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opencc-zeroOct 2021View details →

Stable isotopes reveal variation in consumption of Pacific salmon by brown bears, despite ready access in small streams

Brown bears Ursus arctos consume a wide range of organisms, including ungulates and plants, but Pacific salmon Oncorhynchus spp. are especially important to their diet where their ranges overlap. Although some brown bears minimize antagonistic encounters with other brown bears or infanticide by avoiding streams where salmon spawn, studies generally assume that brown bears with ready access to salmon feed heavily on them. To test this assumption, and the hypothesis that male brown bears would feed more heavily on salmon than females (owing to their sexual size dimorphism), we collected hair samples from brown bears by using barbed wire placed on six small tributaries of Lake Aleknagik, Alaska, USA, where adult Sockeye Salmon Oncorhynchus nerka are readily accessible and frequently consumed by brown bears. Analysis of DNA distinguished among the different brown bears leaving the hair samples, some of which were sampled multiple times within and among years. We assessed the contribution of salmon to the diet of individual brown bears by using carbon and nitrogen stable isotope signatures. The 77 samples analyzed from 31 different bears over 4 y showed isotopic ratios consistent with reliance on salmon, but the wide range of isotopic signatures included values suggesting variable, and in one case considerable, use of terrestrial resources. Stable isotope signatures did not differ between male and female brown bears, nor did they differ between two sides of the lake, despite marked differences in Sockeye Salmon density. We collected the hair samples when salmon were present, so there was some uncertainty regarding whether they reflected feeding during the current or previous season. Notwithstanding this caveat, the results are consistent with the hypothesis that salmon were sufficiently available to provide food for the brown bears and that the considerable isotopic variation among brown bears with access to salmon reflected their age, status, and behavior.

opencc-zeroNov 2021View details →

Stable isotope profile of autumnal migratory bird feathers on Italian Alps

In the study of migration of birds, there are many aspects to be deepened to comprehend both ecology of the species and their geographical connectivity between breeding and wintering grounds. In the last decades, stable isotopes of light elements such as hydrogen, oxygen, nitrogen, carbon and sulphur measured in cheratinous tissues such feathers are increasingly used in order to delineate origin of migrants and to define ecological aspects of birds. Here we present a complete isotopic profile of several passerine species migrating through Italian Alps during post-breeding season. Stable isotope ratios of hydrogen, oxygen, carbon, nitrogen and sulphur were measured in juvenile feathers of 807 individuals of 48 different specie ringed in central Italian Alps during post-breeding migration in the years 2010, 2011, 2012, and 2013. Birds were ringed in two ringing and monitoring stations of Progetto Alpi (<a href="http://progetto-alpi.muse.it/">http://progetto-alpi.muse.it/</a>). No birds were mistreated, and the sampling took place in compliance with the national and international laws in force at the time of the study.

opencc-by-4.0Dec 2021View details →

Chongce ice core stable isotopes and temperature reconstruction (1524-2012 A.D.)

Chongce ice core stable isotopes and temperature reconstruction

Towards a stable global Noctuidae (Lepidoptera) taxonomy

The family Noctuidae is one of the world's most diverse, ecologically successful, and economically important animal lineages; with over 12,000 species in ~1150 genera. We inferred a phylogeny based on eight protein-coding genes (>6,400 base pairs) for the global fauna, greatly expanding upon previous attempts to stabilize the higher classification of Noctuidae by sampling 70 of the 76 widely recognized family-group taxa: 20 of the 21 subfamilies, 32 of the 35 tribes, and 18 of the 20 subtribes. For nearly half of the 341 genera included we sampled their type species. We evaluated seventeen subfamily-level taxa in detail; discussing adult and larval morphology, life history data, and taxonomic implications of our results. We significantly alter current concepts of Acontiinae, Condicinae, Eustrotiinae, Metoponiinae, and Stiriinae. We lowered Bryophilinae and Eriopinae to Bryophilini stat. rev. and Eriopini stat. rev. within Noctuinae. Our results also supported recognition of Cropiinae Keegan and Wagner subf. nov. Other nomenclatural changes we made are as follows. We moved "Acontia" viridifera (Hampson, 1910); "Azenia" virida Barnes and McDunnough, 1916; Aleptinoides; Austrazenia; Chalcoecia; Megalodes; and Trogotorna to Chamaecleini in Acontiinae. We moved Apaustis to Acontiinae and reinstated Emmelia as a valid genus in Acontiinae. We moved Allophyes and Meganephria to Cuculliinae. We moved "Plagiomimicus" navia (Harvey, 1875); Airamia; Alvaradoia; Hypoperigea; Neotarache; and Mesotrosta to Condicinae. We moved Axenus, Azenia, Metaponpneumata, Sexserrata, and Tristyla to Metoponiinae. We moved Pachythrix and "Paramiana" canoa (Barnes, 1907) to Noctuinae. Finally, we moved Cobubatha, Copibryophila, Homolagoa, Tripudia, and Tyta to Noctuidae incertae sedis.

Periphyton carbon and nitrogen stable isotopes detect agricultural stressors in low-order streams

Shifts in the stable isotope signatures of carbon (C) and nitrogen (N) in ecological materials have the potential to indicate environmental disturbances. This study examined the δ13C‰ and δ15N‰ ratios of stream water and periphyton from low-order streams in a landscape influenced by agricultural activities. Our key purpose was to assess the influence of best management practice (BMP) presence and age on C and N isotope values as a potential water-quality assessment. We collected stream water and periphyton from 19 streams within the Upper Delaware River watershed in New York, USA, in each of 4 management categories: 1) recently applied BMP treatments, 2) long-standing BMPs, 3) streams lacking BMPs, and 4) minimally disturbed reference streams. We sampled and analyzed water and periphyton for δ13C‰ and δ15N‰ in a repeated-measures design (BMP category ´ time) from April to November 2013. There were large seasonal differences in stream water δ13C-dissolved organic C (DIC)‰ and δ15NO3-N‰, with strong differences between reference and agricultural streams. Periphyton δ13C‰ and δ15N‰ values also differed strongly across streams draining land with agricultural activities, with 85% higher periphyton δ15N‰ signals in all agricultural categories vs reference streams. Periphyton diatom and chlorophyte taxonomic proportions showed the strongest relationship with periphyton δ13C‰ values, where diatoms were negatively associated with increasing δ13C‰. These results suggest that aqueous and periphytic stable isotopes were sensitive in detecting persistent effects of agriculture on these streams despite BMP mitigation, where nutrient (orthosphosphate, nitrite, and ammonia) levels were non-indicative. These results also suggest that BMPs may not have fully eliminated the negative impacts of agricultural stressors on water quality in impacted streams.

Leaf, stem, and root stable carbon isotope ratios and gas exchange data for 452 plants

This dataset contains a compilation of stable carbon isotope ratios in leaves, stems, and roots for tree saplings and associated gas exchange data. It was used in a book chapter to test whether the relationship between carbon isotope discrimination and the ratio of intercellular to ambient carbon dioxide concentrations differs between leaves and woody tissues. The book chapter is entitled 'Carbon isotope effects in relation to CO2 assimilation by tree canopies' authored by Lucas A. Cernusak and Nerea Ubierna. It is part of the book entitled 'Stable Isotopes in Tree Rings' edited by Rolf T. Siegwolf, J. Renee Brooks, John Roden, and Matthias Saurer. The publisher of the book is Springer International Publishing, with publication in April 2022.

Relating wing morphology and immune function to patterns of partial and differential bat migration using stable isotopes

Migration is energetically expensive and is predicted to drive similar morphological adaptations and physiological trade-offs in migratory bats and birds. Previous studies suggest that fixed traits like wing morphology vary among species and individuals according to selective pressures on flight, while immune defenses can vary flexibly within individuals as energy is variably reallocated throughout the year. We assessed intraspecific variation in wing morphology and immune function in silver-haired bats (Lasionycteris noctivagans), a species that follows both partial and differential migration patterns. We hypothesized that if bats experience energy constraints associated with migration, then wing morphology and immune function should vary based on migratory tendency (sedentary or migratory) and migration distance. We predicted that long-distance migrants would have reduced immune function and more migration-adapted wing shapes compared to resident or short-distance migrating bats. We estimated breeding latitude of spring migrants using stable hydrogen isotope techniques. Our sample consisted primarily of male bats, which we categorized as residents, long-distance northern migrants, short-distance northern migrants, and southern migrants (apparent breeding location south of capture site). Controlling for individual condition and capture date, we related wing characteristics and immune indices among groups. Some, but not all, aspects of wing form and immune function varied between migrants and residents. Long-distance northern migrants had larger wings than short-distance northern migrants and lower wing loading than southern migrants. Compared with resident bats, short-distance northern migrants had reduced IgG while southern migrants had heightened neutrophils and neutrophil-to-lymphocyte ratios. Body fat, aspect ratio, wing tip shape, and bacteria killing ability did not vary with migration status or distance. In general, male silver-haired bats do not appear to mediate migration costs by substantially downregulating immune defenses or to be under stronger selection for wing forms adapted for fast, energy-efficient flight. Such phenotypic changes may be more adaptive for female silver-haired bats, which migrate farther and are more constrained by time in spring than males. Adaptations for aerial hawking and the use of heterothermy by migrating bats may also reduce the energetic cost of migration and the need for more substantial morphological and physiological trade-offs.

Stable persistence of relict populations involved evolutionary shifts of reproductive characters in the genus Tanakaea (Saxifragaceae)

Tertiary relicts often show evolutionary stasis in morphology and ecology and have been hypothesised to retain stable population sizes in refugia. However, recent studies have reported that some relicts evolutionarily shifted their physiology, ecology, and morphology and experienced various patterns of demography. To understand the historical survival of relict plants, a multidimensional study investigating the evolution of ecological and morphological traits as well as population demographic history is needed. The genus Tanakaea (Saxifragaceae) comprises two species in China and Japan. These species share most vegetative characteristics and are sometimes treated as a single species. The distribution pattern is relictual, as the populations are confined to small areas in mesic warm temperate forests less influenced by Quaternary glacial climates. Focusing on the relictual plant group, this study tested the hypotheses of evolutionary stasis and population stability in long-term refugia. Genetic analyses using plastome sequences and genome-wide single nucleotide polymorphisms revealed divergence of the two species approximately 6.8 million years ago and strong genetic differentiation of the regional populations. Demographic analysis revealed that almost all populations retained stable population sizes during glacial-interglacial climate changes, supporting the traditional view. However, morphological assessments revealed a simultaneous shift in breeding systems (from hermaphrodite to dioecy/non-clonal to clonal reproduction) in Japanese species and intraspecific differentiation of leaf traits. Therefore, the relict species do not show evolutionary stasis in every aspect. Changes in reproductive characteristics may have contributed to their long-term in situ survival.

opencc-zeroMar 2022View details →

Supplementary to "A stable foraging polymorphism buffers Galápagos sea lions against environmental change"

All vibrissae photographs, measured relative vibrissae length and raw data of the reproductive history of females used for "A foraging polymorphism buffers Galápagos sea lions against climate change".

opencc-zeroApr 2022View details →

Stable isotope data from: Use of marine vs. freshwater proteins for egg-laying and incubation by sea ducks breeding in Arctic tundra

This data archive contains data used in analyses of protein sources for egg membranes and whole blood of long-tailed ducks (Clangula hyemalis) and Steller's (Polysticta stelleri), spectacled (Somateria fischeri), and king (Somateria spectabilis) eiders. These data have been published in Miller et al. (2022): Use of marine vs. freshwater proteins for egg-laying and incubation by sea ducks breeding in Arctic tundra (Ecosphere).

opennotspecifiedMay 2021View details →

Fig. 4 in Toward a Stable Global Noctuidae (Lepidoptera) Taxonomy

Fig. 4. Continuation of maximum-likelihood tree inferred by RAxML analysis.

opennotspecifiedMay 2021View details →

Fig. 6 in Toward a Stable Global Noctuidae (Lepidoptera) Taxonomy

Fig. 6. Continuation of maximum-likelihood tree inferred by RAxML analysis.

Figure 3 from: Freire CA, Rios LP, Giareta EP, Castellano GC (2017) Oxygen consumption remains stable while ammonia excretion is reduced upon short time exposure to high salinity in Macrobrachium acanthurus (Caridae: Palaemonidae), a recent freshwater colonizer. Zoologia 34: 1-9. https://doi.org/10.3897/zoologia.34.e20173

Figure 3 - Initial (circles) and final (squares) pH and excreted ammonia (N-NH3) in water of M. acanthurus exposed to salinities 0 (control), 10, 20, and 30 psu for 4 (white symbols) and 8 hours (black symbols). Different letters mean differences between salinities within each time of exposure. * = value for 4 hours is different from value for 8 hours within a same salinity, # = initial and final values of water pH are different.

Figures 1-2 from: Freire CA, Rios LP, Giareta EP, Castellano GC (2017) Oxygen consumption remains stable while ammonia excretion is reduced upon short time exposure to high salinity in Macrobrachium acanthurus (Caridae: Palaemonidae), a recent freshwater colonizer. Zoologia 34: 1-9. https://doi.org/10.3897/zoologia.34.e20173

Figures 1-2 - Initial (circles) and final (squares) levels of dissolved oxygen in the water (1) and lactate concentration in the hemolymph (2) of M. acanthurus exposed to salinities 0 (control), 10, 20, and 30 psu for 4 (white symbols) and 8 hours (black symbols). Values near to the lines represent oxygen consumption (mean ± std dev) as a percentage of the initial oxygen concentration (considered 100%, as a reference value). (#) Initial and final levels of dissolved oxygen are different. There were no significant differences between salinities or times (4 and 8 hours) for oxygen consumption and lactate concentration.

Figures 4-5 from: Freire CA, Rios LP, Giareta EP, Castellano GC (2017) Oxygen consumption remains stable while ammonia excretion is reduced upon short time exposure to high salinity in Macrobrachium acanthurus (Caridae: Palaemonidae), a recent freshwater colonizer. Zoologia 34: 1-9. https://doi.org/10.3897/zoologia.34.e20173

Figures 4-5 - Hemolymph osmolality (4) and muscle water content (5) of M. acanthurus exposed to salinities 0 (control), 10, 20, and 30 psu for 4 (white circles) and 8 hours (black circles). Dashed line represents water expected values, from the relationship 1 psu = 30 mOsm/kg H2O, short horizontal lines indicate value of calculated water osmolality for the tested salinities. Different letters mean differences between salinities within each time of exposure. * = value for 4 hours is different from value for 8 hours within a same salinity.

Figure 4 from: Marques TS, Brito ES, Lara NRF, Beloto LM, Valadão RM, de Camargo PB, Verdade LM (2017) The trophic niche of Mesoclemmys vanderhaegei (Testudines: Chelidae): evidence from stable isotopes. Zoologia 34: 1-6. https://doi.org/10.3897/zoologia.34.e19985

Figure 4 - Relationship between the stable isotope compositions (d15N-d13C) and body size (carapace length and body mass) of Mesoclemmys vanderhaegei at Serra das Araras Ecological Station, Mato Grosso state, Brazil.

Figure 3 from: Marques TS, Brito ES, Lara NRF, Beloto LM, Valadão RM, de Camargo PB, Verdade LM (2017) The trophic niche of Mesoclemmys vanderhaegei (Testudines: Chelidae): evidence from stable isotopes. Zoologia 34: 1-6. https://doi.org/10.3897/zoologia.34.e19985

Figure 3 - Corrected standard ellipses (SEAc) overlaping of standard ellipse between males (white circles: dashed line) and females (black circles: black line) of Mesoclemmys vanderhaegei in δ15N-δ13C space.

Figure 2 from: Marques TS, Brito ES, Lara NRF, Beloto LM, Valadão RM, de Camargo PB, Verdade LM (2017) The trophic niche of Mesoclemmys vanderhaegei (Testudines: Chelidae): evidence from stable isotopes. Zoologia 34: 1-6. https://doi.org/10.3897/zoologia.34.e19985

Figure 2 - Niche widths for males and females of Mesoclemmys vanderhaegei estimated by Bayesian standard ellipse areas (SEAB). The black points correspond to the mean SEAB for each group, while shaded boxes representing the 50%, 75% and 95% credible intervals from dark to light grey.

Figure 1 from: Marques TS, Brito ES, Lara NRF, Beloto LM, Valadão RM, de Camargo PB, Verdade LM (2017) The trophic niche of Mesoclemmys vanderhaegei (Testudines: Chelidae): evidence from stable isotopes. Zoologia 34: 1-6. https://doi.org/10.3897/zoologia.34.e19985

Figure 1 - Maps illustrating study site at Serra das Araras Ecological Station, Mato Grosso state, Brazil (Projected Cordinate Sistem; Datum: Sirgas 2000).