape of the resulting functional response depends upon the monotonous property of catch rate, g N where N is the prey biomass. Whenever g N increases strictly, a saturating functional response occurs, but for nonmonotonic g N , a dome-shaped functional response arises. For saturating case, it has been revealed that both prey and predator biomass may oscillate for lower levels of fear and a lower degree of habitat complexity. To stabilize this oscillatory behaviour to a coexistence state, we have to adequately increase the level of fear or degree of habitat complexity. However, for dome-shaped case, more complicated dynamics are observed. In this case, coexistence steady state, if exists, may be locally asymptotically stable for a lower degree of habitat complexity, but for intermediate values, the system is capable of producing multiple coexistence steady states with a bistable phenomenon between predator-free steady state and a coexistence steady state. Moreover, if the level of fear is sufficiently low, the system may experience a supercritical or/and subcritical Hopf bifurcation. In the dynamics of parametric disturbance for the degree of habitat complexity parameter, dome-shaped functional response predicts that disturbance may trap the system into a nearest attractor (either a large amplitude stable limit cycle or predator-free steady state); this can be overcome only by a larger alteration, or sometimes it is impossible to overcome (hysteresis phenomena), whereas the saturating-shaped functional response predicts a system resilience. For both the functional responses, a higher degree of habitat complexity always increases the extinction possibility of the predator, and no level of fear can compensate this biodiversity loss.

Damages to Himalayan White Pine (Pinus wallichiana) by Asiatic Black Bear (Ursus thibetanus) in Kaghan Valley, Pakistan

Tree damage is one of the destructive behaviors of the Asiatic black bear (Ursus thibetanus G. (Baron) Cuvier, 1823), and this type of damage causes great economic loss to the forest. A survey about Himalayan white pine (Pinus wallichiana (A. B) Jacks, 1836) damages was conducted at Kaghan Valley, District Mansehra, Khyber Pakhtunkhwa, Pakistan. Field surveys were carried out within five major sites of Kaghan Valley, including Manshi reserve forest, Kamal Bann reserve forest, Malkandi reserve forest, Noori Bichla reserve forest, and some Guzara forests. Line transects and diameter at breast height (DBH) methods were selected for data collection. Eighteen transects were placed in different sites of the valley. A total of (n = 201) affected trees were observed from eighteen transects, along with a total population of 1081 trees with the encounter rate (ER: 0.657) and the mean DBH is x¯ = 71.97 cm. Among total damages, the most severe (n = 39: 19.4%) were fully damaged with a greater encounter rate. Bark stripping was made during the late winter season and used as foodstuff when natural food is limited in the area. In severe cases, the bear-stripped bark encircles from the entire tree trunk, which results in the drying of trees and, finally, falls. Among all five sites, Manshi reserve forest was greatly affected, where the highest number (n = 76) of tree damage, and (n = 21) the entire diameter of trunks were damaged. People of the study area claimed that the black bear causes great forest damage, as well as crop destruction that leads to high economic loss.

Marine predators algorithm for solving single-objective optimal power flow

This study presents a nature-inspired, and metaheuristic-based Marine predator algorithm (MPA) for solving the optimal power flow (OPF) problem. The significant insight of MPA is the widespread foraging strategy called the Levy walk and Brownian movements in ocean predators, including the optimal encounter rate policy in biological interaction among predators and prey which make the method to solve the real-world engineering problems of OPF. The OPF problem has been extensively used in power system operation, planning, and management over a long time. In this work, the MPA is analyzed to solve the single-objective OPF problem considering the fuel cost, real and reactive power loss, voltage deviation, and voltage stability enhancement index as objective functions. The proposed method is tested on IEEE 30-bus test system and the obtained results by the proposed method are compared with recent literature studies. The acquired results demonstrate that the proposed method is quite competitive among the nature-inspired optimization techniques reported in the literature.

Monitoring Macan Tutul Jawa (Panthera pardus melas Cuvier, 1809) dengan Kamera Trap di Cagar Alam Nusakambangan Timur Kabupaten Cilacap, Provinsi Jawa Tengah

Monitoring of the existence of the Javan Leopard (Panthera pardus melas) in the Nusakambangan Timur Nature Reserve, Cilacap Regency, has been carried out in July-November 2020. Monitoring is carried out using the method of collecting signs of animal presence and installing camera traps. Photos / videos caught on camera traps are counted on the encounter rate. The monitoring results obtained 97 videos which were divided into 6 videos of P.p. melas, 15 videos of wild boar (Sus scrofa), 1 video of mouse deer (Tragulus javanicus), 2 videos of mountain squirrels (Tupaia montana), 1 video of mice (Apodemus sp.) 20 videos of human activities, and 47 videos of non detection. The result of the Encounter Rate calculation shows the result of P.p. melas 4.44 / 100 days; wild boar 11.85 / 100 days; Squirrels 1.48 / 100 days; rats and mouse deer 0.74 / 100 days, respectively. Meanwhile, for the trail of P.p. melas found 2 impurities.

The consequences of chaos: Foraging activity of a marine predator remains impacted several days after the end of a storm

As extreme weather is expected to become more frequent with global climate change, it is crucial to evaluate the capacity of species to respond to short-term and unpredictable events. Here, we examined the effect of a strong storm event during the chick-rearing stage of little penguins (Eudyptula minor) from a mega colony in southern Australia. We investigated how a 3-day storm affected the foraging behaviour of little penguins by comparing their foraging activities and body mass change before, during and after the storm event. As strong winds deepened the mixed layer in the birds’ foraging zone during the storm, penguins increased their foraging trip duration, had a lower prey encounter rate and a lower body mass gain. The adverse effects on the foraging efficiency of little penguins continued several days after the storm ceased; even though the water column stratification had returned as before the storm, suggesting a prolonged effect of the storm event on the prey availability. Thus, short-term stochastic events can have an extended impact on the foraging efficiency of penguins. When occurring at a crucial stage of breeding, this may affect breeding success.

Find me if you can: Pre- and Post-hurricane Densities of the Red-bellied Racer (Alsophis rufiventris) on St. Eustatius, and a review of the genus in the Caribbean

We estimated population densities of the red-bellied racer (Alsophis rufiventris) on the Caribbean island of St. Eustatius in 2011, 2018 and 2019 to determine the likely influence of hurricanes Irma and Maria (September 2017), in addition to evaluating abiotic parameters which may be correlated with its presence. Surveys were conducted at seven sites in 2011 prior to the hurricanes, and at 81 and 108 sites in 2018 and 2019 respectively posterior to the hurricanes. A total of 8.2 ha was surveyed in 2011, and 11.42 ha in 2018/2019. The pre-hurricane (2011) racer density estimate was 9.2/ha (min 7.3 - max 11.6); post-hurricane estimates were 4.6/ha (min 3.4 - max 6.0) in 2018 and 5.0/ha (min 3.8 - max 6.5) in 2019. The pre-hurricane encounter rate of individual racers was 16.0 snakes/hour compared to 0.34 snakes/hour in 2018 and 0.41 snakes/hour in 2019 (post-hurricane). The decrease in encounter rates between 2011 and 2019 implies a negative impact of the hurricanes on racer abundance. Based on calculations of detection probability (0.02 in 2018 and 0.03 in 2019), post-hurricane lambda estimates were 1.82 (95% CI 0.66 - 5.01) in 2018 and 1.60 (95% CI 0.39 - 6.65) snakes/ha in 2019. Given the current small size of the remaining population and the presence of invasive species across the snake's range, this species could be at risk of local extirpation. We suggest conservation actions such as invasive species management and habitat restoration to enable further recovery.