Alpha Female Research Articles

A Ten-year History of the Demography and Productivity of an Arctic Wolf Pack

A pack of two to eight adult wolves (Canis lupus arctos) and their pups was observed during ten summers (1986-95) on Ellesmere Island, Northwest Territories, Canada. The author habituated the wolf pack to his presence in the first summer and reinforced the habituation each summer thereafter. The first alpha female produced four to six pups each year between 1986 and 1989. However, her daughter, who succeeded her as the alpha female, produced only one to three pups each year between 1990 and 1992 and in 1994, and apparently did not whelp in 1993 or in 1995. The tenure of the first alpha male was at least two years, and his successor was alpha male for the remaining eight years of the study. The wolf pack was characterized by highly variable annual productivity. The second alpha male-and-female breeding pair likely was an older brother and a younger sister. Early survival of wolf pups was high and constant, with all pups surviving through August of their first year. The pack's demography was consistent with what is known for wolf packs in other regions of North America, but its productivity was more typical of arctic packs.Key words: wolf, Canis lupus, productivity, demography, breeding tenure, survival

THE SOCIAL STRUCTURE OF CAPTIVE CAPE SPARROW FLOCKS

Summary Slotow, R., Goodfriend, W. & Maclean, G. 1993. The social structure of captive Cape Sparrow flocks. Ostrich 64:63-66. We documented the social structure of two mixed-sex flocks of Cape Sparrows in aviaries. Unlike previous studies on north-temperate passerines, we found that males were not necessarily dominant to females. Some males paired with females, and assisted these females in interactions. By such associations, these females may attain higher status than their individual ability would permit. We removed the dominant male in each group, and noted that the pair bond of the beta pair remained stable, and that a new male paired with the formerly dominant alpha female. The removal of the dominant alpha male may have decreased the alpha female's social status. We found no correlation between any morphometric variable and social status.

Female rank instability in newly formed groups of familiar sooty mangabeys (Cercocebus torquatus atys)

The formation of two new groups of sooty mangabeys (N=6; N=11) comprised of individuals removed from their natal group of 98 animals led to dominance rank challenges with aggression and wounding, though this occurred after an interval of months. Dominance rank challenges were not expected because, unlike rhesus macaques, adult female sooty mangabeys do not affiliate with adult kin significantly more than nonkin and show minimal agonistic aiding even with adult kin, thus rank would seem to be independent of aiding. Moreover, during the last nine years, severe wounding of adults in a large stable group of sooty mangabeys has been virtually absent and agonistic behavior in a stable group of sooty mangabeys is exhibited at a low rate compared to some macaque species. New members in the group of six maintained their relative ranks for 12 weeks after which the beta supplanted the alpha female with no serious wounding. This ranking remained stable for 29 weeks after which the alpha and beta females were supplanted with fatal wounds inflicted to the alpha and less severe wounds to the beta female. The second subgroup also kept their relative ranks initially. However, after 27 weeks the lowest ranking female severely wounded the next to last ranking female and 1 week later attacked and displaced the alpha female with minimal wounding. Fourteen weeks later the beta female (formerly the alpha) attacked and severely wounded the new alpha female and regained the top dominance position. These events suggest that although sooty mangabeys do not exhibit strong kin preferential behavior among adults, they do have defined relationships within the long term, stable group. Removal from those defined relationships allows the possibility of social reorganization that may be mediated by serious aggression.

Dominance Hierarchies and Helper Contributions in Harris' Hawks

We examined dominance hierarchies, mating relationships, and helping by individually marked Harris' Hawks (Parabuteo unicinctus) at 64 nests in Arizona (1984-1988). Dominance hierarchies were linear and always contained an adult female as the most dominant member. We placed hawks into three dominance categories (alpha, beta, and gamma) based on frequencies of supplanting. Pairs without helpers (16%, n = 64) and groups that contained a beta male helper (63%) were the most common social structures. Some groups (11%) contained a second alpha female (alpha-2) that was subordinate to the alpha female and dominant over the alpha male. Of 68 observations of copulatory behavior, 45 (66%) were copulations between alpha males and alpha females. Beta males attempted to copulate with alpha females (23 observations; 34%) but were unsuccessful because of a lack of female compliance. Observations of movements by marked hawks suggested that most gamma helpers were offspring of the alpha pair and that beta males and alpha-2 females were probably unrelated to the alpha pair. Alpha hawks restricted access to the nest by both beta and gamma helpers, but beta males were tolerated closer to the nest than were gamma helpers. Consequently, beta and gamma helpers rarely participated in the direct care of eggs and young but were active in procuring prey, transporting prey to the nest area, and defending the nest from predation by Great Horned Owls (Bubo virginianus).

Group fission in a semifree-ranging population of Barbary macaques (Macaca sylvanus)

During a 16-month study of semifree-ranging Barbary macaques (Macaca sylvanus) the group under observation divided into two groups. Observations were carried out in 1987–1988, at «La Montagne des Singes,” Kintzheim, France. A subgroup of monkeys, which was already cohesive at the beginning of the study, became progressively autonomous in relation to the rest of the main group, during the mating season. Overt aggression between the males of the two groups during this period brought about the fission. Only low-ranking genealogies left their group of origin. Dominance relations between females remained identical in both groups except for one lineage. The alpha male and the alpha female of the subgroup had a close relationship before the fission occurred. The sequence of agonistic intergroup relations is described and analyzed in relation to male sexual competition and female alliance power. The results suggest that: (1) the males of the subgroup instigated the fission because it was the best strategy for them to counter sexual competition; and (2) the females followed the males in order to maintain their alliance network, necessary to insure their dominance status over subordinate females.

Observation of a birth among wild toque macaques (Macaca sinica)

Most toque macaques give birth to their infants during the night when resting arboreally. Here we report on a birth that occurred in daytime (at 0916 hr) and on the ground. The mother was 7.6 years old; the birth was her second. Prepartum behaviors included lordosis, arching of the back, stretching, squatting, rolling on the ground, and anogenital self-examination. During the birth the female was isolated about 100 m from the rest of her group. The mother stood bipedally during parturition and assisted delivery with her hands. The infant was born within 2 min after first appearing at the vulva. It immediately clung to the mother’s leg and vocalized. The mother licked the infant and oriented it toward her ventrum. She resumed foraging behavior within 20 min after parturition. The infant nursed for the first time 2.25 hr after being born. The mother ate part of the placenta, but the alpha female of the group usurped and also ate a portion of it. Curious group members sniffed and looked at the infant but did not touch it.

First Wolf Den in Western U.S. in Recent History

Gray wolves (Canis lupus), once common throughout the conterminous United States, were exterminated everywhere except northeastern Minnesota by the 1930's (Mech 1970). The last wolf taken in Montana by a government trapper was in 1936 (Ream and Mattson 1982). In the northern Rocky Mountains, wolves have been observed and killed occasionally during the past 50 years, but no reproduction or dens have been documented (Brittan 1953; Day 1981; Ream and Mattson 1982; Singer 1979; Weaver 1978). This note describes a wolf den in Glacier National Park (GNP), Montana in 1986 and reports 5 additional dens in GNP and adjacent British Columbia (BC) in 1982, 1985, and 1987. The study area was in the North Fork Flathead River drainage and adjacent Wigwam River drainage immediately to the west and covered approximately 5000 km2. The North Fork originates in BC and flows 50 km southeast where it crosses into the U.S. and forms the west boundary of GNP for 70 km. Wolf surveys in Montana from 1972 to 1979 yielded no evidence of wolf reproduction, and an adult female wolf radio-collared 7 km northwest of GNP in 1979 did not den in 1979 or 1980 (Ream and Mattson 1982). The closest known breeding population to Montana prior to 1982 was approximately 100 km north of GNP in Alberta (Ream and Harris 1986). In 1982, a litter of 7 pups was discovered at a rendezvous site 10 km northeast of GNP (B. McLellan, pers. comm.). On 18 May 1985, McLellan captured a lactating female wolf (W8550) in a grizzly bear (Ursus arctos) leg hold snare, radio-collared and released her, and she returned to her den 12 km north-northwest of GNP within 24 hours. Seven black pups were observed near this den on 8 July 1985. W8550, another gray adult, 3 black adults and the 7 black pups (Magic Pack), moved south into GNP in November 1985, where it remained for most of the time thereafter. The size of the pack was reduced to 8 when 4 members of the pack disappeared in March, 1986. W8550 initiated denning activity 20 km south-southeast of the Canadian border in GNP on 15 April 1986, and remained at the den until 20 May when she began to move short distances. On 31 July she was observed from a fixed-wing aircraft at this den, with 5 pups and 7 other adults. The pack remained at the den and rendezvous site until 29 July when they moved 15 km north to another rendezvous site in GNP. On 6 August the authors hiked in to examine the den. The 1986 den consisted of 5 den openings dug into a flat-topped, heavily forested knoll that rose 3 m above an adjacent 2 ha meadow. Scats and trampled vegetation, and earlier aerial observations, indicated that the meadow was used as a rendezvous site after the pups left the den. The den openings were located within an area of 400 m2 extending 40 m along the edge of the knoll. Den openings were well hidden in Engelmann spruce (Picea engelmanni), Douglas-fir (Pseudotsuga menziesii), and lodgepole pine (Pinus contort) forest, with Engelmann spruce dominating at the immediate den openings. When visited in August, most of the meadow was dry, although wet meadow vegetation dominated the lower portions and the intermittent creek that meandered through the meadow. Three openings were dug down into the flat top surface of the knoll and 2 were dug into the steep, north-facing side. By wriggling in as far as possible and reaching with a 3 m wood stick, we could not reach the end of 1 north-facing den hole, probably the natal den. The other 4 holes were 1, 2, 2, and 3 m in depth. The entrance holes averaged 30 cm in width and 50 cm in height. Another den hole had been dug to a depth of 1 m, 400 m northwest of the den area described above. It probably was dug in the early spring and and not used much as there were only 2 old (>2 months) scats found near the entrance. It was in lodgepole pine, 5 m northwest of a 40 ha meadow and was more conspicuous than the other den holes. W8550 was apparently displaced as the alpha female of the Magic Pack in late January 1987 and was seen alone for several months thereafter north of the border. Later, 4 other members from the Magic Pack joined her and she denned in BC during late May. Remaining members of the Magic Pack denned in GNP in late April but we never found what we were sure was the natal den. Radiocollared male W8401, alone for 2 years, found a mate and denned in late April,40 km west-northwest of GNP in BC, 7 km north of Montana.

Group Fusion Among Wild Toque Macaques: an Extreme Case of Inter-Group Resource Competition

Group Fusion Among Wild Toque Macaques: an Extreme Case of Inter-Group Resource Competition

Social organization of the spotted hyaena Crocuta crocuta. II. Dominance and reproduction

A 4-year study of the social organization of spotted hyaenas in a clan of 60–80 individuals showed that there is a separate dominance hierarchy within each sex. One female and her descendants dominated all others; matrilineal rankings were stable over time because maternal rank is inherited. Cubs of higher ranking females were able to feed at kills in competition with adults more successfully than other cubs, and male offspring of the alpha female were the only males able to dominate adult females. The mating system is highly polygynous: only the behaviourally dominant male was seen to mate, though all other resident males regularly courted females. Among females, there was no correlation between reproductive success and age, size, or social rank. It is postulated that the unusually aggressive sons of the alpha female would probably be highly successful competitors in the context of a polygynous mating system. A primary consequence of female dominance over males is that females and their young have priority of access to food in a highly competitive feeding situation. This competition may have been the selective force that produced female dominance and the associated syndrome of female virilization that is characteristic of the species. Cooperation among related females may be the basis for the matrilineal system, as has been suggested for certain primate species.

The alpha female: observations on captive pigtail monkeys.

In an 11-month study, data on the establishment of dominance and grooming relations were collected over a 3-month period on an all-female pigtail monkey group. Subsequently, 3 adult males were introduced singly to the females and remained in the group for 1 month each. Data on social relations were collected to examine stability among female relationships with and without males present, and the dependence of female dominance on male support. The results revealed: (1) males were accepted into the group and attained dominance; (2) reciprocal affinitive relationships were established between each of the males and the alpha female, and (3) the alpha female's dominance status was independent of male preference for another female.

A description of genealogical rank changes in a troop of Japanese monkeys (Macaca fuscata)

Rank changes among females of a troop of 154 Japanese monkeys (Macaca fuscata) are described. A medium ranking female, with support from the alpha male, successfully challenged the alpha female. Following this dominance shift, almost all members of the two genealogical groups underwent rank changes. The observations provide some evidence that the role of alpha female may be competed for, just as the alpha male position is, in macaque social groups.

Mating relationships and breeding suppression in the dwarf mongoose

Dwarf mongooses live in packs containing a dominant breeding pair. The alpha female produces litters at regular intervals, usually three times per year. Other sexually mature females come into oestrus in synchrony with the alpha female and occasionally become pregnant but may not raise their offspring. Some females which had not been visibly pregnant nursed the young of other females. Early in the alpha female's oestrous cycle the alpha male maintains proximity and copulates with her exclusively, attacking any other adult males which approach. Later he also copulates with other adult females and the beta male mates with the alpha female. The alpha pair are likely to be the parents of the great majority of young born in the pack.

Behavioural Sequences and Strategies of Female Crab-Eating Monkeys, Macaca Fascicularis Raffles, 1821, During Group Formation Studies

Abstract Through introductions, reintroductions and fusion experiments with fourteen adult Macaca fascicularis (one male, thirteen females) we were able to demonstrate the following: 1. During introductions the alpha male and the alpha female perform special functions, and this corresponds to their behaviour in the group. 2. The relationships between the alpha male and the newly introduced animal develop according to a fixed rule with different stages of integration. Stage 1, 'pursuit', is followed by stage 2, 'presenting', stage 3, 'mounting', stage 4, 'biting on the back' and finally stage 5, 'mutual allogrooming'. The same rule applies to dyadic relationships in the females-only group. 3. The alpha female bites the newly introduced animal right at the beginning of the introduction - before or after the male. 4. Among the females there appears to be a natural ranking of animals into high-ranking and low-ranking individuals. Later rank is additionally dependent on various factors, such as time of introduction and relations with other animals. 5. To attain a higher rank, females use certain strategies. Two of these were recognized as the principal ones: avoiding of agonistic altercations and establishment of mutual allogrooming relations with higher-ranking animals.

Status referents in long-tailed macaques (Macaca fascicularis): Precursors and effects of a female rebellion

The antecedents and consequences of a change in status in the female line have been documented in the course of an ongoing study of a captive colony ofMacaca fascicularis. A conjunction of two events appears to have been a cause of the timing. The first is the maturation of the eldest female offspring of the subordinate lineage, and the second the insertion of an intrauterine device into the mother of that lineage. These changes made these two females simultaneously sexual associates of the adult male, while the dominant female of the other lineage was still pregnant. In the course of these events the maturing sub-adult female of the subordinate lineage underwent the most dramatic change of status, eventually rising from the lowest position to that of alpha female. The complex changes which heralded this alternation in status are described in terms of the referent relations and alliances which were evolving in the group.