The species distribution analysis is a prerequisite for identifying and predicting geographic areas where targeted species may be present or conservation strategies may be initiated further if conditions and resources are preferable for them (Rawat et al. 2022). Environmental conditions are pivotal for any living organism's survival in a new condition. The main idea behind species distribution using MaxEnt is to detect probability distribution that has been explained during model analysis. Environmental characteristics and species occurrence data are must for such types of distribution analysis. Previous studies demonstrate that climatic factors play a major role in lepidopteran abundance (Hernandez-Baz et al. 2022). As with other species deserving conservation management, information obtained on the distribution pattern of C. bernardus hierax will be useful in promoting the conditions that sustain the population. Of particular relevance will be the environmental and the climatic factors that favours the distribution and thus the population abundance of C. bernardus hierax. As discussed for the distribution modeling of the Smith’s Blue butterfly, Euphilotes enoptes smithi, the correspondence of the vegetation, edaphic factors and the environmental variables was useful in understanding and predicting the distribution pattern in the Santa Lucia Mountains along the Big Sur coast in Monterey County, California, USA (Arnold & Jensen 2022). A more elaborative approach for linking conservation management of butterflies and SDM is observed through the studies on the Ithomiini across the Neotropics (Doré et al. 2021). Apart from the vegetation and the climatic pattern predicting the distribution pattern of the entire Ithomiini tribe, the effects of the anthropogenic activities could be deduced from the studies. As a consequence, specific steps could be taken for conservation and sustenance of the taxonomic diversity of the Ithomiini tribe of butterflies (Doré et al. 2021). Similar approach of linking vegetation and climatic factors with the species occurrence was adopted for predicting the distribution pattern for Alpine endemic species Erebia calcaria in Slovenia and Austria (DeGroot et al. 2009). Since, the climatic, topographic and edaphic factors influence the availability of the host plant, so will the dependent taxa like the butterfly vary accordingly. For instance, the prediction of the current distributions for showy milkweed (A. speciosa), swamp milkweed (A. incarnata), and monarch (Danaus plexippus) butterflies corresponded with the distribution of the milkweed Asclepias spp., in Idaho, USA (Svancara et al. 2019). In Mexico, the SDM was applied to decipher the distribution pattern of several butterfly species like Pyrisitia proterpia, Danaus gilippus, Zerene cesonia, Archaeoprepona demophon, and Anteos maerula, where vegetation pattern and the climatic factors were the reasonable predictors for the observed pattern of the distribution of the species (Jacinto-Padilla et al. 2017). In China, the distribution and the habitat utilization pattern of the Gainville fritillary butterfly Melitaea cinxia was deduced through SDM (Zhou et al. 2012). The butterfly M. cinxia exhibited strong dependence on the distribution pattern fo the host plant Veronica spicata, justifying that plants, edaphic factors, tophography and the climatic conditions portrays the distribution pattern for the species with high specificity. Apparently, the distribution of the butterflies, like other dependent taxa, will vary with the availability of the host plants which on the other hand will depend on the climatic and edaphic factors. This applies for several other invertebrate species, which are linked with the abundance of the resources at the spatio-temporal scales for a concerned geographical region.
Consideration of bioclimatic variables for species distribution modeling has become more familiar (Franklin 2009). Predictions derived from species distribution modeling can be linked with other ecological parameters like productivity and species abundance (Pearce & Ferrier, 2001; Brambilla & Ficetola 2012; Huntley et al. 2012). The results of our study demonstrated that the regions where average precipitation in the warmest quarter (bio 13) and precipitation seasonality (bio 15) are > 304 mm and > 105 mm are suitable for sustaining this species. Empirical study demonstrates the increase in precipitation positively associated with butterfly diversity (Kehimkar 2008). The results also suggest that increase in mixed/ other trees (con 4) also associated with increase in probability of the occurrence of the species. The results also associated with increase in probability of occurrence with decrease in open water (con 12) and urban / built up (con 9). Empirical studies also showed that butterfly diversity decreases with increase in urban characteristics (Ruszczyk & De Araujo 1992; Blair & Launer 1997; Stefanescu et al. 2004; Dover & Settele 2009).The present study demonstrated that in West Bengal Darjeeling, Kalimpong, Jalpaiguri, Alipurduar, Cooch Behar, North Dinajpur, Purulia, Birbhum and Murshidabad has the suitable condition (maximum and moderate) to sustain this species. The study also indicate that our study area also contain suitable environmental conditions to sustain this species. This report for distribution of Charaxes bernardus hierax may be useful in selecting conservation strategies for the butterfly species in a particular area.