Space Use by Woolly Wolf Canis lupus chanco in Gangotri National Park, Western Himalaya, India

The woolly wolf Canis lupus chanco is increasingly being accepted as a unique taxon that needs immediate protection and management; however, information on its ecology remains limited across its range. We used camera trapping data set of 4 years (2015–2019) to investigate seasonal activity patterns and space use and assessed woolly wolf food habits in the Gangotri National Park, western Himalaya, India. We used generalized linear mixed models to assess the distribution of the wolf about prey, seasonal livestock grazing, human presence, habitat, and seasons. We observed a positive association with elevation and a negative response to an increase in ruggedness. The capture of wolves increased in winters, indicating a possible effect of snow on the ranging pattern. Spatial avoidance to anthropogenic pressure was not evident in our study; however, temporal avoidance was observed. The activity pattern of the wolf varied among seasons. Wolves were mostly active in the morning and late evening hours in summer and showed a diurnal activity pattern in winter. A less diverse diet was observed where the mean percentage frequency of occurrence and relative biomass was highest for bharal, followed by livestock. Himalayan marmot Marmota himalayana, birds, and rodents also form minor constituents to the diet. Synthesizing all three factors (space, diet, and activity), it may be stated that the wolf presence in the region is influenced by both wild prey availability and seasonality. Therefore, conservation of woolly wolves would require securing a vast landscape with optimal wild prey.

Activity pattern of Asiatic black bear (Ursus thibetanus) in Machiara National Park, Azad Jammu and Kashmir, Pakistan

The Asiatic black bear is considered an indicator species of the environment, hence, any change in the environment may alter its activity pattern. We monitored the monthly activity pattern of black bears in the moist temperate forests of Machiara National Park, AJ&K, Pakistan. We used infrared camera traps and indigenous knowledge for data collection from April 2019 to April 2021. Camera traps recorded 109 (inside the forest = 107, outside the forest = 2) independent registrations (IR) within 5541 (692.63 ± 36.72, mean ± SD) camera days. We found that (i) spring and autumn were the lowest activity seasons of black bears inside the forest. (ii) Whereas, the highest activities were recorded in summer with peak activities in August followed by July (χ2 = 203.5, df= 7, P< 0.05). (iii) The activity level sharply declined after August and halted from late November to late April which was clear indication of bears’ hibernation period. We collected indigenous knowledge from 70 selected persons, including hunters, herders, temporary residents and crop raiding victims. We used the data of human observation of latest three years and found that (i) bears remained active from May to November and hibernated rest of the period. (ii) The activities were at their peak inside the forest in summer (May – August) and out of the forest in autumn (September – November) when it preferred to raid the widely cultivated maize crop (Zea mays) in the area. The capturing of black bears by camera traps outside the forest further supported the data provided by local people. Such switching over might have occurred due to the food preferences for Zea mays or easy access to abundant food availability out of the forest area. The current data can help mitigate human black bears conflict and consequently future conservation of black bears in the area.

The hippocampus as a sorter and reverberatory integrator of sensory inputs

In entorhinal-hippocampal networks, the trisynaptic pathway, including the CA3 recurrent circuit, processes episodes of context and space. Recurrent connectivity can generate reverberatory activity, an intrinsic activity pattern of neurons that occurs after sensory inputs have ceased. However, the role of reverberatory activity in memory encoding remains incompletely understood. Here we demonstrate that in mice, synchrony between conditioned stimulus (CS) and unconditioned stimulus (US)-responsible cells occurs during the reverberatory phase, lasting for approximately 15 s, but not during CS and US inputs, in the CA1 and the reverberation is crucial for the linking of CS and US in the encoding of delay-type cued-fear memory. Retrieval-responsive cells developed primarily during the reverberatory phase. Mutant mice lacking N-methyl-D-aspartate receptors (NRs) in CA3 showed a cued-fear memory impairment and a decrease in synchronized reverberatory activities between CS- and US-responsive CA1 cells. Optogenetic CA3 silencing at the reverberatory phase during learning impaired cued-fear memory. Our findings suggest that reverberation recruits future retrieval-responsive cells via synchrony between CS- and US-responsive cells. The hippocampus uses reverberatory activity to link CS and US inputs, and avoid crosstalk during sensory inputs.

Rest-Activity Pattern and Circadian Phase Alterations Across the Alzheimer’s Disease Clinical Spectrum

Actigraphy-derived locomotor activity recordings are novel and critical tools for evaluating rest-activity pattern and circadian phase in humans. We conducted a narrative review assessing rest-activity pattern and circadian phase alterations within various stages of Alzheimer’s disease, in consideration of the reciprocal associations between neurodegeneration and circadian rhythm disruption in patients with Alzheimer’s disease. The goal of this review was to characterize possible associations between circadian rhythm disruption and neurodegeneration in Alzheimer’s disease. To the best of our knowledge, only two studies have assessed rest-activity pattern and circadian phase alterations in the preclinical Alzheimer’s disease stage and the results of the studies were inconsistent. Several studies have evaluated rest-activity pattern and circadian phase alterations in patients with Alzheimer’s dementia. The most replicated findings were delayed phase and increased activity fragmentation, represented as increased intra-daily variability. Unfortunately, many studies performed in dementia patients have not examined neuroimaging biomarkers or structured neuropsychological tests, thus limiting the specification of dementia clinical diagnoses. Future studies should consider a more comprehensive evaluation of various clinical and biomarker characteristics in patients with dementia or Alzheimer’s disease.

WILDLIFE ROADKILL IN THE SURROUNDINGS OF EMAS NATIONAL PARK, CERRADO BIOME, BRAZIL

Roadkill is a serious threat to biodiversity conservation especially when roads are near natural habitats of wildlife, such as the Emas National Park (ENP), a Protected Area in Mid-west Brazil in the Cerrado Biome. We aimed to identify the species killed on a stretch of the GO-341 highway that is tangent to the ENP. We investigated if roadkills were influenced by seasonality, sugar cane harvest and by the activity pattern of the animals (diurnal/nocturnal). We also analyzed if roadkills were aggregated in space, where the roadkill hotspots were located, if they were influenced by seasonality, and if they were different for the most abundant species. The highway was monitored with a vehicle, in the morning, at a speed of 40 to 60 km/hour, daily, with two observers. We covered a total of 4,230 km during the 90-day monitoring period, which included dry and rainy seasons. We recorded 132 wild animals’ roadkills: 67 birds (51 %), 60 mammals (45 %) and 5 reptiles (4 %). We identified 22 vertebrate species, including 13 birds, six mammals and three reptiles. The roadkill rate was 0.03 animals/km/day. During the dry season, the blue-and-yellow macaw (Ara ararauna) had higher roadkill rates. The crab-eating fox (Cerdocyon thous) was the only species with higher roadkill rates during the sugarcane harvest. Most birds killed had diurnal habits, for mammals, no difference was observed concerning the activity pattern. Bird roadkills were aggregated considering the entire data set, as well as for the dry and rainy seasons separately. Mammal roadkills were aggregated only when considering the entire data set. The location of bird roadkill hotspots differed between seasons. The roadkill hotspot location of birds and mammals highly overlapped those observed for the two most abundant species of these taxa, respectively, Ara ararauna and Euphractus sexcinctus.

Entorhinal cortex directs learning-related changes in CA1 representations

Learning-related changes in brain activity are thought to underlie adaptive behaviors. For instance, the learning of a reward site by rodents requires the development of an over-representation of that location in the hippocampus. However, how this learning-related change occurs remains unknown. Here we recorded hippocampal CA1 population activity as mice learned a reward location on a linear treadmill. Physiological and pharmacological evidence suggests that the adaptive over-representation required behavioral timescale synaptic plasticity (BTSP). BTSP is known to be driven by dendritic voltage signals that we hypothesized were initiated by input from entorhinal cortex layer 3 (EC3). Accordingly, the CA1 over-representation was largely removed by optogenetic inhibition of EC3 activity. Recordings from EC3 neurons revealed an activity pattern that could provide an instructive signal directing BTSP to generate the over-representation. Consistent with this function, exposure to a second environment possessing a prominent reward-predictive cue resulted in both EC3 activity and CA1 place field density that were more elevated at the cue than the reward. These data indicate that learning-related changes in the hippocampus are produced by synaptic plasticity directed by an instructive signal from the EC3 that appears to be specifically adapted to the behaviorally relevant features of the environment.

A Behavioural Study of Free Ranging Ceylon Spotted Deer (Axis axis ceylonensis) in Trincomalee, Sri Lanka

Axis axis ceylonensis (Ceylon spotted deer) is a sub species endemic to Sri Lanka. Ecological observations in wild populations of this subspecies have been reported but there is no published research on its behaviour. We report here a behavioural study on a free ranging population of A. a. ceylonensis inhabiting a temple surroundings in Trincomalee, Sri Lanka. Behaviour was quantified by focal sampling on sex age groups in three time zones: 6:30 to 7:30, 12:30-13:30, and 17:00 to 18:00 hours. The deer were more active in the hour after dawn and an hour before dusk. The main activities were feeding and play, the latter common in juveniles. There was a preference to graze on grasses and browse on Ficus sp. leaves. Resting was highest in the afternoon across all groups. This bimodal activity pattern is similar to that of both wild Ceylon and Indian A. axis subspecies despite the absence of predators in the study area. The bimodal activity may be related to thermoregulatory functions while grazing in open grass areas.