Typical Group Size Research Articles

Investigating local concerns regarding large mammal restoration: group size in a growing population of reintroduced bison (Bison bison)

Group size of gregarious ungulates typically are fluid and may be density dependent. Local people in Yukon, Canada, were concerned that increasing abundance of reintroduced bison (Bisonbison) would result in larger groups, leading to increased human-bison conflicts (e.g., property damage, environmental impacts, and aggressive behaviour). Yet, the influence of abundance on group sizes was unknown. To investigate this concern, I used 15 years of group size data (n = 1447 groups) to test the hypotheses that group sizes a) increased with abundance, and b) varied seasonally. To determine the effect of abundance, I assessed summer and late-winter group sizes for three 5-year periods corresponding to a period when the population tripled in size. Neither summer nor late-winter group sizes differed significantly in response to a three-fold change in population density, contrary to my hypothesis and that of local people. Mean and typical group sizes varied seasonally, with those in summer being greatest and those in fall and late winter the smallest. This study provided new information on grouping dynamics of forest-dwelling bison within and between years and demonstrated that group size did not vary in response to a three-fold increase in density, but that there were strong seasonal effects. As such, growing populations of reintroduced bison will likely not result in larger group sizes at the densities observed in this study. The potential for human-bison conflicts may be greatest during summer when bison aggregate. Overall, these data suggest that concerns regarding larger groups due to reintroduced populations growing may not be warranted. Importantly, however, the number of groups on the landscape will increase with population size, and conflicts with local people will likely continue regardless of group size. Acknowledging and addressing the concerns of local people is likely key for increasing their social carrying capacity for reintroduced bison, and successfully restoring them into regional socio-ecological systems.

Common dolphin Delphinus delphis occurrence off the Wild Coast of South Africa

Despite their typical large group sizes, limited research exists on the occurrence of common dolphins Delphinus delphis because of the pelagic, offshore nature of this species and the lack of barriers to their movement in this environment. The main purpose of our study was to investigate the occurrence of common dolphins off the Wild Coast of South Africa (western Indian Ocean) and whether spatiotemporal and environmental conditions affected their encounter rate, relative abundance and mean group size. The annual sardine run in this region, during austral winter (May to July), is considered a main driver of dolphin occurrence; however, our boat-based surveys over the period 2014–2016 indicated that common dolphins occur and feed in this area outside of this time-frame. In terms of environmental factors, the largest group (∼1 250 animals) was found in the deepest waters. Additionally, at Hluleka, dolphins were observed primarily feeding, which could suggest that this coastal area is highly productive. As common dolphin distribution is thought to be correlated with prey distribution, our findings suggest that sufficient prey exists along the Wild Coast both during and outside the annual sardine run to sustain large groups of the dolphins and that their presence in the area is not solely a function of the sardine run.

Comparison of measures of crowding, group size, and diversity

AbstractIn ecology, diversity is often measured as the mean rarity of species in a community. In behavioral sciences and parasitology, mean crowding is the size of the group to which a typical individual belongs. In this paper, focusing mostly on the mathematical aspect, we demonstrate that diversity and crowding are closely related notions. We show that mean crowding can be transformed into diversity and vice versa. Based on this general equivalence rule, notions, relationships, and methods developed in one field can be adapted to the other one. In relation to crowding, we introduce the notion “effective number of groups” that corresponds to the “effective number of species” used in diversity studies. We define new aggregation indices that mirror evenness indices known from diversity theory. We also construct aggregation profiles and orderings of populations based on aggregation indices. By uniting the mathematical interpretation of the ecological notion of diversity and the ethological notion of typical group size (or crowding, in parasitology), our insight opens a new avenue of both theoretical and methodological research. This is exemplified here using real‐life abundance data of avian parasites.

Infectious Disease and Grouping Patterns in Mule Deer.

Infectious disease dynamics are determined, to a great extent, by the social structure of the host. We evaluated sociality, or the tendency to form groups, in Rocky Mountain mule deer (Odocoileus hemionus hemionus) from a chronic wasting disease (CWD) endemic area in Saskatchewan, Canada, to better understand factors that may affect disease transmission. Using group size data collected on 365 radio-collared mule deer (2008–2013), we built a generalized linear mixed model (GLMM) to evaluate whether factors such as CWD status, season, habitat and time of day, predicted group occurrence. Then, we built another GLMM to determine factors associated with group size. Finally, we used 3 measures of group size (typical, mean and median group sizes) to quantify levels of sociality. We found that mule deer showing clinical signs of CWD were less likely to be reported in groups than clinically healthy deer after accounting for time of day, habitat, and month of observation. Mule deer groups were much more likely to occur in February and March than in July. Mixed-sex groups in early gestation were larger than any other group type in any season. Groups were largest and most likely to occur at dawn and dusk, and in open habitats, such as cropland. We discuss the implication of these results with respect to sociobiology and CWD transmission dynamics.

Comparing radio-tracking and visual detection methods to quantify group size measures

Abstract1. Average values of animal group sizes are prone to be overestimated in traditional field studies because small groups and singletons are easier to overlook than large ones. This kind of bias also applies for the method of locating groups by tracking previously radio-collared individuals in the wild. If the researcher randomly chooses a collared animal to locate a group to visit, a large group has higher probability to be selected than a small one, simply because it has more members.2. The question arises whether location of groups by means of finding collared animals has smaller or greater bias than searching for groups by visual observation. If the bias is smaller or same, this method can be recommended for finding groups. However, such a comparison cannot be made by speculation, only by empirical investigation.3. The present study compares the two methods empirically, by statistically comparing group size measures (mean, median, quantiles, frequency distribution, and ‘typical group size’) between two data sets. These data sets comprise of Rocky Mountain mule deer group size values collected in the same area during the same period of time, referring either to groups located by the traditional ‘search and observe method’ or located by tracking formerly collared individuals.4. All group size measures are statistically similar in the two samples, thus we conclude that the two methods yielded similar biases. Although the true group size measures are not known, we presume that both methods have overestimated them. We propose that these results do not necessary apply to other species, thus cannot be generalized. The reason for this is that bias may depend on factors specific to the species: bias of visual observation may depend on how well the species conceals itself in the existing habitat, and the bias associated with finding groups using collared animals is likely dependent on group size distribution and also on the proportion of collared animals in the population.

English

This study was conducted in 2009 and 2011 in the Bale Mountains National Park in Ethiopia to assess social organization of endemic and endangered mountain nyala. The main objectives of this study were to identify social group types of the mountain nyala in the park, and to determine the frequency of occurrences, group sizes and number of age/sex categories in social group types. Based on age/sex composition, five social group types were distinguished: all-male, all-female, male-female, female-juvenile and male-female-juvenile group types. A total of 572 groups and 5187 individuals of mountain nyalas were recorded during the study period. Overall mean and typical group sizes for the species were 9.1 ± 0.5 (range: 1–107) and 24 animals, respectively. Male-female-juvenile social group type was the most frequently observed group type (31% of the total records), contained the highest proportion of animals recorded (64%) and had the largest mean group size (18.5 ± 0.8) and typical group size (31.9) than the other social group types. Lone animals constituted 16.3 and ~2% of the total groups and animals recorded, respectively, in which over two-thirds of them were adult males. Both mean number and proportion of individuals of each age/sex category across social group types significantly increased when they were associated with one or two other age/sex categories than when not associated. In general, data presented here represents the first detailed information available on the species’ social organization behaviour and provides important base-line information. Key words: Group size, mountain nyala, park, social group, social organization.

Effects of males’ presence on female behaviour during the rut

Females’ dispersion during the mating season has been regarded as being determined primarily by the distribution of food resources. However, females’ distribution and behaviour may also be affected by the males’ availability during rut. Indeed, it is challenging to disentangle female dispersion for food from female mate choice. We present the results of female reindeer (Rangifer tarandus) behaviour in two manipulated herds during the peak week of the rut: one without males (MA) and one with males present (MP). Presence of males did not influence mean typical group size of females (MP herd: 10.14, MA herd: 11.85). However, females in the MA herd travelled longer daily distances (1.8 km) compared to females in the MP herd (1.3 km). The proportion of the time females spent feeding (~ 75%), walking (~ 16%), and standing (~ 8%) did not differ between the herds, whereas mating-related behaviour was, as expected, significantly higher in the MP herd, although it accounted for only 1.4% of their observed activity. The high proportion of time spent feeding indicates that females’ movement is driven primarily by maximizing forage intake. No difference in the females’ somatic body weight change during rut between the two herds indicates low cost of female mating related activities during rut. Contrary to our predictions, the results showed that female reindeer behaviour during the mating season is not affected by male availability, male mating or courtship behaviour, but is primarily driven by distribution of food resources.

Group Size Predicts Social but Not Nonsocial Cognition in Lemurs

The social intelligence hypothesis suggests that living in large social networks was the primary selective pressure for the evolution of complex cognition in primates. This hypothesis is supported by comparative studies demonstrating a positive relationship between social group size and relative brain size across primates. However, the relationship between brain size and cognition remains equivocal. Moreover, there have been no experimental studies directly testing the association between group size and cognition across primates. We tested the social intelligence hypothesis by comparing 6 primate species (total N = 96) characterized by different group sizes on two cognitive tasks. Here, we show that a species’ typical social group size predicts performance on cognitive measures of social cognition, but not a nonsocial measure of inhibitory control. We also show that a species’ mean brain size (in absolute or relative terms) does not predict performance on either task in these species. These data provide evidence for a relationship between group size and social cognition in primates, and reveal the potential for cognitive evolution without concomitant changes in brain size. Furthermore our results underscore the need for more empirical studies of animal cognition, which have the power to reveal species differences in cognition not detectable by proxy variables, such as brain size.

A volumetric comparison of the insular cortex and its subregions in primates

The neuronal composition of the insula in primates displays a gradient, transitioning from granular neocortex in the posterior-dorsal insula to agranular neocortex in the anterior-ventral insula with an intermediate zone of dysgranularity. Additionally, apes and humans exhibit a distinctive subdomain in the agranular insula, the frontoinsular cortex (FI), defined by the presence of clusters of von Economo neurons (VENs). Studies in humans indicate that the ventral anterior insula, including agranular insular cortex and FI, is involved in social awareness, and that the posterodorsal insula, including granular and dysgranular cortices, produces an internal representation of the body's homeostatic state. We examined the volumes of these cytoarchitectural areas of insular cortex in 30 primate species, including the volume of FI in apes and humans. Results indicate that the whole insula scales hyperallometrically (exponent = 1.13) relative to total brain mass, and the agranular insula (including FI) scales against total brain mass with even greater positive allometry (exponent = 1.23), providing a potential neural basis for enhancement of social cognition in association with increased brain size. The relative volumes of the subdivisions of the insular cortex, after controlling for total brain volume, are not correlated with species typical social group size. Although its size is predicted by primate-wide allometric scaling patterns, we found that the absolute volume of the left and right agranular insula and left FI are among the most differentially expanded of the human cerebral cortex compared to our closest living relative, the chimpanzee.

Responsiveness to Intervention in Reading

This article describes how a purposeful sample of 62 elementary schools from 17 states implemented a Response to Intervention (RtI) framework for reading. School informants answered surveys and were interviewed about differentiated instruction in Tier 1, screening/benchmarking, where Tier 2 interventions were located, typical group size and the minutes/day of intervention in Tiers 2 and 3 groups, and how students with individualized educational programs (IEPs) in reading were served in the school’s RtI model. Schools reported using differentiated instruction in Tier 1, favored curriculum-based measures for screening/benchmarking and progress monitoring, reported more intensive interventions and more progress monitoring in Tier 3, and used a wide variety of models for serving students with IEPs within the schools’ RtI models.

Group dynamics of Yellowstone pronghorn

Abstract Understanding mechanisms that influence the grouping tendencies of large herbivores is necessary to predict the influence of environmental and human factors on threatened populations. Locations of 53 adult female pronghorn (Antilocapra americana) in Yellowstone National Park during June 1999–April 2005 indicated that mean and typical group sizes and the variation in group size decreased during fawning when females secluded themselves, but became larger and more dynamic during fawn rearing and the rut and winter. Mixed-effects models indicated a strong effect of time of year on mean group sizes, with some evidence that predators negatively affected group sizes during winter. Within-animal variability (0.64) was substantially higher than between-animal variability (0.02). Pronghorn density, snow water equivalent, and predation apparently influenced variations in group size. Multiple regressions indicated effects of pronghorn density and snow water equivalent on typical group size, the size of the g...

Comparing Costs of Telephone vs Face-to-Face Extended-Care Programs for the Management of Obesity in Rural Settings

BackgroundA major challenge after successful weight loss is continuing the behaviors required for long-term weight maintenance. This challenge can be exacerbated in rural areas with limited local support resources. ObjectiveThis study describes and compares program costs and cost effectiveness for 12-month extended-care lifestyle maintenance programs after an initial 6-month weight-loss program. DesignWe conducted a 1-year prospective randomized controlled clinical trial. Participants/settingThe study included 215 female participants age 50 years or older from rural areas who completed an initial 6-month lifestyle program for weight loss. The study was conducted from June 1, 2003 to May 31, 2007. InterventionThe intervention was delivered through local Cooperative Extension Service offices in rural Florida. Participants were randomly assigned to a 12-month extended-care program using either individual telephone counseling (n=67), group face-to-face counseling (n=74), or a mail/control group (n=74). Main outcome measuresProgram delivery costs, weight loss, and self-reported health status were directly assessed through questionnaires and program activity logs. Costs were estimated across a range of enrollment sizes to allow inferences beyond the study sample. Statistical analyses performedNonparametric and parametric tests of differences across groups for program outcomes were combined with direct program cost estimates and expected value calculations to determine which scales of operation favored alternative formats for lifestyle maintenance. ResultsMedian weight regain during the intervention year was 1.7 kg for participants in the face-to-face format, 2.1 kg for the telephone format, and 3.1 kg for the mail/control format. For a typical group size of 13 participants, the face-to-face format had higher fixed costs, which translated into higher overall program costs ($420 per participant) when compared with individual telephone counseling ($268 per participant) and control ($226 per participant) programs. Although the net weight lost after the 12-month maintenance program was higher for the face-to-face and telephone programs compared with the control group, the average cost per expected kilogram of weight lost was higher for the face-to-face program ($47/kg) compared with the other two programs (approximately $33/kg for telephone and control). ConclusionsBoth the scale of operations and local demand for programs are important considerations in selecting a delivery format for lifestyle maintenance. In this study, the telephone format had a lower cost but similar outcomes compared with the face-to-face format.

Risikofaktoren, klinisches Bild, Therapie und Zoonoserisiko bei Kaninchen mit Dermatophytose

The aim of this study was to evaluate the environmental factors, clinical signs, therapy and zoonotic risk of pet rabbits with dermatophytosis. In the present study, questionnaires with separate questions for the veterinarian and the owners were sent to veterinarians who treated rabbits with positive fungal cultures. Eleven of the questionnaires were completed by veterinarians and owners, while eight questionnaires were exclusively answered by the veterinarians. The questionnaires included questions on the environment of the animals (origin, maintenance, feeding, group size, new arrivals, changes), clinical signs, diagnosis, therapy and zoonosis. Trichophyton (T.) mentagrophytes (m.) was the most frequently isolated dermatophyte species (15/19). Half of the animals were younger than five months and female rabbits were affected twice as frequently. In four of 11 cases new rabbits arrived in the household in the weeks prior to the onset of the dermatophytosis and in seven cases the affected animals lived in the household for less than three months. The typical group size was two animals and in half of the cases the companion rabbit was also affected. The rabbits most often showed alopecia with scaling and/or crusts, especially on the head, the ears being affected in half these animals. In three of 11 cases (27.3%) children in the family showed clinical signs of dermatophytosis, with lesions located on the hands, face and shoulder. Pet rabbits with dermatophytosis must be considered a serious zoonotic risk for their owners, especially children. In this study, risk factors for dermatophytosis appear to be the recent acquisition of a new rabbit and the age of the animals. In rabbits with alopecia with scaling and/or crusts on the head, a dermatophyte infection should be ruled out. The owner should be adequately informed about the zoonotic risk of dermatophytosis, especially if children live in the household.

Social structure of the declining resident community of common bottlenose dolphins in the Sado Estuary, Portugal

The resident population of common bottlenose dolphins (Tursiops truncatus) in the Sado Estuary, Portugal, has been declining at least during the past three decades. A complete photographic census produced a current count of 24 animals—19 adults, three subadults and two calves. It appears to be phylopatric and essentially closed, but given the likely importance that exchanges with neighbouring coastal groups may play, even if rare, the most adequate term to define this dolphin should be community and not population. Large groups with all age-classes are common in the community, possibly as a calf and subadult protection strategy, and this may be related to the fact that these age-classes have had high mortality rates in the last decade. Maternity of two calves was determined, and we found that the two mothers adopted different parenting strategies. While one mother spent more time alone with her calf, the other mother spent more time with her calf in larger groups. The average coefficient of association for this community is 0.45, quite high for this species. Associations and typical group size are similar between all individuals, with no patterning according to age-class or sex, which constitutes an atypical trait for dolphin societies. There are also no clear divisions in this community according to cluster analysis. Associations are preferred and long term, lasting approximately 34 days and fitting a pattern of casual acquaintances, where individuals associate for a period of time, disassociate and may reassociate after that. This reflects the fission–fusion character of the community, but in a more stable manner. We think this is caused by a combination of demographic characteristics and a stable and productive environment, which led to a decrease in competition between individuals.

Performance Comparisons of Different Multicast Routing Protocols: ODMRP and AM Route

Multicasting can be efficiently supported a variety of applications that are characterized by a close degree of collaboration, typical for many ad-hoc applications currently envisioned. Within the wired network, well-established routing protocols exist to offer an efficient multicasting service. As nodes become increasingly mobile, these protocols need to evolve to similarly provide an efficient service in new environment. This paper discusses the performance of two proposed multicast protocols for adhoc networks: ODMRP and AMRoute. AMRoute as logical core and are responsible for initiating and managing the signaling component of AMRoute such as detection of group members and tree setup. Logical cores differ significantly from those in CBT and PIM-SM, since they are not a central point for data distribution and can migrate dynamically among number of nodes. Simulation results (using NS-2) specify that AMRoute signaling traffic remains at relatively low level for typical group sizes. ODMRP maintains mesh based on softstate. The results show that in many scenarios ODMRP achieves a higher packet delivery ratio, but results in much higher overheads. Keywords: - ODMRP, AMRoute, MANETs, NS2, Multicasting.

The social organization of sperm whales in the Gulf of California and comparisons with other populations

Intra-specific variation in social organization provides valuable insights into the selective forces driving social evolution. Sperm whales are distributed globally and live far from shore, thus obtaining large sample sizes on social organization in multiple areas is logistically challenging and few comparative studies exist. In order to address how ecological factors influence sociality, we investigated the social organization of sperm whales in the Gulf of California (GoC) using a long-term study (1998–2004) and compare our results to other published studies. Standard photo-identification and behavioural observation techniques were used. Group size was calculated from photographic mark–recaptures using a Petersen estimator. Social organization was investigated using SocProg 2.3. Mean typical group sizes in the GoC were similar to those in the Galápagos Islands, Chile and Seychelles (24.7, 24.8, 30.4 and 18 individuals respectively), but substantially larger than in the Sargasso Sea, Caribbean and northern Gulf of Mexico (12.0, 6.4 and 6.9 individuals respectively). Sperm whale social organization in the GoC best fitted a constant companion/casual acquaintance model, where permanent units sizes were 12.5 individuals and two units usually associated together to form a group. This structure is similar to the situation in the Galápagos Islands and Chile areas. However, groups were more stable in the GoC than in the South Pacific, as groups stayed together for periods of about 80 days versus about ten days in the Galápagos Islands and Chile. It is likely that differences in the social organization between the study areas in the Pacific and Atlantic Oceans were due to differences in predation pressure and/or food resources. We suggest that, site-specific ecological factors are likely to influence fundamental aspects of sperm whale social organization.

Seasonal variation in social organisation and diurnal activity budget of the Greater Rhea (Rhea americana) in the Argentinean pampas

We analysed seasonal variation in the size and composition of groups, and individual behaviour, of a wild population of Greater Rheas (Rhea americana) in the Argentinean pampas. We performed seasonal censuses over 8 years, and made focal observations on 59 individuals from different groups to assess the proportion of time spent in vigilance, feeding, walking, preening or resting, and noted the number of courtship displays, copulations and aggressive interactions. Rheas were solitary or formed groups of 2–20 individuals. Mean typical group-size (TGS) over the year was 7.61 birds but varied significantly with season, TGS decreasing during the breeding season (spring), possibly owing to formation of harems. TGS of males decreased in spring whereas TGS of females did not vary seasonally. During spring, individuals spent more time vigilant and less time feeding, and were involved in many courtship interactions. Most aggression (72%) was between males and mainly occurred during winter and spring, suggesting strong intrasexual competition. Social organisation and group dynamics appear to be profoundly affected by the mating system of the Greater Rhea.

Social organisation and population structure of ungulates in a dry tropical forest in western India (Mammalia, Artiodactyla)

Grouping characteristics and population structure of chital (Axis axis Erxleben), sambar (Cervus unicolor Kerr), nilgai (Boselaphus tragocamelus Pallas) and chinkara (Gazella bennetti Sykes) were studied in dry tropical forests of Ranthambhore Tiger Reserve in semi-arid western India during November 2000 to April 2001. Mean and typical group sizes were highest for chital (winter: 4.7 and 9.2, respectively; summer: 4.5, 7.9), followed by sambar (winter: 3.4, 4.2; summer: 4.2, 6.8), nilgai (winter: 2.9, 4.5; summer: 2.5, 4.9) and chinkara (winter: 2.6, 3.3; summer: 2.5, 3.2). Population structure was biased towards females in chital (86.4 males: 100 females) and sambar (83.2:100), while it was biased towards males in nilgai (116.8:100) and chinkara (119.8:100). Ratio of young to adult females was highest for sambar (38.2 young: 100 females), followed by chinkara (35.2:100), chital (28.0:100) and nilgai (23.9:100). Variations in grouping patterns according to habitat and season have been investigated. The importance of constant monitoring of ungulate population structure is emphasised for this drought prone region.

Dynamic social system in Nubian ibex: can a second mating season develop in response to arid climate?

AbstractWe studied a population of Nubian ibex Capra ibex nubiana in the eastern extreme of its range, the hyper‐arid central desert of the Sultanate of Oman. Long‐term data were collected from January 1983 to December 1997 by direct observation, as well as VHF telemetry on 12 animals (eight from 1987 to 1990; four from 1994 to 1996). We recorded 884 sightings: 40.4% of single animals and 59.6% of groups. Although no significant monthly variation of group size (Jarman's Typical Group Size) was found, there were distinct peaks in March (4.0 ind. group−1) and September (5.1 ind. group−1). Groups of males and females formed especially in March and November, and female–kid groups in February and July–August. Our data may suggest two mating periods: the first one in autumn (similar to the rut of ibex in temperate mountain areas), with kids born in spring/early summer, after winter–spring rainfall, and the second one in spring, with kids born in late summer/autumn, before winter–spring rainfalls. We suggest that the second rutting period may have evolved as a micro‐evolutionary process, with the local population adapting to hyper‐arid environment constraints. The spring mating season may favour only females in prime conditions, who can afford a pregnancy in the local severe summers and will deliver kids when plant greening begins, in the autumn, whereas the autumn (original) mating season may be afforded by any female, but kids will be born in an unfavourable period, before the summer drought.

The DPOSS II compact group survey: first spectroscopically confirmed candidates

This paper presents the results of a pilot redshift survey of 18 candidate compact groups from the distant DPOSS survey that extends to redshift ∼0.2 the available surveys of compact groups of galaxies, mainly Hickson Compact Groups and Southern Compact Groups. The goal of our survey was to confirm group membership via redshift information and to measure the characteristic parameters of a representative, albeit small, sample of DPOSS survey groups. Of the 18 candidates observed, seven are found to be indeed isolated compact groups, i.e. groups with 3 or more concordant members and with no neighbouring known cluster, while 7 are chance projection configurations on the sky. Three remaining candidates, despite having 3 or more concordant member galaxies, are located in the neighbourhood of known clusters, while another candidate turned out to be a dense sub-condensation within Abell 0952. The median redshift of our 7 confirmed groups is z ∼ 0.12, to be compared with a median redshift of 0.03 for the local sample of compact groups by Hickson. The typical group size is ∼50 kpc, and the median radial velocity dispersion is 167 km s −1 , while typical crossing times range from 0.005 H −1 0 to 0.03 H −1 0 with a median value of 0.018 H −1 0 , all similar to the values usually found in the literature for such structures in the local universe. The average mass-to-light ratio for our groups, M/LB ,i s 92h, higher than the value found for nearby Hickson compact groups but lower than that found for loose groups. Our results suggest that, once full redshift information for its members becomes available, the DPOSS sample will provide a reference sample to study the properties of compact groups beyond the local universe.