scholarly journals Effect of predation risk and ectoparasitic louse flies on physiological stress condition of the red-tailed tropicbird (Phaethon rubricauda) from Rapa Nui and Salas & Gómez islands

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9088
Author(s):  
Nicolas Luna ◽  
Andrea I. Varela ◽  
Guillermo Luna-Jorquera ◽  
Katherina Brokordt

Background Introduced predators at seabird colonies and parasites may have lethal and/or sub-lethal consequences for bird populations. We assessed the potential sub-lethal negative effects of these stressors in a native seabird listed as vulnerable in its south-eastern pacific distribution. This study was conducted in two red-tailed tropicbird (Phaethon rubricauda) colonies, one located in Rapa Nui Island, which is threatened by the presence of introduced predators, and the other located in Salas & Gómez Island, which has no introduced predators, but birds are infested by ectoparasitic louse flies. Methods The effects on physiological stress traits of both, predation risk on different nest types (protected and exposed) on Rapa Nui, and different levels of louse flies’ parasitic loads on Salas & Gómez were studied. Three variables were analyzed: the heterophil/lymphocyte (H/L) ratio, the transcriptional levels of mRNA HSP70 in blood, and the body condition. These stress indicators and leukocyte counts were compared between colonies. Results No significant differences were found in any stress indicator between different nest types within Rapa Nui, showing that the effect of predator’s presence was the same for adults nesting in both, protected and exposed nests. No significant correlation was found between louse flies’ parasitic loads and any stress indicators in the birds of Salas & Gómez. Also, there was no difference in any stress indicator between islands. However, a significant opposite trend between islands was found in the eosinophil, lymphocyte, and monocyte counts when related to body condition. Conclusions We found a lack of significant differentiation in all the stress level indicators assessed within and between islands. The presence of louse flies in Salas & Gómez vs. the absence of this parasite at Rapa Nui may be the cause for the significant difference in the trend of eosinophil, lymphocyte and monocyte counts between the islands. However, further studies are necessary to elucidate the reason for this difference and to better investigate the lethal effects of introduced predators on the Rapa Nui colony to evaluate appropriate conservation measures for this native seabird.

2021 ◽  
Vol 11 (6-S) ◽  
pp. 26-32
Author(s):  
Nihad Elsadig Babiker ◽  
Raheeg Mubark Anwer

Background: Aerobic exercise induces physiological stress on the body and brings changes in hematological parameters. This study aimed to determine the effect of playing football as an exercise on the total white blood cell count, absolute Neutrophil, lymphocyte and Platelet counts among Sudanese football players. Material and method:  This was a descriptive case control study, done on a number of football players in Khartoum state, Sudan and conducted within the period from August 2021 to October 2021. Three ml of venous blood samples had been collected from every participant in the study, parameters had been measured and calculated using blood cells counter (Sysmex KX-21N).                                                           Results: When compared the TWBCs, Absolute Neutrophil, Lymphocytes and platelet counts between cases and control there was a significant differences with (P ≤0.05). Also there was a significant difference in the case group before and after one hour of exercise with (P =0.00), and in significant differences between different age groups with (P ≥0.05). Conclusion: Playing football for 1 hour cause a significant increase in the TWBCs, absolute Neutrophils, absolute Lymphocytes and Platelets counts. Age variation has no effect on the measured parameters Keywords: Football, TWBCs, Neutrophils, Lymphocytes and Platelets.


2019 ◽  
Vol 97 (1) ◽  
pp. 50-56
Author(s):  
C.L. Gable ◽  
T.J. Underwood ◽  
G.P. Setliff

House Wrens (Troglodytes aedon Vieillot, 1809) regularly add spider egg cases (Arachnida: Araneae) to their nests, which may be an example of heterospecific cleaning. This behavior involves one animal employing another to remove parasites from their nests. In House Wren nests, juvenile spiders hatching from egg cases may facilitate the reduction of mites that feed on nestlings. We tested this ectoparasite reduction hypothesis by monitoring House Wren nests for spider egg cases and by collecting completed nests to compare the number of spider egg cases and Dermanyssus hirundinis (Hermann, 1804) mites. No significant relationship was found between the number of spider egg cases and number of D. hirundinis mites in nests. We also found no significant relationship between the number of D. hirundinis mites in nests and the body condition of nestlings. Finally, no significant difference was found between the number of D. hirundinis mites in early versus late season nests, but significantly more spider egg cases were added to late season nests. Of a subsample of spider egg cases dissected, we found that 28% contained spider eggs or embryos. We also identified three species of juvenile spiders from House Wren nests using DNA barcoding. Overall, we found no evidence that spider egg cases reduce the number of D. hirundinis mites or engender better quality offspring in House Wren nests.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 467-468
Author(s):  
Fernanda F Santos ◽  
Luciano Brochine ◽  
Vanderlei Benetel Junior ◽  
Maria Laura R Coelho ◽  
Augusto H Gameiro ◽  
...  

Abstract The objective of this study was to evaluate the milk production, body weight, and body condition score (BCS) of ewes fed with different energy levels. Seventy-one ewes were used and distributed in three treatments according to the metabolizable energy (ME, Mcal/kg) levels in the diet: CTL = according to the NRC (2007) recommendation for each stage (gestation and lactation); PLUS = CTL plus 10% of ME per kilogram of dry matter; LESS = CTL less 10% ME per kilogram of dry matter. Body weight and body condition score were evaluated a week before the expected date of parturition, a week after giving birth, and at weaning (60 days). Dairy production was evaluated at 20, 30, 40, 50 and 60 days after giving birth by the indirect method of the two weighing. The experimental design was analyzed as randomized complete blocks. There were no differences on milk production during almost all the lactation curve. Only on day 50 (P = 0.051), CTL was still at peak, while LESS and PLUS had already decreased their production. However, at 60 days, all treatments were already with low production, justifying weaning in this period. Results of weight and BCS showed a significant difference in all periods evaluates. Ewes in the PLUS diet had greater BW and BCS. The BCS before giving birth is expected to be over 3.5 and treatment LESS was the only one that did not achieve this score (2.66, 3.37, 3.83 for LESS, CTL, and PLUS, respectively). At weaning, ewes fed PLUS and CTL had BCS of 3.51 and 2.92, respectively, but treatment LESS had only 1.82. That is prejudicial for the next mating seasonal and this animal. We concluded that LESS diet interfered with the body reserves of sheep.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Frédéric Laberge ◽  
Irene Yin-Liao ◽  
Nicholas J Bernier

Abstract The development of chronic stress indicators for fish is of great interest, but appropriate non-invasive methods are lagging those used in terrestrial vertebrates. Here, we explore the possibility that levels of the stress hormone cortisol in scales could be used as a chronic stress indicator. Three experiments were conducted to assess the temporal profiles of cortisol rise and fall in plasma and scales of goldfish (Carassius auratus) in response to stressors of varying intensity and duration. Results show that a single acute air emersion stressor does not influence scale cortisol content. In contrast, relative to plasma levels, the fall in scale cortisol content following a high-dose cortisol implant is delayed by at least 8 days, and the rise and fall in scale cortisol content in response to unpredictable chronic stress are delayed by at least 7 days. Also, scale cortisol content is spatially heterogeneous across the body surface of goldfish. Overall, since high and sustained circulating cortisol levels are needed to influence scale cortisol content and the rates of cortisol accumulation and clearance are much slower in scales than in plasma, our results show that scales can provide an integrated measure of cortisol production and serve as a chronic stress indicator.


2009 ◽  
pp. 69-73
Author(s):  
Edit Mikó Józsefné Jónás ◽  
Imre Mucsi ◽  
István Komlósi

The authors examined the data of 2767 trial milkings andthe months Body Condition Scores of 479 Holstein dairy cows. The condition loss was significant between the 30-60th days. The improvement of BCS begins only after the 120th day. The change in the milk protein and milk fat content were close after the condition changing. In each period of the lactation the closeness of the relationship among the condition, the milk quantity and the milk composition were different. In the aspect of the milk quantity the most significant difference was between the 2.5 and 4 BCS cows (6.68 kg) in the last period of the lactation.


2016 ◽  
Vol 72 (12) ◽  
pp. 755-759 ◽  
Author(s):  
Monika Bryl ◽  
Hanna Bis-Wencel ◽  
Brygida Ślaska ◽  
Bożena Nowakowicz-Dębek ◽  
Zbigniew Bełkot ◽  
...  

The aim of this study was to assess the impact of the leptin concentration and body weight of mink females on the birth parameters of their kits. Blood samples were collected 3 times during preparation for reproduction, 7±2 days before mating. Total leptin concentration in serum was measured using commercial RIA kits (Millipore, St. Charles, Missouri USA). Research was conducted on 20 clinically healthy scanbrown female minks (Neovison Vison) aged 2-3 years. To evaluate their body condition, the females were divided into two groups based on the BCS scoring system. In the first group, referred to as BCS 2, lean females were included, and the second group (BCS 4) consisted of obese females. In mink dams belonging to BCS 2, the average leptin values were one-fourth of those in the BCS 4 group. The results obtained indicate the influence of the body mass of minks during preparation for reproduction on serum leptin concentration. The results of the Mann-Whitney U test showed a statistically significant difference between weights and leptin concentrations in groups BCS 2 and BCS 4. Among the other traits, such differences were not found. The analysis of results obtained in the two mink groups did not reveal a clear relationship between leptin in the serum of mothers before mating and the birth parameters of their kits.


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