Benefits of an anti-parasite treatment are influenced by within-brood size variation in Tree Swallows (Tachycineta bicolor)

The Auk ◽  
2020 ◽  
Vol 137 (2) ◽  
Author(s):  
Ilsa A Griebel ◽  
Russell D Dawson
Keyword(s):  
Brood Size ◽  
Herd Immunity ◽  
Relative Size ◽  
Size Variation ◽  
Underlying Mechanism ◽  
Tachycineta Bicolor ◽  
Hatching Asynchrony ◽  
Control Group ◽  
Tree Swallows ◽  
Size Hierarchy

Abstract In all animals, susceptibility to parasites can differ among individuals. Young, nest-bound birds are exposed to a diversity of nest-dwelling ectoparasites that typically feed on their blood. Within broods, hatching asynchrony creates size hierarchies that result in morphological and physiological variation among nest mates, and susceptibility to parasites also may vary predictably with this size hierarchy. Our objective was to use a broad-spectrum, anti-parasite drug, ivermectin (IVM), to treat individual nestling Tree Swallows (Tachycineta bicolor) and assess how nestling susceptibility to parasites varied both within and among broods. Broods were either assigned to an IVM group, where half of the nestlings in a brood received IVM injections and half received control injections of pure sesame oil, or to a control group, where all nestlings received oil injections. We found that the IVM treatment reduced parasite loads for broods as a whole, thereby benefiting all nestlings in IVM broods and suggesting our treatment resulted in herd immunity. Specifically, nestlings from IVM broods had higher hemoglobin concentrations, regardless of whether they received injections with IVM or oil, and greater fledging success, than nestlings from control broods. On the contrary, IVM treatment did not strongly affect nestling morphology, with only marginal effects on the growth rate of ninth primary feathers, and the effects of the treatment on 2 other morphological traits depending on temporal factors. Variation in size within broods, however, influenced the chance of an individual fledging, which increased with relative size within a brood, but only under lower parasite loads (i.e. IVM broods). By experimentally manipulating nestling susceptibility to parasites, we have demonstrated variation in nestling response to an anti-parasite treatment both within and among broods, and future studies should investigate the underlying mechanism for why certain nestlings along the brood size hierarchy are more susceptible to parasites.

The costs of reproduction in tree swallows (Tachycineta bicolor)

1991 ◽  
Vol 69 (10) ◽  
pp. 2540-2547 ◽  
Author(s):  
Nathaniel T. Wheelwright ◽  
Joanna Leary ◽  
Caragh Fitzgerald
Keyword(s):  
Life History ◽  
Clutch Size ◽  
Brood Size ◽  
Life History Theory ◽  
Tachycineta Bicolor ◽  
Laying Date ◽  
Tree Swallows ◽  
Costs Of Reproduction ◽  
Return Rates ◽  
Trade Offs

We investigated the effect of brood size on nestling growth and survival, parental survival, and future fecundity in tree swallows (Tachycineta bicolor) over a 4-year period (1987–1990) in an effort to understand whether reproductive trade-offs limit clutch size in birds. In addition to examining naturally varying brood sizes in a population on Kent Island, New Brunswick, Canada, we experimentally modified brood sizes, increasing or decreasing the reproductive burdens of females by two offspring. Unlike previous studies, broods of the same females were enlarged or reduced in up to 3 successive years in a search for evidence of cumulative costs of reproduction that might go undetected by a single brood manipulation. Neither observation nor experiment supported the existence of a trade-off between offspring quality and quantity, in contrast with the predictions of life-history theory. Nestling wing length, mass, and tarsus length were unrelated to brood size. Although differences between means were in the direction predicted, few differences were statistically significant, despite large sample sizes. Nestlings from small broods were no more likely to return as breeding adults than nestlings from large broods, but return rates of both groups were very low. Parental return rates were also independent of brood size, and there was no evidence of a negative effect of brood size on future fecundity (laying date, clutch size). Reproductive success, nestling size, and survival did not differ between treatments for females whose broods were manipulated in successive years. Within the range of brood sizes observed in this study, the life-history costs of feeding one or two additional nestlings in tree swallows appear to be slight and cannot explain observed clutch sizes. Costs not measured in this study, such as the production of eggs or postfledging parental care, may be more important in limiting clutch size in birds.

Experimentally altered plumage brightness of female tree swallows: a test of the differential allocation hypothesis

Behaviour ◽  
2016 ◽  
Vol 153 (5) ◽  
pp. 525-550 ◽  
Author(s):  
Lisha L. Berzins ◽  
Russell D. Dawson
Keyword(s):  
Parental Care ◽  
Brood Size ◽  
Tachycineta Bicolor ◽  
Differential Allocation ◽  
Tree Swallows ◽  
Agonistic Interactions ◽  
Brood Size Manipulation ◽  
Fledging Success ◽  
Female Attractiveness ◽  
Female Tree

The differential allocation hypothesis posits that individuals should invest in the current reproductive attempt according to the attractiveness of their mate, but studies of allocation by males when female traits are manipulated to be more attractive are lacking. In the current study, we experimentally enhanced and reduced the plumage brightness of female tree swallows (Tachycineta bicolor) relative to controls to examine whether males adjust investment in parental care according to female attractiveness, while simultaneously performing a brood size manipulation. Contrary to our predictions, we found no evidence that males provisioned nestlings according to the plumage brightness of females. However, we found that nestling quality and fledging success were lowest when female plumage brightness was reduced and brood size was enlarged. This may be due to the plumage brightness treatment influencing agonistic interactions with other females, and may suggest that plumage brightness is a signal assessed by females.

Influence of intraclutch egg-mass variation and hatching asynchrony on relative offspring performance within broods of an altricial bird

2006 ◽  
Vol 84 (12) ◽  
pp. 1721-1726 ◽  
Author(s):  
Pierre-Paul Bitton ◽  
Russell D. Dawson ◽  
Erin L. O’Brien
Keyword(s):  
Reproductive Success ◽  
Tachycineta Bicolor ◽  
Hatching Asynchrony ◽  
Egg Mass ◽  
Passerine Birds ◽  
Tree Swallows ◽  
Mass Variation ◽  
Offspring Performance ◽  
Asynchronous Hatching ◽  
Rates Of Growth

Rates of growth and size of nestlings at fledging have important consequences for future survival and reproductive success in many passerine birds. Within broods of altricial species, these characteristics are often influenced by size hierarchies established early in the nesting period due to hatching asynchrony and within-clutch variation in egg mass, but the concurrent effect of these factors is poorly understood. We investigated the relative influence of these variables on nestling performance within broods of tree swallows, Tachycineta bicolor (Vieillot, 1808). Nestlings that hatched earlier within nests were heavier and larger than their later-hatched siblings at 4 days of age. Similarly, earlier-hatched nestlings grew their ninth primary flight feathers faster and had longer ninth primaries just prior to fledging than did later-hatched siblings. Differences in egg mass of siblings also contributed to mass and size hierarchies at 4 days of age, but did not affect any other difference in sibling performance. We conclude that within-clutch variation in performance of offspring is determined primarily by size hierarchies resulting from asynchronous hatching. Intraclutch egg-mass variation appears to have little effect on performance of siblings and may be best explained by proximate constraints on females.

Site- and sex-level differences in adult feeding behaviour and its consequences to offspring quality in tree swallows (Tachycineta bicolor) following brood-size manipulation

2007 ◽  
Vol 85 (8) ◽  
pp. 847-854 ◽  
Author(s):  
D.R. Ardia
Keyword(s):  
New York ◽  
Brood Size ◽  
Feeding Rate ◽  
Tachycineta Bicolor ◽  
Tree Swallows ◽  
Offspring Quality ◽  
Brood Size Manipulation ◽  
Feeding Effort ◽  
Adult Feeding ◽  
Habitat Differences

In species with biparental care, males tend to invest less in offspring than do females, likely because of differences in the costs and benefits associated with parental effort. Here I test for sex differences in the response of tree swallows ( Tachycineta bicolor (Vieillot, 1808)) to a brood-size manipulation at two locations differing in food resources, Alaska and New York. I tested sex and habitat differences in how swallows responded to changes in offspring demand. At both sites, both sexes increased effort when feeding enlarged broods, although Alaskan males increased feeding less than Alaskan females. Males decreased feeding effort more to reduced broods than females, but only in Alaska. Food abundance was higher in Alaska than in New York, and Alaskan tree swallows made more feeding visits than New York tree swallows. In New York, food availability did not predict feeding rate and there was no sex difference in the response to brood manipulation. In both sites, male feeding effort was linked with nestling residual body mass, while female feeding effort was correlated with nestling growth rate. This study demonstrates that male tree swallows differ from females by being the first to reduce feeding effort under certain conditions and that male and female feeding rate affects offspring quality differently.

Laying order, hatching asynchrony and nestling body mass in Tree Swallows Tachycineta bicolor

2000 ◽  
Vol 31 (3) ◽  
pp. 329-334 ◽  
Author(s):  
Ethan D. Clotfelter ◽  
Linda A. Whittingham ◽  
Peter O. Dunn
Keyword(s):  
Body Mass ◽  
Tachycineta Bicolor ◽  
Hatching Asynchrony ◽  
Tree Swallows ◽  
Laying Order

The Quantitative Ultrastructure of the Heart Muscle of Japanese Quail by Hypergravitation, Hypodynamy and Combination

1990 ◽  
Vol 48 (3) ◽  
pp. 188-189
Author(s):  
Anton Bózner ◽  
Mikuláš Gažo ◽  
Jozef Dostál
Keyword(s):  
Japanese Quail ◽  
Heart Muscle ◽  
Relative Size ◽  
Combination Group ◽  
Control Group ◽  
Group V ◽  
Group Iii ◽  
Space Flights ◽  
Group I ◽  
Quantitative Ultrastructure

It is anticipated that Japanese quail /Coturnix coturnix japonica/ will provide animal proteins in long term space flights. Consequently this species of birds is of research interest of international space program INTERCOSMOS. In the year 1987 we reported on an experiment /2/ in which the effect of chronic acceleration of 2 G hypergravitation, the hypodynamy and the simultaneous effect of chronic acceleration and the location in the centre of the turntable of the centrifuge on the protein fractions in skeletal muscles was studied. The ultrastructure of the heart muscle was now in this experiments examined as well.Japanese quail cockerels, aged 48 days were exposed to 2 G hypergravitation /group IV/ in a 6,4 m diameter centrifuge, to hypodynamy /group III/ and their combination /group V/, respectively for 6 days / Fig.1/. The hypodynamy in group III was achieved by suspending the birds in jackets without contact the floor. The group II was located in the centre ofthe turntable of the centrifuge. The control group I. was kept under normal conditions. The quantitative ultrastructure of myocard was evaluated by the methods of Weibel/3/ - this enables to determine the number, relative size and volume of mitochondria volume of single mitochondria, defficiency of mitochondrial cristae and volume of myofibrils.

Dietary Quercetin Alleviated DSS-induced Colitis in Mice Through Several Possible Pathways by Transcriptome Analysis

2020 ◽  
Vol 21 (15) ◽  
pp. 1666-1673 ◽  
Author(s):  
Yuanyang Dong ◽  
Jiaqi Lei ◽  
Bingkun Zhang
Keyword(s):  
Antioxidant Capacity ◽  
Underlying Mechanism ◽  
Control Group ◽  
Sequencing Analysis ◽  
Colon Tissue ◽  
Beneficial Effects ◽  
Intestinal Integrity ◽  
Inflammatory Bowel ◽  
Vegetables And Fruits ◽  
Key Pathways

Background: The prevalence of inflammatory bowel disease is rapidly increasing around the world. Quercetin is a flavonoid commonly found in vegetables and fruits and has been reported to exert numerous pharmacological activities such as enhancing antioxidant capacity or suppressing inflammation. Objective: We aimed to explore whether quercetin was effective for IBD and the underlying mechanism of quercetin for the ameliorative effects on the DSS-induced colitis in mice. Methods: Thirty-six mice were randomly assigned to three treatments, including the control group (Ctr), DSS-induced colitis group (DSS) and DSS-induced colitis supplemented with 500 ppm quercetin (DQ500). Colitis was induced by DSS intake, and body weight was recorded every day. After six days administration of DSS, intestinal permeability was measured, and the liver was taken for antioxidant enzyme tests. Colonic tissue was taken for the histopathlogical score and RNA-sequencing analysis. Results: In this experiment, dietary quercetin for 500ppm alleviated the DSS-induced colitis, possibly by strengthening intestinal integrity, liver antioxidant capacity. Based on the results of the transcriptome of colon tissue, several key genes were modulated by quercetin. ERK1/2-FKBP pathway and RXR-STAT3 pathway were involved in the development of IBD, furthermore, in the down-regulation of S100a8/9, FBN2 contributed to lowering the risk of colongenesis. Conclusion: We demonstrated that dietary quercetin alleviated the DSS-induced colitis in mice. This is most likely due to its beneficial effects on intestinal integrity and modulation of several key pathways. Based on our research, quercetin was a promising candidate for IBD and its pharmaceutical effects on both IBD and colongenesis need further research.

scholarly journals Improved response of human gingival fibroblasts to titanium coated with micro-/nano-structured tantalum

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chu-nan Zhang ◽  
Lin-yi Zhou ◽  
Shu-jiao Qian ◽  
Ying-xin Gu ◽  
Jun-yu Shi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Underlying Mechanism ◽  
Cell Number ◽  
Human Gingival Fibroblasts ◽  
Superior Performance ◽  
Control Group ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Gingival Fibroblasts ◽  
Integrin Β1

Abstract Objectives This study aims to evaluate the ability of tantalum-coated titanium to improve human gingival fibroblasts’ adhesion, viability, proliferation, migration performance, and the potential molecular mechanisms. Materials and methods Titanium plates were divided into two groups: (1) no coating (Ti, control), (2) Tantalum-coated titanium (Ta-coated Ti). All samples were characterized by scanning electronic microscopy, surface roughness, and hydrophilicity. Fibroblasts’ performance were analyzed by attached cell number at 1 h, 4 h, and 24 h, morphology at 1 h and 4 h, viability at 1 day, 3 days, 5 days, and 7 days, recovery after wounding at 6 h, 12 h, and 24 h. RT-PCR, western blot were applied to detect attachment-related genes’ expression and protein synthesis at 4 h and 24 h. Student’s t test was used for statistical analysis. Results Tantalum-coated titanium demonstrates a layer of homogeneously distributed nano-grains with mean diameter of 25.98 (± 14.75) nm. It was found that after tantalum deposition, human gingival fibroblasts (HGFs) adhesion, viability, proliferation, and migration were promoted in comparison to the control group. An upregulated level of Integrin β1 and FAK signaling was also detected, which might be the underlying mechanism. Conclusion In the present study, adhesion, viability, proliferation, migration of human gingival fibroblasts are promoted on tantalum-coated titanium, upregulated integrin β1 and FAK might contribute to its superior performance, indicating tantalum coating can be applied in transmucosal part of dental implant. Clinical significance Tantalum deposition on titanium surfaces can promote human gingival fibroblast adhesion, accordingly forming a well-organized soft tissue sealing and may contribute to a successful osseointegration.

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