Parental Care System Research Articles

Multiple origins of freshwater invasion and parental care reflecting ancient vicariances in the bivalve family Cyrenidae (Mollusca)

Habitat transitions in living organisms are key innovations often coupled with species diversification after their successful adaptation to new environment. The Cyrenidae is among the most well-known heterodont bivalve groups that have successfully invaded freshwater systems from brackish water environments and display diverse lineage-specific developmental modes. Phylogenetic and molecular clock-based divergence time analyses using 12 complete mitochondrial genome sequences suggest that Cyrenidae species independently colonized freshwater habitats during three distinct spatial and geological periods: one from the American continents approximately in the Early Jurassic and the two others from Australasian/East Asian continents in the Early/Middle Cretaceous and the Paleogene-Neogene boundary, respectively. This study provides significant insight into the temporal and spatial patterns of multiple freshwater invasions, aligning with ancient vicariance events inferred from different geological timelines of plate tectonics. Additionally, mitogenome phylogeny confirms the earlier hypothesis of the repeated parallel evolution of parental care system within this bivalve group.

Inbreeding avoidance, competition and natal dispersal in a pair-living, genetically monogamous mammal, Azara's owl monkey (Aotus azarae).

Natal dispersal is an important life-history stage influencing individual fitness, social dynamics of groups and population structure. Understanding factors influencing dispersal is essential for evaluating explanations for the evolution and maintenance of social organization, including parental care and mating systems. The social and mating systems of Azara's owl monkeys (Aotus azarae) are infrequent among mammals; these primates are pair-living, serially and genetically monogamous and both sexes directly care for offspring. To evaluate the role that competition and inbreeding avoidance play in shaping dispersal patterns, we used 25 years of demographic and genetic data to examine how variation in timing of natal dispersal is related to social (adult replacements, step-parents, births and group size) and ecological factors (seasonal abundance of resources) in a wild population of A. azarae in Formosa, Argentina. We found that all males and females dispersed from their natal groups, but subadults delayed dispersal when a step-parent of the opposite sex joined the group, indicating that they may perceive these step-parents as potential mates. Dispersal was more probable when resource conditions were better, regardless of age. Overall, agonistic conflict over food and potential mates with adults in the natal group, as well as inbreeding avoidance, contribute to regulating dispersal.

A pheromone receptor in cichlid fish mediates attraction to females but inhibits male parental care

Reproductive behaviors differ across species, but the mechanisms that control variation in mating and parental care systems remain unclear. In many animal species, pheromones guide mating and parental care. However, it is not well understood how vertebrate pheromone signaling evolution can lead to new reproductive behavior strategies. In fishes, prostaglandin F2α (PGF2α) drives mating and reproductive pheromone signaling in fertile females, but this pheromonal activity appears restricted to specific lineages, and it remains unknown how a female fertility pheromone is sensed for most fish species. Here, we utilize single-cell transcriptomics and CRISPR gene editing in a cichlid fish model to identify and test the roles of key genes involved in olfactory sensing of reproductive cues. We find that a pheromone receptor, Or113a, detects fertile cichlid females and thereby promotes male attraction and mating behavior, sensing a ligand other than PGF2α. Furthermore, while cichlid fishes exhibit extensive parental care, for most species, care is provided solely by females. We find that males initiate mouthbrooding parental care if they have disrupted signaling in ciliated sensory neurons due to cnga2b mutation or if or113a is inactivated. Together, these results show that distinct mechanisms of pheromonal signaling drive reproductive behaviors across taxa. Additionally, these findings indicate that a single pheromone receptor has gained a novel role in behavior regulation, driving avoidance of paternal care among haplochromine cichlid fishes. Lastly, a sexually dimorphic, evolutionarily derived parental behavior is controlled by central circuits present in both sexes, while olfactory signals gate this behavior in a sex-specific manner.

Does Caring Breed Contempt? Examining the Hypothesis That Activation of a “Parental” Mindset Causes Harsher Moral Judgments

Prior research (most of which is correlational) has suggested that activation of the parental care motivational system may lead people to make harsher moral judgments of social norm violators. We tested this hypothesis in 8 studies (total N = 1790). Seven of the studies were true experiments in which participants made moral judgments after being randomly assigned to either conditions designed to temporarily activate the parental care system or to a control condition. In one of these experiments, participants viewed photographs of either cute animals or furniture and in 6 additional experiments, participants engaged in an autobiographical writing task in which they recalled and wrote about a time they either cared for a child or—in the control conditions that varied across these experiments—had a different experience. In the final non-experimental study, women were recruited in public places and made moral judgments, the harshness of these judgments was compared between those accompanied by a young child versus not accompanied by a young child. The effects (and non-effects) of these procedures on moral judgments were inconsistent across the 8 studies and an internal meta-analysis of the 7 true experiments provided no compelling evidence that the experimental manipulations influenced moral judgments. We hope that these results offer some guidance to future researchers on what methods might—and might not—be effective in activating the parental care system and can support future work on the influence of parental care on moral cognition.

EFFECTIVE HISTORY IN THE NOVELS TRILOGY OF RARA MENDUT BY Y.B. MANGUNWIJAYA: A GENEALOGICAL STUDY OF MICHEL FOUCAULT

Trilogy of Rara Mendut’s novels are focused on four things with a working method based on Michel Foucault's genealogical theory which examines past events that can be used to see the present. The results of the study include: 1) the parental care system for children shows that children must receive sufficient attention, affection, and wholehearted care for their mental development; 2) unlimited power has an impact on people's misery, many enemies, leading tends to be cruel, and brings destruction; 3) the nature of a person is influenced by environmental factors; and 4) the essence of serving in real life is not one's superiors or institutions but to the people, especially those who are still suffering.

Crustacean Female Sex Hormone (CFSH) Transcript and Protein Profiles and Its Functions in Gradually Developing Adult-Specific-Features during the Prepuberty Molt Cycle of the Blue Crab, Callinectes sapidus

Crustacean female sex hormone (CFSH) plays a pivotal role in developing adult-specific female characteristics, specifically the mating and parental care system of the female blue crab, Callinectes sapidus, manifested after the puberty-terminal molt. Therefore, this study aimed to determine if there is a relationship between CFSH and the development of phenotypes specific to the female C. sapidus during its life cycle and if the continued presence of CFSH is required for developing adult-specific features during the prepuberty molt cycle. First, CasCFSH transcripts in females steadily increase, starting from crab stages 3-4 to prepuberty, except for a decrease at crab stages 15-16. The prepuberty females have the highest CasCFSH transcripts, with ∼5.6-fold higher than adults. CFSH protein levels at prepuberty are the highest but similar to adults. The first and visible secondary female characteristics include a pair of gonopores or a triangular abdomen and four pairs of pleopods seen as early as crab stages at ∼3 (carapace width, CW, 5-7 mm) - 5 (CW 8-10 mm), respectively. The adult-specific female morphological features that are developed gradually throughout the prepuberty molt cycle are manifested only after the puberty-terminal molt. A CasCFSH knockdown study by injecting CasCFSH-dsRNA into prepuberty females at specific molt stages provides further evidence: the continued presence of CasCFSH is required for gradually developing adult-specific morphological features during the prepuberty molt cycle. Overall, the abdomen size is first determined at the intermolt stage. Then, the abdominal shape, gonopores, sternal tubercles, spermathecae, and ovigerous setae and hairs are formed at the intermolt and early premolt stages. Finally, the plumose hairs are developed during intermolt, early, and late premolt stages.

Change in the Parent-Clinician Relationship Throughout the First Year of Treatment in Pediatric Oncology

Challenges in the therapeutic relationship between clinicians and parents of children with cancer have been shown to emerge immediately after diagnosis, but little is known about whether such relationships improve over time. To better understand the potential evolution of parent-clinician relationships over the first year after diagnosis of pediatric cancer. This survey study was conducted from November 2015 to September 2020 at Dana-Farber Cancer Institute/Boston Children's Hospital and Texas Children's Hospital. Participants were oncology clinicians (attending physicians and fellows or nurse practitioners) and parents of children (aged <18 years) with a cancer diagnosis. Surveys were completed at study enrollment (soon after diagnosis [baseline]) and at the 3-month and 12-month follow-up. Children had to have had at least 3 previous clinical visits with a primary oncology clinician. Survey instruments included the parent and clinician versions of the Relationship Challenges Scale, and factors associated with changes in relationships, including parental, clinician, and health care system attributes, were measured. Survey participants included 150 parents (118 women [78.7%]; 98 with White race and ethnicity [65.3%]) and 49 clinicians (39 [79.6%] women; 39 with White race and ethnicity [79.6%]). Parents reported on 175 relationships with clinicians, and clinicians reported on 98 relationships with parents at all 3 time points (baseline, 3-month follow-up, and 12-month follow-up). Of the 175 relationships, 33 (18.9%) were considered to be challenging by parents at baseline, 27 (15.4%) were considered to be challenging at the 3-month follow-up, and 32 (18.3%) were considered to be challenging at the 12-month follow-up. Of the 33 challenging relationships at baseline, 20 (60.6%) resolved at the 12-month follow-up, whereas 13 (39.4%) had persistent challenges. However, 19 relationships that were not challenging at baseline had new challenges at the 12-month follow-up, corresponding to 59.4% of all challenges at the 12-month follow-up. No clinician behaviors were associated with improvement. Strategies used frequently (≥50%) by clinicians in their relationships that were associated with improvement included holding family meetings, apologizing, adapting to the parent's communication style, and devoting extra time and attention. Results of this study showed that some parents experienced challenging relationships with their child's oncology clinicians beginning at diagnosis and throughout the first year after diagnosis. Although many such relationships improved, others worsened, reflecting the vulnerable and stressful nature of parent-clinician relationships.

Social complexity in plateau pikas, Ochotona curzoniae

We investigated factors leading to variation in social complexity or ‘social systems’ among plateau pika family groups within a contiguous local population across 2 years. Plateau pikas are small, diurnal, nonhibernating, sexually monomorphic lagomorphs that occupy family home ranges on open alpine meadows on the Qinghai-Tibetan Plateau. Expression of the social organization, social structure, mating system and parental care system in plateau pikas did not follow expectations from traditional ecological or evolutionary explanations. Variability in plateau pika family group size and the transitions of group size between years allowed us to investigate potential advantages and disadvantages of group living. Evidence that group living served to protect pikas against predation was weak. Although social huddling could have minimized thermoregulatory costs during the extremely cold Tibetan winters, there was no correlation of overwinter survivorship among pika families of different sizes. There was no apparent group-living benefit with regard to foraging, and the occurrence of cohesive social families on the flat, continuous meadow contradicts the hypothesis that sociality is related to patchiness of critical resources. Cost of maintaining burrows appeared unrelated to group size. Most interactions between pikas occurred within family groups and were affiliative (99% of adult interactions; 97% of adult–juvenile interactions), and most interactions between adult males of different family groups were aggressive (96% of interactions). Matings were primarily within families (88% of copulations). Pikas also possess a complex vocal repertoire that enhanced interactions within social families. Demographic constraints associated with variable overwinter survivorship appeared to be the dominant precondition that produced a given family size and mating system type, coupled with selective dispersal by some pikas before the start of the breeding season. Paternal care enhanced juvenile survival, and thus led to an equalization of reproductive success among adults in families with different mating combinations. • Plateau pikas live in families occupying exclusive burrow systems and home ranges. • Pika family group size varied from one to five adults within and between years. • Pikas failed to adhere to conventional explanations for establishment of group size. • Pika families exhibited multiple social mating system types. • Pika families did not adhere to explanations for establishment of mating system types.

Parental Care System and Brood Size Drive Sex Difference in Reproductive Allocation: An Experimental Study on Burying Beetles

Life-history theory predicts that increased resource allocation in current reproduction comes at the cost of survival and future reproductive fitness. In taxa with biparental care, each parent can adjust investment on current reproduction according to changes in their partner’s effort, but these adjustments may be different for males and females as they may have different reproductive strategies. Numerous theoretical and empirical studies have proposed the mechanism underlying such adjustments. In addition, the value of the brood or litter (brood size) has also been suggested to affect the amount of care through manipulation of brood size. While the two conditions have been studied independently, the impact of their interplay on potential sex-dependent future reproductive performance remains largely unknown. In this study, we simultaneously manipulated both care system (removal of either parent vs. no removal) and brood size in a burying beetle (Nicrophorus vespilloides) to understand their joint effect on reproductive allocation and trade-off between current and future reproduction. Our results show that males compensated for mate loss by significantly increasing the level of care regardless of brood size, while females exhibited such compensation only for small brood size. Additionally, with an increase in allocation to current reproduction, males showed decreased parental investment during the subsequent breeding event as a pair. These findings imply a dual influence of parental care system and brood size on allocation in current reproduction. Moreover, the impact of such adjustments on sex-dependent differences in future reproduction (parental care, larvae number, and average larval mass at dispersal) is also demonstrated. Our findings enhance the understanding of sex roles in parental investment and highlight their importance as drivers of reproductive allocation.

Triparental care in the collared flycatcher (Ficedula albicollis): Cooperation of two females with a cuckolded male in rearing a brood.

Certain predominant forms of mating and parental care systems are assumed in several model species among birds, but the opportunistic and apparently infrequent variations of “family structures” may often remain hidden due to methodological limitations with regard to genetic or behavioral observations. One of the intensively studied model species, the collared flycatcher (Ficedula albicollis), is usually characterized by social monogamy with polyterritorial, facultative social polygyny, and frequent extrapair mating and extrapair paternity. During a brood‐size manipulation experiment, we observed two females and a male delivering food at an enlarged brood. A combination of breeding phenology data (egg laying and hatching date), behavioral data (feeding rates) from video recordings at 10 days of nestling age, and microsatellite genotyping for maternity and paternity suggests a situation of an unrelated female helping a pair in chick rearing. Such observations highlight the relevance of using traditional techniques and genetic analyses together to assess the parental roles within a population, which becomes more important where individuals may dynamically switch from their main and presupposed roles according to the actual environmental conditions.

What a cute baby! Preliminary evidence from a fMRI study for the association between mothers’ neural responses to infant faces and activation of the parental care system

Infant facial characteristics, i.e., baby schema, are thought to automatically elicit parenting behavior and affective orientation toward infants. Only a few studies, conducted in non-parents, have directly examined the neural underpinnings of this baby schema effect by manipulating distinctiveness of baby schema in infant faces. This study aims to further our understanding of the intuitive nature of parenting, by studying the baby schema effect in mothers of young children (at least one child aged between 2 and 6 years old). Functional magnetic resonance imaging (fMRI) was used to examine mothers’ (N = 23) neural responses to unfamiliar infant faces varying in distinctiveness of baby schema. Also, it was studied how this neural activation to infant faces was associated with maternal nurturance. Results revealed that infant faces elicited widespread activation in bilateral visual cortices, the hippocampus, sensory-motor areas, parietal and frontal cortices, and the insula, which was not modulated by the distinctiveness of baby schema in the infant faces. Furthermore, higher self-reported maternal nurturance was related to increased neural responses to infant faces in the putamen and amygdala, brain regions known to be associated with reward and salience processing. These findings could suggest that in our small sample of mothers some of the core networks involved in reward and salience processing might be less sensitive to variation in distinctiveness of baby schema. Also, unfamiliar infant faces seem to be rewarding only for mothers who report high nurturance. These findings should be considered preliminary, because they need to be replicated in studies with larger samples.

Dogs' sensitivity to strange pup separation calls: pitch instability increases attention regardless of sex and experience

When separated, young offspring produce separation calls to attract their mother's attention, reduce distance between them and receive maternal care. Previous studies suggest that these calls arouse the caregiver's attention because of their special acoustic structure. Furthermore, under specific conditions separation calls can elicit an approach response even from heterospecific mothers and nonparent conspecifics depending on their sex and parental experience and the species' parental care system. Dogs, Canis familiaris, are good models because we can easily test the effects of a wide range of individual characteristics such as sex, sexual state, age, breed and behaviour traits due to a diverse dog population. Here, we assessed the reaction of sexually mature, intact and neutered dogs to strange 4- and 11-day-old dog pup separation calls, presented from a hidden speaker. We recorded the reactions of former mothers, inexperienced intact females and males and inexperienced neutered females and males to six different repeated playbacks of pup separation call bouts. We tested the effect of sex, sexual state, parental experience and age of the dogs, the fundamental frequency, call length, jitter and nonlinear phenomena ratio of the playbacks and the habituation effect of repeated playbacks. We found a positive correlation between the jitter level of the sound and the dogs' attention, while the fundamental frequency negatively affected the dogs' orientation to the speaker and the door leading to the speaker. The sex, sexual state and parental experience of the dogs did not affect their reactions towards pup separation calls. Based on these results, it seems that dogs' reactions are affected mostly by the acoustics of the separation calls, not their own individual characteristics.

Parental care and the evolution of terrestriality in frogs.

Frogs and toads (Anura) exhibit some of the most diverse parental strategies in vertebrates. Identifying the evolutionary origins of parenting is fundamental to understanding the relationships between sexual selection, social evolution and parental care systems of contemporary Anura. Moreover, parenting has been hypothesized to allow the invasion of terrestrial habitats by the ancestors of terrestrial vertebrates. Using comprehensive phylogenetic analyses of frogs and toads based on data from over 1000 species that represent 46 out of 55 Anura families, we test whether parental care is associated with terrestrial reproduction and several life-history traits. Here, we show that both the duration of care and offspring protection by males and females have coevolved with terrestrial reproduction. Sexual size dimorphism is also related to care, because the large male size relative to female size is associated with increased paternal care. Furthermore, increased egg size and reduced clutch volume are associated with increased care in bivariate but not in multivariate analyses, suggesting that the relationships between care, egg size and clutch volume are mediated by terrestrial reproduction. Taken together, our results suggest that parenting by males and females has coevolved, and complex parenting traits have evolved several times independently in Anura in response to breeding in terrestrial environments.

Author Correction: Direct benefits and evolutionary transitions to complex societies.

In the version of this Article originally published, references were missing from the column "Source(s) for mating and parental care system data" in Supplementary Table 1. The following references have now been added to the relevant species: Brichard 1989 has been added to Chalinochromis popelini, Chalinochromis brichardi and Julidochromis dickfeldi; Clabaut et al. 2007 to Altolamprologus calvus and Julidochromis regani; Konings 1998 to Neolamprologus hecqui; and Kuwamura 1997 to Chalinochromis popelini.

Breeding biology and parental care strategy of the little-known Chinese Penduline Tit (Remiz consobrinus)

The Chinese Penduline Tit (Remiz consobrinus) is a small passerine that breeds in Northeast Asia. Despite its common appearance and its high encounter rate, the breeding biology of this species has remained largely unknown. In this paper, we describe for the first time the breeding biology and parental care system of the Chinese Penduline Tit in the coastal area of Northeast China. As a migratory species of birds, it arrives at the Liaohe Delta in late April, the males establish territories in early May, and breeding pairs build their nests from May to July. Most nest building occurs from mid-May to early June. The females produce small white eggs (egg mass, 1.0 ± 0.1 g) and a clutch size of 6.8 ± 0.6 eggs. The parental care system is complicated in Chinese Penduline Tits: uniparental care is dominant (80%) in this population, with a majority (71%) of female-only care and 9% male care for all brooding nests, together with 4% biparental care and 16% biparental desertion. Chicks hatch after 13.9 ± 1.0 days of incubation and fledge after 22.1 ± 1.0 days. The hatching success and nestling survival are 86.7 and 80.6%, respectively. Furthermore, breeding failure is 23.4%, which is commonly caused by predation and nests blown away by strong winds. Compared to other species of the Remiz genus, the Chinese Penduline Tit shows much similarity to the Eurasian Penduline Tit (Remiz pendulinus) but large differences compared to the White-crowned Penduline Tit (Remiz coronatus) with respect to breeding habitat, breeding density, nest site selection and parental care system. Moreover, the good nest attributes, relatively high nestling survival and low risk of nest failure may contribute to the prevalence of the uniparental care system in this Chinese Penduline Tit population.

Mothers\u2019 neural responses to infant faces are associated with activation of the maternal care system and observed intrusiveness with their own child

Certain infant facial characteristics, referred to as baby schema, are thought to automatically trigger parenting behavior and affective orientation toward infants. Electroencephalography (EEG) is well suited to assessing the intuitive nature and temporal dynamics of parenting responses, due to its millisecond temporal resolution. Little is known, however, about the relations between neural processing of infant cues and actual parenting behavior in a naturalistic setting. In the present study we examined the event-related potentials (ERPs) of mothers (N = 33) watching infant faces of varying attractiveness, in relation to activation of the maternal care system and the mothers’ observed parenting behavior (sensitivity, nonintrusiveness) with their own child (2–6 years old). The results revealed that, irrespective of the cuteness of the infant face, mothers’ neural processing of infant faces involved both early P1 and P2 components (related to orienting/detecting processes) and late positive potentials (LPPs; related to more controlled cognitive evaluation/attentional engagement). Increased early detection and processing of infant faces (reflected by P1 and P2 activity) was related to increased activation of the parental care system. In later stages of face processing, increased attentional engagement with infant faces (as reflected by LPP activity) was associated with more intrusiveness of a mother with her own child during interaction. These findings suggest that individual variations in responses to infant stimuli are associated with individual differences in parental care system activation and parenting quality. Furthermore, the parental care system might be activated relatively automatically, but actual parenting and caregiving behavior requires more conscious control.

Divergence in nest placement and parental care of Neotropical foliage-gleaners and treehunters (Furnariidae: Philydorini)

The Neotropical ovenbirds (Furnariidae) are an adaptive radiation of suboscines renowned for the diversity of their nests. Like most altricial insectivores, they generally exhibit biparental care. One tribe, Philydorini, includes 46 species thought to nest in either underground burrows or tree cavities, nest types traditionally treated as equivalent in phylogenetic studies. Their parental care systems are poorly known, but could help illuminate how uniparental care – typically associated with frugivory – can arise in insectivores. We examined the extent to which nest placement, parental care, and associated reproductive traits map onto two major clades of Philydorini identified by genetic hypotheses. We review published literature and present new information from the Atlantic Forest of Argentina, including the first nest descriptions for Ochre-breasted Foliage-gleaners (Anabacerthia lichtensteini) and Sharp-billed Treehunters (Heliobletus contaminatus). In the Automolus-Thripadectes-Clibanornis clade (including Philydor rufum), 134 of 138 reported nests were in underground burrows. In the Syndactyla-Anabacerthia-Anabazenops clade (including Heliobletus, Philydor atricapillus, and Philydor erythrocercum), 44 of 48 nests were in tree cavities. Remaining nests were in buildings or species-level identification was unclear. At least eight species in the first clade, but none in the second clade, excavated their nest sites. Biparental care was confirmed for nine species in the first clade and one species in the second clade. In contrast, nests of A. lichtensteini and H. contaminatus were attended by a single secretive adult. We propose that species in the Automolus-Thripadectes-Clibanornis clade are underground burrow excavators, and those in the Syndactyla-Anabacerthia-Anabazenops clade are secondary tree-cavity nesters (nonexcavators). We also note that parental care strategies in Furnariidae vary with nest complexity and conspicuousness – from uniparental care in secretive tree-cavity nesters to cooperative breeding in highly vocal builders of elaborate nests – suggesting evolutionary links among nest-building, concealment, and parental care strategies.

Amygdala-midbrain connectivity indicates a role for the mammalian parental care system in human altruism.

Costly altruism benefitting a stranger is a rare but evolutionarily conserved phenomenon. This behaviour may be supported by limbic and midbrain circuitry that supports mammalian caregiving. In rodents, reciprocal connections between the amygdala and the midbrain periaqueductal grey (PAG) are critical for generating protective responses toward vulnerable and distressed offspring. We used functional and structural magnetic resonance imaging to explore whether these regions play a role in supporting costly altruism in humans. We recruited a rare population of altruists, all of whom had donated a kidney to a stranger, and measured activity and functional connectivity of the amygdala and PAG as altruists and matched controls responded to care-eliciting scenarios. When these scenarios were coupled with pre-attentive distress cues, altruists' sympathy corresponded to greater activity in the left amygdala and PAG, and functional connectivity analyses revealed increased coupling between these regions in altruists during this epoch. We also found that altruists exhibited greater fractional anisotropy within the left amygdala-PAG white matter tract. These results, coupled with previous evidence of altruists' increased amygdala-linked sensitivity to distress, are consistent with costly altruism resulting from enhanced care-oriented responses to vulnerability and distress that are supported by recruitment of circuitry that supports mammalian parental care.

Development and application of 14 microsatellite markers in the burying beetle Nicrophorus vespilloides reveals population genetic differentiation at local spatial scales.

Burying beetles (genus Nicrophorus) are relatively rare among insects in providing sophisticated parental care. Consequently, they have become model species in research analysing social evolution, the evolution of parental care and mating systems. We used the recently published N. vespilloides genome and transcriptome to develop microsatellite markers. Specifically, we developed 14 polymorphic markers with five to 13 alleles per locus and used them to investigate levels of genetic differentiation in four south Cambridgeshire (UK) populations of N. vespilloides, separated by 21 km at most. The markers revealed significant genetic structuring among populations (global FST = 0.023) with all but one of the pairwise comparisons among populations being significant. The single exception was the comparison between the two closest populations, which are approximately 2.5 km apart. In general, the microsatellite markers showed lower observed heterozygosity than expected. We infer that there is limited dispersal between populations and potentially also some inbreeding within them and suggest that this may be due to habitat fragmentation. We discuss these results in the context of recent laboratory experiments on inbreeding and beetle flight.

The plight of a plover: Viability of an important snowy plover population with flexible brood care in Mexico

Shorebird populations often rely on wetland habitats, for which they are considered important indicators of ecosystem health. Populations residing at low latitudes remain vastly understudied in comparison with populations from high latitudes. Here we use detailed behavioural and demographic observations during all life stages in combination with stage specific modelling to predict the population trajectory of a snowy plover (Charadrius nivosus) population at Bahía de Ceuta, Sinaloa, Mexico. In North America this shorebird is threatened, with many monitored populations declining. Our stochastic matrix model for the Ceuta population, which closely matched our field observations, suggests that the population is a sink with a 99.8% probability of going extinct within 25years. Low apparent adult survival, which declined over time presumably because of poor reproductive success and/or permanent emigration in response to habitat degradation, had the largest impact on the population trajectory. We recommend urgent habitat management actions to address volatile water levels and hence increase reproductive success of this species at this important breeding site. Acknowledging the relative effects of flexible brood care on individual fitness and population dynamics presents an intriguing dilemma for conservation. We found that the flexible parental care system of snowy plovers affected chick survival: broods deserted by polyandrous females early after hatching had significantly lower survival than broods not deserted or those deserted late. Overall, deserting females raised fewer fledglings in this population than females that cared. Taken together, our study reveals unsustainable variation in local vital rate dynamics. To understand how this population contributes to regional source-sink dynamics, future research should evaluate the importance of immigration and emigration among neighbouring populations.