This book is written in a style to make it easy for the reader to trace the source of most of the material presented by checking the names of authors mentioned with the reference section. There may be some difficulty in pinpointing a specific reference when a particular author has several articles. These notes are intended to guide the reader more specifically to the sources for various sections in a chapter. While the reference section lists only books, journal articles, doctoral dissertations, and published conference proceedings that are readily accessible, the notes contain additional references to material such as conference abstracts or presentations, unpublished reports, institutional reports, newsletters, master's theses and, in some cases, data kindly made available to me by researchers.
The elephant has obviously been the subject of a large number of books catering to different audiences. The selections I list are the more scientific or substantive ones, including personalized accounts of the research of elephant biologists and certain large-format pictorial volumes. The works by Carrington (1958) and Sanderson (1962) are very readable accounts of the natural history of elephants and their relationship to people. Sikes (1971) was possibly the first to provide a technical account of the biology of (African) elephants. Laws, et al. (1975) and Buss (1990) detailed their pioneering research on African elephants in Uganda during the 1960s. The former especially provided much of the basic biological details of elephants for the subsequent African studies. Douglas-Hamilton and Douglas-Hamilton (1975), Hanks (1979), Moss (1988), Poole (1996), and Payne (1998) wrote engaging accounts of their work with African elephants. My early research of Asian elephant ecology was published as a scientific volume (Sukumar 1989a), as well as a popular account (Sukumar 1994a). The pioneering studies by scientists of the Smithsonian Institution on Asian elephants in Sri Lanka (Eisenberg and Lockhart 1972, McKay 1973) were reprinted along with a report by Seidensticker (see Notes 9.3) as a single volume (Eisenberg et al. 1990). Two more recent volumes, one by Daniel (1998) and the other by Lahiri-Choudhury (1999), have likewise brought together very useful pieces of the early literature on Asian elephant natural history, much of it written by hunters.
Eltringham (1982) provided a concise technical overview of the ecology of both African and Asian elephants. Spinage (1994) interwove anecdotal information with the more scientific studies in his descriptive account of the biology of elephants. Among the large-format pictorial books, I would recommend the multiauthor edited volumes of Eltringham (1991) and Shoshani (1992b). Several others on the market focus on the African elephant and are mainly pictorial. A lavishly illustrated recent volume by Gron-ing and Saller (1998), however, covers considerable ground, from evolution to biology and the cultural history of elephants.
Sections 1.1-1.8 Work by Osborn (1936, 1942) remains the most comprehensive source of descriptions of fossil proboscideans as a whole, while Maglio's work (1973) is the most detailed account of fossil elephants (family Elephantidae). The edited volume by Shoshani and Tassy (1996a) should be consulted for the most recent information on the evolution of the proboscideans. The reader may also wish to consult earlier reviews on the subject by Aguirre (1969) and Watson (1946). Deraniyagala's work (1955) contains descriptions of elephant material from Asia, especially Sri Lanka. Popular accounts of proboscidean evolution by Shoshani are available in the volumes edited by Eltringham (1991) and by Shoshani (1992b).
The descriptions of geological climate and vegetation change are based largely on the work of Janis (1993). The account of proboscidean evolution through the ages is based on several articles in Shoshani and Tassy (1996a), including the following references from 1996: Agenbroad and Mead, Caloi et al., Dudley, Fisher, Lister (1996a), Roth, Saunders, Shoshani et al., Tassy, Todd and Roth, and Van den Berg et al. Other specialized articles or reviews to which I referred for this chapter are those by Barry et al. (1985), Beden (1983), Cerling et al. (1997), Chakravarti (1957), Court (1993), Hooijer (1972), Gaeth et al. (1999), Gheerbrant et al. (1996), Koch et al. (1989), Lister (1989, 1996a, 1996b), Lister and Sher (2001), Mahboubi et al. (1984), Quade et al. (1992), Sukumar et al. (1993), Tassy and Shoshani (1988), Turner (1995), Vartanyan et al. (1993), and West (1980). Koch's isotopic study of late Pleistocene proboscideans is also available as an abstract in the Journal of Vertebrate Paleontology, 11 (Supplement 3), 40A, 1991. Lister and Bahn (1994) provided a good general account of mammoth evolution for the nonspecialist.
The term mastodont is sometimes used to encompass both the mammutids and the gomphotheres, but I have used this term in very few places (such as this chapter title) to avoid confusion with the mastodon (refers to only one mammutid—the American mastodon). I have used the term African elephant(s) to encompass both living subspecies of Loxodonta (L. africana africana and L. africana cyclotis).
The work of Martin and Klein (1984) still remains the most comprehensive collection of articles on the late Pleistocene extinctions. Individual articles (all 1984) to which I have referred in this volume include those of Gingerich, Graham and Lundelius, Guthrie, Kiltie, Martin, Webb, and Whittington and Dyke. Haynes (1991) carefully examined the fossil record for evidence of Pleistocene hunting. MacPhee and Marx (1997), Miller et al. (1999), Mosimann and Martin (1975), and Owen-Smith (1987) are other articles on this subject.
The dates given for fossils during the late Pleistocene are usually radiocarbon dates, which differ from calendar dates. In most cases, the calendar age is older than the radiocarbon age by 10%-20%. A radiocarbon date of 10,600 years is thus about 12,250 years in calendar age.
Section 1.9 The phylogeny and molecular genetics of the elephants were based on the work of Fernando et al. (2000), Fleischer et al. (2001), Georgiadis et al. (1994), Hartl et al. (1996), Lowenstein and Shoshani (1996), Nyakaana and Arctander (1999), Thomas et al. (2000), and Whitehouse and Harley (2001). The unpublished data for Sumatra, Malaysia and Borneo of P. Fernando and D. Melnick were presented at the Sixteenth Annual Meeting of the Society for Conservation Biology (SCB) held at Canterbury, U.K. in July 2002. The unpublished data from the southern Indian populations were also presented at the same SCB 2002 meeting by T.N.C. Vidya, P. Fernando,
D. Melnick and R. Sukumar. The Bkm 2(8) DNA probe shows extensive restriction fragment length polymorphism in various eukaryotes and is therefore an efficient probe for genetic fingerprinting; the data from Asian elephants are unpublished results of T. Purohit, R. Sukumar and L. Singh (1999).
The case for two species of African elephants has been in the literature since the early twentieth century, when P. Matchie described the forest elephant in the year 1900. For instance, Sanderson (1962) treated the savanna and the forest elephant as distinct species. Based on morphological measurements, a case was presented in the January 2000 issue of Elephant (a publication of the Elephant Research Foundation) in two articles by Groves and Grubb (2000), and Grubb et al. (2000). An article by L. Tangley (In search of Africa's forgotten forest elephant. Science 275, 1417-1419, 1997) had hinted at the existence of more than one species of Loxodonta. The genetic evidence for two species of Loxodonta was finally presented by Roca et al. (2001), while a more complex taxonomy was suggested by Eggert et al. (2002).
IUCN/SSC refers to the World Conservation Union /Species Survival Commission. The decision of the IUCN/SSC African Elephant Specialist Group to retain the traditional classification of two sub-species of Loxodonta has been reported in page 19 of the January-July 2002 issue of Species, the newsletter of the SSC. I have therefore decided to treat the African savanna elephant and the forest elephant as sub-species in this volume.
The "dare theory" of domestication was applied to the elephant by Baker and Manwell (1983). The major source for this chapter, especially the historical antecedents of Ganesha, was the collection of articles in Brown (1991c). The ones I found especially useful are those by Brown (1991a, 1991b), Dhavalikar, and Narain. Other useful materials on Ganesha are the scholarly books by Getty (1936), Ghurye (1962), and Courtwright (1985) and the popular book by Jagannathan and Krishna (1992). The quotation from O'Flaherty was taken from her foreword to Courtwright (1985).
For ancient Indian history, I used the work of Thapar (1966) and Basham (1967). The term Aryan refers to the "Indo-European speaking people"; it is thus a language or cultural label and should not be confused with race.
The paleoenvironment of South Asia was reviewed by Erdosy (1998). The paleo-ecology of southern India is based on Sukumar et al. (1993). Opinion is divided on the role of climate change in the decline of the Indus Valley Civilization. Enzel et al. (1999) now present evidence suggesting that a period of aridity set in around 4800 years ago in northwestern India, at least 800 years prior to the collapse of this civilization.
Other important sources for this chapter are the works of Digby (1971), Harris (1978), Lahiri-Choudhury (1991a, 1999), Prakash (1961), Achaya (1994), MacKenzie (1987), Rangarajan (2001), and Trautmann (1982). References to the elephant in the Sangam literature have been compiled by E. S. Varadarajaiyer (The Elephant in the Tamil Land, Annamalai University, Tamil Nadu, India, 1945). There are now several translations of the Arthasastra; the one I used is the most recent of these by L. N. Rangarajan (1992). A good introduction to elephants during Mughal times is the work of Ali (1927). S. Moosvi's estimate on captive elephants during Mughal times was presented at a symposium ("Call of the Elephant") held at the Indian Museum, Kolkata (August 18-19, 2001).
Scullard's (1974) account of the use of elephants in Greek and Roman times was also the main source for the history of captive elephants in Africa. Ansell (1971)
suggested that the elephants of North Africa, now extinct, represented a distinct subspecies Loxodonta africana pharaohensis. The quotation by J.-A. Shelton was taken from a presentation she made at a workshop ("Elephants: Cultural, Behavioral, and Ecological Perspectives") held at the University of California, Davis (October 26-28, 2000). P. Martin's observations were made in a BBC Horizon television program in 1996. Ross's 1992 work is an illustrated collection of articles dealing with the relationship between elephants and people in Africa.
Several texts on animal behavior deal with the ecological consequences of a polygynous mating system. The definition of polygyny was taken from the work of Shields (1987). Darwin's observations on this subject are found in Descent of Man and Selection in Relation to Sex (1871). Descriptions of the anatomy of reproductive systems in elephants are available in the work of Sikes (1971), in the edited volume of Mikota et al. (1994), and in several papers listed below.
Section 3.2 The account of estrus in female elephants is based on the work of Bechert et al. (1999), Brannian et al. (1988), Brown and Lehnhardt (1995), Brown (2000), Brown et al. (1991), Chappel and Schmidt (1979), de Villiers et al. (1989), Eisenberg et al. (1971), Greyling et al. (1997), Hanks (1972b), Hanks and Short (1972), Heistermann et al. (1997), Hermes et al. (2000), Hess et al. (1983), Hodges (1998), Hodges et al. (1994, 1997), Jainudeen et al. (1971), Kapustin et al. (1996), Krishnan (1972), Laws (1969), Laws et al. (1975), McNeilly et al. (1983), Moss (1983), Niemuller et al. (1993, 1997), Perrin and Rasmussen (1994), Perry (1953, 1964), Plotka et al. (1975, 1988), Ramsay (1981), Rasmussen et al. (1982, 1996b), Short (1966), Smith et al. (1969), Smith and Buss (1975), Taya et al. (1991), and Watson and D'Souza (1975).
Section 3.3 The discussion of musth, its behavioral ecology, and male elephant reproduction are based on the work of Cooper et al. (1990), Gale (1974), Hall-Martin (1987), Hanks (1973), Jainudeen et al. (1972), Lahiri-Choudhury (1992), Laws et al. (1975), Lincoln and Ratnasooriya (1996), Niemuller and Liptrap (1991), Poole (1987, 1996), Poole and Moss (1981), Poole et al. (1984, 1988), Rasmussen et al. (1984, 1996a, 2002), Short et al. (1967), Slotow et al. (2000). Nilakanta's Matangalila was translated by F. Edgerton (1931). A. Desai's observations on musth in Asian elephants were presented at a symposium in 1993 and are available as an abstract in Daniel and Datye (1995). L. Wingate and B. Lasley's observations on musth were presented at a symposium (Is musth a reproductive event: An examination of arguments for and against this view, pp. 150-156 in A research update on elephants and rhinos: Proceedings of the international elephant and rhino research symposium, June 2001, Vienna, Austria).
Section 3.4 The discussion of sexual selection and mate choice in elephants is based on the work of Anderson (1991), Averianov (1996), Fisher (1958), Folstad and Karter (1992), Freeland (1976), Gadgil (1972), Grafen (1990a, 1990b), Hamilton and Zuk (1982), Laws (1966), Maynard Smith (1982), Parker and Rubenstein (1981), Poole (1989a, 1989b, 1999), Poole and Moss (1989), Sukumar et al. (1988), Watve and Sukumar (1995, 1997), Zahavi (1975), and Zahavi and Zahavi (1997). A follow-up study by C. D. Nath on tusk size and parasite loads in Asian elephants at Nagarahole in southern India did not find any clear patterns (unpublished master's thesis, Saurashtra University, Rajkot, India, 1999).
The ethological perspective on animal conflict is reflected, for instance, in the work of N. Tinbergen (The Study of Instinct, Clarendon Press, Oxford, U.K., 1951) and K. Lorenz (On Aggression, Methuen, London, 1966), but also see the work of Hinde in Animal
Behaviour (29, 535-542, 1981) for an attempt to reconcile the ethological and game theory approaches.
Many of the references for this chapter on the social life of elephants are the same as for chapter 3. The work of Trivers (1985) is a useful introduction to social evolution in animals. The volumes referred to in the introduction are those of Poirier (1972) and Wilson (1975).
Section 4.2 The Asian studies are based on the work of Gadgil and Nair (1984), Nair (1983, 1989), and Sukumar et al. (1997), while the African studies are from Lee (1986, 1987) and Lee and Moss (1986). The parental investment model was from work by Trivers and Willard (1973).
Section 4.3 I used the work of Bradbury and Vehrencamp (1998) and Halliday and Slater (1983) for a general introduction to the subject of animal communication. There is also a diverse range of material on communication in elephants. I referred to that of Berg (1983), Buss et al. (1976), Douglas-Hamilton and Douglas-Hamilton (1975), Easa (1992), Gadgil et al. (1985), Garstang et al. (1995), Goodwin et al. (1999), Heffner and Heffner (1980), Krishnan (1972), Kuhme (1962), Lamps et al. (2001), Langbauer et al. (1989, 1991), Larom et al. (1997a, 1997b), Lindeque and Lindeque (1991), McComb et al. (2000), McKay (1973), Nair (1983), Payne et al. (1986), Poole (1994, 1996), Poole et al. (1988), Rasmussen (1988, 1995, 1998, 2001), Rasmussen and Krishnamurthy (2000), Rasmussen and Munger (1996), Rasmussen and Schulte (1998, 1999), Rasmussen et al. (1982, 1986, 1990, 1993, 1996b, 1997, 2002), Riddle et al. (2000), Sanderson (1878), Schulte and Rasmussen (1999), Sukumar (1994a), Wheeler et al. (1982), and Wiley (1983).
The quote attributed to K. Payne is taken from page 266 of her article (Elephant talk. National Geographic, August 1989, pp. 264-277). The recordings of the African forest elephant by Payne and Gullick were from their unpublished data (2001). Nilakan-tha's Matangalila has been translated by Edgerton (1931).
Section 4.4 The work of Baker (1978) is a massive tome on the subject of animal migration. He defines (pg. 44) "calculated migration" as "migration to a specific destination that is known to the animal at the time of initiation of migration, either through direct perception, previous acquaintance, or social communication", and "non-calculated migration" as "migration to a destination about which, at the time of initiation of the migration, the animal has no information, either memorised, through direct perception, or through social communication".
Published references for home range sizes of elephant populations based on telemetry (both very-high-frequency and satellite-based) studies are given in table 4.5. Hall-Martin's telemetry study at Kruger was reported in The Status and Conservation of Africa's Elephants and Rhinos (D.M.H. Cumming and P. Jackson, editors, International Union for Conservation of Nature and Natural Resources, Gland, Switzerland, 1984). The other (nontelemetry) studies mentioned are those of Datye and Bhagwat (1995a), Desai (1991), Eisenberg and Lockhart (1972), McKay (1973), Sukumar (1989a, 1989b), Rodgers and Elder (1977), and Viljoen (1989). The telemetry study at Rajaji in India was taken from the work of A. C. Williams (Elephants and their habitats in Rajaji-Corbett National Parks, doctoral dissertation in review, Saurashtra University, Rajkot, India, personal communication). The study of S. Chowdhury and colleagues was taken from an unpublished report (Management of elephant populations in West Bengal for mitigating man-elephant conflicts, Wildlife Institute of India, Dehra Dun, 1997). The telemetry study of elephants in the Buxa-Jaldapara Reserves by my research team is ongoing; the results have been presented in a report submitted to the West Bengal Forest Department (Sukumar, R., Venkataraman, A. B., Cheeran, J. V., Majumdar, P. P., Baskaran, N., Dharmarajan, G., Roy, M., Suresh, H. S., Narendran, K. and Mathivanan, A. (2003). Study of elephants in Buxa Tiger Reserve and adjoining areas in northern West Bengal, and preparation of conservation action plan. Centre for Ecological Sciences, Indian Institute of Science, Bangalore).
The discussion on ecological determinants of home range was based on the work of Damuth (1981), Harestad and Bunnell (1979), Kleiber (1947), McNab (1963), OwenSmith (1988), Peters (1983), and Swihart et al. (1988). Rainfall data are taken from various publications mentioned here as well as from an atlas of rainfall for African sites (Nicholson, S.E., Kim, J. and Hoopingarner, J., Atlas of African rainfall and its interan-nual variability. Department of Meteorology, The Florida State University, Tallahassee, Fl., 1988).
Sections 4.5-4.6 References for the discussion on social organization include those by Abe (1994), Anderson and Eltringham (1977), Barnes (1982b), Baskaran (1998), Baskaran et al. (1995), Croze (1974a), Douglas-Hamilton (1972), Douglas-Hamilton and Douglas-Hamilton (1975), Dublin (1983), Eltringham (1977), Fernando and Lande (2000), Hart and Hart (1994), Ishwaran (1981), Kurt (1974), Laws et al. (1975), Lee (1987), Leuthold (1976), McComb et al. (2001), McKay (1973), Moss (1988), Moss and Poole (1983), Poole and Moss (1989), Rensch (1957), Sanderson (1878), Santiapillai et al. (1984), Sukumar (1985, 1989a, 1989b, 1994a), Turkalo and Fay (1995), and Western and Lindsay (1984).
The description of Brooke and Hamilton's elephant hunt of 1863 is given in the work of Sanderson (1878). Chapman's observations are mentioned in Spinage's 1994 work. Mohamad Khan has brought out an undated report (about 1992) of his work (The Malayan Elephant: A Species Plan for Its Conservation, published by the Department of National Parks, Kuala Lumpur, Malaysia). Heindrichs's observations are given in the work of Croze (1974a). Komar and Melamid (2000) provide a popular account of Thailand's painting elephants.
A good introduction to the use of allometry in ecology was given by Peters (1983). Owen-Smith (1988) provided a more detailed comparative account of the feeding ecology of the megaherbivores. Benedict's (1936) classic on elephant physiology is still relevant today.
Section 5.2 The general nature of the elephant's feeding behavior and diet was described by Alexandre (1978), Barnes (1982a), Benedict (1936), Buss (1961), Coe (1972), Field and Ross (1976), Foose (1982), Guy (1975, 1976), Laws and Parker (1968), Laws et al. (1975), Lindsay (1994), McKay (1973), Olivier (1978), Ruggiero (1992), Short (1981), Sukumar (1985, 1989a, 1990), Vancuylenberg (1977), White et al. (1993), Williamson (1975), and Wyatt and Eltringham (1974). Merz's study in the Ivory Coast was based on an unpublished master's thesis (University of Heidelberg, Germany) and was quoted in Eltringham (1982), as were Rees's figures on digestibility.
Section 5.3 Two of the early articles on carbon isotopic variation in plants and the application of this method in dietary studies were by Smith and Epstein (Plant Physiology, 47, 380-384, 1971) and DeNiro and Epstein (Geochimica Cosmochimica Acta, 42, 495-506, 1978). The isotopic studies of elephant diet were based on the work of Koch et al. (1995), Sukumar (1985), Sukumar and Ramesh (1992, 1995), Sukumar et al. (1987), Tieszen et al. (1989), and van der Merwe et al. (1988). Data on rainfall are as concerning the discussion of section 4.4.
Section 5.4 The analytical discussion on elephant foraging was based on the work of Ananthasubramaniam (1979), Anderson and Walker (1974), Bax and Sheldrick (1963), Belovsky (1978, 1984), Benedict (1936), Clemens and Maloiy (1982), Dieren-feld (1994), Dougall et al. (1964), Emlen (1966), Foose (1982), Janis (1976), Kleiber (1947), Laws et al. (1975), Lindsay (1994), McCullagh (1969a, 1969b, 1973), Moore and Sikes (1967), Oftedal (1985), Olivier (1978), Owen-Smith (1988), Owen-Smith and Novellie (1982), Ruggiero and Fay (1994), Sivaganesan and Johnsingh (1995), Sukumar (1989a, 1990), Weir (1972, 1973), and Westoby (1974, 1978).
A more comprehensive treatment of plant secondary compounds and their role in herbivory is found in the work of Freeland and Janzen (1974) and Rosenthal and Janzen (1979). M. K. Hackenberger's work is an unpublished master's thesis (1984) from the University of Guelph, Canada.
Section 5.5 The section on physiological condition was based on the work of Albl (1971), Hanks (1981), Malpas (1977), Laws and Parker (1968), McCullagh (1969a), Vidya and Sukumar (2002), and Williamson (1975).
The literature on the elephant's impact on vegetation is extensive, mostly in the form of scientific articles of individual studies. An early article that reviewed studies from several regions in Africa is that of Laws (1970). The other articles I used for this chapter are listed below.
Section 6.2 The nature of elephant damage to vegetation is described in the work of Barnes (1980, 1983b, 1985), Barnes et al. (1994), Buechner and Dawkins (1961), Croze (1974a, 1974b), Douglas-Hamilton (1972), Field (1971), Guy (1976), Hoft and Hoft (1995), Ishwaran (1983), Lamprey et al. (1967), Laws et al. (1975), Leuthold (1977a), Lewis (1986), Moolman and Cowling (1994), Mueller-Dombois (1972), Savidge (1968), Sukumar (1985, 1989a), Sukumar et al. (1998a), and Thomson (1975); Watson's study at Tsavo was presented in an unpublished 1968 report. I have also presented some of my unpublished data (1988-2000) from permanent plot observations in Mudumalai Sanctuary.
Section 6.3 In addition to several of the references listed in the preceding section, I also referred to the works by Bell and Jachmann (1984), Botkin et al. (1981), Caughley (1976), Duffy et al. (1999), Fowler (1981), Guy (1989), Jachmann and Bell (1984), Kennedy (2000), Lewis (1987), Myers (1973), Norton-Griffiths (1979), Pellew (1983), Prins and Van der Jeugd (1993), Ruess and Halter (1990), Scott (1962), Van de Koppel and Prins (1998), and Western and van Praet (1973).
Section 6.4 The data and models for this section are based on the work of Barnes (1983a), Ben-Shahar (1993, 1996), Dublin (1991, 1995), Dublin et al. (1990), NortonGriffiths (1979), Pellew (1983), Sinclair (1995), and Styles and Skinner (2000). An article by Morell (Science, 278, 2058-2060, 1997) also discussed the recent changes in the Serengeti.
Section 6.5 In addition to several articles used in section 5.2 that dealt with seed dispersal by elephants, I referred to the work of Chapman et al. (1992), Dudley (1999, 2000), Hawthorne and Parren (2000), Howe (1985), Janzen and Martin (1982), Powell (1997), Lieberman et al. (1987), and Redmond (1992). Richard Barnes enlightened me about the Maasai's observations on the link between elephants and the tsetse fly.
For those unfamiliar with the mathematical treatment of population dynamics, any text on ecology or population biology would provide the fundamentals of the subject. Caughley's 1977 work is a good introduction to deterministic models of population dynamics as applied to vertebrates, while Fowler and Smith's 1981 work is a collection of articles from empirical studies of mammalian dynamics.
Section 7.2 References for birth rates in elephant populations are given in table 7.1. Khyne U Mar's compilation for Myanmar timber elephants was presented at a workshop (International Workshop on the Domesticated Asian Elephant, February 510, 2001, Bangkok, Food and Agriculture Organization, Thailand). The section on mortality was based on the work of Barnett (1991), Corfield (1973), Dudley et al. (2001), Lindeque (1988), Sikes (1968, 1971), Sukumar et al. (1997), and Watve (1995) in addition to some of the references in table 7.1 and discussions with V. Krishnamurthy and J. V. Cheeran.
Section 7.3 An overview of life history evolution in mammals was provided by Boyce (1988a, 1988b, 1988c). For a discussion of density dependence in relation to life history in mammals, see the work of Fowler (1981). Most of the other references used are as given in table 7.1. Hedigar is quoted in the work of Perry (1953).
Section 7.4 This section was based on the work of Fowler and Smith (1973), Hanks and McIntosh (1973), Laws and Parker (1968), Laws et al. (1975), and Sukumar (1985, 1989a). The reference to the work of G. Petrides is from a conference presentation (Petrides, G. A. and Swank, W. G. Estimating the productivity and energy relations of an African elephant population. Pp. 831-842 in Proceedings of the Ninth International Grasslands Congress, Sao Paulo, Brazil, 1965). The reference to G. U. Kurup was from an article in a newsletter-journal, Cheetal (13, 5-18, 1971), published by Wildlife Preservation Society, Dehra Dun, India.
The maximum rate of increase in an (African) elephant population was computed by Calef (1988) as 7% per annum, a rate achieved at Addo National Park in South Africa. However, this should not be taken as the norm for all elephant populations as I have argued on considerations of life history variation across habitats. A. Dobson informs me that the medium-term (about 20-year) growth rate of the Amboseli elephant population has been under 2% per annum, very similar to the maximum rate I determined for the Asian elephant in southern India.
Section 7.5 I first presented the results of the stochastic modeling of Asian elephants in the second (1992) edition of my book (see Sukumar 1989a) and later as a full article (Sukumar 1995b). Other references for this section include those of Armbruster et al. (1999), Armbruster and Lande (1993), and Wu and Botkin (1980).
Section 7.6 The tusks of an elephant are premaxillary lateral incisor teeth that are preceded by the deciduous incisors (the tushes). Both the tushes and the tusks develop from one tooth germ. In African elephants, the tushes are replaced at about 1 year by the continually growing permanent tusks in both males and females, while in the Asian elephant, only the males develop permanent tusks.
Tusklessness is much less common in African elephant populations than it is in Asian elephant populations, even when only the males are considered. The overall incidence of tusklessness in African elephants seems to be less than 10% of the population in most regions. It is important to distinguish between the incidence of tusklessness in young animals (a reflection of the underlying genetic patterns) and the observed frequency of tusklessness in older animals (which may be a short-term consequence of poaching for ivory).
Data on tusklessness in African elephants in Uganda were presented by Eve Abe (abstract in Pachyderm, 22, 46-47, 1996), and for Luangwa Valley, they were given by Jachmann et al. (1995). In Uganda, the incidence of tusklessness was very low (less than 2% of elephants shot prior to 1930), but increased to 10% of the overall population by 1988, the direct consequence of the indiscriminate slaughter of tusked elephants during the 1970s. Two-thirds of the elephants over 40 years old were also tuskless, but none younger than 10 years old showed this trait.
A similar trend was seen in the Luangwa Valley, where the frequency of tuskless female elephants in the population went up from about 11% in 1969 (possibly the natural proportion of the population determined by the gene frequencies under Hardy-Wein-berg equilibrium) to 38% by 1989 (as a result of the upsurge in ivory poaching), but then declined again to 29% by 1993 (with the growth of younger tusked elephants into the older age classes, given better protection). Most of the female elephants of Addo National Park are tuskless because the founder population, estimated at just 11 individuals in 1931, was a remnant of a heavily hunted population in this region.
Data on tusklessness among males (locally known as makhnas in India and aliya in Sri Lanka) in Asian elephant populations that I have compiled from various sources (Sukumar 1989a and unpublished data 2002) show that these comprised less than 5% of the male segment of the population in places such as southern India and peninsular Malaysia, about 50% in northeastern India and Myanmar, and over 93% in Sri Lanka. The observed frequencies of makhnas in India during recent years are higher among older bulls because of poaching of tuskers; for instance, about two-thirds of adult bulls in northeastern India are now makhnas.
Other references for this section are the works of Barnes and Kapela (1991), Caughley et al. (1990), Dobson et al. (1993), Kurup (as mentioned regarding section 7.4), Kurt et al. (1995), Milner-Gulland and Beddington (1993), Pilgram and Western (1986a, 1986b), Ramakrishnan et al. (1998), Spinage (1973), Sukumar et al. (1998b), Tiedemann and Kurt (1995), and Wells (1989). The reference to P. M. Chandran concerns a presentation made at a symposium on elephants in Kerala, India (February 23-24, 1990, with the proceedings published by the Kerala Forest Department, Thiru-vananthapuram).
An excellent overview of the elephant in ancient Ceylon (Sri Lanka) is provided by C.W. Nicholas (The Ceylon elephant in antiquity, (i) The Sinhalese period. The Ceylon Forester 1, 52-28, 1954). While the presence of tusked male elephants on the island between the second century B.C. and third century A.D. is hinted (though not conclusive) from the sculptures of the hattipakara or "Elephant Wall" at Anuradhapura, it seems unlikely that wild tuskers existed in any significant numbers after the sixth century A.D. when the rulers of Ceylon imported elephants, presumably Indian tuskers. Writing of this period, Cosmas Indicopleustes, for instance, states that the small tusks (tushes?) of the Ceylon elephant were not used in commerce but that African ivory was being imported into India. Such historical observations and the emerging genetic evidence (Fernando et al. 2000, Fleischer et al. 2001) that the historical trade in elephants have influenced the present-day distribution of elephant genotypes provide justification for seeking alternative explanations for the very low frequency of tuskers in Sri Lanka.
The Tiedemann-Kurt model was modified by us (R. Sukumar and G. Pradhan, unpublished results, 2003) in several respects to make it more consistent with the known biology of the species. Thus, mortality rates were made age-specific in both males and females, while the mean ages at first reproduction in females and in males were higher than in the earlier model; this also gave more realistic population growth trajectories (see section 7.2). The reproductive success of a male elephant was taken to be age-dependent based on Poole (1989a). The sexual selection advantage for a tusker over a makhna was taken to be a constant, irrespective of their relative abundance in the population (as in the Tiedemann-Kurt model) as well as frequency-dependent (with tuskers having the maximum advantage at low frequencies).
Section 8.2 The Asian studies of crop depredation were based on the work by Balasubramanian et al. (1995), Blair et al. (1979), Datye and Bhagwat (1995a, 1995b), de Silva (1998), Mishra (1971), Olivier (1978), Sukumar (1985, 1989a, 1990, 1994a, 1995a), Sukumar and Gadgil (1988), and A. C. Williams (as mentioned in the discussion of section 4.4). The reference to fragmentation and raiding in Kodagu and fig. 8.6 were based on an unpublished report by C. D. Nath and R. Sukumar (Elephant-Human Conflict in Kodagu, Southern India, Asian Elephant Research and Conservation Centre, Bangalore, India, 1998). Ramesh Kumar's data were based on an unpublished report (Ecology of the Asian Elephant, Final Report, 1995) of the Bombay Natural History Society, Bombay, India. The study by S. Choudhury and colleagues is available as an unpublished report (as mentioned in discussion of section 4.4), and so is our work in the Buxa-Jaldapara Reserves (Sukumar et al. 2003, discussed in section 4.4). The African studies were based on the work of Allaway (1979, 1981), Barnes (1996), Bhima (1998), Hoare (1999), Osborn (1998), and Tchamba (1996, 1998).
Section 8.3 Statistics concerning manslaughter by elephants are rather difficult to obtain for most of the range states. Data from India were based on my own records for southern India and elsewhere (Sukumar 1985 and unpublished 2001) as well as from the Project Elephant Directorate, New Delhi (courtesy S. S. Bist 2001). For the state of West Bengal, these were also based on records of the state forest department (compiled by S. Pal Choudhury, 2001). Other references for this section are the work of Barua and Bist (1995), Datye and Bhagwat (1995c), de Silva (1998), Douglas-Hamilton and Douglas-Hamilton (1975), and Njumbi et al. (1996). Discussion of David Western's views is based on personal communication (2001).
Section 8.4 There are few objective assessments of how the impact of humans on habitats affects elephants. I referred to the work of Barnes et al. (1991), Hoare and du Toit (1999), Olivier (1978), Parker and Graham (1989), Ramesh Kumar (as discussed in section 8.2), Silori and Mishra (1995), Struhsaker et al. (1996), Sukumar (1985, 1989a), Watve (1994), Williams (as discussed in section 4.4), and Williams and Johnsingh (unpublished report of Wildlife Institute of India, Dehra Dun, 1997).
Section 8.5 There are several volumes that deal with the use of ivory through history; the one that I used is by St. Aubyn (1987). Barbier et al. (1990) provided a detailed account of the economics of the ivory trade. Parker and Amin (1983) and Douglas-Hamilton and Douglas-Hamilton (1992) gave graphic accounts of ivory poaching in Africa, but with very different perspectives and prescriptions.
The general history of the trade in African ivory was based mainly on the work of Spinage (1973, 1994) plus that of Warmington (1974). The trade since 1950 and consumer patterns were based on the work of Barbier et al. (1990), Douglas-Hamilton (1987), Martin (1980), Martin and Stiles (2002), Martin and Vigne (1989), Parker and Martin (1982), and Poole and Thomsen (1989). The trade since 1989 is also reviewed by H. T. Dublin, T. Milliken and R.F.W. Barnes (Four Years after the CITES Ban: Illegal Killing of Elephants, Ivory Trade and Stockpiles, A Report of the IUCN/SSC African Elephant Specialist Group, Gland, Switzerland, 1995).
For the final part on capture and hunting of Asian elephants, I drew on my earlier account of this subject (Sukumar 1989a, which also provides a list of references) updated from the work of Jayewardene (1994), Lair (1997), Lahiri-Choudhury (1999), Menon (2002), and presentations made at the Bangkok workshop (see the discussion in section 7.2). Excellent accounts of captive elephants in Asia are also available in work by Sanderson (1878), Williams (1950), Stracey (1963), and Gale (1974). Recent estimates of poaching were based on the database of elephant mortality in India maintained jointly by the Asian Elephant Research and Conservation Centre, Bangalore, and the Wildlife Trust of India, New Delhi.
I provided an overview of elephant conservation issues in my 1991a work. Priority landscapes for Asian elephant conservation were given in the action plan by Santiapillai and Jackson (1990) and also in an unpublished report prepared for the World Wildlife Fund-US, Washington, D.C. (Sukumar, R. The Asian elephant: Priority populations and projects for conservation. Asian Elephant Conservation Centre, Bangalore, India, 1998). Venkataraman et al. (2002) provide algorithms for prioritizing southern Indian elephant landscapes. A thought-provoking discussion on a possible schism in the field of conservation biology was initiated by Caughley (1994).
Section 9.2 The theory of viable populations and its application to elephants were discussed by Armbruster and Lande (1993), Boyce (1992), Frankham and Franklin (1998), Franklin (1980), Franklin and Frankham (1998), Johnsingh et al. (1990), Lynch and Lande (1998), MacArthur and Wilson (1967), Shaffer (1981), Sukumar (1989a, 1995b), Terborgh (1976), and Western and Gichohi (1993).
Section 9.3 I referred to the work of Blair et al. (1979), Gorman (1986), Hoare (2001), Kangwana (1995), Lahiri-Choudhury (1991b), O'Connell-Rodwell et al. (2000), Osborn and Rasmussen (1995), Sukumar (1989a, 1991b, 1994b), and Thouless and Sakwa (1995). The reference to R. Piesse is an unpublished typescript (1982). The observations on electric fences in southern India were presented in the work by Nath and Sukumar (unpublished report, 1998; see the discussion in section 8.2). J. Seiden-sticker's prescriptions were given in a report (Managing Elephant Depredations in Agricultural and Forestry Projects, The World Bank, Washington, D.C., 1984).
Sections 9.4-9.5 Published references for these sections on population management are the works of Buss (1977), Cumming et al. (1997), Fayrer-Hosken et al. (2000), Laws (1970), Laws et al. (1975), McLeod (1997), Milewski (2000), Pienaar (1969), Poole (1993), Sinclair (1981, 1995), Spinage (1973), Van Aarde et al. (1999), and Whyte et al. (1998). Pienaar's arguments for culling were from an article (Why elephant culling is necessary, African Wildlife (23, 181-194, 1969). Information on elephant culling is also found in the work of Hanks (1979) and Laws et al. (1975). Martin's compilation of elephants culled in Zimbabwe is found in a report (Elephant Management in Zimbabwe, eds. R. B. Martin and A.M.G. Conybeare, 2nd ed., 1992, Department of National Parks and Wildlife Management, Harare, Zimbabwe). There are several reports and secondary references on Zimbabwe's CAMPFIRE; one of these I referred to is by H. Patel (Sustainable utilization and African wildlife policy: The case of Zimbabwe's Communal Areas Management Programme for Indigenous Resources (CAMPFIRE). Indigenous Environmental Policy Center, Cambridge, Mass., 1998).
The reference to the work at Cat Tien is from an unpublished report of the Cat Tien National Park Conservation Project 2002 (Sukumar, R., Varma, S., Dang, N. X. and Thanh, T. V. The status and conservation of Asian elephants in Cat Tien National
Park, Vietnam. Asian Elephant Research and Conservation Centre, Bangalore, India, and World Wide Fund for Nature, Ho Chi Minh City, Vietnam).
Section 9.6 The literature on poaching and the ivory trade and its regulation is extensive, but mostly in the form of articles and reports. The published works to which I referred are those by Barbier et al. (1990), Dobson and Poole (1992), Jachmann and Billiouw (1997), Leader-Williams and Milner-Gulland (1993), Leader-Williams et al. (1990), Leakey (1992), and Milner-Gulland and Leader-Williams (1992). A comprehensive collection of articles (and views) on the trade is available in the proceedings of the Ivory Trade Review Group (S. Cobb, ed., The Ivory Trade and the Future of the African Elephant, Ivory Trade Review Group, Oxford, U.K., 1987). Two reports on the post-1989 ban scenario in Africa are those by Dublin et al. 1995 (as discussed concerning section 8.5) and E. Martin and D. Stiles (The Ivory Markets of Africa, Save the Elephants, Nairobi, Kenya, 2000). The trade in Asian ivory was covered by V. Menon et al. (A God in Distress: Threats of Poaching and the Ivory Trade to the Asian Elephant in India, 1997,) and V. Menon and A. Kumar (Signed and Sealed: The Fate of the Asian Elephant, 1998,), both published jointly by the Asian Elephant Conservation Centre, Bangalore, India, and the Wildlife Protection Society of India, New Delhi, as well as the work of S. Nash (ed.) (Still in Business: The Ivory Trade in Asia, Seven Years after the Ivory Ban, Traffic International, Cambridge, U.K., 1997), H. Obara (Ivory trade management in Japan, In Proceedings of the African elephant conference, Environmental Investigation Agency, London, 1997), M. Sakamoto (Analysis of the Amended Management System of Domestic Ivory Trade in Japan, Japan Wildlife Conservation Society, Tokyo, 1999), and very recently by E. Martin and D. Stiles (The South and Southeast Asian Ivory Markets, Save the Elephants, Nairobi, Kenya, 2002), and Menon (2002).
The isotopic variation in elephant ivory was presented in the work of van der Merwe et al. (1990) and Vogel et al. (1990).
TRAFFIC refers to Trade Record Analysis of Flora and Fauna in Commerce.
Section 9.7 The classic on captive Asian elephant management is by G. H. Evans (Elephants and Their Diseases: A Treatise on Elephants, Government Press, Rangoon, Burma, 1910). S. S. Bist has recently edited A.J.W. Milroy's Management of Elephants in Captivity (original edition published in 1922; reissued by Natraj Publishers, Dehra Dun, India, 2002). The most recent overview of the captive elephant populations in Asia is that of Lair (1997). The health care of captive elephants, especially in Western zoos, was reviewed by Mikota et al. (1994). Other references for this section are the works of de Alwis (1991), Hermes et al. (2000), Hildebrandt et al. (2000a, 2000b), Krishnamur-thy and Wemmer (1995a, 1995b), Kurt (1995), Sukumar et al. (1997), and Taylor and Poole (1998). The experiment with releasing captive Asian elephants into the wild in Thailand was reported by T. Angkawanish of the Thai Elephant Conservation Center (typescript 1999), while observations of hand-reared African elephant calves were documented by McKnight (1995).
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