Mammalia 2018; aop Aditi Mukherjee, Honnavalli Nagaraj Kumara* and Subramanian Bhupathy a Environmental determinants of activity variation of an overlooked burrowing rodent: the Indian crested porcupine https://doi.org/10.1515/mammalia-2017-0124 Received September 20, 2017; accepted December 7, 2017 Abstract: A study of the activity patterns, time alloca- tion for each activity and variations in activities due to environmental alterations are necessary for understand- ing the biology of any species. This study investigates the relationship of micro-habitat and environmental con- ditions with seasonal and temporal activities of Indian crested porcupines (ICP) around their burrows in Keo- ladeo National Park (KNP), India. This species is consid- ered as a problem species, often ignoring its ecological importance as an ecosystem engineer. Of the 39 sampled burrows, 58.97%, 38.46% and 83.78% were occupied in winter, summer and monsoon, respectively. The esti- mated porcupine density was 3.21 ± 1.32 SD individuals/ km 2 , accounting for a population size of 65.89 ± 27.15 SD individuals. A seasonal shift in rate of emergence was observed in monsoon and winter, when ICP emerged ear- lier, significantly correlating with the sunset timings. The daily activity records of adult ICP outside burrow signifi- cantly peaked in January–February when they prepare the burrows for the gestation period of 90–112 days, fol- lowed by rearing of the offspring. The temporal activity significantly reduced in the full moon nights, perhaps to avoid predators. The study affirms that environmental determinants including the timings of sunrise, sunset and lunar phase significantly affect the variations in tem- poral activity and burrow use patterns of ICP. Keywords: burrow activity; circular statistics; Hystrix indica; Keoladeo National Park; lunar phase. Introduction The burrow systems represent a fundamental ecologi- cal resource for an array of animals (Burns et al. 1989, Hansell 1993, Kinlaw 1999). The burrows in terrestrial habitats are reported from as early as carboniferous period (Voorhies 1974, Olsen and Bolles 1975). They are a crucial refuge, especially in arid and semiarid regions providing protection against extreme temperature, fire and predation (Campbell and Clark 1981, Alkon and Saltz 1988b, Reichman and Smith 1990). Burrows are a con- versant and safe place for reproduction, thus significant in reproductive success (Hoogland 1995) and population growth (Kinlaw 1999). Burrows also have strong biologi- cal influence on their occupants by reinforcing socializa- tion chiefly during mating and rearing the young (Hansell 1993). For example, breeding colonies and cooperative pup rearing is observed in burrowers including the Att- water’s pocket gopher Geomys attwateri Merriam 1895 (Cameron et al. 1988), the wood mouse Apodemus sylvati- cus Linnaeus 1758 (Bujalska and Saitoh 2000), the Wag- ner’s gerbil, Dipodillus dasyurus Wagner 1842 (Gromov et al. 2000), the Mongolian gerbil Meriones unguiculatus Milne-Edwards 1867 (Gromov 2009), the bank vole Clethri- onomys glareolus Schreber 1780 (Gromov and Osadchuk 2013), the meerkat Suricata suricatta Schreber 1776 (Brock and Manser 2016); the black-tailed prairie dog Cynomys ludovicianus Ord 1815 (Grassel et al. 2016); wherein year- ling and subadults participate in rearing activities along with parents of the litters. Burrowing vertebrates are the potential ecosystem engineers (Voorhies 1974) having the capability of modi- fying habitats, thus directly or indirectly regulating the resource availability for other species (Hansell 1993, Jones et al. 1994, 1997, Lynn and Detling 2008). They are known to have positive and negative effects on the ecosystem, species richness and abundance at small scales, but an overall positive effect at larger scales in ecological and a Subramanian Bhupathy passed away on April 28, 2014. *Corresponding author: Honnavalli Nagaraj Kumara, Sálim Ali Centre for Ornithology and Natural History, Anaikatty (Post), Coimbatore 641 108, Tamil Nadu, India, e-mail: honnavallik@gmail.com. http://orcid.org/0000-0002-7958-6395 Aditi Mukherjee: Sálim Ali Centre for Ornithology and Natural History, Anaikatty (Post), Coimbatore 641 108, Tamil Nadu, India; and Manipal Academy of Higher Education, Madhav Nagar, Manipal 576 104, Karnataka, India. http://orcid.org/0000-0002-6957-0381 Subramanian Bhupathy: Sálim Ali Centre for Ornithology and Natural History, Anaikatty (Post), Coimbatore 641 108, Tamil Nadu, India Authenticated | honnavallik@gmail.com author's copy Download Date | 2/9/18 5:56 AM