Bright colours in distasteful prey warn off predators, but processes associated with ontogenetic acquisition of warning colours and distasteful compounds have been studied in only a few organisms. Here, we study spotted lanternflies (Lycorma delicatula; Fulgoridae) that change to red colouration when they narrow their host plant preferences to primarily the tree of heaven (Ailanthus altissima; Simaroubaceae), which is chemically defended by quassinoids. In experiments, we showed that birds taste-avoided lanternflies collected on Ailanthus but not those collected on the secondary hosts. Birds also taste-avoided seeds infused with ailanthone, the main quassinoid sequestered from Ailanthus by lanternflies as shown through mass spectrometry analyses. Hence, the narrowing of host preferences by lanternflies synchronizes the timing of change to red colour with the acquisition of quassinoid defenses. A schematic graphical population-level model of these processes is provided. This is the first report of quassinoid sequestration by insects and the first evidence that Simaroubaceae plants provide defensive chemicals to insects. This is the first report of a fulgoroid insect sequestering identified chemical defenses. The results highlight the importance of the pan-tropical taxon Fulgoridae for evolutionary biology of complex aposematic strategies and for understanding the links between timing of defense sequestration, timing of host plant preference shifts, and timing of colour change.
Globally, an increase in the transportation and expansion of the pet market is the most important cause of the invasion of non-native species. Invasion of non-native species disturbs native ecosystems and leads to socio-economic problems. The pet trade involving turtles has been globally recognized as the route through which non-native species enter ecosystems. As a result, the invasion of non-native turtles worldwide is causing problems such as competition, predation, transmission of parasites, and hybridization with native turtles. Every year, both the number of non-native turtles imported as pets in the Republic of Korea and the number of introduced species found in the wild is increasing. However, the current status of non-native turtles in the wild is not well known, posing major challenges to their management. In this study, we aimed to determine the current status of non-native turtles introduced into the wild in Korea. We analyzed the factors associated with the detection and distribution of non-native turtles. In total, 1587 of non-native turtles (three families, six genera, and 13 species including subspecies) were found in 648 sites in Korea: Chelydra serpentina, Mauremys sinensis, Chrysemys picta bellii, Graptemys ouachitensis, G. pseudogeographica pseudogeographica, G. p. kohni, Pseudemys concinna, P. nelsoni, P. peninsularis, P. rubriventris, Trachemys scripta elegans, T. s. scripta, and T. s. troostii. There was relationship between the distribution of non-native turtles and environmental factors such as precipitation and temperature. Moreover, human factors such as number of human populations and size of region were significantly related with the distribution and number of non-native turtles. In conclusion, it is likely that human factors are associated with the influx of invasive turtles to the natural habitat, while the possibility of survival and adaption for the turtles is associated mainly with environmental factors. Our result will be an essential guideline not only for understanding the current status of non-native turtles in Korea, but also for establishing strategies for management and control.
Endotherms dissipate heat to the environment to maintain a stable body temperature at high ambient temperatures, which requires them to maintain a balance between heat dissipation and water conservation. Birds are relatively small, contain a large amount of metabolically expensive tissue, and are mostly diurnal, making them susceptible to physiological challenges related to water balance and heat dissipation. We compiled total evaporative water loss (TEWL) measurements for 174 species of birds exposed to different temperatures and used comparative methods to examine their relationships with body size, ambient temperature, precipitation, diet, and diel activity cycle. TEWL in the thermoneutral zone (TNZ) was associated primarily with body mass and activity phase. Larger and more active-phase birds, with their higher metabolic rates, lost more water through evaporation than smaller, resting-phase birds, particularly at higher thermal exposures. However, maximum temperature of the natural habitat became an important determinant of TEWL when birds were exposed to temperatures exceeding the TNZ. Species from hotter climates exhibited higher TEWL. Adaptation to arid climates did not restrict evaporative water loss at thermal conditions within the TNZ, but promoted evaporative water loss at exposures above the TNZ. The TEWL of granivores, which ingest food with low water content, differed little from species with other food habitats under all thermal conditions. The effects of environmental covariates of TEWL were dissimilar across thermal exposures, suggesting no evidence for a tradeoff between water conservation in the TNZ and heat dissipation at exposure to higher temperatures. Thus, birds may be able to acclimate when climate change results in the need to increase heat dissipation due to warming, except perhaps in hot, arid environments where species will need to depend heavily upon evaporative cooling to maintain homeothermy.
The field metabolic rate (FMR) of an endothermic animal represents its energy expenditure in a natural environment, or its energy budget, and its field water flux (FWF) reflects the animal's water requirements. We examined FMR of 103 species and FWF of 75 species of adult birds from direct field measurements using the doubly labelled water method, and used the phylogenetic generalized least squares method to conduct a phylogenetically informed, comprehensive analysis of the relationship between FMR, FWF and multiple environmental and biological variables. Field metabolic rate was strongly positively associated with body mass with an allometric exponent of 0.66, and seabirds had lower FMR than terrestrial species. Birds consuming plant matter had lower FMR compared to omnivores, carnivores or nectarivores and low ambient temperature was associated with higher FMR. There was little evidence for phylogenetic covariance in FMR, even though previous studies identified a phylogenetic signal for basal metabolic rate. Life‐history traits, such as fecundity and migration, were also not strongly associated with FMR. Field water flux was strongly positively associated with body mass with an allometric exponent of 0.61, and was strongly related to precipitation but not to temperature. Diet and habitat use had significant effects on FWF, with nectarivores and marine species exhibiting higher values than granivores and forest birds. Thus, FMR and FWF are affected similarly by body size and differently by environmental temperature and precipitation, while the roles of diet, life‐history traits and habitat are more nuanced and generalities remain elusive. A free Plain Language Summary can be found within the Supporting Information of this article.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.