Reproductive Pair Research Articles

P-569 Reciprocal expanded carrier screening for intended parents and gamete donors: experience of a global surrogacy support network

Abstract Study question Is expanded carrier screening an effective tool to identify carriers of clinically relevant genes and determine the reproductive risk between a donor and recipient pair? Summary answer This study has determined that there is a strong rationale for performing matching according to expanded carrier screening results, especially for gamete donor programs. What is known already Carrier screening (CS) identifies carriers of autosomal recessive (AR) and/or X-linked (XL) genetic conditions to establish reproductive risk. If both partners (egg and sperm providers) carry a pathogenic variant in the same gene (co-carriage), there is 25% risk that offspring will be affected. The same risk is present for egg providers who carry an XL disorder. In expanded carrier screening (ECS), many clinically relevant conditions are screened simultaneously using a single-panel approach. The implementation of ECS is becoming commonplace across gamete donor banks. Providing recipients with a matching panel is key in determining reproductive risk and suitable treatment options. Study design, size, duration In this retrospective review, data was collected for 104 gamete recipients and 31 gamete donors who underwent ECS between March 2021-January 2024. ECS was provided through a single genetic testing laboratory, using a whole exome sequencing (WES) platform. The panel used for the gamete donors/recipients consisted of approximately 500 AR genes; optional analysis of 66 X-Linked genes was available for biologically female donors/recipients. Participants/materials, setting, methods In total, 104 gamete recipients were screened against one or more donor(s) using the same ECS panel. All donors/recipients underwent testing in a clinical setting and received pre/post-test genetic counselling, where required. The testing laboratory provided the referring clinician with the results for each individual. Matching was overseen by My Surrogacy Journey and the relevant donor bank. Donor-recipient match reports were requested from the testing laboratory. Individual and matched reports were used for this review. Main results and the role of chance In total, 76.9% (80/104) of gamete recipients presented with a positive result in at least one clinically relevant gene that could have an impact on reproductive planning. Between the 80 positive gamete recipients, 177 gene variants were carried; variant classification was available for 132 variants (74.6%). The majority of gene variants carried were classified as pathogenic (59.9%), meaning that these variants are associated with causing disease. Most frequently, recipients were carriers of a variant in 1-3 genes (1 gene: 36.3%; 2 genes: 27.5%; 3 genes: 22.5%). In addition to this, 77.4% (24/31) of gamete donors were identified to carry a variant in at least one clinically relevant gene, which includes one egg donor (3.2%; 1/24) who was a carrier of an XL condition. This meant that despite the lack of co-carriage in the AR gene(s) of interest, the recipient could not proceed with this donor due to the associated risk (25%). Of the 43 recipients matched with a donor, 9.3% (4/43) showed a high reproductive risk (25%) due to their reciprocal matching results. This expanded carrier screening strategy demonstrates significant utility in identifying positive carrier status and supporting donor-recipient matching programmes by determining high risk reproductive pairs. Limitations, reasons for caution This study was retrospective in nature. The majority of recipients were Caucasian (∼80% of cases). Ethnic groups are not homogenous; there can be significant genetic, cultural, and environmental diversity between/within ethnic groups. Decision outcome data should be collected to improve this work. Wider implications of the findings The findings from this analysis suggest that there is a strong rationale for performing donor-recipient matching using an ECS approach. Increasing awareness and accessibility of ECS in this setting should be a global initiative, with the ultimate aim of reducing the burden of genetic disease in donor-conceived offspring. Trial registration number N/A

Types and Fecundity of Neotenic Reproductives Produced in 5-Year-Old Orphaned Colonies of the Drywood Termite, Cryptotermes domesticus (Blattodea: Kalotermitidae)

Orphaned colonies of Cryptotermes domesticus readily produce replacement reproductives and continue propagation. In this study, we aimed to investigate the production and fecundity of neotenic reproductives in 5-year-old colonies of C. domesticus after orphaning. All 15 experimental colonies were successfully re-established by the neotenic reproductive pair. Three types of neotenic reproductives with various wing-bud lengths were observed: type I with micro wing buds, type II with short wing buds, and type III with long wing buds. Four patterns of pairs made up of these neotenics, namely, type I + type II, type I + type III, type II + type II, and type II + type III, exhibited reproductive capacities similar to those of the primary reproductive pair. We speculated that these neotenic reproductives were derived from various nymphal instars. The 5-year-old colonies had three instars of nymphs, with the majority being in the second instar, followed by the first. Thus, the combination of neotenic reproductives with short wing buds and micro wing buds was the dominant differentiation pathway of the orphaned colonies. After the removal of the original primary reproductive pair, the nymphs matured into neotenic reproductives and took over reproduction in the colony in 107.40 ± 15.18 days. This study highlights the importance of quarantine and routine inspection of wood, as well as the significance of early prevention and control of C. domesticus infestation in wood. Moreover, this study confirms the high differentiation and reproductive capacities of C. domesticus.

Intraspecific behavior patterns of hoary fox (Lycalopex vetulus), a solitary canid endemic to Cerrado, Central Brazil

ABSTRACT The hoary fox, Lycalopex vetulus, is a small insectivorous canid endemic to grasslands of Central Brazil. Herein we characterize hoary fox social behavior, based on qualitative and quantitative differences in intraspecific communication among males, females, and subadults. A family group, two reproductive pairs and three other adult individuals of unidentified social status were directly observed from 1995 to 2001, for the continuous recording of all occurrences of behavioral events. Hoary fox exhibited behaviors related to communication and food consumption. A total of 4,240 behavioral events were recorded, most in the categories ‘Consumption’ (58%) and ‘Olfactory’ (23%). The frequencies of signaling types varied among individuals according to sex, age, and socioecological phase. Olfactory signalings were more frequent in adult males, and during the Mating and Dispersal phases. Acoustic signalings were more frequent in adult females and individuals rearing the young. ‘Consumption’ and ‘Tactile’ behaviors were more frequent in subadults. The hoary fox intraspecific communication is characteristic of solitary canids, but during mating season and rearing period, individuals become more ‘socialized.’ Data on courtship and mating, partnership dissolution phase, and the breakup of the family group until young dispersal, are necessary for a better understanding of intraspecific communication of the hoary fox.

Social Network Changes in Cotton-Top Tamarins (Saguinus oedipus) after the Birth of New Infants.

Cotton-top tamarins (Saguinus oedipus) are characterized by a system of cooperative breeding where helpers, in addition to the reproductive pair, contribute to infant care. Grooming interactions between individuals play an important role in establishing social relationships, creating an interconnected social network in the group. We used social network analysis to investigate the social structure of two groups of cotton-top tamarins with different sizes and compositions and study whether they remain stable after the birth of new infants. We also investigated the possible correlation between the time spent carrying infants and an increase in the grooming centrality. We found that group A (n = 13) had a stable grooming network that showed consistent stability after the birth, although group B (n = 8 and no adult helpers) changed its grooming network and showed a lower density after the birth. Infant carrying was not correlated with increased grooming centrality after the birth. These findings highlight the usefulness of social network analysis in the study of group structure in cooperatively breeding primates and suggest that the birth of offspring has a greater impact on the stability of groups without adult helpers.

Expanded carrier screening for reproductive risk assessment: An evidence-based practice guideline from the National Society of Genetic Counselors.

Expanded carrier screening (ECS) intends to broadly screen healthy individuals to determine their reproductive chance for autosomal recessive (AR) and X-linked (XL) conditions with infantile or early-childhood onset, which may impact reproductive management (Committee Opinion 690, Obstetrics and Gynecology, 2017, 129, e35). Compared to ethnicity-based screening, which requires accurate knowledge of ancestry for optimal test selection and appropriate risk assessment, ECS panels consist of tens to hundreds of AR and XL conditions that may be individually rare in various ancestries but offer a comprehensive approach to inherited disease screening. As such, the term "equitable carrier screening" may be preferable. This practice guideline provides evidence-based recommendations for ECS using the GRADE Evidence to Decision framework (Guyatt et al., BMJ, 2008, 336, 995; Guyatt et al., BMJ, 2008, 336, 924). We used evidence from a recent systematic evidence review (Ramdaney et al., Genetics in Medicine, 2022, 20, 374) and compiled data from peer-reviewed literature, scientific meetings, and clinical experience. We defined and prioritized the outcomes of informed consent, change in reproductive plans, yield in identification of at-risk carrier pairs/pregnancies, perceived barriers to ECS, amount of provider time spent, healthcare costs, frequency of severely/profoundly affected offspring, incidental findings, uncertain findings, patient satisfaction, and provider attitudes. Despite the recognized barriers to implementation and change in management strategies, this analysis supported implementation of ECS for these outcomes. Based upon the current level of evidence, we recommend ECS be made available for all individuals considering reproduction and all pregnant reproductive pairs, as ECS presents an ethnicity-based carrier screening alternative which does not rely on race-based medicine. The final decision to pursue carrier screening should be directed by shared decision-making, which takes into account specific features of patients as well as their preferences and values. As a periconceptional reproductive risk assessment tool, ECS is superior compared to ethnicity-based carrier screening in that it both identifies more carriers of AR and XL conditions as well as eliminates a single race-based medical practice. ECS should be offered to all who are currently pregnant, considering pregnancy, or might otherwise biologically contribute to pregnancy. Barriers to the broad implementation of and access to ECS should be identified and addressed so that test performance for carrier screening will not depend on social constructs such as race.

Vocal behaviour, parasitic infection, chronic stress and body condition in rufous‐naped wrens (Campylorhynchus rufinucha)

We explored the relationship between haemosporidian infection (infected vs. uninfected), parasite load, heterophil:lymphocyte ratio, body condition and vocal behaviour of the Rufous‐naped Wren Campylorhynchus rufinucha. Our results, albeit based on a small sample size, showed no evidence of an association between vocal behaviour and infection status, heterophil:lymphocyte ratio or body condition. Infections did not vary between localities. Our results showed, however, that infection status was associated with a higher song rate, and that in males and females belonging to the same reproductive pair there was a strong positive correlation in terms of infection status and parasite load.

Parent-offspring turn-taking dynamics influence parents’ song structure and elaboration in a singing primate

Parent-offspring interactions are essential to interpret animal social evolution and behavior, but their role in mediating acoustic communication in animals that interact vocally is still unclear. Increasing evidence shows that primate vocal communication is way more flexible than previously assumed, and research on this topic can provide further information on how the social environment shaped vocal plasticity during the evolution of the Primate order. Indris communicate through elaborated vocal emissions, usually termed songs. Songs are interactive vocal displays in which all members of the family group alternate their emissions, taking turns during chorusing events. We aimed to understand whether specific rules regulate the turn-taking of different group members and investigate the flexibility of indris’ vocal behavior when co-singing with their offspring. We found that social factors can influence the turn-taking organization in a chorus, as offspring were more likely to drop out from the parents’ duet than join in, and we speculate that overlap might signal competition by members of the same-sex. The duet between the reproductive pair was the most common type of singing organization, followed by a duet between mothers and sons and the triadic interaction between mother, father, and son. Interestingly, parents’ solo singing seems to stimulate offspring to vocalize, and we also found that mothers and fathers simplify, at least in part, song elaboration when chorusing with offspring. Our results indicate that indris can perform short-time adjustments to the number of co-emitters and their identity: our approach is advantageous in highlighting the multilevel influences on primate vocal flexibility. Moreover, it provides evidence that some aspects of our vocal plasticity were already present in the lemur lineage.

Re] Reproductive pair correlations and the clustering of organisms

Re] Reproductive pair correlations and the clustering of organisms

Spatio-temporal inhabitation of settlements by Hystrix cristata L., 1758

Settlements are usually shared at different times by semi-fossorial mammals. Porcupine reproductive pair shows high den-site fidelity, but no data are available on the spatio-temporal inhabitation of settlements. In this investigation, the spatio-temporal inhabitation of settlements by crested porcupine families was investigated using camera-trapping as well as the ethological factors affecting the settlements selection. The crested porcupine resulted to be the main inhabitant of settlements surveyed in the present study. Each settlement was inhabited exclusively by one porcupine family. Five out of six porcupine families, each alternatively and complementarily inhabited the same two settlements. In all the five monitored families, settlements selection doesn’t follow a seasonal pattern. Settlement inhabitation of porcupines resulted positively affected by cohabitation with badger, while presence of porcupettes did not affect settlements selection. Long periods of settlement inhabitation were positively affected both by the presence of porcupettes and cohabitation with badger. The pattern of settlements inhabitation in relation to their availability and porcupine population density as well as factors promoting porcupine-badger cohabitation should be further investigated. New ethological knowledge obtained in this investigation could be involved in the evaluation of the ecological epidemiology of infectious diseases between porcupine and badger within a one health approach and may be a useful tool for a sustainable management of semi-fossorial mammals.

Variation in escape response of Himalayan marmots (Marmota himalayana) under different human disturbances

AbstractWe measured flight initiation distance (FID) and distance fled (DF) of Himalayan marmots (Marmota himalayana) from three populations suffering different human disturbances when they are near (<5 m) and away from (>5 m) a potential refuge to analyze the effects of varied disturbance intensity on their FID, DF, and the interaction between the two parameters. We found that: (1) highly disturbed individuals have shorter FIDs and smaller standard deviation of FID relative to undisturbed individuals, but there was no difference between lowly disturbed and undisturbed individuals. The diversifications arise possibly because extensive disturbance enhances the risk perception threshold of highly disturbed marmots but their lowly disturbed congeners; (2) the DF of highly disturbed individuals was shorter than undisturbed individuals, possibly because heavy disturbances drive reproductive pairs to dig more burrows in the habitat, resulting in the reduced inter‐burrow distance and thus decreased DF. No similar diversifications were observed between lowly disturbed individuals and individuals in the other two populations, possibly because reproductive pairs from low disturbance population concentrate their burrows, resulting in shorter DF when they are near their burrows, but longer DF when they are farther away; and (3) unlike lowly and undisturbed marmots, FID of highly disturbed individuals under different DFs differed significantly, potentially because shorter inter‐burrow distance reduced their flight costs, resulting in more tolerance of human proximity. Nevertheless, the DF‐derived risk perception threshold of undisturbed and lowly disturbed individuals drives them to prioritize fleeing when threatened. Generally, the escape response of Himalayan marmots under different human disturbances is determined by the interaction between predation risk and flight costs.

Genetic analysis of hybridization between white-handed (Hylobates lar) and pileated (Hylobates pileatus) gibbons in a contact zone in Khao Yai National Park, Thailand.

Natural hybridization has played various roles in the evolutionary history of primates. Its consequences range from genetic introgression between taxa, formation of hybrid zones, and formation of new lineages. Hylobates lar, the white-handed gibbon, and Hylobates pileatus, the pileated gibbon, are largely allopatric species in Southeast Asia with a narrow contact zone in Khao Yai National Park, Thailand, which contains both parental types and hybrids. Hybrid individuals in the zone are recognizable by their intermediate pelage and vocal patterns, but have not been analyzed genetically. We analyzed mitochondrial and microsatellite DNA of 52 individuals to estimate the relative genetic contributions of the parental species to each individual, and the amount of introgression into the parental species. We obtained fecal samples from 33 H. lar, 15 H. pileatus and four phenotypically intermediate individuals in the contact zone. Both mitochondrial and microsatellite markers confirmed distinct differences between these taxa. Both H. lar and H. pileatus contributed to the maternal lineages of the hybrids based on mitochondrial analysis; hybrids were viable and present in socially normal reproductive pairs. The microsatellite analysis identified ten admixed individuals, four F1 hybrids, which corresponded to phenotypic hybrids, and six H. lar-like backcrosses. All 15 H. pileatus samples were identified as originating from genetically H. pileatus individuals with no H. lar admixture; hence, backcrossing is biased toward H. lar. A relatively low number of phenotypic hybrids and backcrossed individuals along with a high number of parental types indicates a bimodal hybrid zone, which suggests relatively strong bias in mate selection between the species.

Effects of human activity on the habitat utilization of Himalayan marmot (Marmota himalayana) in Zoige wetland.

Human activity is increasingly and persistently disturbing nature and wild animals. Affected wildlife adopts multiple strategies to deal with different human influences. To explore the effect of human activity on habitat utilization of Himalayan marmot (Marmota himalayana), habitat utilization patterns of three neighboring marmot populations in habitats affected differently by human activities were recorded and compared. We found that (a) distance between reproductive burrows (a represent of reproductive pairs) becomes shorter under the influence of human activities, and more burrows were dug as temporary shelters, resulting in shorter distance between those shelters and shorter distance flee to those shelters and, consequently, shorter flight initiation distance when threatened. More burrows that are closer to the disturbed habitats improve the ability to escape from threats. (b) Reproductive burrow site selection of the species is determined by the availability of mounds in the habitat, and breeding pairs selectively build reproductive (also the hibernation) burrows on mounds, potentially to improve surveillance when basking and the drainage of burrows. Human activities generally drive breeding pairs away from the road to dig their reproductive burrows likely to reduce disturbance from vehicles. However, even heavy human activity exerts no pressure on the distance of reproductive burrows from the road or the mound volume of the high disturbance population, potentially because mounds are the best burrowing site to reproduce and hibernate in the habitat. Marmots deal with disturbance by digging more burrows in the habitat to flee more effectively and building reproductive burrows on mounds to gain better vigilance and drainage efficiency.

Life expectancy, family constellation and stress in giant mole-rats (Fukomys mechowii).

Giant mole-rats (Fukomys mechowii) are remarkably long-lived subterranean rodents (maximum recorded lifespan as reported here greater than 26 years) that live in families with one reproductive pair (breeders) and their non-reproductive offspring (non-breeders). Previous studies have shown that breeders live on average approximately twice as long as non-breeders, a finding contradicting the classic trade-off between reproduction and lifespan. Because recent evidence points to the hypothalamic-pituitary-adrenal axis as playing an important role in shaping the pace of ageing in mole-rats, we analysed the influence of the social environment of giant mole-rats on intrafamilial aggression levels, indicators of long-term stress, and, ultimately, mortality. Behavioural data indicated that family constellation, especially the presence or the absence of parents, influences agonistic behaviour. As a measure of long-term stress, we established a non-invasive method of extracting and measuring cortisol from hair of giant mole-rats. Interestingly, orphaned non-breeders exhibited significantly lower levels of cortisol and lower mortality rates than did non-breeders living with both parents. Because hypercortisolism is harmful in the long-term, intrafamilial stress could help explain the earlier onset of senescence in non-breeders, resulting in a shorter lifespan. Our findings suggest that the social environment should be considered as a further factor in ageing studies involving group-living animals. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'

Import of Palmer amaranth (Amaranthus palmeri S. Wats.) seed with sweet potato (Ipomoea batatas (L.) Lam) slips

Palmer amaranth is one of the most economically important and widespread weeds of arable land in the United States. Although no populations are currently known to exist in Canada, its distribution has expanded northward such that it is present in many of the states bordering Canada and multiple pathways exist for its introduction. In this short communication, we report on the transport of viable Palmer amaranth seed on imported sweet potato slips. A reproductive pair of Palmer amaranth seedlings were identified from soil accompanying imported sweet potato slips in 2018. Identification was confirmed using species-specific single nucleotide polymorphisms.

Brain Laterality Demands that Two Human Species Exist: Evidence from Hemisity and Familaial Polariity

The asymmetric location of functional units in the bilateral brain of animals and humans is the topic of brain laterality. So far, five lateralized functions have been discovered in humans: handedness, language ability, spatial skills, facial recognition, and emotion recognition. Recently a sixth asymmetric functional element bearing upon personality has been discovered. It is the larger side of the split bilateral anterior cingulate cortex (ACC). This appears to be the final output element of the brain’s executive system, of which by logic there can be only one. Hemisity is the binary measure, based upon eight MRI validated biophysical and questionnaire methods. It determines whether a person was born with the larger side of the ACC on the right or left side of the brain. Which side of the ACC is largest varies among the general population in a seemingly random manner, yet with a genetic basis because true-breeding lineages exist. The corpus callosum of subjects was up to three times larger when the larger ACC was on the right, than on the left. There are over 30 measurable differences in in individual characteristics and behaviors of male or female persons whose larger ACC was on the right compared to those with it on the left. Familial Polarity refers to the mating outcomes of the four reproductive pairs: RM-LF; RF-LM; RM-RF; LM-LF. The first two “opposites attract” reproductive pairs were true breeding, producing offspring that were “like father like son, like mother like daughter”. The offspring of the last two “same-same” pairs, were not true breeding, but rather their offspring were random in sex and hemisity. The simplest explanation for these results is that life on earth originated twice, once in deep sea vents and once in warm surface ponds. This resulted in two trees of life, one Patripolar (RM-LF) harem forming, the other Matripolar (RF-LM) territorial. Africa was the first subcontinent to evolve life to the level of primates, which upon docking populated the eastern hemisphere Eurasia in six waves. The first was the patripolar orangutans who settled in the empty far-east to become the orientals. Then next wave was the matripolar bonobos who stopped at India, and was followed by four later waves out of Africa. These alternating populations were immiscible and adversarial, with wars dominating their interfaces. This continues into the present day. Understanding Familial Polarity helps bring understanding and thus peace to the globe.

The role of dopamine signaling in prairie vole peer relationships

Dopamine signaling mediates the formation of some types of social relationships, including reproductive pair bonds in the socially monogamous prairie vole (Microtus ochrogaster). In addition to these pair bonds with mates, prairie voles demonstrate selective preferences for familiar same-sex peers. The dependence of peer relationships on dopamine signaling has not been tested, and the mechanisms supporting these relationships may differ from those underlying pair bonds. We examined the effects of pharmacological manipulations of dopamine signaling on peer partner preference and socially conditioned place preference in female prairie voles. Haloperidol blockade of dopamine receptors at multiple doses did not alter selective preferences for familiar same-sex partners, suggesting that dopamine neurotransmission is not necessary for the formation of prairie vole peer relationships, unlike mate relationships. Dopamine receptor agonist apomorphine facilitated peer partner preferences under conditions normally insufficient for partner preference formation; however, in the absence of effects from blockade, it is difficult to distinguish between a role for dopamine in partner preference formation and the generally rewarding properties of a dopamine agonist. Prairie voles exhibited socially conditioned place preferences for new but not long-term same-sex peers, and these preferences were not blocked by haloperidol. These results suggest that prairie vole peer relationships are less dependent on dopamine signaling than pair bonds, while still being rewarding. The data support distinct roles of dopamine and motivation in prairie vole peer relationships relative to mate relationships, suggesting that reproductive bonds are mediated differently from non-reproductive ones.

Genetic consequences of social structure in the golden-crowned sifaka

Many species are structured in social groups (SGs) where individuals exhibit complex mating strategies. Yet, most population genetic studies ignore SGs either treating them as small random-mating units or focusing on a higher hierarchical level (the population). Empirical studies acknowledging SGs have found an overall excess of heterozygotes within SGs and usually invoke inbreeding avoidance strategies to explain this finding. However, there is a lack of null models against which ecological theories can be tested and inbreeding avoidance quantified. Here, we investigate inbreeding (deviation from random mating) in an endangered forest-dwelling pair-living lemur species (Propithecus tattersalli). In particular, we measure the inbreeding coefficient (FIS) in empirical data at different scales: SGs, sampling sites and forest patches. We observe high excess of heterozygotes within SGs. The magnitude of this excess is highly dependent on the sampling scheme: while offspring are characterised by a high excess of heterozygotes (FIS < 0), the reproductive pair does not show dramatic departures from Hardy–Weinberg expectations. Moreover, the heterozygosity excess disappears at larger geographic scales (sites and forests). We use a modelling framework that incorporates details of the sifaka mating system but does not include active inbreeding avoidance mechanisms. The simulated data show that, although apparent “random mating” or even inbreeding may occur at the “population” level, outbreeding is maintained within SGs. Altogether our results suggest that social structure leads to high levels of outbreeding without the need for active inbreeding avoidance mechanisms. Thus, demonstrating and measuring the existence of active inbreeding avoidance mechanisms may be more difficult than usually assumed.

Estrous cyclicity and reproductive success are unaffected by translocation for the formation of new reproductive pairs in captive red wolves (Canis rufus)

This study investigated possible female-related causes for inconsistent success among reproductive pairs in the zoo-based red wolf (Canis rufus) population. Females (n = 13) at seven institutions were assessed for evidence of ovulation and normal reproductive cycles through the measurement of estradiol and progesterone metabolite excretion in feces. Fecal cortisol metabolites (FCM) were also measured. Factors potentially affecting FCM and/or estrous cyclicity were recorded, including exhibit status (on vs. off), reproductive history (proven vs. unproven), copulatory behaviors (ties observed: yes or no), pregnancy/parturition (pups or no pups produced), and translocation before the observed breeding season (yes or no). No differences were observed in baseline FCM between females housed on versus off-exhibit (p = .46) or between females producing pups and those who did not (p = .19). Baseline FCM were significantly lower among females observed in copulatory ties compared to females never observed in a tie (p = .04), and tended to be higher in females translocated before the breeding season compared to females in existing reproductive pairs (p = .11), and among historically unproven females compared to proven females (p = .11). All females evaluated had an endocrine profile indicative of ovulation and among the four females translocated to be paired with a new male before the breeding season, two had successful pregnancies, producing litters. Therefore, despite observed differences in baseline FCM among factors, estrous cyclicity and reproductive success are unaffected by translocation for the formation of new reproductive pairs in the zoo-based red wolf population.

Mating system of Thrichomys fosteri in the Brazilian Pantanal: spatial patterns indicate promiscuity

Animal mating systems provide key insights into the relationship between evolutionary processes and ecological factors such as the spatio-temporal fluctuation of resource abundance. Characteristics of mating systems can be inferred from the spatial distribution of conspecifics and the arrangement of reproductive pairs. Here we used home-range size and overlap for Thrichomys fosteri in the Brazilian Pantanal to infer the mating system on this echimyid rodent. Our aims were to verify the existence of sexual dimorphism, to test whether home-range size varied with the sex and body weight of the individuals, to evaluate the degree of home-range overlap, to estimate mean population density, and to infer individuals’ mating system. Twenty one individuals (15 males and six females) were radio tracked from 14 to 349 days, with the number of locations by individuals ranging from 19 to 193 locations. There was a male-biased sexual dimorphism in body weight where males were 1.36 times heavier than females. Males’ home-range size increased with their body weight, while for females there was no relationship. There was extensive home-range overlap between both sexes, and no evidence of territoriality. Mean population density ranged from 0.9 to 3.03 individuals/ha. Our results indicate that multiple mates were available for both sexes, characterizing a promiscuous mating system.

High numbers of unrelated reproductives in the Australian ‘higher’ termite Nasutitermes exitiosus (Blattodea: Termitidae)

Social insect colonies are among the most complex social organisations in nature, with reproductive and non-reproductive individuals co-ordinating to maintain the survival of the colony. Multiple reproductive schemes occur in social insects, from simple schemes with one founding reproductive pair, to more complex ones involving within-colony inbreeding and more than two unrelated reproductives. Colony breeding schemes and genetic structure remain understudied in termites, compared to the Hymenoptera. In this study, we performed the first genetic characterisation of the colony breeding structure of Nasutitermes exitiosus (Blattodea: Termitidae), an endemic Australian termite with a broad distribution across southern mainland Australia. We analysed the genetic structure of 60 N. exitiosus colonies from the Eastern part of its distribution, using microsatellites and mitochondrial sequence data. We found that most colonies were headed by one founding pair of reproductives, although some colonies exhibited a more complex breeding structure, including within-colony inbreeding and the presence of multiple unrelated reproductives. We found evidence for the presence of seven unrelated queens in one colony, to our knowledge, the highest number of unrelated queens yet found in a termite from the family Termitidae. We found some evidence for genetic isolation by distance, indicating that the species is a relatively poor disperser over long ranges.