Seed predation by insects across a tropical forest precipitation gradient

1. Pre‐dispersal predation of seeds by insects can be an important source of plant mortality, with consequences for plant population dynamics and community diversity. 2. The intensity and host‐specificity of natural enemies, including seed predators, is predicted to vary systematically across environmental gradients. These trends could contribute to large‐scale patterns in diversity, such as the widely observed positive relationship between plant species richness and precipitation. However, fundamental information on inter‐ and intraspecific seed predation is lacking at the landscape scale. 3. We assessed the intensity of seed predation by insects at eight forest sites spanning a steep precipitation and plant species‐richness gradient in Panama. We dissected freshly abscised fruits and seeds of woody plants to measure rates of predation, and assessed host‐specificity by rearing insects from them. 4. On average, 22.6% of dissected seeds were predated across 31 host species. Species‐specific and site‐level seed predation rates and the number of seed predator species reared per host were not significantly associated with annual rainfall or dry season water deficit. 5. In total, 45 seed predator morphospecies were reared from seeds of 16 plant species. Host‐specificity was high, with 91% of seed predator morphospecies associated with just one plant species. 6. Our results support evidence that pre‐dispersal insect seed predators are highly host‐specific and exhibit great intraspecific, interspecific and landscape‐scale (i.e. between‐site) variation in seed predation intensity. Host‐specific seed predators, particularly those causing moderate to high seed predation rates, could influence plant population dynamics and local community structure

Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

Background: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. Methods: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. Findings: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96–1·28). Interpretation: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. Funding: National Institute for Health Research Health Services and Delivery Research Programme

Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

BACKGROUND: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. METHODS: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. FINDINGS: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96-1·28). INTERPRETATION: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. FUNDING: National Institute for Health Research Health Services and Delivery Research Programme

Population changes in Gharial (Gavialis gangeticus) vary spatially in Chitwan National Park, Nepal

Gharials, large crocodilians found only in South Asia, are widely seen as a flagship species for river conservationin Nepal, especially in Chitwan National Park, where a headstart program has supplemented the populationsince 1981. The population has shown signs of recovery only in the last decade, so continued monitoring of populationtrends is vital for conservation. We conducted annual winter population surveys for gharial in Chitwan between 2017and 2022, during which we also characterized riverbank substrate availability and basking preferences. We documentedpotential threats to the species in Chitwan throughout the year. Overall, we counted an increasing number of Gharialsin Chitwan; however mixed-effects modelling of Gharial encounter rate showed that increasing encounters rates are notevenly distributed throughout available habitat, with some river stretches having stable or decreasing trends. Encounterrates on the Rapti River increased in all transects, compared to more variable results on the Narayani River, likelyattributable to higher levels of human disturbance and the impact of captivity on habitat selection. Fewer Gharials wereseen in transects with high levels of disturbance due to sand mining and the extraction of river substrates, highlightingthis threat as a major concern. Regular reports of bycatch in illegal gillnets was the major observed source of mortality.A lack of an increasing population trend in the stretch above a large barrage suggests that recruitment is minimal inthis area, and the dam likely has a negative impact on upstream Gharial recruitment. We cautiously suggest that theChitwan population is recovering, but that recovery is hampered by threats, especially substrate extraction, illegal gillnetfishing, and river fragmentation by a dam

Using functional traits to identify conservation priorities for the world’s crocodylians

1. Over half of all crocodylians are threatened with extinction, with many species considered to be functionally extinct throughout their historical ranges. How such losses impact crocodylian functional diversity (FD) and its conservation is poorly understood, but can be investigated using measurable traits. Where such information is unavailable, phylogenetic diversity (PD) has been proposed as an effective strategy to capture FD, but this assumption is not well tested. 2. We constructed a global trait database for 28 extant crocodylians, and quantified their FD, distinctiveness and groupings. Functionally distinctive crocodylians include the most and least evolutionarily distinct species, likely because unusual trait values and combinations can be produced by both evolutionary isolation and evolutionarily recent adaptive radiation. We identified four functional groups of crocodylians, within which species have similar ecological roles. Highly distinctive species, such as the gharial, fit less well into functional groups. 3. We combined functional distinctiveness (FUD) and threat ranking scores to prioritise species for conservation. The metric is termed Ecologically Distinct and Globally Endangered (EcoDGE), and we tested how well it operates to preserve crocodylian FD among extant Crocodylia. Under current extinction scenarios, 32%–38% of crocodylian FD might be lost within 100 years. Losses increase to 48% if all threatened species go extinct, with Asia identified as a hotspot of threatened FD in crocodylians. Highly threatened distinctive species lead this extinction scenario, exacerbated by clusters of species sharing traits linked to high extinction risk. These traits include habitat specialism and lower reproductive investment; in contrast, species that tolerate climate extremes are more resilient. 4. Prioritising at-risk species based on FUD and threat status appears to be an effective way to conserve present-day crocodylian diversity. Conservation prioritisation based on the EcoDGE metric performed well to minimise projected losses in FD. Among extant crocodylians, FD losses are projected when high diversity overlaps with high extrinsic threats. 5. We then examined the utility of PD-based measures as surrogates for FD conservation, to better understand the advantages and drawbacks of such substitutions. A PD-based measure such as the Evolutionarily Distinct and Globally Endangered metric provided an effective tool to capture FD in our tests