Trunk spines of trees: a physical defence against bark removal and climbing by mammals?

BACKGROUND AND AIMS

The defensive role of spines has previously been related to leaves, young shoots and reproductive organs. However, some woody species harbour spines on their trunks where none of those organs are present. Several explanations are plausible: they could be (1) climbing aids, (2) remnants from defence of leaves or reproductive organs during an earlier development phase, or (3) an as-yet undescribed defence. Here we investigate whether they could play a role against either bark feeding or preventing climbing animals accessing food resources in the tree canopy.

METHODS

We described 31 woody species with spines on their trunk, growing in a botanical garden, to test whether morphological strategies could be identified and suggest what could be their most likely function. As testing their function is difficult experimentally for large pools of species, we performed virtual experiments to evaluate the potential roles of trunk spines against bark removal and climbing animals of different sizes. We then compared for each species and their confamilial non-spiny species the nutritional profiles of leaf, bark and reproductive organs to test whether trunk spines were associated with a nutritious organ (more likely targeted by herbivores).

KEY RESULTS

We identified four morphological syndromes of trunk spines. Two corresponded to already known functions (anchorage for lianas and crown defence against large ground mammals), and two strategies are newly described trait syndromes with traits suggesting a defence against bark feeding and climbing mammals. By simulation, we show how each strategy could translate into defence against debarking and prevent herbivores from climbing.

CONCLUSIONS

We identified trunk spine strategies and the criteria to classify them, their most likely function and the likely feeding mode and size of animal against which different trunk spine strategies may be effective. We discuss further perspectives for testing their function and their ecological significance.

Food habits of indian crested porcupine (Hystrix indica) (Kerr 1792), in district Bagh, Azad Jammu and Kashmir

The Indian Crested Porcupine (Hystrix indica) is classified as an agricultural pest species. It feeds on plants and crops; hence, it is responsible for massive financial losses worldwide. The current study was conducted to assess the diet composition of Indian Crested Porcupine in District Bagh, Azad Jammu and Kashmir (AJ&K). Thus, fecal samples were collected and examined from different sampling sites. Reference slides of the material collected from the study area were prepared for identification of dietary components in fecal pellets. A total of 80 fecal samples were collected and processed. Percent relative frequencies (P.R.F.) were calculated for each plant species recovered from pellets. Data revealed that Indian Crested Porcupine consumed 31 plant species in its diet, among them Zea mays (34.31±7.76) was the most frequently selected species followed by Rumex obtusifolius (15.32±2.57) and Melia azedarach (12.83±4.79). The study revealed that the greatest diversity of (n=20) plant species were consumed in summer season while minimum (n=13) species were used during winter. Among the parts of plants, stem was highly consumed in spring (57.2%) as compared to seed in fall (36.7%) while spikes and leaf were the least recovered parts from the fecal matter. The Berger-Parker diversity index showed highly diversified food (10.92) in the summer time of the year as compared to the autumn season (2.95). This study provides a baseline for the diet preference of this pest in the study area. Based on current findings, a detailed investigation on damage assessment, exploration, habitat use and management of Indian Crested Porcupine in AJ&K has been recommended.

Functional traits of the world's late Quaternary large-bodied avian and mammalian herbivores

Prehistoric and recent extinctions of large-bodied terrestrial herbivores had significant and lasting impacts on Earth's ecosystems due to the loss of their distinct trait combinations. The world's surviving large-bodied avian and mammalian herbivores remain among the most threatened taxa. As such, a greater understanding of the ecological impacts of large herbivore losses is increasingly important. However, comprehensive and ecologically-relevant trait datasets for extinct and extant herbivores are lacking. Here, we present HerbiTraits, a comprehensive functional trait dataset for all late Quaternary terrestrial avian and mammalian herbivores ≥10 kg (545 species). HerbiTraits includes key traits that influence how herbivores interact with ecosystems, namely body mass, diet, fermentation type, habitat use, and limb morphology. Trait data were compiled from 557 sources and comprise the best available knowledge on late Quaternary large-bodied herbivores. HerbiTraits provides a tool for the analysis of herbivore functional diversity both past and present and its effects on Earth's ecosystems.

Evidence of scavenging behaviour in crested porcupine

The vegetarian diet of many herbivorous mammals is supplemented with proteins of animal origin, especially in young individuals and in breeding females, to provide key proteins necessary for both growth and breeding. Among porcupine species, only the Cape porcupine (Hystrix africaeaustralis) has been observed to consume carrion flesh. From June to August 2019, a pigeon carcass was placed together with corn in 7 study settlements and near 2 monitored capture-traps, in order to assess the carrion flesh feeding habits of the crested porcupine (Hystrix cristata). Scavenging behaviour was recorded on four occasions. All the recorded individuals were adults and at least one was female. This demonstrates that the crested porcupine occasionally does eat flesh. Such evidence raises important questions concerning the relationship between feeding habits and the physiological needs of this herbivorous rodent.

Hystrix brachyura Bezoar Characterization, Antioxidant Activity Screening, and Anticancer Activity on Melanoma Cells (A375): A Preliminary Study

Porcupine bezoars (PBs) are masses of undigested calcareous concretions formed within the gastrointestinal tract. There are undocumented claims that PBs have antioxidant activity and can treat cancers. However, limited scientific study has been carried out to verify these traditional claims. Hence, this study was conducted to characterize the chemical profile and validate the antioxidant and anticancer activity against melanoma cells (A375). PB extract was initially subjected to Fourier-transform infrared spectroscopy (FTIR), gas chromatography⁻mass spectrometry (GCMS), total phenolic content (TPC), and total flavonoid content (TFC) analyses. The bioautography of antioxidant assays, namely 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazy (DPPH), and β-carotene was performed. An in vitro A375 cell viability assay, apoptosis assay, cell cycle arrest assay, and gene expression assay were carried out as well. The experimental finding revealed 5,10-diethoxy-2,3,7,8-tetrahydro-1H,6H-dipyrrolo[1,2-a:1',2'-d]pyrazine, ursodeoxycholic acid, and cholest-5-en-3-ol (3 beta)-, carbonochloridate are major compounds detected in PB extract. PB extract has low phenolic content, viz. 698.7 ± 0.93 (µg GAE/5 mg dry weight). The bioautography antioxidant assays revealed a potent antioxidant effect (ABTS > DPPH > β-carotene), with free radical scavenging activity. Furthermore, PB extract exhibited dose- and time-dependent inhibition of cancer activity on A375 cells due to the exhibition of apoptosis via an intrinsic pathway.