Dietary preference of Assamese Macaque Macaca assamensis McClelland, 1840 (Mammalia: Primates: Cercopithecidae) in Dampa Tiger Reserve, India

: Dietary composition and selection of food items are important approaches for the flexibility and adaptability of macaques in different natural habitats. With a wide distribution range, Assamese Macaques feed on various food types. This study reports the consumption of 57 plant species from 30 families. A total of 2,233 scans resulted in 16,381 feeding behavioral records during the study period from 2018 to 2020. Macaques appear to be primarily folivorous in Dampa as leaves (young & mature) constitute 44.74% of their daily dietary intake while the fruit consumption was found to be 25.31% of the total dietary intake. Plant species like Artocarpus lakoocha (15.65%), Albizia procera (12.03%), Glochidion hyneanum (10.53%), Diospyros glandulosa (9.49%), and Albizia lebbeck (7.28%) contributed significantly to macaque’s diet compare to other plants. No significant variation was observed on time spent for feeding on leaves, fruits, flowers, and seeds in both different months and seasons of the year. The highest percentage of the diurnal time invested on feeding activity was (59.04%) in the month of January (winter season), which may be due to the cold climate and scarcity of proper feeding items and the least was (35.19%) in June where food resources are more readily available. The richness of fruiting plants in Dampa Tiger Reserve appears to fulfill the dietary requirement of Assamese Macaque and therefore intactness of forest resources is necessary for their development and conservation.

For Focus, Scope, Aims, and Policies, visit https://threatenedtaxa.org/index.php/JoTT/aims_scopeFor Article Submission Guidelines, visit https://threatenedtaxa.org/index.php/JoTT/about/submissionsFor Policies against Scientific Misconduct, visit https://threatenedtaxa.org/index.php/JoTT/policies_variousINTRODUCTION Diet or food selection is an important trade in an animal's life.Adaptation and alteration in dietary patterns account for the major ecological and behavioral differences among primate species especially in wild (Koirala et al. 2017;Ghimire et al. 2021).Dietary preference provides useful information on individual food species necessary for survival, insight into its level of dietary specialization, resource partitioning and also on monitoring strategies for threatened and elusive primates (Koirala & Chalise 2014;Koirala et al. 2017;Khatiwada et al. 2020).Assamese Macaque Macaca assamensis is one of the most widely distributed nonhuman primate species in southeastern Asia.They have a wide distribution range across the region inhabiting different forms of forest habitat such as evergreen broadleaf forests, deciduous broadleaf forests, mixed broadleaf, and conifer forests (Boonratana et al. 2008;Timmins & Duckworth 2013;Boonratana et al. 2020).It is categorized as a 'Near Threatened' species by the IUCN Red List of Threatened Species and listed as an Appendix II species of the Convention on International Trade in Endangered Species (CITES) (Boonratana et al. 2020;Ghimire et al. 2021) and also as Scheduled II species by the Indian Wildlife Protection Act, 1972.Assamese Macaques (AM) are known to invest more than two-fifths (>40%) of the diurnal time on feeding (Ghimire et al. 2021) and are adaptable foragers able to modify their diet seasonally, being more folivorous in the dry season and more frugivorous in the wet season.
Understanding the temporal availability of food to a particular species is crucial when examining the drivers of their feeding strategies (Bessa et al. 2015).Macaques in the tropics tend to consume more fruit and fewer leaves than temperate-living macaques (Hanya 2004;Tsuji et al. 2013;Hung et al. 2015;Li et al. 2019Li et al. , 2020)).
In recent years, the landscapes of northeastern India have witnessed swift alteration in the form of reduction of primary forest, shifting cultivation, mono-plantations, forests fire, habitat fragmentation due to constructions, threatening the primate diversity of the region (Choudhury 2001;Srivastava 2006;Choudhury 2011;Mazumder et al. 2014).Dampa Tiger Reserve (DTR), harbors several species of primates that inhabit the forest very close to the buffer areas and thereby have high chances of encroaching on the agricultural crop fields that are adjacent to the core.Such encroachment may lead to human-primate negative interactions due to crop loss suffered by local farmers.Hence understanding the feeding ecology of this species and developing suitable measures to mitigate them is necessary in the area.Till date, the macaque's response to such variations in the accessibility of food resources during seasonal changes is not yet reported in this region.As there is a scarcity of information on the feeding ecology and pattern of food selection, we intend to provide new insight to the food habits and dietary preferences of AM in the tropical forest of DTR in Mizoram, India, and possibly contribute for better management and conservation of the species and its habitat in the region.

Study area
The study was conducted from September 2018 to August 2020 at .43 E) located in the western part of Mizoram in Mamit district along the international border to Bangladesh.The reserve comprises a core area of 500 km 2 and a buffer 488 km 2 , covering mountainous terrains, and elevation ranging 250-1,100 (Figure 1) (Johnson et al. 2021).The natural vegetation is distinct by the tropical evergreen to semi-evergreen of undulating, rugged in nature consisting of alternating ridges, medium hills, and slopes of mostly bamboo forest classified under the Cachar tropical evergreen and semi-evergreen: 1B/C3 and 2B/C2 forest, tropical moist deciduous forests: 3C/ C3b and 3C2S1, sub-montane type: 2B1b (Champion & Seth 1968).The moist valley is lofty and evergreen, runs parallel along the rivers, steeper slopes have more deciduous elements, often with sympodial bamboos in the understory (Vanlalsiammawii et al. 2020).Weather pattern is characterized by a tropical humid climate with distinct cold (November-February), summer (March-June), and rainy (May-October) seasons.The temperature ranges from 4°C in winter (January) to 36°C in summer (May-June).The average annual rainfall is 2,200 mm.Forest canopy at lower elevation is 30-35 m, with evergreen and some deciduous trees

Study subjects
The feeding ecology and dietary pattern of AM in DTR was determined by marking and following a particular troop.We observed for their daily activities and feeding plants from September 2018 to August 2020.The observation of AM in the field was conducted continuously during the study period along the adjacent buffer fringe.The time spent for monitoring AM was maximum, i.e., 10-12 h during dry seasons (winter and spring) and Minimal in monsoon (i.e., 6-7 h).Constraints faced during the survey period include inaccessible terrains, leeches, and bad weather conditions.Days lost to bad weather condition was compensated by the addition of observation hours and days during the dry and spring season.The individuals of the focal troop were identified with the help of different external characters and appearances such as body structure, facial features, fur color, cut marks, skin colour, and tail carriage.The troop consisted of two adult males, three adult females, five sub-adult females, three sub-adult males, two juveniles, and four infants that were classified by sex and age based on coloration, body size, and development of sexual characteristics following earlier established physical descriptions (Ulibarri & Gartland 2021).

Habitat and Vegetation sampling
Habitat and vegetation types in the study sites were determined by a stratified sampling method.We employed nine plots randomly in square subplots measured (20 x 20) m 2 in the Teirei range (23.68° N, 92.4° E and 23.66 N, 92.41° E) within an elevation range of 687-836 m.All sampling was made on foot on a transect line that were previously marked.The observation was made using a binocular, GPS, and digital camera.All the trees within the quadrats were identified to the species level (Sawmliana 2013;Hegde & Manpoong 2017), counted and their diameter at breast height was measured at approximately 1.37 m above the ground.The dominance of each species within a plot was calculated as the relative density (RD) and relative frequency (RF), following Irmayanti et al. (2022) and ultimately determined the Important Value Index IVI value for each plant species in a plot by summing the relative density (RD), relative basal area (RBA), and relative frequency (RF) following Deori et al. (2016).

Dietary composition and feeding activity
Data on the dietary composition and feeding behavior of AM were collected by direct observations in the field following the methods of Chalise et al. (2013).The feeding data was collected for 24 months from September 2018 to August 2020.Observations were noted down every 10 minutes per hour using direct observation of both adult male and female individuals from the time they were encountered to until out of sight via focal individual sampling, starting from 0600 h to 1700 h.Sampling was carried out for 5-10 consecutive days of every month (Solanki et al. 2008) until the focal individual under observation disappeared from view sight or retired to sleeping site (Altmann 1974;Bartlett 1999).The focal individual was randomly determined among adults prior to the observation and we focused mainly on adult male and female individuals and made 6 to 12 entries per day on information such as consumed food plants, food items, and feeding time based on the season.The feeding items or plant parts consumed were categorized as leaves (both young and mature leaves), flowers, fruits, seeds, and shoots.The time spent feeding on different food items was calculated as per Gupta & Kumar (1994): where, T a = Percent time spent on feeding activity N a = Number of records with feeding activity, and N = Total number of records for the day

Data Analysis
Kruskal-Wallis test was performed to determine the monthly and seasonal variation in time devoted to each plant part and the number of plant species consumed.A 'P' Value of <0.05 was considered statistically significant.SPSS version 16.0 software (SPSS Inc Chicago, Illinois, USA) and GraphPad Prism ver.8.2 were used for statistical and graphical analysis.

Dietary composition and feeding activity
In the study, 203 days of the survey resulted in 2,233 scans and 16,381 behavioural records.AM was observed to forage on 57 plant species from 30 families (Table 1).The number of food plant species consumed in each observation month ranges from 20 to 43 (32.42 ± 6.56) (Table 3).While plant species namely A. lakoocha, C. graffithii and all species of Albizia were fed throughout the year; species like V. quinata, P. timoriana, and H. kurzii were consumed in the least number (Table 3).Members of the family Moraceae (9), Meliaceae (5), Mimosaceae (4), and Euphorbiaceae (4) contributed to the most number of feeding plants in AM's diet, while the other listed plant families represent two or one plant species at most (Figure 2).Among the feeding plant species, trees accounted for 91%, herbs for 7%, and climbers/ vines for 2%.AM was found to munch on different plant parts such as fruits, leaves (young & matured), flowers, shoots, and seeds.Leaves formed the highest proportion of AM diet with 44.74% followed by fruits (25.31%), flowers (15.66%) seeds (12.14%), and shoots (2.14%) (Figure 3).Among the feeding plant species 13 species contributed for >1% feeding times.The major feeding plants of AM were identified to be Artocarpus lakoocha (15.65%),Albizia procera (12.03%),G. hyneanum (10.53%),D. glandulosa (9.49%), Albizia lebbeck (7.28%), Cephalotaxus graffithii (4.53%), and F. auriculata (4.20%) as it was observed to spend more time on this plants species.While plants such as Walsura robusta (0.31%), Phyllanthus emblica (0.30%), Terminalia myriocarpa (0.21%), Vitex quinata (0.12%) were found to be consumed in the least quantity (Table 1).Plants such as A. lakoocha, Albizia procera, Diospyros glandulosa, P. serratum, Dendrocalamus longispathus, and Duabanga grandiflora were identified to contribute with most number of consumable parts.Soft or tender shoots of D. longispathus and M. baccifera were the plants whose shoots were fed by AM.Distribution of feeding plant species indicates that Melocana baccifera (20), Dendrocalamus longispathus (18), Caesalpinia cucullata (16), Musa ornata (14), and Walsura robusta (13) were present in the highest number in the sampled quadrats although it does not represent the feeding utility by AM in its diet.

Monthly and seasonal effect on feeding phenology
In the present observation, leaves (young and mature) and fruits constituted the major food items of AM and they invested more time for feeding on these food items.Leaves, both young and mature leaves formed the highest bulk of AM's diet, as they were available throughout the years and no significant variation was observed on time spent on feeding leaves in different months of the year (X 2 = 19.46,df =11, p >0.05) (Figure 4).Similarly, there was no significant variation in the time spent on feeding of leaves in different seasons (X 2 = 3.429, df = 2, p >0.05).Fruits were most abundant during monsoon/summer and constituted the major food item during the month of June to August.They were observed to feed maximum fruits in the month of August (44.62% of the total food items), and the least consumption of fruits was recorded in the month of February (3.48% of the total food items).Time spent on feeding of fruits did not show significant variation in different months (X 2 = 15.87,df = 11, p >0.05) and seasons (X 2 = 4.571, df = 2, p >0.05).The highest consumption of flowers was observed in the month of February (28.05%), however, no significant variation in the time spent on feeding of flowers was observed monthly and seasonally J TT

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(Table 4).Seeds were found to be consumed mainly in winters when there was a scarcity of fleshy fruits, and the highest seed consumption was recorded in January (12.4%).Shoots of bamboo sp. were fed only in monsoon (June-October) and the total time spent on feeding of shoots during the observation period was only 2.14%.
Plant species such as Cephalotaxus graffithii, Diospyros glandulosa, A. lakoocha, Albizia chinensis, and Bombax insigne were observed to be eaten throughout the year and thus represent the primary sources of nutrients for AM.The highest percentage (59.03%) of the diurnal time invested on feeding was in the month of January and the least (35.19%) was in the month of June (Table 4).

DISCUSSION
Primates have a diverse feeding ecology and are highly adaptable in their dietary requirement.Dietary flexibility has permitted primates to live in a variety of habitats including tropical forests, semi-evergreen forests, montane forests, limestone bamboo forests, and secondary degraded forests (Timmins & Duckworth 2013;Mazumder et al. 2014;Huang et al. 2015;Koirala et al. 2017;Boonaratana et al. 2020).Similar to other findings across southeastern Asia, AM in DTR are also primary folivorous as leaves (young & mature) constitute 44.74% of their daily dietary intake compared to 25.32% of fruit (Srivastava 1999;Chalise et al. 2013;Zhou et al. 2011;Huang et al. 2015;Ghimire et al. 2021).Young leaves, when available were the major food items (spring and pre-monsoon).Contrastingly, mature leaves were the preferred food items during winter.Although the availability of young leaves decreased markedly from November to February, a high level of leaves was maintained in the diet of AM almost year-round as reported by Srivastava (1999) and Zhou et al. (2011).The scarcity of most young leaves during the dry winter season was compensated by some of the major food plants that thrived throughout the dry season in the study sites like Albizia chinensis, A. lebbeck, A. procera, A. lakoocha, Bombax insigne, and Protium serratum (Table 3).Apart from leaves, the amount of time invested among other food items such as, fruits, flowers, and seeds were high.We suggest that they like to avoid leaves (especially mature) and try to intake other more nutritive food whenever possible.Similar to this observation, AM in central Nepal switched between the young and mature leaves according to their availability, but the higher preference been the young leaves (Ghimire et al.J TT 2021).In the study, it was observed that the abundance of plant species has no correlation with the selection of feeding items.Plant species like Ficus auriculata, Bombax ceiba, and Melocana baccifera although were dominant and widely distributed, more preference was given to species like Albizia sp., Ficus sp., and Artocarpus lakoocha, which are in accordance with reports of Zhou et al. (2011) and Ghimire et al. (2021).AM are adaptable foragers able to modify their diet seasonally, being more folivorous in the dry season and more frugivorous in the wet season or post-monsoon (Li et al. 2019;Ghimire et al. 2021).Many studies have shown a strong correlation between rainfall and fruit availability in the dry season from November to March (Zhou et al. 2006(Zhou et al. , 2011)).AM in DTR spent majority (>44 % on average) of their diurnal time on feeding.They devoted more time in search of food items during the winter months (November-February) when resources were limited in cold and dry periods.Seasonal variation in the diet of AM was clearly linked to seasonal fluctuation in food availability which is a common observation across their home ranges.AM greatly altered their diet with a mixture of plant items including fruits, flowers, leaves, shoots and even seeds.While primate species such as Hoolock Gibbon Hoolock hoolock, Stump-tailed Macaque Macaca arctoides, and Rhesus Macaque Macaca mulatta are frequently encountered in crop fields (Mazumder et al. 2014), no such observation was made in DTR region, although they are reports available of crop raiding by AM in their home ranges (Regmi et al. 2013;Adhikari et al. 2018).The richness of fruiting plants in DTR appears to fulfill the dietary requirement of AM as no incidences of human-primate negative interactions are reported from the region and co-habitation was also observed between AM and other primate species.However, with the increase in settlement areas along the periphery of DTR, more dependency on forest resources, construction of road networks, and clearing of forests for cultivation, such conflict are inevitable in near future.Although in some cases, AM was found to survive in disturbed habitats, but the long-term consequences on reproduction and survival are unknown (Srivastava 2006).Hence understanding the feeding ecology of AM and adapting timely measures will be important for preventing human-AM negative interactions as well as conservation of primates in the region.

CONCLUSION
The macaques, changed their diets in accordance with the season and availability of food items as they appear to be folivorous in the dry and pre-monsoon season and more frugivorous in the monsoon and postmonsoon seasons.They consumed a wide range of trees, herbs, shrubs, and climbers.It is happening that the primates in northeastern India have been forced into crop raiding because of the loss of their natural habitat from various anthropogenic activities.However, it is evident that some species have clearly learned to co-exist with humans by raiding crops.Conflicts of this kind are likely to increase in the future as the human Threatened Taxa | www.threatenedtaxa.org| 26 August 2022 | 14(8): 21487-21500 21489 J TT

Figure 2 .
Figure 2. Diversity of feeding plant species.

Figure 4 .
Figure 4. Monthly variation in feeding budget of Assamese Macaque Macaca assamensis.