Phylogenetics,population structure and genetic diversity of the endangered southern brown bandicoot (<Emphasis Type="Italic">Isoodon obesulus</Emphasis>) in south-eastern Australia

The southern brown bandicoot (Isoodon obesulus) has undergone significant range contractions since European settlement, and it is now considered Endangered throughout south-eastern mainland Australia. This species currently has a highly fragmented distribution inhabiting a mosaic of habitats. This project uses mitochondrial DNA (mtDNA) and microsatellite data to determine levels of genetic diversity, population structure and evolutionary history, which can aid wildlife managers in setting priorities and determining management strategies. Analyses of genetic diversity revealed low levels of mtDNA variability (mean h=50.42%, =0.76%) and divergence (mean d_A=0.29%) across all regions investigated, and was among the lowest recorded for marsupials. These data indicate a relatively small female effective population size, which is most likely a consequence of a large-scale population contraction and subsequent expansion occurring in pre-history (mismatch distribution analysis, SSD P-value=0.12). Individuals from the Sydney region experienced significant reductions in microsatellite diversity (A=3.8, H_E=0.565), with the Garigal National Park (NP) population exhibiting genetic reduction signatures indicating a recent population bottleneck. Population differentiation analysis revealed significant genetic division amongst I. obesulus individuals from Sydney, East Gippsland and Mt Gambier regions (=0.176–0.271), but could not separate the two Sydney populations (Ku-ring-gai NP and Garigal NP). Based on these data and habitat type, translocations could readily be made between the two Sydney populations, but not between the others. Phylogenetic comparisons between I. obesulus and I. auratus show little support for current Isoodon taxonomy, consistent with the findings of Pope etal. 2001. We therefore recommend the recognition of only three I. obesulus sub-species and suggest that these comprise a single morphologically diverse species that once was widespread across Australia.     

Hunting differentially affects mixed-sex and bachelor-herds in a gregarious ungulate, the impala (Aepyceros melampus: Bovidae)

We investigated herd-sizes and herd-compositions of Impala ( Aepyceros melampus ) inside a protected area [Lake Mburo National Park (LMNP) in western Uganda] and the unprotected adjacent ranchland [the Ankole Ranching Scheme (ARS)]. Impala experience intense hunting and poaching in the study area, and poaching is especially strong on the ARS. We found evidence for changes in overall group-sizes in both mixed-sex and pure bachelor herds between areas in and outside LMNP. Mixed-sex herds strongly decreased in size outside the National Park, but bachelor herds even slightly increased in size. While the group-composition of mixed-sex herds was very similar in areas in and outside LMNP, bachelor herds comprised more yearlings and subadult males on the ARS. Our study suggests that effects of hunting and other human nuisance may differ between herd types: mixed herds probably decrease in size because females are more strongly hunted. Around LMNP, impala are usually hunted using nets and spears, thereby increasing the hunters' chance of being injured. Poachers therefore prefer hornless females (and their calves), as it is less dangerous to handle net-caught females than males. As a result, males are less hunted, but increased vigilance and, therefore, reduced aggression among the members of a bachelor herd, may account for the observed increase in herd sizes and changes in group-compositions.     

Leadership of herd progressions in the Thornicroft's giraffe of Zambia

In cohesive social groups, travel progressions are often led by dominant or older individuals, but the leadership traits of individuals residing in flexible social systems are poorly known. Giraffe reside in herds characterized by fission–fusion dynamics frequently mediated by kinship. We analyzed 41 years (1971–2012) of longitudinal data collected from a community of Thornicroft's giraffe (Giraffa camelopardalis thornicrofti) living around South Luangwa National Park, Zambia, to assess the characteristics of herd leaders. Movement of giraffe in a single file progression was not associated with either season or time of day, but progressions were significantly more likely to occur when giraffe traveled in open areas. The oldest female in a herd was significantly more likely to be at the front position than expected, occupying the leadership niche on 79% of observations. We reason that matriarchal leadership in giraffe, as in African elephants, Loxodonta africana, is associated with resource learning. Giraffe societies are constructed on a heretofore unrecognized foundation that integrates relatedness and familiarity with matriarchal leadership in herd movement.     

Factors affecting vigilance in springbok: importance of vegetative cover, location in herd, and herd size

Vigilance in vertebrates is often inversely related to group size. We present evidence that distance to bushes and location within the herd are also critical factors in vigilance in springbok (Antidorcas marsupialis) in Etosha National Park, Namibia, where they are the preferred prey of cheetahs (Acinonyx jubatus). Most springbok feed in heterospecific herds, both by grazing on grass and browsing on bushes. We studied 1245 animals; variations in vigilance (time alert) were explained by location within the herd, distance to bushes and roads, number of springbok in each herd, and gender and age. Vigilance time decreased with increasing herd size, with increasing distance to bushes and roads, and with density. Springbok on the edge of herds devoted significantly more time to vigilance than did those in other locations, and vigilance in edge animals decreased with group size. Adults were more vigilant than young, and males were more vigilant than females. Position within the herd, and distance from bushes, were the most important variables influencing vigilance. Location in the herd and gender/age affected both browsing and grazing springbok, although other factors accounted for the differences in vigilance between browsing and grazing springbok: 1) group size was not significant for browsers, but it was for grazers, and 2) distances to bushes and road were not significant for browsers, but they were for grazers. These data relate to the risk from predators and the benefits from other group members. Springbok in bushes cannot see all members of the herd, cannot derive early warning from many group members, and are more at risk from predators because the latter can hide in the bushes. Received: 17 May 1999 / Received in revised form: 30 August 1999 / Accepted: 29 November 1999     

Buffalo Herd Structure and its Repercussions for Condition of Individual African Buffalo Cows

The African buffalo Syncerus caffer was studied in Lake Manyara National Park, Tanzania. Emphasis was placed on the study of (individual) buffalo cows, which live in mixed herds. Buffalo herds are discrete social units and females were never observed in another herd than their own. The herd showed a structure with respect to the distribution of sex-age classes. Individual cows generally kept the same location within the herd. The location in the herd appeared to be coupled to food intake and was strongly related to physical condition. The best location (highest intake and best condition) was between the front and the centre of the herd, the worst location was the rear of the herd (when moving or grazing). Females with calves appeared to have the highest position in the hierarchy as determined from the rate of displacement over food; adult bulls did not interact with cows. Few births were observed during the late dry season and it appears that there is a calving peak at the end of the long rains. Conception rate increased when cows increased in condition and dropped when cows lost condition. Cows showed a strong seasonality in condition but bulls on average hardly changed in condition, except for a loss in condition during the inferred conception peak. Buffalo herds in Manyara showed a fusion-fission pattern independent of season but strongly influenced by the size of the herd: large herds split more often than smaller ones. In large herds, buffalo grazed closer together than in small herds and it appeared likely that competition was more severe in large herds. Animals in the rear of a large herd lost condition faster during the dry season than animals in the best location in the herd, and especially cows in the rear split off most frequently from the herd to graze in a smaller fragment. From the literature on cattle, it is inferred that the reproductive success of cows in the rear of the herd will be lower than of cows in the best location, and this differential is confirmed by the behaviour of adult bulls. It is as yet unclear what the advantage is for adult cows in the rear of a large herd to stay in that herd but the sharing of information with more successful individuals seems a good candidate.     

Microsatellite variation in the reintroduced Pennsylvania elk herd

Relocation programs have restored elk (Cervus elaphus) to portions of its vast historical range. We examine the consequences of these relocation programs by assessing variation at 10 microsatellite loci in three elk herds, a source herd (Yellowstone National Park), a large herd reintroduced from Yellowstone (Custer State Park) and a bottlenecked herd reintroduced from both Yellowstone and Custer (the Pennsylvania herd). Observed single locus heterozygosities ranged from 0.000 to 0.739. Multi-locus heterozygosities ranged from 0.222 to 0.589. Although significant differences were detected among all three herds, the Yellowstone National Park and Custer State Park herds possessed similar levels of variation and heterozygosity, and the genetic distance between these two herds was small. The Pennsylvania herd, on the other hand, experienced a 61.5% decrease in heterozygosity relative to its source herds, possessed no unique and few rare alleles, and the genetic distances between the Pennsylvania herd and its sources were large. Simulations were performed to identify bottleneck scenarios in agreement with levels of variation in the Pennsylvania herd. Our data confirm that the rate of population growth post-relocation may have important genetic consequences and indicate that theoretical predictions regarding the maintenance of genetic variation during relocation events must be viewed with caution when small numbers of a polygynous species are released.     

Population status,structure and activity patterns of the Bohor reedbuck Redunca redunca in the north of the Bale Mountains National Park,Ethiopia

The Bohor reedbucks Redunca redunca (Pallas, 1767) were studied in the Bale Mountains National Park (BMNP), Ethiopia to assess their population ecology and activity patterns. The total count method was used to assess population size. Activity patterns of a herd were studied with five minutes recording intervals. There were 406 Bohor reedbucks in the study area of which 96.8% (n = 393) was confined to the Gaysay‐Adelay area. The population was female‐biased. Excluding juveniles, 57.1% (n = 232) was females and 33.5% (n = 136) was males. More adults (71.7%, n = 291) were observed than sub‐adults (18.9%, n = 77) and juveniles (9.4%, n = 38). The herd size of Bohor reedbucks varied from 3 to 5. Herds were seen in aggregations of up to 59 individuals during the dry season in swamp grassland habitat. The maximum number observed in such aggregations during the wet season was 38. The diurnal activity pattern showed feeding peaks early in the morning and late in the afternoon, with resting during the mid‐day. Two feeding peaks were observed in the nocturnal activity phase: one during dusk and the other around midnight. In contradiction to the general concept of occurrence of smaller herds during the dry season, the Bohor reedbucks aggregate in swamps during the dry season. They were also active during night and day time.     

Seasonal home ranges of elephants (Loxodonta africana) and their movements between Sabi Sand Reserve and Kruger National Park

We studied the seasonal home ranges and space use of three breeding herds of elephants (Loxodonta africana) for 3–5 years in an area comprising South Africa’s Sabi Sand Reserve (SSR) and Kruger National Park (KNP). Global Positioning System (GPS) transmitters were attached to the matriarchs of three herds and set to transmit a single daily location. Each herd was located in SSR 31%, 60% and 84% of the time. During the wet summer months, the herds walked longer distances and occupied larger seasonal home ranges than during the corresponding dry winter period. Core areas were centred on riverine habitats within both parks, with all three herds exhibiting closer distances to rivers and artificial water holes than would be expected if they were moving randomly. Home ranges within SSR overlapped much of the park. However, in KNP they occupied discrete areas with little overlap. Much of the movement between the two parks occurred along well‐defined corridors. This study shows that elephant herds depended upon the resources of both parks, providing an insight into their within‐ and between‐seasonal movements. This highlights the importance of ongoing co‐operation between wildlife managers from both parks when forming policy.     

The numbers and distribution of buffalo in the Ruwenzori National Park*, Uganda

The buffalo (Syncerus coffer (Sparrman)) in the Ruwenzori National Park, Uganda were censused by means of aerial survey. Details of earlier censuses of buffalo from the air are given. Herds were located by flying along flight lines 1–6 km apart at a height of 300 m above ground. Buffalo in small herds and in bachelor groups containing less than thirty animals were counted individually but most herds were photographed and the number of buffalo counted from the prints. Two full photographic counts were made in November 1968 and December 1969 and subsequently, counts of herds only were made four times a year during each wet and dry season. The total numbers of buffalo were estimated from the herd counts on the basis of the mean herd size and percentage of bachelors recorded earlier. A total of 17 835 buffalo, comprising 16 749 in 165 herds and 1086 bachelor bulls, was recorded in 1968 and 18 040 buffalo made up of 17 141 in 162 herds and 899 bachelors were counted in 1969. The mean herd size was 101-5 in 1968 and 105-8 in 1969 with bachelors representing 6-1% and 5-0% of the totals in 1968 and 1969 respectively. The mean size of the bachelor groups was 4–7 and 3-3 in 1968 and 1969 respectively. The density of the buffalo was the same each year at twelve animals per sq. km. If only the preferred habitat is considered, the density becomes thirty-eight buffalo per sq. km. The mean areas occupied by a single herd were 9-4 and 9-6 sq. km in 1968 and 1969 respectively. The mean area of preferred habitat used by one herd was 2–9 sq. km each year. It is concluded that herd counts are not a satisfactory method for assessing the total buffalo population although they have value as indices, provided the same observer is used. However, they do suggest in the present work that there is a slight but definite seasonal movement of buffalo into forested areas or towards permanent water during the dry season.     

唐家河自然保护区扭角羚的兽群结构及数量分布

四川唐家河自然保护区有扭角羚480-520只。喜聚群活动,其兽群可分为家群、族群和聚集群。并随季节变化而有分群和合群现象。此外还有游离于群体之外的独羚,多为成年雄体。其兽群幼仔占17.52±6.48,亚成体占17.25±9.16%,成体占65.23±12.59%,聚集群中成体雄雌比为1：8,雌体占多数。     

Bio-economic model to evaluate twinning rate using sexed embryo transfer in dairy herds

A stochastic bio-economic model has been used to determine the effects of new reproductive technologies over a 15-year period. A strategy of using conventional artificial insemination (AI) or embryo transfer (ET) using two sex-controlled embryos at different conception rates (CRs) and herd sizes resulted in a 24 state model. The genetic means of AI population increased over the years, and the genetic means of milk production for all of the embryo strategies were greater than those of AI. In addition, the genetic means of milk yield using different embryo-based scenarios in the expanding herds were greater than those for the fixed herds. The net profit of using sexed ET in the expanding herds was greater (P < 0.05) than that of fixed size herds. In general, there was a roughly consistent trend in net profit per cow for sexed ET strategies in the expanding herds over the years, but there was an increasing trend in net profit per cow for sexed ET strategies in the fixed herds over the years. Medium to high CRs for ET and the use of sex-controlled embryo systems, especially for induction of twin births to produce dairy replacements, will be critical elements of a system that produces significant numbers of female calves. The greater number of female calves produced in the sex-controlled scenarios allows the farmer to select animals with the best genetic potential as dairy replacement heifers; therefore, the rate of genetic gain increased in the dairy herd. Results of sensitivity analyses showed that a significant decrease in the production costs and increase in the ET performance are essential for embryo-based technologies to be profitable.     

Vaccination prepartum enhances the beneficial effects of melatonin on the immune response and reduces platelet responsiveness in sheep

Background

Eradication of bovine tuberculosis (bTB) through the application of test-and-cull programs is a declared goal of developed countries in which the disease is still endemic. Here, longitudinal data from more than 1,700 cattle herds tested during a 12?year-period in the eradication program in the region of Madrid, Spain, were analyzed to quantify the within-herd transmission coefficient (??) depending on the herd-type (beef/dairy/bullfighting). In addition, the probability to recover the officially bTB free (OTF) status in infected herds depending on the type of herd and the diagnostic strategy implemented was assessed using Cox proportional hazard models.

Results

Overall, dairy herds showed higher ?? (median 4.7) than beef or bullfighting herds (2.3 and 2.2 respectively). Introduction of interferon-gamma (IFN-??) as an ancillary test produced an apparent increase in the ?? coefficient regardless of production type, likely due to an increase in diagnostic sensitivity. Time to recover OTF status was also significantly lower in dairy herds, and length of bTB episodes was significantly reduced when the IFN-?? was implemented to manage the outbreak.

Conclusions

Our results suggest that bTB spreads more rapidly in dairy herds compared to other herd types, a likely cause being management and demographic-related factors. However, outbreaks in dairy herds can be controlled more rapidly than in typically extensive herd types. Finally, IFN-?? proved its usefulness to rapidly eradicate bTB at a herd-level.     

Modeling Tuberculosis Dynamics,Detection and Control in Cattle Herds

Epidemiological models are key tools for designing and evaluating detection and control strategies against animal infectious diseases. In France, after decades of decrease of bovine tuberculosis (bTB) incidence, the disease keeps circulating. Increasing prevalence levels are observed in several areas, where the detection and control strategy could be adapted. The objective of this work was to design and calibrate a model of the within-herd transmission of bTB. The proposed model is a stochastic model operating in discrete-time. Three health states were distinguished: susceptible, latent and infected. Dairy and beef herd dynamics and bTB detection and control programs were explicitly represented. Approximate Bayesian computation was used to estimate three model parameters from field data: the transmission parameter when animals are inside (β_inside) and outside (β_outside) buildings, and the duration of the latent phase. An independent dataset was used for model validation. The estimated median was 0.43 [0.16–0.84] month⁻¹ for β_inside and 0.08 [0.01–0.32] month⁻¹ for β_outside. The median duration of the latent period was estimated 3.5 [2]–[8] months. The sensitivity analysis showed only minor influences of fixed parameter values on these posterior estimates. Validation based on an independent dataset showed that in more than 80% of herds, the observed proportion of animals with detected lesions was between the 2.5% and 97.5% percentiles of the simulated distribution. In the absence of control program and once bTB has become enzootic within a herd, the median effective reproductive ratio was estimated to be 2.2 in beef herds and 1.7 in dairy herds. These low estimates are consistent with field observations of a low prevalence level in French bTB-infected herds.     

Comparison between the complete mtDNA sequences of the blue and the fin whale,two species that can hybridize in nature

The sequence of the mitochondrial DNA (mtDNA) molecule of the blue whale (Balaenoptera musculus) was determined. The molecule is 16,402 by long and its organization conforms with that of other eutherian mammals. The molecule was compared with the mtDNA of the congeneric fin whale (B. physalus). It was recently documented that the two species can hybridize and that male offspring are infertile whereas female offspring may be fertile. The present comparison made it possible to determine the degree of mtDNA difference that occurs between two species that are not completely separated by hybridization incompatibility. The difference between the complete mtDNA sequences was 7.4%. Lengths of peptide coding genes were the same in both species. Except for a small portion of the control region, disruption in alignment was usually limited to insertion/deletion of a single nucleotide. Nucleotide differences between peptide coding genes ranged from 7.1 to 10.5%, and difference at the inferred amino acid level was 0.0–7.9%. In the rRNA genes the mean transition difference was 3.8%. This figure is similar in degree to the difference (3.4%) between the 12S rRNA gene of humans and the chimpanzee. The mtDNA differences between the two whale species, involving both peptide coding and rRNA genes, suggest an evolutionary separation of 5 million years. Although hybridization between more distantly related mammalian species may not be excluded, it is probable that the blue and fin whales are nearly as different in their mtDNA sequences as hybridizing mammal species may be. Correspondence to: Ú. Árnason     

Assessment of Favorable Attitudes Toward Pets: Development and Preliminary Validation of Self-Report Pet Relationship Scales

ABSTRACT

Large herds pose the risk of worsening human—cattle relationships by reducing human contact and thus increasing the risk of accidents. In a survey on 35 dairy farms in Switzerland and Germany, different aspects of human—cow relationships were investigated. The effects of size of herd compared to other factors are presented here. Size of herds in the study varied from eight to 92 cows. On 35 farms the behavior of stockpersons toward their cows was observed directly during milking; personality characteristics of stockpersons were obtained by self-report-inventories, and a questionnaire on management practices was completed. Cows' avoidance distances toward a person were measured, and the social behavior of herds was observed directly.

Size of herd correlated significantly negatively with the percentage of cows with an avoidance distance of zero (r_s=-0.52, p≤0.01), but there was no correlation with the median of avoidance distances per herd. Concerning the behavior of stockpersons, size of herd showed a significant negative correlation with the intensity/quality of contact with the cows (r_s=-0.51, p≤0.05), and a slightly significant correlation with the total number of talking to/touching interactions with the cows in the milking parlor (r_s=-34, p≤0.05). Quality of handling was not affected by size of herd, but the ability of the stockpersons to identify cows (r_s=-0.59, p≤0.001), and the frequency of brushing cows decreased with increasing sizes of herd (r_s=-0.52, p≤0.01). In regression analysis, the influence of size of herd on the intensity/quality of contact (CON) was confirmed, but showed a much smaller effect than the personality or attitudes of the stockpersons. Additionally, size of herd had no effect on avoidance distances. This was due to the elimination of the effects of CON.

The small influence of size of herd on human-animal relationship parameters was mediated by the intensity of contact with the cows, but is much less important compared to other factors, e.g. the personality and attitudes of stockpersons. Smaller herds facilitated good relationships between a stockperson and his/her cows, but good human—animal relationships were also possible in big herds, and were observed even in the biggest herd (92 cows).     

Economic Aspects of Disease Monitoring with Special Reference to Bovine Paratuberculosis

Monte Carlo simulation models were used to evaluate the feasibility and potential results of a proposed national survey of the prevalence of bovine paratuberculosis (PTB) in dairy herds in Norway. The expected herd prevalence was assumed to be 0.2% in the simulations. Infected herds were classified as detected if 1 animal was sero-positive. With a sample size of 6000 herds at least 1 truly infected herd was detected in 99% of the iterations. The low sensitivity of the ELISA test, the assumed low herd prevalence, the typical low within-herd prevalence of PTB and the small herd sizes in Norway all present problems in detection of the disease. The results showed that the ratio between false-positive herds and true positive herds detected had a median of 70:1. At the assumed herd prevalence of 0.2% and a cost/test of 70 NOK the median cost of detecting 1 infected herd was approximately 900,000 NOK. If 2 positive reactors were needed to classify a herd "infected" the median cost of detecting 1 infected herd was 5,055,000 NOK. Our results suggest that a randomized national prevalence survey would not be feasible, due to the low probability of detecting infected herds and because of the high number of false-positive reactions that would be expected.

     

The feral goats of Kielderhead Moor

Herds of feral goats are present along the high ground of the Scottish Borders at the College, Hindhope, Kielderhead Moor (the study area), Bewcastle Fell and Roan Fell.
In the study area the nannies remained solitary, or in the company of their yearlings on the steep ground below the high moor throughout the winter. After the birth of their kids in March two female herds were formed each with a herd billy which came from the two male herds which were present through the winter on the high moor. The male herds left the study area in the spring and their ranges are not known. The two female herds maintained separate ranges on the high moor until the end of August when they combined into one large herd and were joined by a strange herd of billies which had not previously been seen.
After the first three or four days of its life the kid is left in a hiding place for most of the day whilst its mother ranges widely grazing with the herd. The kids join the herd when they are about six weeks old.
The Kielderhead Moor goats had a recruitment rate of 0–29/nanny/year and the females have a further expectation of life of 3–7 years. Figures for the billies are unreliable as disappearances of males from the moor are more likely to be the result of emigration than of deaths. While the herds of nannies have fairly restricted home ranges there is some evidence to suggest that many of the billies wander freely along the Borders.
In the early part of the summer the sheep and goats are eating very similar proportions of the plants present on the moor. Later on in the season there is a divergence with the sheep eating less Calluna while the goats eat less Eriophorum , but as the Trichophorum becomes available both animals include this in their diet.     

Can pre-collected register data be used to identify dairy herds with good cattle welfare?

Background

Pre-recorded register data from dairy herds are available in almost all Nordic countries. These databases can be used for research purposes, and one of the research areas is animal welfare. The aim of this study was to investigate if pre-recorded register data could be used to identify herds with good welfare, and to investigate if a combination of register data sets could be used to be able to more correctly distinguish between herds with good welfare and herds with welfare deficiencies.

Methods

As a first step, nine animal-based measurements on calves, young stock and cows in 55 randomly selected herds were performed on-farm as the basis for a classification of welfare at the herd level. The definition for being a case herd with “good welfare” was no score lying among the 10% worst in any of the nine welfare measurements. Twenty-eight of the 55 herds were cases according to this definition. As a second step, 65 potential welfare indicators, based on register data in a national dairy database, were identified by expert opinion. In the final step, the extent to which the suggested welfare indicators predicted farms’ as having good welfare according to the stated definition was assessed. Moreover, the effect of combining in sequence a previously developed model that identified herds with poor welfare with the present model identifying herds with good welfare was investigated.

Results

The final set of welfare indicators used to identify herds with good animal welfare included two fertility measures, cow mortality, stillbirth rate, mastitis incidence and incidence of feed-related diseases (including gastrointestinal disturbances but excluding paralyses and cramps). This set had a test sensitivity of correctly classifying herds with no score lying among the 10% worst of the nine welfare measurements of 96 %. However, the specificity of the test was only 56% indicating difficulties for the test to correctly classifying herds with one or more scores lying among the 10% worst. Combining the previously developed model with the present model, improved the welfare classification.

Conclusions

This study shows that pre-collected register data may be used to give approval to dairy farms with “good welfare” and that combining different sets of register data can improve the classification of herd welfare.

     

The composition and function of all‐male herds of Thornicroft's giraffe,Giraffa camelopardalis thornicrofti,in Zambia

Temporary all‐male social groups are formed in a number of animal species. We examined 34 years of data collected from 36 male Thornicroft's giraffe in the Luangwa Valley, Zambia, to test a set of predictions related to five possible functions of all‐male herds (predator protection, practicing aggressive skills, prolonging life, nutritional demands and resource learning). We found that all‐male herds were significantly smaller than mixed‐sex herds, usually contained a mature bull, and were not dependent upon season or habitat. Dyadic associations between males in single sex herds were quite weak, with <25% of potential male dyads sighted together in an all‐male herd. Our data are best explained as a resource learning strategy adopted by males to obtain more extensive knowledge about the habitat, including both food and female distribution. However, other benefits in the form of predator protection, dietary intake and sharpening competitive skills for future contests over estrous females also seem to mediate formation of giraffe all‐male groups. We conclude that the primary advantage of roaming in all‐male herds changes during the life history of males.     

The differences among Jewish communities—Maternal and paternal contributions

The haplotypes of Y chromosome (paternally inherited) and mtDNA (maternally inherited) were analyzed in representatives of six Jewish communities (Ashkenazic, North African, Near Eastern, Yemenite, Minor Asian/Balkanian, and Ethiopian). For both elements, the Ethiopian community has a mixture of typically African and typically Caucasian haplotypes and is significantly different from all others. The other communities, whose haplotypes are mostly Caucasian, are more closely related; significant differences that were found among some of them possibly indicate the effects of admixture with neighboring communities of non-Jews. The different contribution of the Y chromosome and mtDNA haplotypes to the significant differences among the communities can be explained by unequal involvement of males and females in the different admixtures. In all communities, except the Ethiopians, the level of diversity () for Y chromosome haplotypes is higher than that for mtDNA haplotypes, suggesting that in each community the people who become parents include more males than females. An opposite proportion (more females than males) is found among the Ethiopians. Correspondence to: U. Ritte