Article Figures & Tables
Figures
- Fig. 1.
Experimental time line. EPO, erythropoietin.
- Fig. 2.
Effects of avian EPO and anti-EPO on hematocrit (Hct) and hemoglobin (Hb). Hct (A) and Hb (B) data are least-squares means±s.e.m. Anti-EPO, n=10; EPO, n=10; vehicle, n=11. Linear mixed effect model (e.g. Hct∼Treatment*Time+Body mass).
- Fig. 3.
Effects of EPO and anti-EPO on the number of strikes, flight duration, cost of transport and power. (A) Change in the number of strikes in the first 30 min of flight (ΔStrikes30). (B) Change in the number of strikes in the first 105 min of flight (ΔStrikes105). (C) Change in flight duration (ΔDuration). (D) Change in cost of transport (ΔCOT). (E) Change in power (ΔPower). Data are least-squares means±s.e.m. Anti-EPO, n=8; EPO, n=7; vehicle, n=7. General linear model (e.g. ΔStrikes30∼Treatment). *P<0.05; NS, not significant.
- Fig. 4.
Effects of EPO and anti-EPO on altitude attained and flight duration at altitude. Altitude (A) and altitude duration (B) data are least-squares means±s.e.m. For A: anti-EPO, n=6; EPO, n=6; vehicle, n=6; for B: anti-EPO, n=6; EPO, n=1; vehicle, n=4. Kruskal–Wallis test (e.g. Altitude∼Treatment). Note: there are no error bars associated with the EPO group in B because only one EPO-dosed bird attained 3000 m, when altitude duration was quantified. *P<0.05; **P<0.01; NS, not significant.
- Fig. 5.
Effects of exercise at high altitude on Hct, glucose, antioxidant capacity (OXY) and reactive oxygen metabolites (dROMs). Hct (A), glucose (B), OXY (C) and dROMs (D) data are least-squares means±s.e.m. Anti-EPO, n=6; EPO, n=6; vehicle, n=6. Treatments groups were pooled for A–C. In A, Altitude refers to birds that were flown at low altitude during pre-treatment and high altitude during post-treatment; End refers to birds that were flown at low altitude during both pre- and post-treatment. Linear mixed effect model (e.g. Hct∼Treatment*Time+Body mass). *P<0.05; **P<0.01; NS, not significant.
- Fig. 6.
Hypothetical post hoc rationale for the effects of anti-EPO on flight performance at low and high altitude. In the low-altitude condition, anti-EPO birds had lower performance as a result of the lower than optimal Hct values and consequently lower oxygen carrying capacity, but in the high-altitude condition they had higher flight performance because their initially low Hct was closer to a new ‘optimal Hct’ for exercise as a result of lower blood viscosity, at least over the short period measured in our study.
Article navigation
Related articles
Cited by...
More in this TOC section
Similar articles
Other journals from The Company of Biologists
Meet the Editors at SICB Virtual 2021
Reserve your place to join some of the journal editors, including Editor-in-Chief Craig Franklin, at our Meet the Editor session on 17 February at 2pm (EST). Don’t forget to view our SICB Subject Collection, featuring relevant JEB papers relating to some of the symposia sessions.
2020 at The Company of Biologists
Despite 2020's challenges, we were able to bring a number of long-term projects and new ventures to fruition. As we enter a new year, join us as we reflect on the triumphs of the last 12 months.
The Big Biology podcast
JEB author Christine Cooper talks to Big Biology about her research. In this fascinating JEB sponsored podcast she tells us how tough zebra finches adjust their physiology to cope with extreme climate events.
Developmental and reproductive physiology of small mammals at high altitude
Cayleih Robertson and Kathryn Wilsterman focus on high-altitude populations of the North American deer mouse in their review of the challenges and evolutionary innovations of pregnant and nursing small mammals at high altitude.
Read & Publish participation extends worldwide
“Being able to publish Open Access articles free of charge means that my article gets maximum exposure and has maximum impact, and that all my peers can read it regardless of the agreements that their universities have with publishers.”
Professor Roi Holzman (Tel Aviv University) shares his experience of publishing Open Access as part of our growing Read & Publish initiative. We now have over 60 institutions in 12 countries taking part – find out more and view our full list of participating institutions.