Climate change and cutaneous water loss of birds

Williams, Joseph B.; Muñoz‐Garcia, Agustí; Champagne, Alex M.

doi:10.1242/jeb.054395

Cited by 26 publications

(10 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Weathers and Caccamise (1978) investigated seasonal changes in the thermal physiology of Monk Parakeets (Myiopsitta monachus) and found that TEWL at T a ≈ 20 -30 °C was lower in winter, a result the authors related to reduced water availability in winter. Several workers have found that birds can significantly augment CEWL through changes in water vapour diffusion resistance via alterations in the composition of lipids in the stratum corneum (Haugen et al 2003;Muñoz-Garcia et al 2008;Williams et al 2012). Arad et al (1987), for example, observed an overall reduction in TEWL in dehydrated pigeons at T a ≈ 45 °C due to reductions in CEWL.…”

Section: Evaporative Water Lossmentioning

confidence: 99%

Avian thermoregulation in the heat: efficient evaporative cooling in two southern African nightjars

et al. 2016

View full text Add to dashboard Cite

Nightjars represent a model taxon for investigating physiological limits of heat tolerance because of their habit of roosting and nesting in sunlit sites during the heat of the day. We investigated the physiological responses of Rufous-cheeked nightjars (Caprimulgus rufigena) and Freckled nightjars (Caprimulgus tristigma) to high air temperatures (T ) by measuring body temperature (T), resting metabolic rate (RMR) and total evaporative water loss (TEWL) at T ranging from 10 to 56 °C. Both species became hyperthermic at T > T . Lower critical limits of thermoneutrality occurred at T between 35 and 37 °C, whereas we detected no clear upper critical limits of thermoneutrality. Between T ≈ 37.0 and 39.9 °C, rates of TEWL increased rapidly with T. At T ≥ 40 °C, fractional increases in mass-specific TEWL rates were 78-106% of allometric predictions. Increasing evaporative heat dissipation incurred only small metabolic costs, with the RMR of neither species ever increasing by more than 20% above thermoneutral values. Consequently, both species displayed extremely efficient evaporative cooling; maximum evaporative heat dissipation was equivalent to 515% of metabolic heat production (MHP) at T ≈ 56 °C in C. rufigena and 452% of MHP at T ≈ 52 °C in C. tristigma. Our data reiterate that caprimulgids have evolved an efficient mechanism of evaporative cooling via gular fluttering, which minimizes metabolic heat production at high T and reduces total heat loads. This likely aids in reducing TEWL rates and helps nightjars cope with some of the most thermally challenging conditions experienced by any bird.

show abstract

Section: Evaporative Water Lossmentioning

confidence: 99%

Avian thermoregulation in the heat: efficient evaporative cooling in two southern African nightjars

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Ecological aspects of thermoregulatory performance in doves and quail Williams et al (2012) has suggested that desert birds need the capacity to increase EWL during periods of extreme heat in order to maintain sub-lethal T b , while minimizing dehydration over the long term. In this study, we found that the thermoregulatory performance and water balance of mourning and white-winged doves differed greatly from that of the sympatric Gambel's quail.…”

Section: Body Temperature and Heat Tolerance Limitmentioning

confidence: 99%

Avian thermoregulation in the heat: resting metabolism, evaporative cooling and heat tolerance in Sonoran Desert doves and quail

Smith

O'Neill

Gerson

et al. 2015

Journal of Experimental Biology

View full text Add to dashboard Cite

Birds in subtropical deserts face significant thermoregulatory challenges because environmental temperatures regularly exceed avian body temperature. To understand the differing susceptibility of desert birds to increasing temperatures, we examined thermoregulatory performance and estimated heat tolerance limits (HTLs) for three Sonoran Desert nesting bird species -Gambel's quail, mourning doves and white-winged doves. Using flow-through respirometry we measured daytime resting metabolism, evaporative water loss and real-time body temperature at air temperatures (T air ) from 30°C to 66°C. We found marked increases in resting metabolism at the upper critical temperature (T uc ), which was significantly lower in the quail (T air =41.1°C) than in both dove species (T air =45.9-46.5°C). Gambel's quail maintained low resting metabolic rates and low rates of evaporative water loss at their T uc (0.71 W and 1.20 g H 2 O h −1 , respectively), but were more sensitive to increasing air temperature, reaching their HTL at T air of 52°C. Mourning doves and white-winged doves maintained low resting metabolic rates (0.66 and 0.94 W), but higher rates of evaporative water loss (1.91 and 2.99 g H 2 O h −1 ) at their T uc and reached their HTL at T air of 58-60°C. Mass-specific evaporative water loss in white-winged doves (147 g) and mourning doves (104 g) was 45% and 30% greater, respectively, than the rate observed in Gambel's quail (161 g) at T air of 48°C. Higher rates of evaporation and higher T uc made the doves exceptionally heat tolerant, allowing them to maintain body temperatures at least 14°C below air temperatures as high as 60°C (140°F).

show abstract

“…Estimates calculated from the difference between water gain and cloacal fluid output have also yielded high EWL values for sunbirds and honeyeaters (Collins, 1981;Fleming and Nicolson, 2003;Lotz and Nicolson, 1999). Nothing is known of the partitioning of evaporation between cutaneous and respiratory routes, but cutaneous EWL is influenced by hydration state in other birds (Williams et al, 2012). Unfortunately, the high excretory output of avian nectarivores complicates the direct measurement of EWL, and the pharmacokinetic method has proved unreliable for its estimation (Purchase et al, 2013b).…”

Section: The Potential Role Of Evaporationmentioning

confidence: 99%

Drinking problems on a ‘simple’ diet: physiological convergence in nectar-feeding birds

Nicolson

Fleming

2014

Journal of Experimental Biology

View full text Add to dashboard Cite

Regulation of energy and water are by necessity closely linked in avian nectarivores, because the easily available sugars in nectar are accompanied by an excess of water but few electrolytes. In general, there is convergence in morphology and physiology between three main lineages of avian nectarivores that have evolved on different continents -the hummingbirds, sunbirds and honeyeaters. These birds show similar dependence of sugar preferences on nectar concentration, high intestinal sucrase activity and rapid absorption of hexoses via mediated and paracellular routes. There are differences, however, in how these lineages deal with energy challenges, as well as processing the large volumes of preformed water ingested in nectar. While hummingbirds rely on varying renal water reabsorption, the passerine nectarivores modulate intestinal water absorption during water loading, thus reducing the impact on the kidneys. Hummingbirds do not generally cope with salt loading, and have renal morphology consistent with their ability to produce copious dilute urine; by contrast, as well as being able to deal with dilute diets, honeyeaters and sunbirds are more than capable of dealing with moderately high levels of added electrolytes. And finally, in response to energy challenge, hummingbirds readily resort to torpor, while the passerines show renal and digestive responses that allow them to deal with short-term fasts and rapidly restore energy balance without using torpor. In conclusion, sunbirds and honeyeaters demonstrate a degree of physiological plasticity in dealing with digestive and renal challenges of their nectar diet, while hummingbirds appear to be more constrained by this diet.

show abstract

Climate change and cutaneous water loss of birds

Cited by 26 publications

References 69 publications

Avian thermoregulation in the heat: efficient evaporative cooling in two southern African nightjars

Avian thermoregulation in the heat: efficient evaporative cooling in two southern African nightjars

Avian thermoregulation in the heat: resting metabolism, evaporative cooling and heat tolerance in Sonoran Desert doves and quail

Drinking problems on a ‘simple’ diet: physiological convergence in nectar-feeding birds

Contact Info

Product

Resources

About