scholarly journals Common Loon, Gavia immer, Breeding Success in Relation to Lake pH and Lake Size Over 25 Years

2009 ◽  
Vol 123 (2) ◽  
pp. 146 ◽  
Author(s):  
Robert Alvo
Keyword(s):  
Breeding Success ◽  
Low Ph ◽  
Single Pair ◽  
Gavia Immer ◽  
Common Loon ◽  
Sulphur Deposition ◽  
Acidic Lakes ◽  
Ph Range ◽  
Lake Size ◽  
Critical Ph

I monitored Common Loon (Gavia immer) breeding success in relation to lake pH (range 4.0–8.5) between 1982 and 2007 on 38 single-pair lakes (5–88 ha) in the Sudbury, Ontario, area. No chicks fledged on lakes with pH < 4.4. Chicks fledged on lakes with slightly higher pH only if the lakes were relatively large. Acidic lakes became less acidic as sulphur dioxide emissions from the Sudbury smelters and sulphur deposition from other long-range sources decreased. Two lakes initially too acidic to support successful loon reproduction eventually had successful reproduction. One loon pair used two large acidic lakes (combined area 140 ha) connected by shallow rapids, and one of the adults made extremely long dives (average = 99 s) while foraging for the chicks. One chick died on that lake after apparently ingesting a very large food item; the lack of smaller items was attributed to the lake’s acidity. My results suggest that a shortage of food for chicks is the main reason why low pH reduces breeding success. I suggest that, for lakes without high levels of dissolved organic carbon (DOC), the critical pH for loon breeding success is approximately 4.3, and the suboptimal pH is approximately 4.4–6.0.

The breeding success of common loons (Gavia immer) in relation to alkalinity and other lake characteristics in Ontario

1988 ◽  
Vol 66 (3) ◽  
pp. 746-752 ◽  
Author(s):  
Robert Alvo ◽  
David J. T. Hussell ◽  
Michael Berrill
Keyword(s):  
Breeding Success ◽  
Benthic Algae ◽  
Gavia Immer ◽  
Acidic Lake ◽  
Acidic Lakes ◽  
Common Loons ◽  
Breeding Attempt ◽  
High Alkalinity ◽  
Highly Correlated ◽  
High Level

We examined the breeding success of common loons (Gavia immer) and made observations of loons feeding their young on small lakes (5.3–75 ha) with different alkalinities (−73 to 1804 μequiv./L) near Sudbury, Ontario. Alkalinity, pH, and conductivity were highly correlated with each other. There was a significant positive relationship between successful breeding and alkalinity on 68 lakes surveyed in 1982. Discriminant analysis showed that alkalinity, area, and colour of the lake contributed significantly to discrimination among lakes with successful, unsuccessful, and no breeding attempts. Lack of a breeding attempt tended to be associated with small, brown, low-alkalinity lakes, and successful breeding with large, clear, high-alkalinity lakes. For lakes with breeding attempts in 1982–1984, alkalinity (all years), depth (1983), and area (1984) provided significant discrimination between unsuccessful lakes and those on which young were raised. Unsuccessful breeding resulted primarily from brood mortalities on acidic lakes. Adult loons were more successful at securing fish on high-alkalinity lakes than on low-alkalinity lakes, and this may reflect differences in fish densities. A pair of loons attempting to raise a chick on a fishless, acidic lake fed the chick benthic algae and possibly benthic invertebrates, but flew to other lakes to feed themselves. We suggest that the high level of brood mortalities on acidic lakes resulted from a shortage of suitable food for the young.

Acid–base and electrolyte responses to low pH maintained by phosphate–citrate buffers in the bathing medium of the larval salamander Ambystoma tigrinum

1988 ◽  
Vol 66 (11) ◽  
pp. 2383-2389 ◽  
Author(s):  
Marie L. DeRuyter ◽  
Daniel F. Stiffler
Keyword(s):  
Low Ph ◽  
Blood Analysis ◽  
Ambystoma Tigrinum ◽  
Initial Increase ◽  
Bathing Medium ◽  
Arterial Ph ◽  
Ph Range ◽  
External Ph ◽  
Critical Ph ◽  
Pulmonary Excretion

Larval Ambystoma tigrinum were exposed to an external pH of 3.5 to 7.5 using phosphate – citrate buffers in the bathing medium. Blood analysis of cannulated Ambystoma tigrinum at pH 5.5, 4.5, and 3.5 indicated their ability to maintain relatively stable arterial pH at the two higher values; however, at pH 3.5, the blood pH diminished over the 12-h period before death. The greater stability of arterial pH at higher external pH is partially due to a reversal of an initial increase in arterial [Formula: see text]. This may not be due entirely to pulmonary excretion of CO2 as it also occurred in animals that were forced to exchange gases solely across the skin – gill unit by being deprived of access to an air space. This result suggests increased skin – gill perfusion and (or) ventilation as a mechanism for lowering arterial [Formula: see text]. Sodium transport across the skin of A. tigrinum was measured over a buffered pH range of 3.5 to 7.5. Na+ influx decreased from 1.0 ± 0.1 μequiv. 10 g−1 h−1 (mean ± SEM) at pH 7.0 to 0.1 ± 0.1 μequiv. 10 g−1 h−1 at pH 3.5. Na+ efflux increased to 38.1 ± 8.7 μequiv. 10 g−1 h−1 from 4.1 ± 0.9 μequiv. 10 g−1 h−1 as pH declined from 7.0 to 3.5. Calcium added to the buffer at pH 4.5 decreased Na+ efflux at that pH. Na+ fluxes measured in nonbuffered, low-pH solutions revealed qualitatively similar patterns with lower efflux rates and lower critical pH values.

Common Loon (Gavia immer)

2020 ◽  
Author(s):  
David C. Evers ◽  
James D. Paruk ◽  
Judith W. McIntyre ◽  
Jack F. Barr
Keyword(s):  
Gavia Immer ◽  
Common Loon

Reproduction of selected Mollusca in some low alkalinity lakes in south-central Ontario

1985 ◽  
Vol 63 (3) ◽  
pp. 511-515 ◽  
Author(s):  
M. R. Servos ◽  
J. B. Rooke ◽  
G. L. Mackie
Keyword(s):  
Low Ph ◽  
Acidic Lakes ◽  
Recruitment Failure ◽  
South Central ◽  
Summer Growth ◽  
Growth And Reproduction

Growth and reproduction of several species of molluscs were examined in six low alkalinity lakes in south-central Ontario. Amnicola limosa (Gastropoda: Amnicolidae) held through the summer of 1982 in cages in acidic lakes (pH 5.78–5.89) grew slower (p < 0.01) than those held in less acidic lakes (pH 6.03–6.84). The development of eggs of A. limosa in the laboratory was impaired at and below pH 5.0 and delayed at pH 5.5 relative to pH 6.0. Hence the recruitment failure and elimination of A. limosa that has been reported in acidifying lakes may be caused by reduced summer growth and (or) impaired development of the eggs. In contrast, Pisidium spp. (Bivalvia: Pisidiidae) do not appear to be adversely affected by low pH in the lakes in this study (pH 5.78–6.84). Caged Pisidium equilaterale did not have reduced growth in the acidic lakes during the summer of 1982. Pisidium casertanum and Pisidium ferrugineum had only slightly reduced (p < 0.05) fecundity (number of extramarsupial larvae per adult) in acidic lakes relative to less acidic lakes sampled in 1980.

Juvenile survival in common loons Gavia immer: effects of natal lake size and pH

2012 ◽  
Vol 43 (3) ◽  
pp. 280-288 ◽  
Author(s):  
Walter H. Piper ◽  
Jason S. Grear ◽  
Michael W. Meyer
Keyword(s):  
Juvenile Survival ◽  
Gavia Immer ◽  
Common Loons ◽  
Lake Size

scholarly journals THE ABSORPTION SPECTRUM OF VISUAL PURPLE

1938 ◽  
Vol 21 (4) ◽  
pp. 411-430 ◽  
Author(s):  
Aurin M. Chase ◽  
Charles Haig
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Light Transmission ◽  
Low Ph ◽  
The Other ◽  
Distilled Water ◽  
Color Purity ◽  
Chemical Combination ◽  
Ph Range ◽  
Sensitive Group

The absorption spectra of visual purple solutions extracted by various means were measured with a sensitive photoelectric spectrophotometer and compared with the classical visual purple absorption spectrum. Hardening the retinas in alum before extraction yielded visual purple solutions of much higher light transmission in the blue and violet, probably because of the removal of light-dispersing substances. Re-extraction indicated that visual purple is more soluble in the extractive than are the other colored retinal components. However, the concentration of the extractive did not affect the color purity of the extraction but did influence the keeping power. This suggests a chemical combination between the extractive and visual purple. The pH of the extractive affected the color purity of the resulting solution. Over the pH range from 5.5 to 10.0, the visual purple color purity was greatest at the low pH. Temperature during extraction was also effective, the color purity being greater the higher the temperature, up to 40°C. Drying and subsequent re-dissolving of visual purple solutions extracted with digitalin freed the solution of some protein impurities and increased its keeping power. Dialysis against distilled water seemed to precipitate visual purple from solution irreversibly. None of the treatments described improved the symmetry of the unbleached visual purple absorption spectrum sufficiently for it to resemble the classical absorption spectrum. Therefore it is very likely that the classical absorption spectrum is that of the light-sensitive group only and that the absorption spectra of our purest unbleached visual purple solutions represent the molecule as a whole.

Common Loon (Gavia immer)

1997 ◽  
Author(s):  
Judith W. McIntyre ◽  
Jack F. Barr
Keyword(s):  
Gavia Immer ◽  
Common Loon

scholarly journals Additional Data and Perspectives on Interspecific Aggression in the Common Loon, Gavia immer

2011 ◽  
Vol 125 (1) ◽  
pp. 61
Author(s):  
Martin L. Morton ◽  
Maria E. Pereyra
Keyword(s):  
Additional Data ◽  
Gavia Immer ◽  
Common Loon ◽  
Interspecific Aggression ◽  
Aythya Americana ◽  
The Common

We witnessed the killing of a female Redhead (Aythya Americana) by a male Common Loon (Gavia immer). The wound was delivered into the abdomen from below, and death occurred because of a torn, hemorrhaging liver. This same Common Loon also threatened a female Ring-necked Duck (Aythya collaris) with ducklings. We hypothesize that interspecific aggression by loons might be energetically costly but is sometimes adaptive because it deters predators.

Sign in / Sign up

Export Citation Format

Share Document