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Invasive rats are one of the world's most successful animal groups that cause native species extinctions and ecosystem change, particularly on islands. On large islands, rat eradication is often impossible and population control, defined as the local limitation of rat abundance, is now routinely performed on many of the world's islands as an alternative management tool. However, a synthesis of the motivations, techniques, costs, and outcomes of such rat-control projects is lacking. We reviewed the literature, searched relevant websites, and conducted a survey via a questionnaire to synthesize the available information on rat-control projects in island natural areas worldwide to improve rat management and native species conservation. Data were collected from 136 projects conducted over the last 40 years; most were located in Australasia (46%) and the tropical Pacific (25%) in forest ecosystems (65%) and coastal strands (22%). Most of the projects targeted Rattus rattus and most (82%) were aimed at protecting birds and endangered ecosystems. Poisoning (35%) and a combination of trapping and poisoning (42%) were the most common methods. Poisoning allows for treatment of larger areas, and poison projects generally last longer than trapping projects. Second-generation anticoagulants (mainly brodifacoum and bromadiolone) were used most often. The median annual cost for rat-control projects was US$17,262 or US$227/ha. Median project duration was 4 years. For 58% of the projects, rat population reduction was reported, and 51% of projects showed evidence of positive effects on biodiversity. Our data were from few countries, revealing the need to expand rat-control distribution especially in some biodiversity hotspots. Improvement in control methods is needed as is regular monitoring to assess short- and long-term effectiveness of rat-control. Las ratas invasoras son uno de los grupos animales más exitosos a nivel mundial que ocasionan la extinción de especies nativas y cambios en los ecosistemas, particularmente en las islas. En las islas grandes, la erradicación de las ratas es generalmente imposible y el control de población, definido como la limitación local de la abundancia de ratas, hoy en día se practica rutinariamente en muchas de las islas del mundo como una herramienta alternativa de manejo. Sin embargo, se carece de una síntesis de motivaciones, técnicas, costos y resultados de dichos proyectos de control de ratas. Revisamos la literatura, buscamos sitios web relevantes, y realizamos una encuesta por medio de un cuestionario para sintetizar la información disponible sobre los proyectos de control de ratas en las áreas naturales isleñas en todo el mundo para así mejorar el manejo de ratas y la conservación de especies nativas. Se recolectaron datos de 136 proyectos que se realizaron en los últimos 40 años; la mayoría se ubicaron en Australasia (46 %) y el Pacífico tropical (25 %) en ecosistemas boscosos (65 %) y franjas costeras (22 %). La mayoría de los proyectos estaban enfocados en Rattus rattus, y la mayoría (82 %) estaban centrados en la protección de aves y ecosistemas en peligro de extinción. Los métodos más comunes fueron el envenenamiento (35 %) y una combinación de trampas y veneno (42 %). El envenenamiento permite tratar con áreas más grandes y generalmente dura más tiempo que el trampeo. Los anti-coagulantes de segunda generación (principalmente el brodifacoum y la briomadiolona) fueron los más usados. El costo medio anual de los proyectos de control de ratas fue de US$17,262 o de US$227/ha. La duración media de los proyectos fue de cuatro años. Para el 58 % de los proyectos, se reportó una reducción en la población de ratas, y el 51 % de los proyectos mostró evidencias de un efecto positivo sobre la biodiversidad. Nuestros datos provienen de pocos países, lo que revela la necesidad de expandir la distribución del control de ratas, especialmente en algunos puntos calientes de biodiversidad. Se necesita mejorar los métodos del control, así como un monitoreo regular para evaluar la efectividad del control de ratas a corto y largo plazo.

The rare cricetid rodent Bibimys Massoia, 1980 contains three extant species that are distributed in the lowlands of eastern South America between 35°S and 20°S and distinguished mostly by subtle morphological and genetic features. Several fragmented jaws belonging to this genus were recovered from Late Quaternary deposits located in northeastern Brazil, forming part of a rich archaeological and paleontological small mammal assemblage that has been recovered from caves in the Serra da Capivara, state of Piauí. This material is described herein as belonging to a new species, the most hypsodont member of the genus. The specimens also represent an extralimital occurrence of this sigmodontine, as the nearest extant population of Bibimys is ∼1,200 km to the south. Because there are few reliable records of extinct small mammals from the Pleistocene–Holocene transition on the South American continent, in describing this new sigmodontine we extend the records of past biodiversity preserved in the Quaternary deposits of tropical South America. This new species likewise highlights that the Serra da Capivara deposits are promising for understanding the evolutionary history of cricetid rodents.

Invasive alien species are one of the primary threats to native biodiversity on islands worldwide. Consequently, eradicating invasive species from islands has become a mainstream conservation practice. Deciding which islands have the highest priority for eradication is of strategic importance to allocate limited resources to achieve maximum conservation benefit. Previous island prioritizations focused either on a narrow set of native species or on a small geographic area. We devised a prioritization approach that incorporates all threatened native terrestrial vertebrates and all invasive terrestrial vertebrates occurring on 11 U.K. overseas territories, which comprise over 2000 islands ranging from the sub‐Antarctic to the tropics. Our approach includes eradication feasibility and distinguishes between the potential and realistic conservation value of an eradication, which reflects the benefit that would accrue following eradication of either all invasive species or only those species for which eradication techniques currently exist. We identified the top 25 priority islands for invasive species eradication that together would benefit extant populations of 155 native species including 45 globally threatened species. The 5 most valuable islands included the 2 World Heritage islands Gough (South Atlantic) and Henderson (South Pacific) that feature unique seabird colonies, and Anegada, Little Cayman, and Guana Island in the Caribbean that feature a unique reptile fauna. This prioritization can be rapidly repeated if new information or techniques become available, and the approach could be replicated elsewhere in the world.

Evolutionary constraints and ecological pressures influence species' morphological diversity. The aim of this study was to explore patterns of morphological variation, to investigate the influence of environmental variables on morphological differentiation, and assess the strength of phylogenetic signal for the cranium and mandible in spiny rats of the genus Trinomys. We examined 377 crania and mandibles of all species of the genus Trinomys. We used geometric morphometric methods based on two-dimensional anatomical landmarks to describe cranium and mandible shape and size. Phylogenetic signal was tested using the K statistics and associations between morphology and environmental variables were made using a phylogenetic partial least squares analysis. We found marked differences in size and shape in the synchranium among species, especially in the segregation of T. albispinus and T. yonenagae from the other species, which in turn greatly overlapped both in size and shape spaces. We found a weak phylogenetic signal for size of the synchranium and intermediate phylogenetic signals for shape, a pattern similar to other studies. Differentiation of the synchranium shape in Trinomys was associated largely with precipitation-related variables, while the association between size and environmental variables was weak. Notably, Trinomys species inhabiting xeric environments had relatively larger tympanic bullae.

The Lesser bandicoot rat Bandicota bengalensis (Gray and Hardwicke, 1833) is a murid rodent distributed mostly in Asia that can cause substantial negative economic impact in urban and rural areas. Until now, the species has been mostly restricted to the Asian region; and no specimen has been captured or reported as a stowaway arriving to an American port. Here, I report on one specimen captured in Callao’s maritime port, Peru, during sanitary inspection surveillance, identified based on external and cranial characteristics, and similar meristic reported values. This finding shows the potential threat of this species as an invasive alien species and highlights the need for strengthening invasive species protocols on ships.

Agriculture and pastureland for cattle grazing are common land uses in Mediterranean landscapes. These activities significantly alter the habitat conditions, affecting the body conditions of wild communities, especially those with low vagility, such as small mammals. We aimed to evaluate how cattle grazing and the habitat composition affected the body condition of the wood mouse Apodemus sylvaticus in a southern Mediterranean agroforestry system using the Scale Mass Index (SMI) as an indicator of individuals condition. To assess variation in body condition, wood mice were live-trapped in a gradient of grazed sites with different stocking intensities, as well in sites excluded to grazing at different time periods (1998, 2004, and 2008). Wood mice body conditions were influenced by both microhabitat and macrohabitat drivers, with sex-biased patterns, while for the females, only the shrub species had an influence (a microhabitat variable); for the males, both the shrub species and the undercover density (and specifically their interaction) were the important drivers (microhabitat and macrohabitat variables). Unexpectedly, the physical condition variation detected between periods was not directly proportional to the exclusion period, but rather, a certain degree of similarity was found between the different sites (sites excluded since 2004 paired with grazed sites). These results suggest that the presence of food and shelter are determinants to the wood mouse’s physical condition: for females, securing food sources enhance the body condition, while for males, the degree of cover, and consequently refuge against predators, seems to be determinant. These results reinforce the need for sustainable landscape management to assure the maintenance of habitat heterogeneity.

Rattus norvegicus (Norway rat) is one of the most abundant and geographically widespread mammals. Ecological studies focusing on urban Norway rat populations are restricted to temperate regions, and data describing populations from tropical cities are lacking. We compared the morphometrics and demographic characteristics of rats captured in urban low-income settlements in Salvador, Brazil, to a season, environmental area of capture, and sex-matched sample from Baltimore, Maryland. Norway rats of both sexes were significantly smaller in Salvador, although the threshold mass marking sexual maturity was equivalent for both cities. Pregnancy rates were comparable (∼50%); however, juveniles were commonly trapped in Salvador (20%) while they were rarely trapped in Baltimore during winter months (2%). These findings suggest that tropical and temperate rats differ with respect to body metrics, while size at sexual maturity is similar. Further studies conducted over different seasons are required before any firm conclusions are reached; however, this study provides preliminary support for Bergmann's rule that species at higher absolute latitude are larger than the same species sampled at lower latitudes.

El presente artículo analiza la viabilidad de la zoocría de chigüiros (Hydrochoerus hydrochaeris, Linnaeus 1766) en el departamento del Caquetá como alternativa productiva frente a los sistemas tradicionales de ganadería bovina y avícola. Para ello, se llevó a cabo una revisión sistemática de literatura, aplicando la metodología de la teoría fundamentada y siguiendo los lineamientos de la declaración PRISMA 2020 para la identificación, selección y evaluación de estudios. Los resultados indican que la cría de chigüiros ofrece ventajas significativas en términos de productividad y de contribución a la seguridad alimentaria en comunidades rurales de la región amazónica. Además, se encontró que la zoocría de esta especie genera un impacto ambiental menor en comparación con los sistemas pecuarios tradicionales, lo que contribuye a la conservación de los ecosistemas locales y a la reducción de la deforestación. También se identificaron barreras normativas y logísticas para la implementación de zoocriaderos en el Caquetá, aunque se destaca el potencial económico y ecológico de estos sistemas. En conclusión, la zoocría de chigüiros no solo favorece la preservación de la fauna silvestre, sino que también representa una opción sostenible para el desarrollo socioeconómico regional y la seguridad alimentaria de las comunidades locales. This article analyzes the feasibility of capybara (Hydrochoerus hydrochaeris, Linnaeus 1766) farming in the Department of Caquetá as a productive alternative to traditional cattle and poultry farming systems. A systematic literature review was conducted, applying grounded theory methodology and following the PRISMA 2020 guidelines for the identification, selection, and evaluation of relevant studies. The findings show that capybara farming offers significant advantages in terms of productivity and its potential contribution to food security in rural communities of the Amazon region. Additionally, it was determined that this production system has a lower environmental impact compared to conventional livestock farming, promoting the conservation of local ecosystems and contributing to deforestation reduction.Despite the identification of regulatory and logistical barriers to the implementation of capybara breeding operations in Caquetá, the economic and ecological potential of such systems remains noteworthy. In conclusion, capybara farming not only supports the conservation of native wildlife but also represents a sustainable alternative for regional socioeconomic development and the strengthening of food security in local communities.

The small mammals observed in the archaeological records made us think about the way they were exploited and the extension of these practices in Patagonia, continental and insular. This paper proposes that some species of Caviomorpha rodents were intensively exploited by hunter-gatherers societies who lived in Patagonia since late Holocene. Bones, meat and skin of the animals were used. From the available documentation it has been possible to state this practice continued until last century. In addition we have verified the gathering activity was guided by sex and age, and linked with the biological and social reproduction. To give support to these assumptions we made taphonomic analysis on the small mammal assemblages and we revised historical and ethnographical documents. The information comes from two periods: colonial, s. XVI-XVIII and independent, s. XIX-XX. The use of small mammals and its predilection by Patagonian populations was recorded since the first contact episode back to 1520. For selk’nam people from northern Tierra del Fuego it became even one of the main food items and considered a delicacy.

From May to September 2011, a total of 138 wild rodents of the Cricetidae family were collected in the cities of Anhembi, Bofete and Torre de Pedra, in São Paulo State. All animals were examined for the presence of ticks, which were collected and identified at species level in the laboratory by morphological examination (for adults, nymphs and larvae) and molecular biology, by sequencing of a fragment of the 16S mitochondrial rDNA (for larvae). A total of 47 ticks (21 larvae and 26 nymphs) were collected from rodents, identified as 21 larvae and 23 nymphs of Amblyomma ovale (collected on Oligoryzomys nigripes , Oligoryzomys flavescens , Sooretamys agouya and Nectomys squamipes ), two nymphs of Ixodes schulzei (O. nigripes and O. flavescens ) and an Amblyomma sculptum nymph in S. agouya . The overall prevalence of parasitism by A. ovale was 4.3% for larvae, and 10.1% for nymphs. The mean intensity of parasitism was 3.5 larvae/parasitized animal, and 1.6 nymphs/parasitized animal. One O. nigripes was found parasitized by both larva and nymph of A. ovale , and another O. nigripes was parasitized simultaneously by an I. schulzei nymph and five A. ovale nymphs. This research reports the following unpublished records: A. ovale on O. flavescens , O. nigripes and S. agouya ; A. sculptum on S. agouya ; and I. schulzei on O. flavescens and O. nigripes . RESUMO: De maio a setembro de 2011, um total de 138 roedores silvestres da família Cricetidae foram coletados nos municípios de Anhembi, Bofete e Torre de Pedra, no estado de São Paulo. Todos os animais foram examinados quanto à presença de carrapatos, os quais foram coletados e identificados ao nível de espécie em laboratório, através de análises morfológicas (para adultos, ninfas e larvas) e por biologia molecular para confirmar estas análises, através do sequenciamento de um fragmento do gene 16S rDNA mitocondrial (para uma parte das larvas). Um total de 47 carrapatos (21 larvas e 26 ninfas) foi coletado dos roedores, sendo identificados como 21 larvas e 23 ninfas de Amblyomma ovale (coletados sobre Oligoryzomys nigripes, Oligoryzomys flavescens, Sooretamys agouya e Nectomys squamipes ), duas ninfas de Ixodes schulzei (em O. nigripes e O. flavescens ) e uma ninfa de Amblyomma sculptum em S. agouya. A prevalência geral de parasitismo por A. ovale foi de 4,3% e de 10,1% para larvas e ninfas, respectivamente. As intensidades médias de parasitismo foram de 3,5 larvas/animal parasitado e de 1,6 ninfas/animal parasitado. Um O. nigripes foi encontrado parasitado simultaneamente por larva e ninfa de A. ovale , e outro O. nigripes estava parasitado simultaneamente por uma ninfa de I. schulzei e cinco ninfas de A. ovale . O presente trabalho reporta os seguintes registros inéditos: A. ovale em O. flavescens, O. nigripes e S. agouya; A. sculptum em S. agouya; e I. schulzei em O. flavescens e O. nigripes.