scholarly journals Artificial selection for predatory behavior results in dietary niche differentiation in an omnivorous mammal

2021 ◽  
Author(s):  
Anni M Hämäläinen ◽  
Mikko Kiljunen ◽  
Esa Koskela ◽  
Pawel Koteja ◽  
Tapio Mappes ◽  
...  

The diet of an individual is a result of the availability of dietary items and the individual's foraging skills and preferences. Behavioral differences may thus influence diet variation, but the evolvability of diet choice through behavioral evolution has not been studied. We used experimental evolution combined with a field enclosure experiment to test whether behavioral selection leads to dietary divergence. We analysed the individual dietary niche via stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) in the hair of an omnivorous mammal, bank vole, from 4 lines selected for predatory behavior and 4 unselected control lines. Predatory voles had higher hair δ15N values than control voles, supporting our hypothesis that predatory voles would consume a higher trophic level diet (more animal vs. plant foods). This difference was significant in the early but not the late summer season. The δ13C values also indicated a seasonal change in the consumed plant matter and a difference in food sources among selection lines in the early summer. These results imply that environmental factors interact with evolved behavioral tendencies to determine dietary niche heterogeneity. Behavioral selection thus has potential to contribute to the evolution of diet choice and ultimately the species' ecological niche breadth.

1979 ◽  
Vol 51 (1) ◽  
pp. 17-24
Author(s):  
Markku Käpylä ◽  
Paavo Niemelä

A list of nectar and pollen sources of honeybee (Apis mellifera L.) in southern Finland based on 44 500 flower records is presented. Only the common wild and cultivated species are included, 139 species altogether. The flowering times are shown with an accuracy of two weeks. The most important food sources during spring (April—May) are Salix spp., and Tussilago farfara: during early summer (late May and June) Salix spp., Taraxacum officinale, Acer platanoides, Vaccinium vitis-idaea, Barbarea vulgaris, Ribes spp., Malus domestica, Sorbus aucuparia, and Geranium sylvaticum; during mid-summer Trifolium repens, T. hybridum, Rubus idaeus, Tilia cordata, Epilobium angustifolium, and Cirsium arvense; during late summer and early autumn Calluna vulgaris, Arctium tomentosum, Sonchus arvensis and Leontodon autumnalis.


2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 12-13
Author(s):  
Jordan Adams ◽  
Rodney Farris ◽  
Scott Clawson ◽  
Earl Ward ◽  
Paul Beck

Abstract We evaluated the effects of supplementing dried distillers’ grains cubes (DDGS) and re-implantation of steers (n = 149; BW = 238 ± 13.8 kg) grazing tall fescue (Festuca arundinacea)/bermudagrass (Cynodon dactylon) pastures (n = 9 pastures, 7.2 ± 2.90 ha) from 14 April to 17 September 2020 (n = 155 d) in a split-plot design on steer performance and forage production. Main plot supplemental treatments (n = 3 pastures/treatment) included 1) Fertilized Control (FC), no supplementation on fertilized pastures (112 kg N/ha); 2) Fertilized Supplement (FS), supplemental DDGS fed at 2.9 kg 3-d/wk on fertilized pastures; and 3) Supplement (S), supplemented DDGS at 0.75% BW/d on unfertilized pastures prorated for 5-d/wk feeding. Steers were previously implanted during receiving with 40 mg trenbolone acetate and 8 mg estradiol (REV-G; Revalor G, Merck Animal Health). On July 7, steers in each pasture were randomly assigned to one of three re-implant treatments: 1) no re-implant; 2) REV-G; or 3) 200 mg progesterone and 20 mg estradiol (Synovex S, Zoetis Animal Health). Steers in FS and S gained more (P < 0.01) than FC throughout the trial and final BW was greater (P < 0.01) for FS and S compared with FC. Unexpectedly, re-implanting had no effect on ADG (P = 0.57) or BW (P = 0.34), but statistical power may be lacking. Supplemental efficiency was greater in the late summer for FS (P = 0.05) compared to S. Fertilizing pastures in FS and FC did not affect biomass (P = 0.39), however, CP was increased (P = 0.01) and acid and neutral detergent fibers tended to decrease (P = 0.06) relative to S in the early summer (April, May, June, and July), but did not differ in late summer (August and September). Based upon our analysis, DDGS is a suitable supplement and can replace N fertilizer for steers grazing introduced pastures.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 46-46
Author(s):  
Zane N Grigsby ◽  
Paul A Beck ◽  
Stacey A Gunter

Abstract This research was conducted to determine effects of supplementation and implanting on BW gain by steers grazing mixed grass prairie (n = 12 pastures, 19.9 ± 0.7 ha) in northwest Oklahoma. Three main plot treatments were: 1) Negative Control (NC), no supplementation, 2) Positive Control (PC), supplemented with DDGS cubes, 1.8 kg/steer on alternate days in late summer, 3) High Supplement (HS), 1/3 increase in stocking rate with 0.75% BW supplemental DDGS cubes all season. Steers (n = 125, BW = 223.1 ± 23.2 kg) were stocked at 2.2 ha/steer for PC and NC, 1.3 ha/steer for HS. Grazing was from May 17 – September 27 (132 d). All steers were implanted with 200 mg progesterone and 20 mg estradiol benzoate (SYN, Synonvex S, Zoetis Animal Health) on May 17. On July 18 three reimplant treatments were applied: 1) no reimplant; 2) SYN; or 3) 40 mg trenbolone acetate and 8 mg estradiol (Revalor G, Merck Animal Health). Data were analyzed using the PROC MIXED in SAS as a split-plot experimental design. In early summer HS had 0.26 kg greater (P < 0.01) ADG than NC and PC. Late summer gains of PC were 0.33 kg/d more (P ≤ 0.01) than NC; and HS gained 0.49 and 0.16 kg/day more (P ≤ 0.04) than NC and PC, respectively. Gain per hectare for PC (46 kg/ha) were greater (P < 0.01) than NC (35 kg/ha) and more than doubled (P < 0.01) with HS (89 kg/ha). Reimplanting had no effect on ADG (P ≥ 0.28). Late season supplementation with PC resulted in supplemental efficiency of 2.7 kg supplement/kg added gain compared with NC. Increased stocking rates with season long supplementation in HS resulted in supplemental efficiency of 3.8 kg supplement/kg added gain per hectare. Based on these data, a 100% DDGS cube is an effective supplement option to increase BW gain during the late summer or increase carrying capacity and gain during the summer grazing period in northwestern Oklahoma.


2017 ◽  
Vol 57 (3) ◽  
pp. 539 ◽  
Author(s):  
P. Beck ◽  
T. Hess ◽  
D. Hubbell ◽  
M. S. Gadberry ◽  
J. Jennings ◽  
...  

The objective of this study was to evaluate the effects of including alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) on herbage nutritive value compared with monocultures of bermudagrass fertilised with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha over four grazing seasons. In autumn, at the end of the fourth year and in the spring before the fifth grazing season, alfalfa and clover plants were killed and the carryover N benefit of CLVR or ALF was compared with N fertilisation rates during the fifth year. Across years, N fertilisation rate increased herbage mass and carrying capacity linearly; whereas herbage production from CLVR and ALF swards was equivalent to 56N, were greater than 0N and less than 112N. Herbage mass in CLVR and ALF swards was greater than fertilised bermudagrass swards in the spring and did not differ from fertilised bermudagrass in the early summer. In late summer herbage accumulation of CLVR and ALF swards appeared to decrease, limiting the herbage mass in the legume pastures compared with 56N and 112N. Carrying capacity of CLVR and ALF swards was greater than fertilised bermudagrass in the spring and early summer, but did not differ from fertilised swards in the late summer. The N benefit of including legumes in bermudagrass swards can alleviate the reliance on synthetic N fertilisation with little overall effect on pasture carrying capacity.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Carmelo Peter Bonsignore

The phenology ofCapnodis tenebrionisadults was presented with reference to two different climate conditions. In a temperate moderate-warm climate, adult density showed two separate peaks during the year: one in early summer of the overwintering generation and one with beetles emerging in the late summer. In a warmer semiarid climate, the overwintering adults and the new generation overlapped during summer with a continuous increase of adult density. The difference in the average annual temperature between areas during the study period was almost3∘C, and, in the warmer area, the new generation ofC. tenebrionisemerged at least one month earlier. To make a prediction of adult presence, a model utilizing degree-days was developed from data collected over a five-year period. Models obtained from equations (Logistic 4-parameter,y(x)=yo+a/(1+(x/xo)b)) of each year were developed to describe the relationship between degree-day accumulation (with a minimal threshold activity temperature of14.21∘Ccalculated in the laboratory) and the cumulative percentage of adult presence. According to the overall model, the 50% of overwintering beetles occurred at 726 degree-days (Biofix: 1st March) and the emerging beetles occurred at 801 degree-days (Biofix: 1st July). The results show that a change in temperature is an important aspect that highlights the adaptability of this species.


2015 ◽  
Vol 148 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Jonathon R. Newman ◽  
Diane Wagner ◽  
Patricia Doak

AbstractFor quaking aspen (Populus tremuloides Michaux; Salicaceae) the rate of extrafloral (EF) sugar secretion is increased by defoliation and decreased by drought. Although wholesale blocking of EF nectar has been shown to reduce ant (Hymenoptera: Formicidae) visitation to aspen, the effect of more subtle and realistic variations in nectar availability on ant recruitment is unknown. Working in Alaskan boreal forest (United States of America), we reduced and supplemented EF nectar availability on potted aspen ramets of three genotypes and surveyed visitation by free-living Formica fusca (Linnaeus) (Hymenoptera: Formicidae). Ants were more responsive to a subtle increase in sugar availability than to a decrease. While nectar reduction had no effect on ant visitation, nectar supplementation increased ant visitation to one aspen genotype by 70% during an early summer trial. Average ant visitation to different aspen genotypes varied during the late summer, indicating that aspen genotype can influence attractiveness to ants. We conclude that natural induction of EF secretion in response to herbivory may benefit aspen through improved ant recruitment, though the response is dependent on aspen genotype and time of year. Differences among aspen genets in attractiveness to ants could influence the relative success of genotypes, especially in settings in which aspen regenerates from seed.


2017 ◽  
Vol 14 (5) ◽  
pp. 1165-1179 ◽  
Author(s):  
Diana Zúñiga ◽  
Celia Santos ◽  
María Froján ◽  
Emilia Salgueiro ◽  
Marta M. Rufino ◽  
...  

Abstract. The objective of the current work is to improve our understanding of how water column diatom's abundance and assemblage composition is seasonally transferred from the photic zone to seafloor sediments. To address this, we used a dataset derived from water column, sediment trap and surface sediment samples recovered in the NW Iberian coastal upwelling system. Diatom fluxes (2.2 (±5.6) 106 valves m−2 d−1) represented the majority of the siliceous microorganisms sinking out from the photic zone during all studied years and showed seasonal variability. Contrasting results between water column and sediment trap diatom abundances were found during downwelling periods, as shown by the unexpectedly high diatom export signals when diatom-derived primary production achieved their minimum levels. They were principally related to surface sediment remobilization and intense Minho and Douro river discharge that constitute an additional source of particulate matter to the inner continental shelf. In fact, contributions of allochthonous particles to the sinking material were confirmed by the significant increase of both benthic and freshwater diatoms in the sediment trap assemblage. In contrast, we found that most of the living diatom species blooming during highly productive upwelling periods were dissolved during sinking, and only those resistant to dissolution and the Chaetoceros and Leptocylindrus spp. resting spores were susceptible to being exported and buried. Furthermore, Chaetoceros spp. dominate during spring–early summer, when persistent northerly winds lead to the upwelling of nutrient-rich waters on the shelf, while Leptocylindrus spp. appear associated with late-summer upwelling relaxation, characterized by water column stratification and nutrient depletion. These findings evidence that the contributions of these diatom genera to the sediment's total marine diatom assemblage should allow for the reconstruction of different past upwelling regimes.


2012 ◽  
Vol 64 (2) ◽  
pp. 585-595 ◽  
Author(s):  
Jelena Rakocevic

Phytoplankton seasonal succession and spatial heterogeneity were studied in Lake Skadar from February to December 2004. A total of 167 taxa from 6 algal divisions were observed, with Bacillariophyta being best represented (52.8%). The general pattern of phytoplankton seasonal succession in Lake Skadar was: Bacillariophyta in the spring, Chlorophyta in early summer, Cyanobacteria and Chlorophyta in late summer and Bacillariophyta and Chlorophyta in autumn and winter. Distinct spatial heterogeneity was observed. The central, open part of the lake (pelagic zone) was characterized by dominant euplanktonic species, mostly diatoms, whereas the western and northwestern parts (more isolated and shallower) had higher abundance of greens and blue-greens and a higher percentage of resuspended benthic-epiphytic forms in the phytoplankton community. Comparison with former phytoplankton data showed distinct differences in terms of the qualitative and quantitative composition of the phytoplankton community of Lake Skadar, which indicates lake deterioration.


Author(s):  
Tatyana Aleksandrovna Khlyzova

Satyr fauna of the Southern trans-Urals is represented by 24 species, 2 of which - P. afra and E. medusa - are included in the Red Book of the Kurgan region as species of vanishing number and range. In terms of the wintering phases of satyrs of the Kurgan region, they are possible to be divided into 2 ecological groups: wintering caterpillars (19 species) and wintering pupae (2 species). The hibernating phases of C. hero , P. afra and C. persephone haven’t been identified. Among satyrs divided by the wideness of trophic specialization of caterpillars there exist broad oligophages and broad polyphages. According to the flight terms of imago satyrs of the Southern trans-Urals, they can be divided into 3 phenological groups: early-summer (6 species), summer (15 species) and late-summer (1 species). Satyr fauna in the region generally can be called forest-steppe. According to the peculiarities of the passage of the main parts of the areas, the satyrs can be divided into 3 groups. The first group unites 4 species that are widespread in the northern and southern forest-steppe, the herbage-grass-turf-grass steppe. The second group includes 16 species that occur only in the forest-steppe zone. The third group consists of 4 species, whose most favorable habitats are located in the herbage-turf-grass steppe. According to the landscape-biotope confinement, regional satyrs can be divided into 4 ecological groups: inhabitants of pine-small-leaf forests, inhabitants of the small forest - campestral landscape, inhabitants of steppes and steppe areas, eurybionts. The fauna of glades of pine-small-leaf forests is mostly rich in species. The generality of the species composition of the satyrs of the small forest - campestral and steppe landscapes reaches 53%. First of all, this is due to the quick spread of cereals in these landscapes, which are fodder plants for caterpillars of most species of this family.


ZooKeys ◽  
2016 ◽  
Vol 633 ◽  
pp. 1-93 ◽  
Author(s):  
Jose Fernandez-Triana ◽  
Caroline Boudreault ◽  
Joel Buffam ◽  
Ronald Maclean

Microgastrinae wasps (Hymenoptera, Braconidae) from the city of Ottawa and its surroundings (a 50-km radius circle, ~7,800 km2) were studied based on 1,928 specimens collected between 1894 and 2010, and housed in the Canadian National Collection of Insects. A total of 158 species from 21 genera were identified, which is by far the highest number of species ever recorded for a locality in North America. An annotated checklist of species is provided.Choerasparasitellae(Bouché, 1834) andPholetesornanus(Reinhard, 1880) are recorded for the first time in the Nearctic (previously only known from the Palearctic region),Cotesiadepressa(Viereck, 1912) is recorded for the first time in Canada (previously only known from the United States), andCotesiahemileucae(Riley, 1881) andProtapantelesphlyctaeniae(Muesebeck, 1929) are recorded for the first time in the province of Ontario. In Ottawa the most diverse genera areCotesia,Apanteles,Microplitis,Pholetesor,Microgaster, andDolichogenidea, altogether comprising 77% of the species found in the area. A total of 73 species (46%) were represented by only one or two specimens, suggesting that the inventory for Ottawa is still relatively incomplete. Seasonal distribution showed several peaks of activity, in spring, summer, and early fall. That general pattern varied for individual species, with some showing a single peak of abundance either in the summer or towards the end of the season, others species attaining two peaks, in late spring and late summer, or in early summer and early fall, and yet others attaining up to three different peaks, in spring, summer and fall. At least 72 of the Microgastrinae species from Ottawa have been previously associated with 554 species of Lepidoptera as hosts – but those historical literature records are not always reliable and in many cases are based on data from areas beyond Ottawa. Thus, our knowledge of the associations between the 158 species of microgastrine parasitoids and the caterpillars of the 2,064 species of Lepidoptera recorded from Ottawa is still very incomplete.


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