/ دوشنبه, 14 اسفند,1396

Evidence of seed germination in scats of the Asiatic Black Bear Ursus thibetanus in Iran

Hadi Fahimi, Ali T. Qashqaei, Mehdi Chalani, Zeinab Asadi, Siamak Broomand, Nahid Ahmadi & Gholam Hosein Yusefi

Dispersal and germination of fruit seed by omnivorous mammals such as bears is common in nature (Traveset & Willson, 1997). The importance of Asiatic Black Bears Ursus thibetanus Cuvier, 1823 in seed dispersal and germination have been documented in India and Japan (Koike et al., 2012; Sathyakumar & Viswanath, 2003). However, little is known about the role of Asiatic Black Bears (hereafter Black Bears) in seed germination and dispersal in other parts of the species range in Asia. In Iran, Black Bears are rare, least studied, and thus much of their ecology remains largely unknown (Yusefi, 2013). Typical of other areas, the diet of Black Bear in Iran consists of herbs, both wild and cultivated fruits, and animal matter (Ghadirian, Qashqaei, Soofi, Abolghasemi, & Ghoddousi, 2017). Seed germination and dispersal of date palm Phoenix dactylifera by Black Bears is common local knowledge in Baluchestan of Iran (Ziaie, 2008); however, no study has addressed the role of the species in this respect in the country. Here, we report the first evidence of date palm seed dispersal and germination (Figure 1) in the scats of Black Bears from the ‘Shushin’ area in Nikshahr County, which is located in Sistan and Baluchestan province, southeast of Iran.

Shushin area (26°09'–26°15'N, 60°04'–60°10'E) includes two very dry landscapes with annual average precipitation less than 200 mm; lowlands (88 km2 ; 431–550 m a.sl.) and highlands (32 km2 ; 550–1049 m). There are five villages in the west of the study area, a main road in north, three villages in south, and Nikshahr city in east. This region along with other areas in Baluchestan province may be the driest habitat in which Black Bears have been recorded (Yusefi, 2013). The Shushin area is a non-protected and arid mountainous area and home of several other species, including Wild Goat (Capra aegagrus), Wild Sheep (Ovis vignei), Persian Leopard (Panthera pardus), Indian Crested Porcupine (Hystrix indica) and Wild Boar (Sus scrofa) (Ahmadzadeh, Liaghati, Kiabi, Mehrabian, Abdoli, & Mostafavi, 2008). We collected 58 scats of the Black Bear in Ziploc and put them in plastic bags between late spring and early autumn 2011 using opportunistic scat sampling method. We soaked scats, washed, separated and counted seeds, and identified food items by a reference collection.

Date palm was found to be the main food item (n = 55; Frequency of Occurrence FO% = 94.8%) for Black Bears in the area. Other items were rare in scats: herbaceous plants (n = 7; 12.1%); Oriental Hornet, Vespa orientalis (n = 2; 3.4%); Christ’s thorn jujube, Ziziphus spina-christi (seeds number = 21), Domestic Goat, Capra hircus, unidentified Hymenoptera, and lizards (n = 1, 1.7% for each item). FO% of human-based items (date palm and domestic goat) were thus 94.8% (n = 55) and nature-based items 13.8% (n = 8). The average number of date palm seeds in scats was 12.5 ± 5.6 (2–22). During scat washing, we recovered nine rooted seeds of date palm from three scats (Figure 1; 5.2% from total scats and 5.4% from scats contained date palm). FO% of rooted seeds (n = 9) was 1.3% from 686 date palm seeds as total sample size in 55 scats.

In accordance with Ghadirian et al. (2017), the date palm that is the main cultivated fruit in southeast Iran was also the most important food item of Black Bears in Shushin. Poor habitat with high poaching, high degradation, scarcity of natural food items, and low production, have led to high human-bear conflict in the region, and many Black Bears have been killed by local people in retaliation for palm trees damage (Ghadirian et al. 2017; Gutleb & Ziaie, 1999; Yusefi, 2013). Other dietary items with low FO%, especially insects, lizard and goat, were lower abundant items in the area, and non-date palm fruits are available seasonally for Black Bears.

The species is listed as “vulnerable” in the IUCN Red List; however, the small Iranian population, as well as south Pakistan population (U. t. gedrosianus), is categorized as “critically endangered” (Garshelis & Steinmetz, 2016; Servheen, Herrero & Peyton, 1998). Although the Black Bear is protected by the Iranian Department of the Environment, the species still need conservational projects, public awareness and more poaching fine (€ 8750 in 2017) (Fahimi, Yusefi, Madjdzadeh, Damangir, Sehhatisabet, & Khalatbari, 2011).

The Black Bear (called mum in Baluchestan) is regarded as pest by Iranian farmers and livestock herders; however, knowledge of the important role of Black Bears as dispersers of date palm seeds, and thus the restoration of natural woodlands, may help improve the attitude of local people towards this species.

Black Bears disperse date palm seeds to steep slopes far from palm groves in Iranian Baluchestan (Ziaie, 2008). It is likely that Black Bears also play a role in the dispersal and germination of the seeds of other important plant species, such as Kakarsinghee, Pistacia khinjuk, Persian turpentine, Pistacia atlantica, Indian olive, Olea europaea ssp. cuspidata, Christ’s thorn jujube, Ziziphus spina-christi (Ghadirian et al., 2017). Emphasising the ecological importance of seed dispersal and germination by Black Bear may highlight the importance of conserving this very small population of endangered Black Bears in Shushin and other areas of Iran such as Bashagard and Dehbakri in Hormozgan and Kerman provinces.

Acknowledgments

We thank to the Department of the Environment, Yazd University, and the Persian Wildlife Heritage Foundation, and Mr H. Atabai, head of Nikshahr office of the Department of the Environment, for supporting the study. We also appreciate the help of S. C. P. Coogan for improving the paper.