Search Results (74)

Animal protein production represents a complex system of lives transformed into nutrition, with profound ethical and environmental implications. This study provides a quantitative analysis of animal lives required to produce human-consumable protein across major food production systems. Categorizing animal lives based on cognitive complexity and accounting for all lives involved in production, including direct harvests, reproductive animals, and feed species, reveals dramatic variations in protein efficiency. The analysis considers two categories of animal life: complex-cognitive lives (e.g., mammals, birds, cephalopods) and pain-capable lives (e.g., fish, crustaceans). Calculating protein yield per life demonstrates efficiency differences spanning more than five orders of magnitude, from 2 g per complex-cognitive life for baby octopus to 390,000 g per life for bovine dairy systems. Key findings expose disparities between terrestrial and marine protein production. Terrestrial systems involving mammals and birds show higher protein yields and exclusively involve complex-cognitive lives, while marine systems rely predominantly on pain-capable lives across complex food chains. Dairy production emerges as the most efficient system. Aquaculture systems reveal complex dynamics, with farmed carnivorous fish requiring hundreds of feed fish lives to produce protein, compared to omnivorous species that demonstrate improved efficiency. Beyond quantitative analysis, this research provides a framework for understanding the ethical and ecological dimensions of protein production, offering insights for potential systemic innovations. Full article

Memory is a fundamental neurological function, essential for animal survival. Over the course of vertebrate evolution, elaborations in the forebrain telencephalon create new memory mechanisms, meaning basal vertebrates such as amphibians must have a less sophisticated system of memory acquisition, storage, and retrieval than the well-known hippocampal-based circuitry of mammals. Personality also appears to be a fundamental vertebrate trait and is generally defined as consistent individual behavior over time and across life history stages. In anuran amphibians (frogs), personality studies generally ask whether adult frogs retain the personality of their tadpole stage or whether personality shifts with metamorphosis, an idea behavioral ecologists term adaptive decoupling. Using a multidisciplinary perspective and recognizing there are ~7843 species of frogs, each with some molecular, morphological, physiological, or behavioral feature that makes it unique, we review, clarify, and provide perspective on what we collectively know about memory and personality and their mechanisms in anuran amphibians. We propose four working hypotheses: (1) as tadpoles grow, new telencephalic neurons become integrated into functional networks, producing behaviors that become more sophisticated with age; (2) since carnivores tend to be more bold/aggressive than herbivores, carnivorous anuran adults will be more aggressive than herbivorous tadpoles; (3) each amphibian species, and perhaps life history stage, will have a set point on the Shy–Bold Continuum; and (4) around this set point there will be a range of individual responses. We also suggest that several factors are slowing our understanding of the variety and depth of memory and personality possibilities in anurans. These include the scala natura approach to comparative studies (i.e., the idea that one frog represents all frogs); the assumption that amphibians are no more than simple reflex machines; that study species tend to be chosen more for convenience than taxonomic representation; and that studies are designed to prove or disprove a construct. This latter factor is a particular hindrance because what we are really seeking as scientists is not the confirmation or refutation of ideas, but rather what those ideas are intended to produce, which is understanding. Full article

The analysis of activity patterns is a valuable tool for understanding the temporal organization of mammal communities, which is determined by biological requirements, resource availability, and competitive pressures both within and between species. Research on this ecological aspect can contribute to the development of effective conservation strategies. Cloud forest is an ecosystem of high biological relevance, as this provides habitat for a wide diversity of species in Mexico, including endemic, emblematic, and threatened taxa. Our main objectives were to analyze mammalian activity patterns and predator–prey relationships in the cloud forest of the El Cielo Biosphere Reserve, Tamaulipas, Mexico. From 2018 to 2020, twenty camera trap stations were installed, and independent photographic records were obtained, divided into 24 one-hour intervals, and subsequently classified as diurnal, nocturnal, crepuscular, or cathemeral. Temporal activity was estimated using circular statistics in RStudio v4.3.1, and activity overlap between major carnivores and their prey was assessed using the ‘overlap’ package in R. A total of 18 medium- and large-sized mammal species were recorded in this study. The activity of four species was seasonally influenced, with a predominantly nocturnal pattern observed during the dry season. The activity overlap analysis revealed potential temporal similarity between predators and their prey. For example, Panthera onca exhibited a high overlap with Mazama temama (Δ = 0.83), Puma concolor with Nasua narica (Δ = 0.91), and Ursus americanus with M. temama (Δ = 0.77). These findings suggest that the activity patterns of certain species can be influenced by seasonality and that large predators may favor specific prey whose activity overlaps with their own. Full article

We examined three decades of changes in the mammal fauna of Estonia, Latvia, and Lithuania in the context of climate variability, land use transformation, and anthropogenic pressures. We compiled distributional, abundance, and status data from publications, atlases, official game statistics, and long-term monitoring programs, and we evaluated trends using compound annual growth rates or temporal indices. Our review identified losses such as regional extinctions of garden dormice and European mink, declines in small insectivores (e.g., pond bats and shrews) and herbivores (e.g., Microtus voles), and the contraction of boreal specialists (e.g., Siberian flying squirrels). However, we also identified gains, including increases in ungulate numbers (e.g., roe deer, red deer, fallow deer, moose, and wild boars before African swine fewer outbreak) and the recovery of large carnivores (e.g., wolves and lynxes). Invasions by non-native species (e.g., American mink, raccoon dog, and raccoon) and episodic disturbances, such as African swine fever and the “anthropause” caused by the SARS-CoV-2 pandemic, have further reshaped community composition. The drivers encompass climatic warming, post-socialist forest succession, intensified hunting management, and rewilding policies, with dispersal capacity mediating the responses of species. Our results underscore the dual legacy of historical land use and contemporary climate forcing in structuring the fauna dynamics of Baltic mammal communities in the face of declining specialists and invasive taxa. Full article

The Eurasian otter (Lutra lutra) is a widespread semiaquatic carnivorous mammal in Eurasia. The nominate subspecies (L. l. lutra) occupies vast areas between Western Europe and the Russian Far East, but its phylogeography and genetic diversity are still unclear across Northern Eurasia. Another subspecies, L. l. meridionalis, located in the Caucasus mountains, is morphologically almost identical to L. l. lutra but needs genetic revision. We compared the genetic diversity of Eurasian otters from Russia and Armenia using a mtDNA fragment (820 bp) and 20 autosomal microsatellite loci (N = 117). A total of 32 haplotypes were observed with 17 novel haplotypes. The MtDNA median-joining network was mostly star-shaped with a branch of haplotypes from Far Eastern Russian otters. Both mtDNA analysis and Bayesian clustering of microsatellite data indicated that Far Eastern otters are more genetically differentiated than European and Siberian otters (Φst = 0.565 and 0.467; Rst = 0.306 and 0.256), as well as Caucasian otters (L. l. meridionalis) from Russia and Armenia (Φst = 0.515, Rst = 0.253). Haplotype and nucleotide diversities of Far Eastern otters are also the highest between sample groups (H = 0.882, π = 0.003) and, of Caucasian otters, the lowest (H = 0.464, π = 0.001). Our results suggest Caucasian otters are more similar to the otters from European Russia than to the other groups (but with lower genetic diversity) and lack the genetic variability typical to different subspecies. On the contrary, otters from the Russian Far East are more genetically differentiated, have higher genetic diversity than otters from Europe, and likely belong to another genetic lineage. Full article

This research presents an in-depth analysis of large mammal remains first discovered in 1932 in the archaeological area of ancient Rome, central Italy, during the work for the opening of Via dell’Impero (VFI). This work describes the faunal assemblage, its current preservation status, and uses tephrochronology to assess its age. Additionally, it provides paleoecological insights into the evolution of the mammalian fauna in Latium, central Italy, from MIS 13 to MIS 7. Analysis of the fossils updates the identification previously proposed by De Angelis d’Ossat, confirming the presence of Palaeoloxodon antiquus, Cervus elaphus, and Bos primigenius. However, in contrast to the previous author, the hippopotamus remains are assigned to Hippopotamus cf. antiquus, and a second deer is identified as Dama sp.. Furthermore, gnawing marks on the hippopotamus femur suggest the presence of a middle-sized carnivore. Tephrochronological investigation was conducted on pumice retrieved from the VFI fossiliferous layer and ash extracted from sediments adhering to the fossil surfaces. The major element composition of the glass from all pumice/ash samples shows a strong affinity with the Vico β unit, allowing correlation with the Fucino record and constraining the deposition of the VFI fossiliferous level between <406.5 ± 1.3 ka and >405.7 + 1.5/−1.6 ka. Radiometric dating is particularly useful for large mammal faunas of MIS 11-MIS 7, a period lacking significant faunal renewals, as Latium mammalian faunas are often dominated by species (elephants, red deer, aurochs) with broad chronological ranges. Full article

To explore the molecular targets for regulating glucose metabolism in carnivorous fish, the turbot (Scophthalmus maximus) was selected as the research object to study. Farnesoid X receptor (FXR; NR1H4), as a ligand-activated transcription factor, plays an important role in glucose metabolism in mammals. However, the mechanisms controlling glucose metabolism mediated by FXR in fish are not understood. It was first found that the protein levels of FXR and its target gene, small heterodimer partner (SHP), were significantly decreased in the high-glucose group (50 mM, HG) compared with those in the normal glucose group (15 mM, CON) in primary hepatocytes of turbot. By further exploring the function of FXR in turbot, the full length of FXR in turbot was cloned, and its nuclear localization function was characterized by subcellular localization. The results revealed that the FXR had the highest expression in the liver, and its capability to activate SHP expression through heterodimer formation with retinoid X receptor (RXR) was proved, which proved RXR could bind to 15 binding sites of FXR by forming hydrogen bonds. Activation of FXR in both the CON and HG groups significantly increased the expression of glucokinase (gk) and pyruvate kinase (pk), while it decreased the expression of cytosolic phosphoenolpyruvate carboxykinase (cpepck), mitochondrial phosphoenolpyruvate carboxykinase (mpepck), glucose-6-phosphatase 1 (g6pase1) and glucose-6-phosphatase 2 (g6pase2), and caused no significant different in glycogen synthetase (gs). ELISA experiments further demonstrated that under the condition of high glucose with activated FXR, it could significantly decrease the activity of PEPCK and G6PASE in hepatocytes. In a dual-luciferase reporter assay, the FXR could significantly inhibit the activity of G6PASE2 and cPEPCK promoters by binding to the binding site ‘ATGACCT’. Knockdown of SHP after activation of FXR reduced the inhibitory effect on gluconeogenesis. In summary, FXR can bind to the mpepck and g6pase2 promoters to inhibit their expression, thereby directly inhibiting the gluconeogenesis pathway. FXR can also indirectly inhibit the gluconeogenesis pathway by activating shp. These findings suggest the possibility of FXR as a molecular target to regulate glucose homeostasis in turbot. Full article

The gut microbiome is essential for the health of carnivorous mammals, including the endangered Siberian tiger (Panthera tigris altaica). However, limited research exists on the gut microbiome of captive Siberian tigers, especially regarding how diet and health status influence microbial diversity. This study addresses this gap by investigating the gut microbiome diversity and composition of six captive-born Siberian tigers housed at the Baekdudaegan National Arboretum in South Korea, using 16S rRNA gene sequencing. The study aimed to examine how diet and health status influence microbial communities, providing baseline data for managing captive tigers. Alpha diversity analysis revealed significant variation in microbial richness and evenness, with Tigers 2 and 6 exhibiting the highest microbial diversity and Tiger 3 the lowest, likely due to its surgical history and limited diet. Beta diversity analysis showed distinct microbial community structures influenced by diet and health. Taxonomic profiling identified Firmicutes and Bacteroidota as the dominant phyla, with Clostridium sensu stricto more prevalent in healthier tigers, while Escherichia-Shigella and Proteobacteria were abundant in tigers with lower diversity, suggesting dysbiosis. Comparisons with other tiger species confirm that diet, health, and captivity significantly shape the gut microbiome. These findings highlight the need for personalized health management in captive environments. Full article

We utilized camera traps to evaluate animal diversity, relative abundance, and the extent of anthropogenic activities in the Jhalana Reserve Forest (JRF), located in Jaipur, with a population of 3.9 million people. Between November 2017 and November 2019, camera traps were strategically deployed in the tourist zone and peripheral areas, capturing 16,328 photos. This study represents the first comprehensive baseline assessment of animal diversity in the JRF, documenting 39 species, including 18 bird species, 14 mammals, and 6 domestic species, alongside human activity. Among the 14 mammal species, 7 were carnivores. Notably, we identified 25 individual Indian leopards (Panthera pardus fusca) during 2017–2018, comprising 8 males and 17 females, highlighting the leopard as the apex predator in the JRF. Concurrently, domestic animals accompanied by humans were observed within the JRF. However, rigorous conservation efforts and patrols by the Rajasthan Forest Department resulted in a notable decline in human activity, from 28.04% in 2017–2018 to 3.92% in 2018–2019, with domestic animal activity reaching zero in the latter period. Consequently, the relative abundance of wildlife species increased during the study period of 2018–2019, underscoring the positive impact of conservation strategies implemented by authorities. Our findings establish that camera-trapping methodology collates definitive baseline data, assesses mammal diversity, and evaluates relative abundance in reserve forests within human-dominated landscapes. We strongly recommend a further study to assess the avifauna diversity. This study provides critical insights to inform the development and implementation of conservation strategies in similar protected areas. Full article

The Vallparadís Section encompasses various geological layers that span a significant chronological range, extending from the latest Early Pleistocene to the early Middle Pleistocene, covering a timeframe from approximately 1.2 to 0.6 Ma. This period holds particular importance, as it coincides with a significant climatic transition known as the Early–Middle Pleistocene Transition, a pivotal phase in Quaternary climatic history. This transition, marked by the shift from a 41,000-year obliquity-driven climatic cycle to a 100,000-year precession-forced cyclicity, had profound effects on the Calabrian carnivorous mammal communities. Notably, the once diverse carnivore guild began to decline across Europe during this period, with their last documented occurrences coinciding with those found within the Vallparadís Section (e.g., Megantereon or Xenocyon). Concurrently, this period witnessed the initial dispersals of African carnivorans into the European landscape (e.g., steppe lions), marking a significant shift in the composition and dynamics of the region’s carnivorous fauna. Full article

Wildlife trafficking and human–wildlife conflict are major causes of species decline. The illegal nature of wildlife trafficking makes it hard, and sometimes dangerous, to study. ‘Mansión Mascota’ is a veterinary clinic in Guayaquil, Ecuador, which, through agreement with the Ecuadorian Ministry of the Environment, receives confiscated wildlife for treatment. Mansión Mascota also receives injured and abandoned wildlife brought in by the authorities and the public. Between January 2018 and September 2022, the clinic received 3212 wild animals from ≥171 taxa, including mammals, birds, reptiles, and amphibians. Through the classification of records based on reported use, native distribution, and evidence of capture/pet keeping, we were able to classify 1127 animals of 68 species as subject to wildlife trafficking. Turtles were the most abundant group (69%). The majority of turtles (91%) and primates (80%) were of Amazonian origin, whereas 90% of psittacines and 97% of carnivores had potential coastal origins. Threatened and conservation-dependent species were common in the traffic. Furthermore, ≥955 animals of 106 species were brought to the clinic due to anthropogenic wildlife conflict. Trafficking, combined with the high number of injured animals, highlights the synergistic threats facing wildlife in Ecuador. Full article

Records from online biodiversity databases (including citizen science data) can play a crucial role in enhancing scientific knowledge about the abundance, distribution, and population trends of poorly studied species which are usually not properly monitored. This study aims to demonstrate the utility of data hosted in GBIF in detecting the likely decline of species common and widely distributed in the past, but whose conservation status is now uncertain, such as the weasel (Mustela nivalis) in Spain. To address this, we analyzed data on its presence in Spain from 2008 to 2022 available on GBIF.org, and compared it with the distribution data from the Atlas of Mammals of Spain published in 2007. The results indicate that: (i) data from GBIF.org reveal a moderate decline (negative trend) in the weasel population in Spain during the study period; (ii) the species has been recorded in a limited number of 10 × 10 km UTM-squares (Universal Transverse Mercator) within its distribution range as defined by the 2007 atlas; and (iii) there are large areas of Spain in which the species has not been detected in recent years. These findings highlight the concerning conservation status of this carnivorous species and underscore the value of data from open access platforms such as GBIF in identifying potential silent extinctions. Full article

Red pandas evolved from carnivores to herbivores and are unique within Carnivora. Red pandas and carnivorous mammals consume milk during the suckling period, while they consume bamboo and meat during the adult period, respectively. Red pandas and carnivorous mammal ferrets have a close phylogenetic relationship. To further investigate the molecular mechanisms of dietary changes and nutrient utilization in red pandas from suckling to adult, comparative analysis of the whole transcriptome was performed on stomach tissues from red pandas and ferrets during the suckling and adult periods. The main results are as follows: (1) we identified ncRNAs for the first time in stomach tissues of both species, and found significant expression changes of 109 lncRNAs and 106 miRNAs in red pandas and 756 lncRNAs and 109 miRNAs in ferrets between the two periods; (2) up-regulated genes related to amino acid transport regulated by lncRNA-miRNA-mRNA networks may efficiently utilize limited bamboo amino acids in adult red pandas, while up-regulated genes related to amino acid degradation regulated by lncRNAs may maintain the balance of amino acid metabolism due to larger daily intakes in adult ferrets; and (3) some up-regulated genes related to lipid digestion may contribute to the utilization of rich nutrients in milk for the rapid growth and development of suckling red pandas, while up-regulated genes associated with linoleic acid metabolism regulated by lncRNA-miRNA-mRNA networks may promote cholesterol decomposition to reduce health risks for carnivorous adult ferrets. Collectively, our study offers evidence of gene expression adaptation and ncRNA regulation in response to specific dietary changes and nutrient utilization in red pandas during suckling and adult periods. Full article

Bacteria and phages are two of the most abundant biological entities in the gut microbiome, and diet and host phylogeny are two of the most critical factors influencing the gut microbiome. A stable gut bacterial community plays a pivotal role in the host’s physiological development and immune health. A phage is a virus that directly infects bacteria, and phages’ close associations and interactions with bacteria are essential for maintaining the stability of the gut bacterial community and the entire microbial ecosystem. Here, we utilized 99 published metagenomic datasets from 38 mammalian species to investigate the relationship (diversity and composition) and potential interactions between gut bacterial and phage communities and the impact of diet and phylogeny on these communities. Our results highlight the co-evolutionary potential of bacterial–phage interactions within the mammalian gut. We observed a higher alpha diversity in gut bacteria than in phages and identified positive correlations between bacterial and phage compositions. Furthermore, our study revealed the significant influence of diet and phylogeny on mammalian gut bacterial and phage communities. We discovered that the impact of dietary factors on these communities was more pronounced than that of phylogenetic factors at the order level. In contrast, phylogenetic characteristics had a more substantial influence at the family level. The similar omnivorous dietary preference and closer phylogenetic relationship (family Ursidae) may contribute to the similarity of gut bacterial and phage communities between captive giant panda populations (GPCD and GPYA) and omnivorous animals (OC; including Sun bear, brown bear, and Asian black bear). This study employed co-occurrence microbial network analysis to reveal the potential interaction patterns between bacteria and phages. Compared to other mammalian groups (carnivores, herbivores, and omnivores), the gut bacterial and phage communities of bamboo-eating species (giant pandas and red pandas) exhibited a higher level of interaction. Additionally, keystone species and modular analysis showed the potential role of phages in driving and maintaining the interaction patterns between bacteria and phages in captive giant pandas. In sum, gaining a comprehensive understanding of the interaction between the gut microbiota and phages in mammals is of great significance, which is of great value in promoting healthy and sustainable mammals and may provide valuable insights into the conservation of wildlife populations, especially endangered animal species. Full article

Taenia crassiceps is a zoonotic tapeworm of the genus Taenia that is distributed throughout the Northern Hemisphere. Wild and domestic carnivores are final hosts, while rodents and rabbits are primarily intermediate hosts, although many other mammals may harbour the larval stage, Cysticercus longicollis. This case report aims to describe C. longicollis infection in a lemur and molecularly characterise the isolated parasite. The excised lesion was subjected to morphological and histopathological examination, which revealed cysticerci of the tapeworm. Formalin-fixed and paraffin-embedded block (FFPEB), as well as the cysticerci fixed with formalin stored for one year, were subjected to molecular analysis, which aimed at detecting the partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of Taenia sp. Based on the morphological characteristics, the parasite was identified as a metacestode of T. crassiceps. The presence of the cox1 gene was detected using polymerase chain reaction (PCR) in all samples. A randomly selected PCR product was sequenced and compared with other sequences from the GenBank database, confirming that the detected parasite was T. crassiceps. This article reports the first case of T. crassiceps cysticercosis in a lemur (Lemur catta) in Croatia and emphasises the potential risk of transmission from wild carnivores. Full article