Life history and behavioral type in the highly social cichlid Neolamprologus pulcher

Many studies have found that seemingly unconnected behaviors are correlated into behavioral syndromes. These behavioral syndromes may be the consequence of interindividual variation in life-history strategies. Only few studies have investigated the role of behavioral syndromes in cooperatively breeding species, despite the fact that one would expect particular large variation in behavior due to the wealth of life-history decisions a cooperative breeder faces. In a longitudinal study, we repeatedly tested individuals of the cooperatively breeding cichlid Neolamprologus pulcher for exploration, boldness, and aggression and tested whether these behaviors were sex specific; whether they were interrelated; and whether they were connected to growth and to 2 major life-history decisions, helping, and dispersal. In both sexes, explorative behavior was correlated over time, even though after sexual maturity males increased their exploration rate. In both sexes, exploration, boldness, and aggression correlated when mature, and in females, helping behavior was part of the syndrome. No relationships with growth were detected. Helping and dispersal were related to each other in males, whereas females hardly dispersed. We suggest that the differences in the life histories between males and females (male dispersal vs. female philopatry) lead to the differences in behavioral types observed and also to the differences in the stability of the behavioral syndromes between the sexes. The links between dispersal and helping in males and the behavioral types and helping in females highlight the necessity to study multiple traits to understand the evolution and maintenance of variation in cooperative behavio

Waggle dance distances as integrative indicators of seasonal foraging challenges

Even as demand for their services increases, honey bees (Apis mellifera) and other pollinating insects continue to decline in Europe and North America. Honey bees face many challenges, including an issue generally affecting wildlife: landscape changes have reduced flower-rich areas. One way to help is therefore to supplement with flowers, but when would this be most beneficial? We use the waggle dance, a unique behaviour in which a successful forager communicates to nestmates the location of visited flowers, to make a 2-year survey of food availability. We “eavesdropped” on 5097 dances to track seasonal changes in foraging, as indicated by the distance to which the bees as economic foragers will recruit, over a representative rural-urban landscape. In year 3, we determined nectar sugar concentration. We found that mean foraging distance/area significantly increase from springs (493 m, 0.8 km2) to summers (2156 m, 15.2 km2), even though nectar is not better quality, before decreasing in autumns (1275 m, 5.1 km2). As bees will not forage at long distances unnecessarily, this suggests summer is the most challenging season, with bees utilizing an area 22 and 6 times greater than spring or autumn. Our study demonstrates that dancing bees as indicators can provide information relevant to helping them, and, in particular, can show the months when additional forage would be most valuable

Life history and behavioral type in the highly social cichlid Neolamprologus pulcher

Many studies have found that seemingly unconnected behaviors are correlated into behavioral syndromes. These behavioral syndromes may be the consequence of interindividual variation in life-history strategies. Only few studies have investigated the role of behavioral syndromes in cooperatively breeding species, despite the fact that one would expect particular large variation in behavior due to the wealth of life-history decisions a cooperative breeder faces. In a longitudinal study, we repeatedly tested individuals of the cooperatively breeding cichlid Neolamprologus pulcher for exploration, boldness, and aggression and tested whether these behaviors were sex specific; whether they were interrelated; and whether they were connected to growth and to 2 major life-history decisions, helping, and dispersal. In both sexes, explorative behavior was correlated over time, even though after sexual maturity males increased their exploration rate. In both sexes, exploration, boldness, and aggression correlated when mature, and in females, helping behavior was part of the syndrome. No relationships with growth were detected. Helping and dispersal were related to each other in males, whereas females hardly dispersed. We suggest that the differences in the life histories between males and females (male dispersal vs. female philopatry) lead to the differences in behavioral types observed and also to the differences in the stability of the behavioral syndromes between the sexes. The links between dispersal and helping in males and the behavioral types and helping in females highlight the necessity to study multiple traits to understand the evolution and maintenance of variation in cooperative behavior

Habitat saturation, benefits of philopatry, relatedness, and the extent of co-operative breeding in a cichlid

Co-operative breeding in vertebrates may emerge due to subordinates delaying dispersal when free breeding habitat is not available (‘habitat saturation' hypothesis, HS). However, delayed dispersal might also be due to younger individuals postponing dispersal to when they are more competitively able or have more to gain from breeding independently ("benefits-of-philopatry” hypothesis, BP) or to when inclusive fitness benefits no longer outweigh the benefits from independent breeding ("kin selection” hypothesis, KS). Here, we show in three experiments that both HS and BP determine the extent of co-operative breeding in the cichlid Neolamprologus pulcher. Contrary to the KS, individuals significantly avoided settlement with related individuals, and an additional settlement experiment confirmed this result. Our results suggest that kin structure in these cichlids emerges from limits on dispersal, but if such barriers are absent, cichlids prefer to settle with unrelated individuals to maximize the benefits of direct reproductive participatio

Behavioral type and growth rate in a cichlid fish

Behavioral syndromes or animal personalities may emerge due to covariation with different life-history strategies individual animals pursue, like risk-associated feeding rates translating in different growth trajectories. However, less clear is how this might affect individuals in cooperatively breeding species, where subordinates assist dominants in raising offspring, and growth has profound life-history and social consequences. Here, we examined the effects of behavioral type on growth rates and feeding in the cooperatively breeding cichlid fish Neolamprologus pulcher, comparing growth rates of individuals settled inside a group (dominant or subordinate) or unsettled fish (aggregation) of different behavioral types (bold-shy continuum) under a feeding regime where food could not be monopolized. Controlling for other factors, we found no effect of the behavioral type on the growth rates of dominants and subordinates in either sex. In contrast, bold female aggregation fish were significantly growing faster in length compared with shy female aggregation fish, whereas no such effect was detected in male aggregation fish. These growth rate differences were largely matched by differences in feeding rates, but locomotion appeared more important in determining growth than feeding rate. Our results show that differences in social status may need to be taken into account when testing for correlations between behavioral type and growth in vertebrates, and cautions that growth adjustments may get obscured due to correlated changes in other costly behaviors, like locomotio

Repeatability and Heritability of Behavioural Types in a Social Cichlid

Aim. The quantitative genetics underlying correlated behavioural traits (‘‘animal personality”) have hitherto been studied mainly in domesticated animals. Here we report the repeatability (R) and heritability (h2) of behavioural types in the highly social cichlid fish Neolamprologus pulcher. Methods. We tested 1779 individuals repeatedly and calculated the h2 of behavioural types by variance components estimation (GLMM REML), using 1327 offspring from 162 broods from 74 pairs. Results. Repeatability of behavioural types was significant and considerable (0.546), but declined from 0.83 between tests conducted on the same day, to 0.19 on tests conducted up to 1201 days apart. All h2 estimates were significant but low (e.g., pair identity h2 = 0.15 ± 0.03 SE). Additionally, we found significant variation between broods nested within the parent(s), but these were not related to several environmental factors tested. Conclusions. We conclude that despite a considerable R, h2 in this cichlid species is low, and variability in behavioural type appears to be strongly affected by other (non)genetic effects

Intra-dance variation among waggle runs and the design of efficient protocols for honey bee dance decoding

Noise is universal in information transfer. In animal communication, this presents a challenge not only for intended signal receivers, but also to biologists studying the system. In honey bees, a forager communicates to nestmates the location of an important resource via the waggle dance. This vibrational signal is composed of repeating units (waggle runs) that are then averaged by nestmates to derive a single vector. Manual dance decoding is a powerful tool for studying bee foraging ecology, although the process is time-consuming: a forager may repeat the waggle run 1- >100 times within a dance. It is impractical to decode all of these to obtain the vector; however, intra-dance waggle runs vary, so it is important to decode enough to obtain a good average. Here we examine the variation among waggle runs made by foraging bees to devise a method of dance decoding. The first and last waggle runs within a dance are significantly more variable than the middle run. There was no trend in variation for the middle waggle runs. We recommend that any four consecutive waggle runs, not including the first and last runs, may be decoded, and we show that this methodology is suitable by demonstrating the goodness-of-fit between the decoded vectors from our subsamples with the vectors from the entire dances

Implementation of a multiprofessional, multicomponent delirium management guideline in two intensive care units, and its effect on patient outcomes and nurse workload: a pre-post design retrospective cohort study.

AIM OF THE STUDY Delirium is a frequent intensive care unit (ICU) complication, affecting 26% to 80% of ICU patients, often with serious consequences. This study aimed to evaluate the effectiveness, costs and benefits of following a standardised multiprofessional, multicomponent delirium guideline on eight outcomes: delirium prevalence and duration, lengths of stay in ICU and hospital, in-hospital mortality, duration of mechanical ventilation, and cost and nursing hours per case. It also aimed to explore the associations of delirium with length of ICU stay, length of hospital stay and duration of mechanical ventilation. METHODS This retrospective cohort study used a pre-post design. ICU patients in an historical control group (n = 1608) who received standard ICU care were compared with a postintervention group (n = 1684) who received standardised delirium management – delirium risk identification, preventive measures, screening and treatment – with regard to eight outcomes. The delirium management guideline was developed and implemented in 2012 by a group of experts from the study hospital. As appropriate, descriptive statistics and multivariate, multilevel models were used to compare the two groups and to explore the association between delirium occurrence and the selected outcomes. RESULTS Twelve percent of the 1608 historical controls and 20% of the 1684 postintervention patients were diagnosed with delirium according to the ICD-10 delirium diagnosis codes. Patients being treated for heart disease, and those with septic shock, ARDS, renal insufficiency (acute or chronic), older age and higher numbers of comorbidities were significantly more likely to develop delirium during their stay. Multivariate models comparing the historical controls with the post intervention group indicated significant differences in delirium period prevalence (odds ratio 1.68, 95% confidence interval [CI] 1.38–2.06; p <0.001), length of stay in the ICU (time ratio [TR] 0.94, CI 0.89–1.00; p = 0.048), cost per case (median difference 3.83, CI 0.54–7.11; p = 0.023) and duration of mechanical ventilation (TR 0.84, CI 0.77–0.92; p <0.001). The observed differences in the other four outcomes – in-hospital mortality, delirium duration, length of stay in the hospital, and nursing hours per case – were not significant. Delirium was a significant predictor for prolonged duration of mechanical ventilation and for both ICU and hospital stay. CONCLUSION Standardised delirium management, specifically delirium screening, supports timely detection of delirium in ICU patients. Increased awareness of delirium after the implementation of standardised multiprofessional, multicomponent management leads to increased therapeutic attention, a prolongation of ICU stay and increased costs, but with no influence on mortality

A hospital-wide evaluation of delirium prevalence and outcomes in acute care patients : a cohort study

Background: Delirium is a well-known complication in cardiac surgery and intensive care unit (ICU) patients. However, in many other settings its prevalence and clinical consequences are understudied. The aims of this study were: (1) To assess delirium prevalence in a large, diverse cohort of acute care patients classified as either at risk or not at risk for delirium; (2) To compare these two groups according to defined indicators; and (3) To compare delirious with non-delirious patients regarding hospital mortality, ICU and hospital length of stay, nursing hours and cost per case. Methods: This cohort study was performed in a Swiss university hospital following implementation of a delirium management guideline. After excluding patients aged < 18 years or with a length of stay (LOS) < 1 day, 29′278 patients hospitalized in the study hospital in 2014 were included. Delirium period prevalence was calculated based on a Delirium Observation Scale (DOS) score ≥ 3 and / or Intensive Care Delirium Screening Checklist (ICDSC) scores ≥4. Results: Of 10′906 patients admitted, DOS / ICDSC scores indicated delirium in 28.4%. Delirium was most prevalent (36.2–40.5%) in cardiac surgery, neurosurgery, trauma, radiotherapy and neurology patients. It was also common in geriatrics, internal medicine, visceral surgery, reconstructive plastic surgery and cranio-maxillo-facial surgery patients (prevalence 21.6–28.6%). In the unadjusted and adjusted models, delirious patients had a significantly higher risk of inpatient mortality, stayed significantly longer in the ICU and hospital, needed significantly more nursing hours and generated significantly higher costs per case. For the seven most common ICD-10 diagnoses, each diagnostic group’s delirious patients had worse outcomes compared to those with no delirium. Conclusions: The results indicate a high number of patients at risk for delirium, with high delirium prevalence across all patient groups. Delirious patients showed significantly worse clinical outcomes and generated higher costs. Subgroup analyses highlighted striking variations in delirium period-prevalence across patient groups. Due to the high prevalence of delirium in patients treated in care centers for radiotherapy, visceral surgery, reconstructive plastic surgery, cranio-maxillofacial surgery and oral surgery, it is recommended to expand the current focus of delirium management to these patient groups

Emerging Themes from the ESA Symposium Entitled “Pollinator Nutrition: Lessons from Bees at Individual to Landscape Levels”

Pollinator populations are declining (Biesmeijer et al., 2006; Brodschneider et al., 2018; Cameron et al., 2011; Goulson, Lye, & Darvill, 2008; Kulhanek et al., 2017; National Research Council, 2007; Oldroyd, 2007), and both anecdotal and experimental evidence suggest that limited access to high quality forage might play a role (Carvell, Meek, Pywell, Goulson, & Nowakowski, 2007; Deepa et al., 2017; Goulson, Nicholls, Botias, & Rotheray, 2015; Potts et al., 2003, 2010; Vanbergen & The Insect Pollinators Initiative, 2013; Vaudo, Tooker, Grozinger, & Patch, 2015; Woodard, 2017). Multiple researchers are earnestly addressing this topic in a diverse array of insect-pollinator systems. As research continues to be published, increased communication among scientists studying the topic of nutrition is essential for improving pollinator health