Identification: Males reach 8–10 feet in length and have a massive neck, shoulders, and mane; females are smaller.

Social Organization

During the breeding season, females of each of these species aggregate into groups among which a smaller number of males are distributed. This organization has been mistakenly interpreted as a “harem” structure, when in fact males have little control over the movements of the females, whose grouping is often the result of seeking each other out while simultaneously avoiding males. In the Northern Fur Seal, nonbreeding animals and juveniles gather on islands separate from the breeding areas; nonbreeding groups also occur in the other two species. Outside of the mating season, Australian and New Zealand Sea Lions form smaller mixed-sex groups, while Northern Fur Seals are oceangoing, relatively solitary, and sex-segregated during the fall, winter, and spring.

Description

Behavioral Expression: In Australian and New Zealand Sea Lions, homosexual mounting is common: one male mounts the other from behind (as in heterosexual copulation) and makes pelvic thrusts against the other male. Homosexual copulation can take place either on the beach or in the surf (the latter especially among older males). All age groups participate, although there is often an age difference between the two males, with the younger male typically mounting the older one (especially in New Zealand Sea Lions). Among younger males, homosexual behavior is often a component of play-fighting, in which the two males stand chest to chest and push against one another, with each trying to grab the other’s neck in his mouth. Female Australian Sea Lions also occasionally mount one another, but lesbian mounting is more common in Northern Fur Seals. During the mating season, one female sometimes copulates with another by mounting her and performing pelvic thrusts; the mounted female often facilitates the homosexual mount by arching her back and extending her flippers, thereby making her genital region more accessible to the other female.

Frequency : Homosexual behavior occurs fairly frequently in Australian and New Zealand Sea Lions and occasionally in Northern Fur Seals.

Orientation: In Australian and New Zealand Sea Lions, younger males that do not associate with female groups may engage exclusively in homosexual activity, since many such individuals (which make up 81 percent of the New Zealand, and 33 percent of the Australian, male population) do not mate heterosexually. In New Zealand Sea Lions, adult breeding males also sometimes participate in homosexual mounting, making them bisexual, whereas in Australian Sea Lions, adult breeding males are exclusively heterosexual. In Northern Fur Seals, all females that participate in lesbian mounting are also active heterosexually, since they also mate with males. In fact, nearly all females involved in homosexual activity are mothers, although not all mothers engage in homosexual mounting. However, the amount of homosexual activity that an individual female participates in may be equal to or greater than her heterosexual activity, since females usually mate with a male only once during the entire breeding season.

Nonreproductive and Alternative Heterosexualities

In all three of these eared seals, significant proportions of the population do not breed. As noted above, more than 80 percent of New Zealand Sea Lion adult males, and a third of Australian Sea Lion males, do not participate in heterosexual mating. In Northern Fur Seals most males younger than nine years old do not mate because they cannot compete with older males for access to females, while most breeding males actually participate in reproduction for only a single season out of their entire lives. The average male copulates with females only 3–4 times during his life, and many males never do so. In addition, 8–17 percent of females on the breeding grounds do not get pregnant each year, and females generally reproduce only once every five years or so. In fact, nearly 60 percent of the total population consists of nonbreeders that do not even attempt to reproduce. Australian Sea Lions are unusual among mammals in having an exceptionally long or “supra-annual” breeding cycle, 17–18 months from mating to birth (most mammals complete the cycle in less than a year, allowing them to breed annually). Part of the reason for this extended cycle is because of the phenomenon known as DELAYED IMPLANTATION (also found in other seals), in which the fertilized egg fails to develop and instead remains in “suspended animation”—in this species, for as long as eight or nine months. In addition, late-term abortions are relatively common in Australian Sea Lions. Implantation in Northern Fur Seals is delayed for four to five months, but about 11 percent of embryos fail to implant or are aborted or reabsorbed.

In addition to this separation between insemination and fetal development, there is notable spatial and temporal segregation of the sexes in these species. In Northern Fur Seals, males and females go separate ways once the mating season is over: females range widely over the north Pacific Ocean while males remain in the Bering Sea. Since males and females interact for only two months out of the year, this means that the majority of their lives are spent apart from each other. Furthermore, the two sexes are often antagonistic when they are together. Male Northern Fur Seals sometimes try to prevent females from leaving their territory by throwing them bodily and flipping them into the air. Two males may also try to claim the same female by grabbing her with their jaws—sometimes while she is actually giving birth—causing severe lacerations or even death in the resulting tug-of-war. In Australian Sea Lions, “gangs” of younger males roam through the colony, sexually harassing females and attacking those that try to get away. A male New Zealand Sea Lion was once observed trying to copulate with a dead female New Zealand fur seal (Arctocephalus forsteri ), which he may have killed during a previous mating attempt. Sexual interactions between Northern Fur Seals and California sea lions (Zalophus californianus ) also occur, and male Northern Fur Seals have also been known to attempt forcible copulation with pups of their own species. In addition, male (and occasionally female) Australian Sea Lions often savagely attack pups, shaking, tossing, and biting them. Death from the resulting injuries is the primary cause of mortality for pups on land, accounting for nearly a fifth of all pup deaths in this species. About 17 percent of all Northern Fur Seal pup fatalities are due to attacks from adults (usually females).

In spite of these severe obstacles facing adult females and young seals, a number of innovative shared parenting or “day-care” arrangements have developed in these species. In Australian Sea Lions, females take turns watching over and defending a group of pups. In Northern Fur Seals, pups gather in nursery groups or PODS for protection while their mothers are away at sea—which is most of the time, since mothers usually spend only one day ashore each week and may be gone for up to 16 days at a time. Female Australian Sea Lions that have lost their own pup also sometimes try to abduct another female’s youngster.

IDENTIfICATION: A huge pinniped (up to 12 feet and 3,500 pounds in males) with sparsely furred, brownish orange skin, a bristled “mustache,” and prominent tusks in adult males. DISTRIBUTION: Throughout the

Arctic. HABITAT: Shallow waters, coastal areas, ice floes. STUDY AREAS: Round Island, Bristol Bay, Alaska; Coats Island, Hudson Bay; Bathurst and Dundas Islands, Northwest Territories, Canada; New York Aquarium; subspecies O.r. divergens, the Pacific Walrus, and O.r. rosmarus, the Atlantic Walrus.

Social Organization

From January to March (the breeding season), Walruses congregate far from shore on and around pack ice, where heterosexual courtship and mating take place. The mating system is polygynous—males generally copulate with several different females without forming long-lasting heterosexual bonds. During the summer and early fall, males gather together in large aggregations numbering in the thousands, typically on islands that are used for this purpose year after year. These “haul-outs” are sex-segregated. When both males and females are present, they tend to occupy distinct areas; more typically, however, the haul-outs are entirely male, since females and their young migrate to the far north to spend the summer.

Description

Behavioral Expression: In the shallow waters off the coast of the summer haul-out grounds, male Walruses engage in homosexual courtship, sexual, and affectionate activities. Pairs of males—sometimes as many as 50 animals at a time—float at the surface of the water by inflating special pouches in their throat, which act like the buoyant sacs in a life vest. While floating and swimming, the males—especially younger ones—rub their bodies against one another, clasp and embrace each other with their front flippers, touch noses, and loll together in groups. Males sometimes even sleep together in the water—pairs or groups of males float vertically at the surface (a posture known as BOTTLING), one behind the other, each male clasping the one in front of him in a “sleeping line.” Males also perform courtship displays for other males, employing a number of extraordinary behaviors and sounds that are also used in heterosexual courtship. Typically a younger male displays to an older one, and courting males often situate themselves in the water near a favorite cliff face, boulder, or rock formation at the water’s edge. The spectacular display consists of inflation of the throat pouches—often preceded by head bowing—interspersed with dives by one or both males, and an incredible series of vocalizations that form a courtship “song.” In homosexual encounters, at least three types of calls are used: KNOCKS, which are rapid, clicklike sounds resembling castanets, produced by “chattering” the cheek teeth underwater; a metallic BELL call, which is an eerie gonglike sound thought to be produced underwater by striking the throat pouches with the flippers to generate air pulses; and a short, piercing WHISTLE made through pursed lips when the Walrus resurfaces.

During same-sex courtship, sometimes one male rubs his erect, arm-sized penis with his front flipper. Overt sexual behavior between males takes the form of mounting (in the shallow water): one male clasps another with his flippers from behind, thrusting his pelvis and erect penis against the other male’s anal region. Younger males mount older ones and vice versa. Although most homosexual behavior is confined to the summer haul-outs, younger males sometimes also mount adults or other younger males during the breeding season. Groups of younger Walruses may crowd around an older male and roll on top of him; in addition, an adult male occasionally sings his courtship songs to a group of younger males or is accompanied by a younger attendant male while he sings. Often, his companion surfaces and dives in synchrony with him. This behavior, known as SHADOWING, occurs regardless of whether the adult is courting a female. In addition, male Walruses in captivity have been observed participating in cross-species homosexual encounters with male Gray Seals.

A male Walrus mounting another male off the coast of Round Island (Alaska), thrusting his erect penis (visible below the surface of the water) in the other male’s anal region.

Frequency: Male Walruses engage in homosexual activities frequently during the summer haul-outs: approximately a quarter of all social interactions of males in the shallow waters involve same-sex affectionate, courtship, or sexual behaviors. On average, each male participates in such activity roughly five times per hour when in the water, and contact between males (including sexual and courtship behaviors) occupies about 3 percent of the overall time spent by males in the water. Up to 2 percent of the total male population (which may number more than 3,000) may be in the water at any one time engaging in homosexual activities. During the breeding season, up to a third of mounting activity may take place between younger males or between adult and younger males, and 2-19 percent of singing males have a younger male companion “shadowing” them.

Orientation: Because male Walruses achieve sexual maturity approximately four years before they actually participate in breeding, a sizable segment of the population is probably involved exclusively in homosexuality for a portion of their lives. Roughly 40-60 percent of all sexually mature males—those between the ages of 10 and 14—do not participate in heterosexual mating, and a large proportion of these males engage in homosexual activity. Most older males are seasonally bisexual, courting and copulating with females during the mating season and participating in same-sex activities during the summer and early fall; some, however, also engage in same-sex mounting and companionships during the breeding season.

Nonreproductive and Alternative Heterosexualities

As noted above, male Walruses experience a delay in their breeding careers, since most do not begin mating heterosexually until about 40 percent of their maximum life span is over. Once they do begin procreating, often only a small percentage of males actually copulates each year, perhaps as few as a quarter of all adult males. Among females, about half of the individuals over the age of 23 are nonbreeding, experiencing a postreproductive or “menopausal” period that may last for 7 or more years. Because of their long pregnancy (15-16 months) and nursing period (two years), most breeding-age females do not reproduce every year. One reason the pregnancy is so long is because of DELAYED IMPLANTATION: after mating, the fertilized egg fails to implant in the uterus and temporarily stops developing, remaining in “suspended animation” for four to five months. This results in an even longer period that the two sexes are separated. Although their social life is characterized by extensive sex segregation (see above), Walruses do sometimes copulate outside of the mating season. Heterosexual matings have been recorded in nearly all months of the spring and fall. Because males have a distinct yearly sexual cycle—their testes are essentially dormant except during January-March—most of this sexual activity is nonreproductive. Even during the mating season, Walruses participate in a variety of nonprocreative sexual behaviors. REVERSE mountings, in which the female clasps the male from behind and mounts him, occur in the water, and younger, sexually immature individuals also mount each other. Females have also been observed sucking their partner’s penis as well as kneading it to erection with their flippers prior to copulation (in captivity). Outside of the breeding season, males masturbate by stroking their penis with a front flipper, sometimes accompanied by knock sounds or STRUM calls (the latter sounding something like the strumming of fingers on a guitar or zither). In addition, interspecies heterosexual copulations with Gray Seals have been seen in captivity.

As in many other polygamous mammals, female Walruses generally raise their young on their own, occasionally supplemented with a number of alternative parenting arrangements. Unrelated females and males may assist in the care and protection of calves, nursery groups of youngsters sometimes play together while their mothers are occupied during the mating season, and orphaned calves are commonly adopted by other mothers or nonbreeding females. Occasionally, females even try to steal or “kidnap” calves from other females. Unfortunately, the lives of a calf and its mother are often endangered by male violence. Calves are sometimes gored by a male’s tusks, while mass tramplings may occur on haul-out sites—often triggered by belligerent Walrus bulls roaming through groups of females and their young. In some locations, such stampedes occur regularly, littering the beach with hundreds and even thousands of carcasses each year. Nearly a quarter of all fatalities are calves less than six months old, while 15 percent are aborted fetuses.

IDENTIFICATION: A large (8-14 foot), streamlined, seal-like animal with a rounded tail, foreflippers but no hind legs, and a thick, hairless skin. DISTRIBUTION: Coastal waters and rivers of southeastern United States, the Caribbean, and northeastern Brazil; vulnerable. HABITAT: Shallow tropical and subtropical waters with abundant aquatic plants. STUDY AREAS: Crystal and Homosassa Rivers, Florida; subspecies T.m. latirostris, the Florida Manatee.

Social Organization

West Indian Manatees are generally solitary and only moderately social; however, they may congregate in loose herds of two to six animals. Some herds are cosexual, while others are “bachelor” groups of younger males.

Description

Behavioral Expression: Male West Indian Manatees of all ages regularly engage in intense homosexual activities. In a typical encounter, two males embrace, rub their genital openings against each other, and then unsheathe or erect their penises and rub them together, often to ejaculation. During a homosexual mating, the two males often tumble to the bottom, thrusting against each other and wallowing in the mud as they clasp each other tightly. A wide variety of positions are used, including embracing in head-to-tail and sideways positions, often with interlocking penises or flipper-penis contact. All of these are distinct from the position used for heterosexual copulation, in which the male typically swims underneath the female on his back and mates with her upside down. Lasting for up to two minutes, homosexual copulations are generally four to eight times longer than heterosexual ones. Before they engage in sexual activity, males often “kiss” each other by touching their muzzles at the surface of the water. In addition, several other types of affectionate and tactile activities are a part of homosexual interactions, including mouthing and caressing of each other’s body, nibbling or nuzzling of the genital region, and riding by one male on the back of the other (a behavior also seen in heterosexual interactions). Sometimes a male emits vocalizations indicating his pleasure during homosexual activity, variously described as high-pitched squeaks, chirp-squeaks, or snort-chirps. If, however, he is not interested in participating, he may emit a squealing sound, slapping his tail as he flees from the other male (just the way females do when trying to escape from unwanted advances of males).

Often several males participate at the same time in homosexual interactions: groups of up to four animals have been seen kissing, embracing each other in an interlocked “hug,” thrusting, and rubbing their penises against one another. These homosexual “orgies” can last for hours as new males arrive to join the group, subgroups form and re-form, and participants leave and return. Homosexual behavior is often part of a social activity known as CAVORTING, in which animals travel and splash about in groups, nuzzling, grabbing, chasing, rubbing, and rolling against one another. Cavorting groups can be mixed-sex or all-male.

Frequency: Homosexuality is common among West Indian Manatees. In addition, males spend on average about 11 percent of their time in cavorting groups.

Orientation: Most male Manatees are probably bisexual, since homosexual behavior is sometimes interspersed with, or develops out of, heterosexual interactions when more than one male is involved. However, much homosexual activity occurs independent of heterosexual activity, and some males may engage primarily in same-sex interactions.

Nonreproductive and Alternative Heterosexualities

Heterosexual interactions in West Indian Manatees often involve considerable harassment and coercion of females by males. Large, jostling herds containing as many as 17-22 males relentlessly pursue females in heat as well as nonfertilizable females, attempting to copulate with them and often following them for weeks at a time. In her attempts to escape from the males, the female may violently slap her tail, twisting and turning as she dives away, or else tear through the underwater vegetation, even plunging into the mud or stranding herself onshore. Calves whose mothers are being pursued sometimes get lost or are fatally fatigued or injured. Female Manatees generally reproduce only once every three years, and at any given time, only about 30-40 percent of all females are reproducing. Most male Manatees have a distinct seasonal sexual cycle as well, with their testes generally dormant and not producing sperm during the winter months. Females raise their young on their own with no help from the males. However, a mother will occasionally allow another female to nurse her calf or may leave her calf in the company of other mothers and/or their calves while she goes off to feed on her own.

Other Species

Homosexual activity has also been observed in Dugongs (Dugong dugon), a species of Manatee that inhabits Australasian waters. A pair of captive males, for example, engaged in courtship and sexual behaviors with each other, including rolling, nudging, gentle biting, and splashing, often with erect penises. Although same-sex activity has yet to be documented in wild Dugongs, most observations of mating activity for this species in the wild involve individuals whose sex has not been unequivocally determined.

Hoofed Mammals

DEER

WHITE-TAILED DEER

IDENTIFICATION: A medium-sized deer (approximately 3 feet tall at shoulder) with a white undertail and multipronged antlers that sweep forward. DISTRIBUTION: Southern Canada, United States except Southwest, Mexico south to Bolivia and northeastern Brazil. HABITAT: Varied, from thickets to open country. STUDY AREAS: Welder Wildlife Refuge, Sinton, Texas; Edwards Plateau, Llano County, Texas; subspecies 0.v. texanus, the Texas White-tailed Deer.

MULE DEER

IDENTIFICATION: A stocky, grayish deer with a black-tipped tail and antlers that branch into two equal portions. DISTRIBUTION: Western North America, northern Mexico. HABITAT: Semiarid forest, brushlands. STUDY AREAS: Waterton and Banff National Parks, Alberta, Canada; University of British Columbia, Canada; near Fort Collins, Colorado; subspecies O.h. hemionus, the Rocky Mountain Mule Deer, and O.h. columbianus, the Black-tailed Deer.

Social Organization

During most of the year, White-tailed and Mule Deer live in sex-segregated groups: females form groups with other does and their offspring, while males (bucks) live in “bachelor” groups or on their own. During the rutting season, males form short-lived, consecutive “tending bonds” with multiple females—a form of polygamy or “serial monogamy.” Larger cosexual groups may also form during the winter.

Description

Behavioral Expression : Adult male White-tailed Deer sometimes mount each other, as do yearling males (especially during the nonbreeding season); occasionally a younger male mounts an older one during this activity. Homosexual mounts (like heterosexual ones) are usually preceded by one male nuzzling the other’s rear end, and sometimes one male mounts another twice in a row; occasionally the mounting buck has an erection. The mount may be briefer than a male-female copulation, but the same duration as heterosexual nonreproductive mounts (5-15 seconds, as opposed to 15-20 seconds). Yearling Mule Deer occasionally mount each other during SPARRING MATCHES—ritualized, nonviolent contests in which the bucks lock horns. During this activity one male might assume a stiffened posture, similar to a female’s before copulation. The other male—sometimes younger or smaller than the first—then mounts him, after first licking and smelling the special scent-producing glands on his hind legs. Female Mule Deer also sometimes mount each other when in heat; in addition, some does court other females using a chasing sequence known as RUSH COURTSHIP. In this behavior (which also occurs in heterosexual contexts), they race toward another female, stopping abruptly and sometimes pawing the ground, pacing, leaping into the air while twisting their body, or running in circles or figure eights; this causes the other doe to become excited and aroused. Adult male White-tailed Deer frequently develop “companionships” or bonds with one (or occasionally two) other adult males in their buck groups; male companions are generally not related to each other. These strong attachments constitute the stable “core” of each buck group, and although male companions typically separate during the breeding season, they usually resume their bonds once mating is over.

An extraordinary form of transgendered deer occurs in some populations of White-tails. These animals, which are genetically male but actually combine characteristics of both males and females, are sometimes called VELVET-HORNS because their antlers are permanently covered with the special “velvet” skin that in most males is shed after the antlers have grown. Their antlers are usually only spikes (without the extensive branching of other males’ antlers) and they slope backward and sometimes have enlarged bases. Physically, velvet-horns often have body proportions and facial features more typical of does, while their testes are small and undeveloped (and in fact the animals are infertile). A similar type of transgender is found among Mule Deer, where the animals are known as CACTUS BUCKS owing to the distinctive shape of their antlers (which sometimes also have elaborate spikes, prongs, and asymmetrical growths). Velvet-horns usually form their own social groups of three to seven animals and live separately from both does and nontransgendered males. In fact, they are often harassed and attacked by other deer. Nontransgendered White-tails (both does and bucks of all ages, even fawns) threaten velvet-horns who try to approach them—forcing them to remain no less than ten feet away—while bucks may actively charge velvet-horns to drive them away. When threatened, velvet-horns flee without giving the standard alarm signals of other deer (stamping their feet, snorting or whistling, and raising their tails). Sometimes, groups of up to six bucks “gang up” on a velvet-horn, chasing and even violently attacking it by gashing its rump with their antlers. As a result, velvet-horns are extremely wary around other deer, venturing near feeding areas cautiously and always remaining in groups on the periphery, or else refusing to approach at all when other deer are present. Interestingly, velvet-horns are almost always in superior physical condition compared to nontransgendered males, precisely because they do not breed. The rutting season is extremely taxing on breeding bucks, who rarely eat and may lose up to a quarter of their body weight. In contrast, velvet-horns consistently have excellent body fat deposits and are in prime shape.

A male White-tailed Deer mounting another buck

A transgendered “velvet-horn” White-tailed Deer

Two types of gender-mixing females also occur among White-tailed and Mule Deer, both bearing antlers (females in these species do not usually have antlers). In one type, the antlers are similar to those of velvet-horns: they are permanently covered in velvet, are never shed, and are either spikes or asymmetrically branching. Unlike velvet-horns, such females are usually fertile, mating heterosexually and becoming mothers. The other type is a more complete form of intersexuality: the antlers are hard and polished, more closely resemble those of males in their branching structure, and may even be shed seasonally. These individuals usually combine both male and female sexual traits, such as having the genitalia and/or reproductive organs of both sexes, or partial organs of each sex, or chromosomes of one sex combined with the genitalia of the other.

Frequency: Homosexual mounting probably occurs only occasionally among White-tailed and Mule Deer; however, in one study of White-tails, two out of ten observed mountings were same-sex. Up to 10 percent of males are velvet-horns in some areas, although their incidence fluctuates. In some years they may constitute as many as 40-80 percent of all males in a given population. One study of a White-tailed Deer population over 14 years found that 1-2 percent of the females had antlers; overall, approximately 1 in every 1,000-1,100 does is antlered.

Orientation: Most Deer that participate in same-sex mounting probably also engage in heterosexual courtship and copulation. Gender-mixing Deer that are fertile (almost always genetically female) are usually heterosexual (i.e., they mate with genetic males), while nonfertile transgendered Deer (e.g., velvet-horns) are probably asexual or associate only with other transgendered Deer.

Nonreproductive and Alternative Heterosexualities

Deer participate in a variety of nonprocreative sexual behaviors besides homosexuality. White-tails sometimes engage in heterosexual mountings outside of the mating season, which are nonreproductive for two reasons. They often do not involve penetration, and bucks have a seasonal sexual cycle, so that during the spring and summer their testes are small and produce little, if any, sperm. Mating episodes among Mule Deer during the breeding season often involve the male performing extensive non-insertive sexual activity prior to actual copulation: in this activity he mounts the female with his penis erect (unsheathed) but without penetration. These mounts may be fairly lengthy—up to 15 seconds—and frequent (anywhere from 5 to more than 40 in one session). Bucks of both species sometimes masturbate in a unique fashion: the penis is first unsheathed and licked, then stimulated by moving it back and forth (via pelvic rotations and thrusts) in its sheath or against the belly until orgasm is reached. Because their antlers are actually sensitive—even erotic—organs (as in several other species of Deer), buck Mule Deer also sometimes sexually stimulate themselves by rubbing their antlers on vegetation. Incestuous activity—including fawns mounting their mothers—also occurs in these species.

As mentioned above, sex segregation is a notable feature of White-tailed Deer society. This pattern usually begins during the fawning period, when does become aggressive toward adult males and may even kick and chase them away. When their male fawns become yearlings, females also drive them away in the same violent fashion. In addition to nonbreeding transgendered animals, other nonreproducing individuals occur. White-tail bucks often do not mate until they are three to five years old; because of the physical stresses of reproduction, bucks that delay breeding may actually grow larger than those that reproduce earlier. When breeding does occur, females of both species sometimes terminate their pregnancies by aborting the fetus or reabsorbing the embryo. This probably occurs in 1-10 percent of Mule Deer pregnancies, but is more likely to happen when unfavorable climate and forage would make it difficult for mothers to feed and care for their young.

WAPITI/RED DEER