Development of nephrotic ICGN mice--the origin, reproductive ability, and incidence of glomerulonephritis

ICGN is a strain of spontaneous nephrotic mice with nonproliferative glomerular lesions. It was derived from an outbred Yok: ICR colony in our laboratory. The renal disease constantly occurred in animals of the first to the tenth generations (greater than 13.0%; 70 days of age). When affected males were mated with unaffected females, the incidence of the disease in their offspring was 38.8% (n = 49) at 70 days after birth. When both parents were affected, their offspring were all affected (n = 12). The disease evenly progressed in both sexes. It usually began 40 to 150 days after birth and death occurred within two months after onset. The animals usually showed sufficient reproductive ability as long as unaffected females were used for mating.     

Nest-founding behavior induced in the first descendants ofPolistes dominulus Christ (Hymenoptera: Vespidae) colonies

Summary First descendants' founding ability was tested inP. dominulus colonies by experimentally removing the original nests and queens 21–24 days after the first emergence. Foundation tests were carried out after three different periods had elapsed after the removal and the results were analyzed with regards to the effects of participation in social tasks, duration of stay within the colony and seasonal factors. 1.Immediately after the removal, the foundations that occurred were performed almost entirely by workers, regardless of the duration of their stay within the colony. The number of foundations depended on the season in which the females had emerged. 2.Two months and four months after the removal, foundations were made by only a small number of females (workers and non-workers). These females, which were therefore able to found a nest the year they were born, were mostly among the very first-born individuals in the colonies. 3.The following year after hibernation: females (workers and non-workers) which had stayed for only a short time within the colony (1–15 days) had the highest survival rates. The foundation rates among the surviving females depended only on seasonal factors, since the foundation rates were higher among the non-workers which had emerged later in the season. The results throw some light on the first descendants' nest-founding potential in colonies developing under natural conditions, where many workers in fact stay for only a short time at the nest.     

Combined Olfactory Contact with the Parent Colony and Direct Contact with Nonbreeding Animals Does Not Maintain Suppression of Ovulation in Female Naked Mole-Rats (Heterocephalus glaber)

The study investigated the role of odor cues from two naked mole-rat colonies, in conjunction with behavioral cues from nonbreeding colony members, in maintaining suppression of ovulation in subordinate female naked mole-rats isolated from the two parent colonies. Four high ranking nonbreeding female naked mole-rats were removed from their respective parent colonies and singly housed in separate burrow systems. For a 64-day period, the removed females were maintained in daily odor contact with their parent colony by daily rotating soiled bedding material between the parent colony and the burrow systems of removed females. In addition, subsets of nonbreeding animals from the respective parent colony were regularly moved into the burrow systems of removed females for 2-day periods during this 64-day period. Removed females were therefore in continual social contact with subsets of parent colony animals except for the breeding pair. All four removed females exhibited raised levels of urinary progesterone (< 2 ng/mg Cr) indicative of the onset of ovarian function within 3 days of being separated from the parent colony. Removed females exhibited a normal ovulatory cycle with levels of progesterone remaining elevated for 25–35 days (mean concentration of progesterone ± SEM; 16.2 ± 2 ng/mg Cr). Initiation of aggression and sexual behavior by removed females increased significantly when they were isolated from the parent colony. The results demonstrated that odor cues from the complete colony in conjunction with behavioral / tactile / vocal cues from the nonbreeding colony members were not the major cues maintaining reproductive suppression in nonbreeding female naked mole-rats. Instead, our results suggest that female reproductive suppression in naked mole-rats is caused by a dominance-related behavioral mechanism requiring direct contact with the breeding female.     

Birth sex ratios and maternal social rank in a captive colony of rhesus monkeys (Macaca mulatta)

Data from a 35-year study of rhesus macaques (Macaca mulatta) at Madingley, Cambridge, were used to investigate sex ratio biases associated with maternal rank. Data were available from two colonies, the Old colony (1960–81) and New colony (1982–93). Overall, top-ranking mothers gave birth to 30.9% sons, while non-top mothers gave birth to 58.4% sons. Among non-top mothers, middle- and bottom-ranking ones had 59.0 and 55.0% sons, respectively. Top mothers' daughter biases were strongest in matrilines with two adult females in the year the infants were conceived (15.4 sons and 14.3% sons in Old and New colonies). Non-top mothers' son biases (88.9 and 71.0% in Old and New colonies) were strongest in matrilines with 3 females. The findings are discussed in relation to the colonies' small matriline sizes and data on breeding performance and infant survival, which indicate the costs to mothers of different rank of having different sex infants. Overall, top-ranking mothers were more likely to breed in two successive years (78.6%) than non-top mothers (56.7%). Infant survival to 7 days was significantly higher in the New colony (89.0%) than the Old colony (75.3%), with daughters born to Old colony mothers doing especially poorly. We point out that between-group and between-species comparisons of sex ratio effects depend critically on how females are assigned to rank categories, and require information about divergences of sex ratios from 50:50 in each category. © 1996 Wiley-Liss, Inc.     

Philopatry and colony fidelity of Shags Phalacrocorax aristotelis on the east coast of Britain

Shag Phalacrocorax aristotelis colonies from the Firth of Forth south to the Fame Islands (SE Scotland and NE England) were surveyed in 1982 and 1983 for nesting Shags ringed as chicks or adults in the previous 20 years. On average, 5% of 863 Shags ringed as chicks were breeding away from their natal colony, and only 1% of 401 marked adults had left their breeding colony. The proportion p of chicks that settled at or beyond distance D from the natal colony followed the relationship p = 0.263D-^0.771, implying that more Shags moved 10 km or beyond to breed than expected from diffusion models or a constant-rate dispersal model; adjusted for birds that settled outside the study area, the relationship was p = 0.314D^-0771. There was no effect of colony size on emigration rate, but females showed a greater tendency to settle away from the natal colony than did males. At the natal colony, more males (69%) than females (47%) nested within 300 m of their birthplace. Two mechanisms appear to determine where a Shag settles to breed: a navigational one governing the return to the natal colony, plus the competitive process of nest-site establishment.     

Experimental study of foundation and development ofAnelosimus eximius colonies in the tropical forest of French Guiana

Summary Possibilities for new colony foundation inAnelosimus eximius (Theridiidae) were tested with isolated females (both with and without egg sacs) and with groups of individuals (groups from 150 to 250 spiders). Experimental groups were deposited in three different habitats: within the forest, on the forest edge (where natural colonies develop most frequently) and outside the forest (low savannah or areas cleared of vegetation, but in which plant life had started to grow back between the path and the forest edge).Isolated adult females had very low founding success: less than 13 % settled and spun a web; the presence of an egg sac provided by investigators was not an influencing factor. Webs of isolated females had the same architectures as those of colonies with several hundreds of individuals. This web was a horizontal sheet linked to a thick vertical network of threads.All groups of 150 to 250 spiders established colonies in appropriate habitats. The colonies outside the forest, and more than 90 % of the colonies along the forest edges successfully developed during the one month observation period. Conversely, 35 % of the colonies in the forest disappeared either a few days after being placed there, or one or two weeks after. In the latter case, spiders apparently left their webs, and all silk structures were left intact. No dead spiders were found in the webs.Average web surface areas increased in all colony types with age, except for those placed in the forest. In these colonies, the number of individuals decreased, and there were fewer egg sacs than in the colonies placed outside the forest.Results are discussed with regard to natural colony distribution along open paths and to the dispersive characteristics of this spider species.     

Laboratory Evaluation of a Laboratory-selected Organophosphate-resistant Strain of Amblyseius finlandicus (Acari: Phytoseiidae) for Possible Use in Finnish Apple Orchards

The survival of adults and immatures, and reproduction at rates of 150, 300 and 900 ppm a.i. of azinphosmethyl were compared among four types of Amblyseius finlandicus females and their offspring; a laboratory-selected colony (SEL16) resistant to azinphosmethyl, an unselected base colony (Tuorla), reciprocal F1 females from crosses between SEL16 and a very susceptible colony (Hiekkaharju). The SEL16 and reciprocal F1 females had a higher survivorship than the unselected Tuorla base colony after 2 and 4 days on leaves treated with the three concentrations of insecticide. Azinphosmethyl decreased oviposition by the surviving females of all types, but the decrease was smaller in the SEL16 strain than in the base colony. The survivorship of immatures of SEL16 on fresh azinphosmethyl residues after 6 days was low at all three concentrations, but no survivors were found in the base colony at any of the concentrations. Females deposited significantly more eggs on the untreated areas of the leaves. The importance of this behavior for biological control is discussed. There were no significant differences in developmental rate, ovipositional rate, sex ratio and ovipositional period between the SEL16 and unselected base colony on untreated leaf substrates, suggesting that resistance was not associated with decreased fitness. A mode of inheritance study indicated that azinphosmethyl resistance was incompletely dominant. This was also suggested by the results of bioassays, where the reciprocal F1 females performed nearly as well as the SEL16 strain on leaves treated with field rates of azinphosmethyl.     

Social and seasonal influences on the reproductive cycle in female mandrills (Mandrillus sphinx)

We present 12 years of perineal swelling data for a semifree-ranging colony of mandrills (Mandrillus sphinx), and evaluate the influence of rank, parity, and seasonality on reproductive parameters. Female sexual swellings showed a seasonal pattern, with August the median month of ovulation. Overlapping periovulatory periods did not decrease the likelihood of conception. Females showed their first genital swelling at age 3.6 years (n = 28; range, 3.2-4.6 years), and higher-ranking females experienced their first swelling earlier than low-ranking females. Median postpartum amenorrhea (PPA) duration was 208 days (n = 92; range, 74-538 days). PPA was longer in primiparous females than in multiparous females, but PPA duration was unrelated to female rank. Median follicular phase duration was 24 days for the first cycle after parturition (n = 84; range, 12-40 days), shortening to 17 days in subsequent cycles (n = 55; range, 6-39 days). The follicular phase was longer in nulliparous females than in parous females, but was unrelated to female rank. Median cycle length (from one sexual swelling breakdown to the next) was 38 days (n = 57; range, 18-108 days). Eighty-seven percent of conceptions occurred within two cycles, and half of the nulliparous females conceived during their first swelling cycle. Lower-ranking females were more likely to require more cycles to conceive than higher-ranking females. The cycling phase was significantly longer in nulliparous females than in parous females, and was also significantly longer in lower-ranking females than in higher-ranking females. We discuss the influence of provisioning on female reproductive parameters, the influence of parity and rank on the different phases of the interbirth interval, and the evolution of long and variable follicular phases in mandrills.     

Individuality in northern lapwing migration and its link to timing of breeding

We tracked eight adult northern lapwings Vanellus vanellus (six females and two males) from a Dutch breeding colony by light‐level geolocation year‐round, three of them for multiple years. We show that birds breeding virtually next to each other may choose widely separated wintering grounds, stretching from nearby the colony west towards the UK and Ireland, and southwest through France into Iberia and Morocco. However, individual lapwings appeared relatively faithful to a chosen wintering area, and timing of outward and homeward migration can be highly consistent between years. Movements of migratory individuals were usually direct and fast, with some birds covering distances of approximately 2000 km within 2 to 4 days of travel. The two males wintered closest and returned earliest to the breeding colony. The female lapwings returned well before the onset of breeding, spending a pre‐laying period of 19 to 54 days in the wider breeding area. Despite the potential for high migration speeds, the duration that birds were absent from the breeding area increased with distance to wintering areas, a pattern which was mainly driven by an earlier outward migration of birds heading for more distant wintering grounds. Moreover, females that overwintered closer to colony bred earlier. A large variation in migration strategies found even within a single breeding colony has likely supported the species’ responsiveness to recent climate change as evidenced by a shortened migration distance and an advanced timing of reproduction in Dutch lapwings since the middle of the 20th century.     

Behaviour of one-year-old rhesus monkeys in a strange situation

When one-year old rhesus monkeys and their mothers were removed from the colony to a strange situation, infants' activity was initially low compared with behaviour six days later. Although absolute values did not differ between males and females, correlations did. That is, three days after return to the colony, correlations with baseline colony behaviour were significantly positive for females, while males had one significantly negative correlation. On the other hand, males had more significant correlations than females when behaviour in the strange situation was correlated with colony scores. Of the six individuals that had adverse early experience, five showed extreme behaviour. The exception was CT, son of a female with a very low ‘excitable’ score. In fact for all males, mothers' colony scores were significantly correlated with sons' behaviour in the strange situation.     

Reproductive biology, development, and planula behavior in the Caribbean gorgonian Pseudopterogorgia elisabethae

Abstract. The reproductive biology, development, and planula behavior of the gorgonian Pseudopterogorgia elisabethae were studied at 2 sites in the Bahamas between 1996 and 2001. Colonies were gonochoric, and females brooded planulae on the colony surface. Gonads were observed only in colonies 18 cm high or larger. Spawning was asynchronous within and between sites but was concentrated 2–10 days after the new moons from late November through early January. Fertilized eggs developed into planulae over 1–2 days and the planulae remained attached to the surface of the female colony for an additional 2–4 days. Planulae were negatively buoyant and field observations suggest that larvae may settle within tens of meters of the maternal colony. P. elisabethae is harvested for natural products, and information on the reproduction of this commercially important species is crucial to the understanding of its population biology and to the development of management plans for the conservation of the species.     

Dominance and aggression in social groups of male and female rats

Two experiments were performed to examine aggression and dominance in domestic male and female $\text{Rattus norvegicus}$ living in small mixed-sex (3 males and 3 females) groups. Experiment 1 examined the development of aggression in females. A single female (alpha) within each of the six colonies tested showed the preponderance of attacks on male intruders placed into the home-cage when male colony residents were absent. Over 12 weeks of intruder-aggression training female alphas showed only a mild nonsignificant elevation of aggressive behavior. A comparison of aggression of male and female colony alphas tested with opponents of each sex revealed that aggression was mainly directed at like-sex opponents, and that female attack was more defensive in character than male attack regardless of opponent sex. The highest intensity of aggression occurred when male alphas confronted male intruders. Although intruders never showed offense toward male residents, 61% of intruding males showed offense in response to attack by females.Experiment 2 investigated the relationship between aggressive dominance and competitive measures of dominance within each of 10 mixed-sex colonies. Alpha stat s of male and female colony residents did not reliably predict priority of access to food or water in tests of direct resource competition with like-sex colony members. When colony males were simultaneously tested for copulation, the copulatory behavior of alpha males was significantly greater than that of other colony males. Results are discussed in relation to the role of aggression in the reproductive strategy of male and female $\text{Rattus norvegicus}$.     

Relaxation of reproductive suppression in non-breeding female naked mole-rats, Heterocephalus glaber

Ninety-four non-reproductive female naked mole-rats, from seven colonies, were studied in terms of vaginal perforation, vaginal smears and urinary concentrations of oestradiol-17β and progesterone in relation to the time of parturition of the breeding female, the queen. The study concentrated mainly on the period from nine days prepartum to 13 days postpartum of 12 births. Sixty-eight percent ( n = 253) of the non-reproductive females had detectable urinary concentrations of oestradiol-17β and many of these had perforated vaginas throughout the study period. These females showed a significantly increased urinary concentration of oestradiol six days prior to parturition of the queen. In females with undetectable concentrations of oestradiol-17β, the proportion with perforated vaginas increased from six days prepartum (54%) to reach a peak on the day of parturition (92%) of the queen. Urinary progesterone-concentrations were 0.7nmol/mmol creatinine at some stage in the study period in 90% of the females and scattered short peaks or spikes were experienced by all these females, but without synchronization between the females in a colony and without any detectable correlation with the time of parturition of the queen. Maximal concentrations in some females were comparable to the values in cycling breeding females during the luteal phase, but were of a much shorter duration than in breeding females. Vaginal smears did not show clear cyclic patterns.     

Colony dynamics in a primitively eusocial halictine beeLasioglossum (Dialictus) zephyrum (Hymenoptera: Halictidae)

Summary Proximate control of colony dynamics was studied in the primitively eusocial halictine beeLasioglossum (Dialictus) zephyrum using allozyme markers. The results indicate that workers produce on average 15% of the male brood (range=0–50%) in small laboratory colonies made up of unrelated, single-generation, uninseminated females. This proportion is not influenced by colony size, but is influenced by the relative size of the queen. Large queens are more successful in dominating their workers than are small queens, the queen being defined as the female that is the mother of most of the brood produced in the colony. Older and larger females tend to become queens. Thus, while small differences in age (up to 4 days) influence which female becomes a queen, her ability to control her workers is primarily influenced by her relative size. The proportion of reproduction that is co-opted by the queen is negatively correlated with colony reproductivity (the number of males/day/female). Colony reproductivity is also negatively correlated with the standard deviation in size among females.     

Fine-scale spatial genetic correlation analyses reveal strong female philopatry within a brush-tailed rock-wallaby colony in southeast Queensland

We combine spatial data on home ranges of individuals and microsatellite markers to examine patterns of fine-scale spatial genetic structure and dispersal within a brush-tailed rock-wallaby (Petrogale penicillata) colony at Hurdle Creek Valley, Queensland. Brush-tailed rock-wallabies were once abundant and widespread throughout the rocky terrain of southeastern Australia; however, populations are nearly extinct in the south of their range and in decline elsewhere. We use pairwise relatedness measures and a recent multilocus spatial autocorrelation analysis to test the hypotheses that in this species, within-colony dispersal is male-biased and that female philopatry results in spatial clusters of related females within the colony. We provide clear evidence for strong female philopatry and male-biased dispersal within this rock-wallaby colony. There was a strong, significant negative correlation between pairwise relatedness and geographical distance of individual females along only 800 m of cliff line. Spatial genetic autocorrelation analyses showed significant positive correlation for females in close proximity to each other and revealed a genetic neighbourhood size of only 600 m for females. Our study is the first to report on the fine-scale spatial genetic structure within a rock-wallaby colony and we provide the first robust evidence for strong female philopatry and spatial clustering of related females within this taxon. We discuss the ecological and conservation implications of our findings for rock-wallabies, as well as the importance of fine-scale spatial genetic patterns in studies of dispersal behaviour.     

Relatedness,parentage, and philopatry within a Natterer’s bat (<Emphasis Type="Italic">Myotis nattereri</Emphasis>) maternity colony

Given their cryptic behaviour, it is often difficult to establish kinship within microchiropteran maternity colonies. This limits understanding of group formation within this highly social group. Following a concerted effort to comprehensively sample a Natterer’s bat (Myotis nattereri) maternity colony over two consecutive summers, we employed microsatellite DNA profiling to examine genetic relatedness among individuals. Resulting data were used to ascertain female kinship, parentage, mating strategies, and philopatry. Overall, despite evidence of female philopatry, relatedness was low both for adult females and juveniles of both sexes. The majority of individuals within the colony were found to be unrelated or distantly related. However, parentage analysis indicates the existence of a number of maternal lineages (e.g., grandmother, mother, or daughter). There was no evidence suggesting that males born within the colony are mating with females of the same colony. Thus, in this species, males appear to be the dispersive sex. In the Natterer’s bat, colony formation is likely to be based on the benefits of group living, rather than kin selection.     

The social structure and reproductive biology of the common mole-rat, Cryptomys h. hottentotus and remarks on the trends in reproduction and sociality in the family Bathyergidae

Cryptomys h. hottentotus occurs in mesic and semi-arid regions of South Africa. It lives in colonies ofup to 14 individuals, in which reproduction is limited to one ofthe largest males and the largest female in the colony.
Reproduction and details of colony size and the number of breeding animals in a colony are described for one complete and two incomplete field-captured colonies. One incomplete colony was kept in captivity for more than 3 years, whereas the complete colony was autopsied.
The social hierarchy of the common mole-rat is almost linear and has a value of 0.7 1 calculated from Landau's linearity index. Subordinate mole-rats weighed less than dominant mole-rats. The reproductive mole-rats are the dominant animals within the colony. The non-reproductive females rank lowest in the hierarchy.
Mating was not confined to a particular season, but occurred more frequently during the summer months. The alpha male initiated pre-copulatory behaviour. The gestation length is 55 to 66 days (n = 2). Two litters each of three pups were born to the colony during captivity. The pups were relatively altricial. They wandered out of the nest 5 days after birth, began to eat solids when 10 days old, and were fully weaned at 4 weeks. When 2 weeks old the pups began to spar with each other and with some of the adult colony members, but levels of aggression were never high. The pups did not disperse but were incorporated into the colony, this suggesting that C. h. hottentotus colonies are largely composed of related individuals.     

Social stress,mortality and aggression in colonies and burrowing habitats

High mortality was found within six mixed-sex groups of Long-Evans rats living in burrowing habitats with 58% of subordinate males dying within 4 mo. of group formation. By contrast, no subordinate deaths occured during this time in six identical adult groups(3 males and 3 females) housed in similar (1 m square) colony cages without burrows. Although aggression against intruders was also much greater in habitats than colonies --through 400 days postformation--subordinate deaths did not appear to result from direct physical injury. It seems that mimicing key features of the rat's environment enhances intermale conflict and social stress, even while providing partial protection from biting attack. Behav. Proc.:     

Establishment of a deer mouse (Peromyscus maniculatus rufinus) breeding colony from wild-caught founders: comparison of reproductive performance of wild-caught and laboratory-reared pairs

The deer mouse (Peromyscus maniculatus) is a natural reservoir for several human pathogens, but little is known about the mechanisms by which such pathogens are maintained in nature. As a first step toward developing a colony of deer mice that were permissive for infection with Sin Nombre (SN) hantavirus, we collected 68 wild P. maniculatus rufinus from central New Mexico. Mice from this cohort were used to establish 26 breeding pairs, of which 85% were fertile. In subsequent generations, fertility decreased slightly to 73% (N = 59) in laboratory-reared F1 and F2 pairs. Wild-caught females delivered 7.2 litters on average (range, 1 to 18), whereas laboratory-reared pairs delivered 5.5 (range, 1 to 13). The average time between pairing and first litter was 106 days for wild-caught animals, whereas that for laboratory-reared pairs was 71 days. None of the pairs displayed a seasonal breeding preference. Cannibalistic behavior increased from 5% in founders to 26% in laboratory-reared pairs. Mean litter size for wild-caught females was 4.3, whereas that for laboratory-reared dams was 4. Founding animals have been maintained in captivity for longer than 2 years, with only 2 deaths (4.8%). Our colony is competent for infection with SN virus. Thus, it should be useful for testing of models for maintenance of SN virus in wild rodents, and other aspects of the virus-host relationship.     

Mate switching and copulation behaviour in King Penguins

Extra‐pair paternity (EPP) in monogamous birds may result from either extra‐pair copulations (EPCs) or mate switching. In this study of King Penguins in South Georgia, we observed no EPCs at all, an effect of very efficient mate guarding. Onshore males fast and need not divert attention to foraging or to defending nest or territory, as this species has neither. However, we found that mate switching was common. On average 38% (range: 29%–56%; three years pooled) of the birds established pair bonds with at least one initial partner before switching to the partner they bred with (i.e. the “pair mate”). Of the observed copulations of 44 studied females, 22% were with initial partners and 78% with the pair mate. This and the high proportion of mate switching suggest that roughly 10% of the females could have received sperm from males other than the pair mate. The average copulation frequency was 0.026 h^?1, resulting in an estimated 8.2 copulations per clutch (which consists of one egg). That more copulations than necessary for fertilisation occur suggests that males try to protect paternity by sperm competition, and that this is a result of the potential for EPP due to mate switching in King Penguins. All observed copulations except one took place between days 13 and 5, with the peak 7.5 days prior to egg‐laying. The birds found their pair mates (often not the same as in the previous year) on average about 10 days before egg‐laying, and always established themselves at the outskirts of the colony about 8 days before egg‐laying. Thus, most copulations occurred around the time the birds joined the colony. We suggest that it is adaptive to obtain a breeding spot early, because the colony will grow and pairs joining later will protect the offspring. Additionally, we suggest that early copulation outside the colony is adaptive because of the risk of failing to fertilise the egg when copulating among aggressive neighbours inside the dense colony. Based on these two arguments we suggest a “safe place hypothesis” to explain the early copulation peak in King Penguins.