This study was undertaken on behalf of the USGS/BRD/PIERC Haleakala Field Station (island of Maui, Hawaii) to better understand axis deer (Axis axis ) that inhabit Maui. The objectives of the study were to (1) determine the distribution and habitat preference of axis deer on Maui, (2) determine the behavior patterns of the deer, including movements and foraging, (3) characterize their ecological and social needs, (4) describe signs left by deer that reveal their presence and utilization of a site, and (5) offer insight regarding deer influx into Waikamoi Preserve and Haleakala National Park.
Field work was conducted from January to early April 1996. In addition, interviews of local citizens were also conducted to expand upon the field observations; the cooperation of these individuals was helpful and sincerely appreciated. Permission given to study the deer on the Haleakala Ranch, The Nature Conservancy's Waikamoi Preserve, as well as the Ulupalakua Ranch is gratefully acknowledged. The staff of Haleakala National Park and The Nature Conservancy were especially helpful as was Sumner Erdman of the Ulupalakua Ranch.
Eight axis deer (three bucks, four does, and one male fawn) were brought to the Hawaiian Islands in December 1867 and released on Molokai Island in January 1868. Later several deer were transferred to Oahu; a herd was present on Diamond Head prior to 1898 and an additional herd became established in Moanahua Valley about 1910 (Tomich 1986). In 1920, twelve deer of the Molokai population were transplanted to Lanai (Graf & Nichols 1966). Deer populations flourished on Oahu, Molokai, and Lanai. Variable hunting pressure has existed on these populations since the early years and has been the main management tool. On Molokai the population increased to 1000 within 20 years and reached perhaps 7500 before specific control measures were taken; hired hunters killed more than 3500 during 1900-1901 (Tomich 1986).
In September 1959, five axis deer (two bucks and three does) from the existing Hawaiian population were introduced to Maui at the 457 m (1500 ft.) elevation on Pu'u O 'Kali about 6 km east of Kihei; later, in July 1960, four additional deer (one buck and 3 does) were released at the Kaonoulu Ranch, near the 1959 release site. By 1968, the Maui population was estimated to be 85-90 animals (Kramer 1971). By 1995, the population on the Ulupalakua Ranch alone was >500 (Erdman, pers. comm.) and reports of deer have occurred over much of Maui. Highest numbers occur nearest the original release site and extend southward around the leeward side of the Island; few deer presently occur along the windward slopes. Year-round hunting is now permitted.
From the study on Molokai and Lanai by Graf & Nichols (1966), mature male axis deer have a mean shoulder height of 0.94 m (36 in) and weight of 72 kg (158 lb) [high being 98-110 kg], whereas females on the average have a shoulder height of 0.75 m (30 in) and weight of 45 kg (100 lb) [high being 55-64 kg]. Males (> 1 yr) have antlers which in older bucks can attain a beam length of 94 cm (37 in). White spots on a russet hair coat are characteristic of all sex/age classes; the face and neck of does are often slightly lighter in color than bucks. Individual hairs are soft and flexible, unlike the brittle hair of North American cervids. Hoofs of the front feet are slightly longer than those of the hind feet, measuring from 4.1 to 6.1 cm. The toes taper to a sharp point. Sexual dimorphism is not evident from the size of the track.
In axis deer (chital), the basic social unit is a matriarchal family group consisting of an adult female, her offspring of the previous year, and a fawn. Groups composed of two or more of these family units often occur and may be accompanied by additional deer of mixed sex/age classes (Fuchs 1977); mixed sex/age groups are frequent in the rutting season (Khan & Vohra 1993). Two additional associations commonly seen among chital are all-male herds and nursery herds, the later consisting of only females with fawns (Fuchs 1977). Herds of over 500 individuals have been observed, but smaller groupings are more typical (Tak & Lamba 1984). In Texas, average monthly herd size varied from 2-15 individuals (Fuchs 1977), whereas in India 5-38 were noted (Schaller 1967); feeding groups are regularly larger than resting groups. In Sri Lanka, 27% of the groups (> 2; n=1003) observed by de Silva & de Silva (1993) consisted of 2-4 individuals; solitary deer were also rather common. They noted bachelor herd mean size was 4.6, with 16 being the largest; Schaller's (1967) largest all-male herd was 23; Tak & Lamba's (1984) high was 92 . In general, herd stability of axis deer is poor; marked individuals, both male and female, have been observed to change associations frequently, sometimes daily (Schaller 1967; Fuchs 1977; Miura 1981). Thus, the most cohesive unit is that of mother and young (de Silva & de Silva 1993).
During the Molokai/Lanai study of Graf & Nichols (1966), the deer avoided being away from forest cover during the heat of the day and when humans were around. Thus most open-area feeding occurred in late afternoon, during the night, and during the first hours of daylight. In cooler weather, feeding extended over much of the day. Grazing activity was found to occur throughout the day in Sri Lanka but tended to lessen during mid-day hours when shade-seeking among trees replaced grazing on grasslands (de Silva & de Silva 1993); the deer commonly visited water holes in late afternoon. In India (Tak & Lamba 1984), deer feeding activity peaked at dawn and sunset during the cold as well as hot seasons, with more prolonged peaks in the cold season. However, during the rainy season, feeding was in bouts at various hours presumably because of intermittent rain and/or because food was in abundance. Most studies have noted that rest occurs periodically when not feeding; Schaller found (1967) rest was especially routine after midnight until shortly before dawn. On overcast days, axis deer tend to remain more active on grasslands and do not seek the shade of trees during mid-day (e.g., Schaller 1967; Tak & Lamba 1984).
Annual home ranges of males tend to be larger than those of females; ranges also vary depending on resource availability. Moe & Wedde (1994) monitored radio-tagged deer in Nepal and found ranges for females were 62% of those for males in the cool-dry season, 67% in the hot-dry season, and 55% during the monsoon; male home range were approximately 100 ha, whereas female ranges were approximately 60 ha. At other locations, authors have estimated ranges of individual deer as large as 600 ha (e.g., Schaller 1967; Fuchs 1977). Chital are rarely found above an altitude of 1160 m (3500 ft) in their native Asian habitats, including Nepal (Schaller 1967), or on Molokai and Lanai (Graf & Nichols 1966).
The axis deer is primarily a grazer, preferring newly-sprouting grasses (Tak & Lamba 1984; Elliott & Barrett 1985; Henke et al. 1988); yet during the year numerous plant species are eaten (e.g., Schaller 1967; Tak & Lamba 1984; Dinerstein 1987 & 1989). The rate of feeding is about 90 bites per minute (Schaller 1967). Graf & Nichols (1966) noted Molokai/Lanai deer grazed when grass was green and abundant; browsing occurred when grass was scarce or when browse was particularly palatable or accessible. In India, chital have been observed to shift during peak dry periods from eating especially grasses to eating other plants materials, such as fruit of Emblica and Xeromphis (e.g., Schaller 1967; Johnsingh 1981).
How often axis deer drink appears to depend on season and availability. Schaller (1967) concluded at least two treks (at sunrise and late in afternoon) were made to water each day during the hot season; fewer trips were made in other seasons. The duration of drinking was normally less than 90 sec. Mineral licks were also utilized periodically, where deer supplemented their diet with added phosphate, calcium, and perhaps other minerals (Schaller 1967).
The mean defecation rate has been estimated under wild conditions at 24.0 pellet groups/deer/day (Dinerstein 1980) and under captive conditions at 28.0 pellet groups/deer/day (Dinerstein & Dublin 1982); little difference was noted between sexes or age groups. According to Graf & Nichols (1966), fecal pellets of Molokai/Lanai axis deer ranged in size from 6-9.5 mm in diameter and 13-25 mm in length. The pellets often were tear-drop shaped with a nipple on one end and a slight indention on the other; they were also other shapes, such as cylinders with evenly rounded ends. Scats appeared dark green and soft when fresh but later changed to dark brown or black and became dry and hard. Until fawns fed extensively on vegetation (3-5 wks), they produced soft, viscous scats; thereafter, fawn pellets appeared like those of older deer. Fawns < 1 mo were inclined to urinate only in quiet, sheltered spots. Buck fawns, like older males, commonly urinated while recumbent and resting.
In the Hawaiian Islands, axis deer reproduction is aseasonal; yet >90% of mature females produce fawns annually when forage is good (Graf & Nichols 1966). Males are fertile year-round. Breeding, fawning, as well as the shedding and regrowth of antlers occur throughout the year. Although all stages of reproduction and development can be observed in the field in any season, some trends have been noted. Most fawns are born from mid-November to April and the peak antler maturation as well as rut activity occur from April to August. Both sexes reach puberty toward the end of their first year of age, although some females have been known to breed and conceive earlier. Multiple estrous cycles occur each year. Gestation appears to be 7.5 months. Does come into breeding condition within a few months after giving birth (Graf & Nichols 1966). Chapple et al. (1993) determined a mean estrous cycle of 19.3 days (range 17-21) and average gestation of 234.5 days (range 228-239). Single fawns are the norm; twinning is rare (Graf & Nichols 1966).
Prior to giving birth, a female leaves her yearling and other companions and seeks a secluded spot. The fawn is kept hidden for 2-3 weeks and is cared for only by the mother. Usually the fawn is left in a recumbent position in a well-protected place; the doe returns periodically to nurse the infant, often after an absence of 1-2 hours. When danger appears, the doe runs off alone leaving the fawn recumbent and hidden; the doe makes a "yup" call as she bounds away as if to call attention to herself to draw the intruder away from her infant. Nursing lasts only 10-15 seconds and undoubtedly occurs periodically throughout the day; a hand-reared fawn eagerly consumed 550 ml (18 oz) of milk three times per day. Fawns mouth vegetation in their first week and gradually begin to consume plant materials over the next month until considerable amounts are taken. Weaning occurs soon after the fawns reach four months of age; thereafter, fawns regularly consume water but not before (Graf & Nichols 1966).
In recent years, axis deer have occurred intermittently at elevations of 2150 m (7000 ft) or higher along the south, west, and northwest borders of Haleakala National Park and in the Waikamoi Preserve managed by The Nature Conservancy. Perhaps these small groups of deer are induced to temporarily enter such habitats when ecological conditions worsen at lower elevations due to drought, poor forage, or harassment (e.g., by dogs or hunters). Nevertheless, when conditions change they seem to return to lowers elevations; similar altitudinal movements were reported by Graf & Nichols (1966) on Lanai. During 1995, control efforts have eliminated two deer from Waikamoi Preserve. As recently as September 1995, a small group (< 6) of deer were still inhabiting the Waikamoi Preserve and occasionally foraging in shrubland upslope of Hosmer Grove along the National Park fenceline; however, during the course of this study most if not all of those deer had shifted downslope to the vicinity of the Ukelele Camp area of Haleakala Ranch.
The deer tended to be gregarious, with solitary individuals (adults of both sexes) noted on only 14% of the encounters. The largest aggregation observed was 24 deer -- a mixed age/sex grouping formed by the temporary clustering of several subunits. Of the 93 encounters where social composition could be determined, groups of 2 were observed more than other arrangements; mean group size overall was 3.87 (range 1-13). For groups of 2 or more, the mean group size was 4.34. Antlered males were present on 22.3% of the encounters. When groups contained more than one male with antlers, group size averaged 7.81; large bachelor groups of 10-13 were encountered, where half of the individuals clearly had antler development. Bucks with antlers > 0.5 m in length were seen alone as well as in large groups. Mothers with young were noted on 29% of the encounters; on one occasion (22 March) a lone doe was accompanied by two fawns, each were half her shoulder height.
Deer were seen foraging at all hours of daylight; yet when mid-day hours were sunny and hot, the deer tended to seek tree shade during mid-day and were not out in the open foraging on grasses. On cloudy days, the deer were not inclined to seek tree shade and remained more visible. The mean number of individual deer observed during each hour of observation at the Papaka region of the Ulupalakua Ranch was determined; the trend was for a bimodal distribution in activity to occur, with a morning peak from 0730-0930 and an afternoon peak at 1430-1630. Occasionally deer could be seen while under shade trees; at such times, they were sometimes recumbent, but just as often they were standing, browsing, walking, or exhibiting locomotor play. Bouts of recumbent rest and sleep were observed in deer at various hours even among shrubs and away from the cover of trees; sternal recumbency lasted about 0.5 hr before deer returned to a standing posture. During deepest sleep, the neck and head drooped, causing the chin to contact the substrate; eyes were closed.
Deer were seen moving to or from the general vicinity of water troughs at various hours during the day; yet only twice were deer viewed at a trough per se -- at 1414 hr (2 Feb) and 1437 hr (13 Mar). When deer had an apparent destination, they moved steadily along a trail in single-file fashion. Sometimes these movements appeared to be toward or away from water sources; sometimes the destination was for shade or forage site. Most treks were of less than 0.2 km; yet I observed one group of four deer travel without pause for more than 1 km over a span of 25 min; their trek was continuing when I lost view of them because of the terrain. By contrast, movements of foraging deer appeared undirected and occurred in a slow walk, with each individual seemingly taking a different path. Individual deer appeared to occupy a core area of approximately 1-2 hectares over a day's observation. None of the deer were marked or distinctive enough to assure me I was seeing the same individuals on different days, thus I can conclude nothing about home range size.
Foraging was typically a grazing pattern with mouth activity close to the ground; target plants seemed to be grasses, but observational distances were too great to allow me to verify most plants consumed. Brief browsing occurrences were seen to occur on kukui leaves and yellow oleander flowers and/or leaves. At lower elevations, browse lines were evident in kiawe habitats accessible to deer, but where fences prevented or impeded travel, kiawe trees were foliated more evenly throughout their height.
Defecation and urination were not often seen and did not occur at specific sites. Concentrations of pellets seemed to be related to time spent at a site; frequently-used loafing areas had more pellets than sites merely traversed by deer. Scats collected at the Ulupalakua study site varied in appearance from rounded-end cylinders (resembling pill capsules) to squat pellets having one or both ends flattened. Pellets with one end flattened typically had a centralized nipple at the opposite end. Deer pellets found on Haleakala Ranch adjacent to the west boundary of Waikamoi Preserve were of similar appearance and size to those collected at Ulupalakua; so also were goat pellets collected near the west fence of the National Park where deer did not frequent. Because deer and goat pellets are not sufficiently dissimilar, distinguishing axis deer from goats by scats alone is not prudent (using pellet measurements and/or general appearance) except for the occasional spherical-shaped pellets seemingly unique to goats.
The habitat used by deer on the Ulupalakua Ranch was crisscrossed with game trails. The deer utilized such trails whenever moving from one place to another, except during a foraging bout. Single-file locomotion was typical, with individuals commonly separated by < 3 body lengths. Deer went between strands rather than over barbed-wire fences; at rock walls, they took advantage of a low spot and used stepping stones. Flight behavior occurred with deer taking the quickest and easiest route away from the intruder, usually using a trot or gallop without bounding. The rapid withdrawal ended as soon as the deer were out of view from the intruder, i.e., after a dash of about 10 meters, thus the deer remained in the geographical area previously occupied. Most of the flight responses I observed occurred without a vocalization or display by the deer; they simply withdrew, quickly and stealthily. However, I did observe one occasion where flight appeared to be used as a distraction display to lure me away from a neonate. On this occasion, two does sequentially gave "yow" vocalizations plus a conspicuous bounding display and ran off in the same direction; I did not follow them but instead continued to approach the place they had occupied moments before, there I discovered a tiny fawn lying secluded among the shrubs. Nearly every day I did field observations, some "yow" vocalizations were heard; deer in the immediate vicinity of a vocalizer would become alert but not alarmed. In general, the deer did not appear highly perceptive or alert to intruders; often I got close to them (10-30 m) without causing alertness or alarm. When vehicles drove through the area, the deer alerted only momentarily before returning to their previous activity. Shotgun noise from the neighboring Papaka Sporting Clays facility to the southwest were basically ignored.
Antlered deer were evident during the study -- some had hardened antlers and many others were in velvet. Courtship and mating were not observed. Many does had young fawns at their side; some had older young instead, suggesting reproduction was aseasonal in this population. Yearling males tended to be grouped with other males, whereas yearling females seemed to remain with their mother. Bucks with large antlers were seen to be solitary as well as with bachelor and mixed groups. Interactions with conspecifics always seemed friendly. However, on one afternoon (9 Feb) I observed what may have been a predator/prey response or an agonistic interaction between young males and perhaps a dominant male. It began with the alertness of individuals in a "bachelor" group that grew to a dozen deer. Half of the individuals had some antler growth; none had large antlers. These individuals faced frequently to the SW and remained close to each other (< 2 m) as they foraged and moved in that direction. "Yow" calls were given periodically beginning at 1442. At one point (1505), still oriented SW, they began to bob and occasionally shake their heads in a ritualized manner, as if uneasy and/or signaling. They continued to move slowly and cautiously SW. At 1537, just after the terrain blocked my view, I heard a burst of 3-4 "yows" and suddenly three deer came back into view and ran southward briefly, then stopped and faced where they had been, and finally emitted "yows" periodically until commencing to graze at 1601; the other deer in the "bachelor" herd never reappeared.
Play behavior, especially locomotor play, was frequently seen. In locomotor play, one to several deer would exhibit bouts of frisky movement to and from other deer -- circling, kicking, bobbing head and neck, turning, and changing speed and direction. One deer would often recruit others to join in the game. Youngsters as well as full-grown deer would be involved. After several minutes the individuals would cease play, at least for some minutes before starting again. Sometimes individuals would playfully interact with a neighbor using a lowered-neck, extended-head gesture; these interactions sometimes induced weak chases. Young males occasionally locked antlers in play with bucks of similar antler development and sometimes with more mature males; these pushing sessions ended within a second or two. On one play occasion, two spike bucks reared and briefly sparred face-to-face with one's forelegs grasping the other's neck, in what Fuchs (1977) called flailing.
Unlike most other deer species, axis deer do not readily jump obstacles, such as fences. Thus they are initially deterred by a mesh-type fence they cannot step over or pass under. The higher the fence the more it deters; axis deer are stymied by a relatively low fence (e.g., > 1 m). Jumping is a last alternative and directly proportional to the deerŐs motivational state and experience. Deer are inclined to be gregarious and prefer familiar terrain. Once an individual has gotten on the other side of a barrier, it normally desires to return to familiar ground and to rejoin companions. Therefore, passive control should be considered whenever deer have inadvertently entered a fenced area and show evidence of trying to exit the site. One-way exit gates installed along the fence allow such deer to depart, utilizing their tendency to search the fenceline for an escape route. The design and placement of a one-way gate are crucial in order to take advantage of a deer's behavioral tendencies and to not cause avoidance or oversight of the exit; for example, deer will tend to discover and use a corner escape route rather than one created along a straightaway.
When deer have penetrated a new habitat and no longer remain near a fenceline, something more than passive control may be warranted, such as shooting. Axis deer do not readily penetrate dense forest except by using trails. Unfortunately, existing trails and roadways often provide the necessary access. In time, deer utilize new trails they have themselves created. But while deer are new to a forest habitat, control measures can be focused along existing pathways. The greater the trail network, the more accessible the area will be to axis deer and the more difficult will be the control of deer habitation. Existing cattle and human trails should be allowed to become overgrown and unusable as pathways; forest openings should likewise be allowed to reforest to eliminate potential forage sites for deer. Efforts should be made to prevent having experienced, well-established deer occupying and populating forbidden sites; for this reason, moderate levels of control will likely be needed on a continual basis as long as deer populations exist on Maui.
Fortunately higher elevations of Haleakala, including most of the crater and dense ohia/koa forest regions, are not prime axis deer habitats. These ungulates prefer areas where grasses are more abundant, sites near tree or shrub cover. Temporary influxes of deer may occur at high elevations when conditions are not adequate in the lowlands, e.g., due to drought or when harassment drives deer away from preferred areas; yet those deer will likely return to former sites when permitted to do so as conditions improve. Care should be taken not to drive or entice intruding deer further into the interior of preserves. Control measures, therefore, should be designed to induce and direct deer to leave highland areas and forest interiors and return to lower elevations. For example, hunting and deer drives should begin at the interior and work outward.
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