Ecological relationships between Common Murres, Uria aalge, and Thick-billed Murres, Uria lomvia, at the Gannet Islands, Labrador. II. Breeding success and site characteristics

1987 ◽  
Vol 65 (7) ◽  
pp. 1630-1637 ◽  
Author(s):  
T. R. Birkhead ◽  
D. N. Nettleship
Keyword(s):  
Breeding Success ◽  
Breeding Site ◽  
Uria Aalge ◽  
Uria Lomvia ◽  
Short Supply ◽  
Breeding Sites ◽  
Ecological Relationships ◽  
Site Characteristics ◽  
Common Murres ◽  
Flat Ground

At the Gannet Islands, Labrador, the proportion of Thick-billed Murres (Uria lomvia) that successfully reared a chick that left the colony was significantly lower (mean = 63%) than that of Common Murres (Uria aalge; 82%) in each of 3 years of study. The physical and social features of the breeding site were the only factors known to influence breeding success. For both murre species, breeding success increased with ledge width, and whereas most Common Murres bred on the widest ledges, relatively few Thick-billed Murres did so. The success of each species did not differ significantly on ledges of the same width. We suggest that Common and Thick-billed murres competed for breeding sites and that Common Murres obtained a disproportionate share of the "best" sites. This occurred because Common Murres outnumbered Thick-billed Murres by about 40:1 and because cliff habitat was in short supply. Whereas Thick-billed Murres bred only on cliffs, Common Murres were able to breed on cliffs and flat ground nearer sea level. Additional circumstantial evidence supports the idea that Common and Thick-billed murres at the Gannet Islands compete for breeding sites.

Ecological relationships between Common Murres, Uria aalge, and Thick-billed Murres, Uria lomvia, at the Gannet Islands, Labrador. I. Morphometrics and timing of breeding

1987 ◽  
Vol 65 (7) ◽  
pp. 1621-1629 ◽  
Author(s):  
T. R. Birkhead ◽  
D. N. Nettleship
Keyword(s):  
Egg Laying ◽  
Laying Date ◽  
Uria Aalge ◽  
Uria Lomvia ◽  
Ecological Relationships ◽  
Ice Breakup ◽  
Common Murre ◽  
Common Murres ◽  
Adult Body Weight ◽  
One Year

Several aspects of the breeding biology of Common Murres (Uria aalge) and Thick-billed Murres (Uria lomvia) in 1981–1983, at the Gannet Islands, Labrador, are described. At this colony there were ca. 60 000 pairs of Common Murres, and 1400 pairs of Thick-billed Murres. Common Murres were slightly heavier and had significantly shorter wings, and longer, narrower bills than Thick-billed Murres. The timing of egg laying varied between years (late breeding in one year was associated with late ice breakup), but the median laying date of Common Murres was consistently earlier (by up to 10 days) than that of Thick-billed Murres. For both species median laying dates fell between mid and late June each year. Common Murre eggs were larger and relatively longer than Thick-billed Murre eggs, but in both species fresh egg weight was about 11% of adult body weight. Incubation periods were similar in each species (33 days), but chick-rearing periods were longer in Common Murres (24 days) than in Thick-billed Murres (21 days) in all years. Seasonal patterns of colony attendance were broadly similar in the two species each year, except that Common Murres showed a consistent increase in numbers between laying and chick departure, and tended to remain at the colony for less time after chicks had departed compared with Thick-billed Murres. All birds of both species left the colony by mid-September each year.

scholarly journals Postfledging Occupancy of Breeding Sites by Female Common Murres (Uria Aalge)

The Auk ◽  
2003 ◽  
Vol 120 (1) ◽  
pp. 75-81
Author(s):  
Michael P. Harris ◽  
Sarah Wanless
Keyword(s):  
Breeding Site ◽  
Uria Aalge ◽  
Breeding Sites ◽  
Daily Frequency ◽  
Common Murres ◽  
Males And Females

Abstract Virtually all female Common Murres (Uria aalge) continued to visit the colony after their mate had taken the chick to sea. There were significant differences among years, but the average time between a chick fledging and a female last being seen at the colony was 13 days (range 0–36). In over 99% of instances, the female was at her breeding site. On ∼5% of days she was joined by another male, and in a few cases (8% of those days) copulation was observed. None of those transient matings persisted into the next season, even when the original male did not return; thus, we found no support for the hypothesis that females might be looking for replacement mates in case they were widowed. The most successful females (in terms of breeding output over several years) tended to have the longest periods of postfledging visiting, apparently because such birds fledged their chicks early in the season, but there was no difference in daily frequency of attendance. We conclude that successful males and females were maximizing time spent occupying the best breeding sites, even to the extent that only one adult took the chick to sea to complete its development.

Breeding site characteristics and breeding success in Thick-billed Murres

1985 ◽  
Vol 63 (8) ◽  
pp. 1880-1884 ◽  
Author(s):  
T. R. Birkhead ◽  
E. Greene ◽  
J. D. Biggins ◽  
D. N. Nettleship
Keyword(s):  
Regression Analysis ◽  
Breeding Success ◽  
Population Regulation ◽  
Breeding Site ◽  
Site Quality ◽  
Mortality Factors ◽  
Uria Lomvia ◽  
Site Characteristics ◽  
Bylot Island

Breeding site characteristics of Thick-billed Murres, Uria lomvia, differed significantly between Cape Hay, Bylot Island, and Coburg Island, N.W.T., Canada. Logistic regression analysis showed that at both colonies site characteristics had significant effects on breeding success. At Coburg Island the slope and width of the ledge were the most important factors, whereas at Cape Hay the number of walls and neighbours, and to a lesser extent the width of the ledge, best explained the variation observed in breeding success. Egg and chick mortality factors differed at each colony. At Coburg Island most eggs were lost through accidentally rolling off ledges, and at this colony birds on level sites on broad ledges were most successful. At Cape Hay most mortality of eggs and chicks occurred as a result of rock- and ice-falls; sites offering some protection were the most productive. Comparisons are made with other studies, and the role of breeding site quality in population regulation is discussed.

Ecological segregation among Thick-billed Murres (Uria lomvia) and Common Murres (Uria aalge) in the Northwest Atlantic persists through the nonbreeding season

2015 ◽  
Vol 93 (6) ◽  
pp. 447-460 ◽  
Author(s):  
L. McFarlane Tranquilla ◽  
W.A. Montevecchi ◽  
A. Hedd ◽  
P.M. Regular ◽  
G.J. Robertson ◽  
...  
Keyword(s):  
Environmental Data ◽  
Uria Aalge ◽  
Uria Lomvia ◽  
Ecological Segregation ◽  
Nonbreeding Season ◽  
Interspecific Differences ◽  
Common Murres ◽  
Movement Strategy ◽  
Wintering Areas ◽  
Latitudinal Range

To study the influence of inter- and intra-specific interactions on patterns of ecological segregation in nonbreeding habitat, we used geolocators to track year-round movements of congeneric and partially sympatric Thick-billed Murres (Uria lomvia (L., 1758)) and Common Murres (Uria aalge (Pontoppidan, 1763)) from seven Canadian colonies during 2007–2011. Locations from 142 individuals were (i) examined for species- and colony-specific spatiotemporal patterns, (ii) mapped with environmental data, and (iii) used to delineate core wintering areas. Compared with Common Murres, Thick-billed Murres dispersed across a wider range of latitudes and environments, had larger winter ranges, and showed greater variation in seasonal timing of movements. These interspecific differences were consistent at two scales: among colonies spanning a wide latitudinal range and at a sympatric colony. Intraspecifically, nonbreeding ecological segregation was more pronounced among colonies of Thick-billed Murres than of Common Murres: colonies of Thick-billed Murres tended to follow distinct movement patterns and segregate by latitude, whereas colonies of Common Murres segregated very little; moreover, the extent of segregation was more variable among Thick-billed Murres than Common Murres. For Thick-billed Murres, rather than complete divergence of winter ecological niche from Common Murres, we found a “widening” of an overlapping niche. This strategy of increased movement flexibility may enable Thick-billed Murres to mitigate competition both intra- and inter-specifically; we propose this movement strategy may have played a role in species divergence.

Breeding behaviour and reproduction in the Pampa de Achala toad, Bufo achalensis

2005 ◽  
Vol 26 (4) ◽  
pp. 451-458 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
Breeding Site ◽  
Reproductive Behaviour ◽  
Breeding Population ◽  
Male Reproductive Success ◽  
Breeding Sites ◽  
Size Dependent ◽  
Breeding Populations ◽  
Site Characteristics ◽  
Capture Recapture ◽  
First Time

AbstractDuring 1999 and 2000 the reproductive behaviour, breeding site characteristics and reproduction of Bufo achalensis were studied mainly at La Ciénaga stream, Pampa de Achala, Argentina, using capture-recapture and skeletochronology methods. Breeding activity occurred from mid-August to mid-September and was explosive. Males and females congregated at night at selected, but scarce, breeding sites, resulting in a patchy distribution of small breeding populations near to the stream source. The sex ratio (♂ : ♀) of the breeding population ranged between 0.65 : 1 and 1.16 : 1. On average, breeding males were larger and older than breeding females. Although most females and males reached sexual maturity at four and five years of age, some bred for the first time at the ages of three and four years respectively. Neither size dependent nor size assortative pairings were found. Male reproductive success was not related to body size (SVL) but was related to the number of nights spent at a breeding site. Females laid between 700-2,390 eggs. Eggs hatched approximately nine days after deposition and larval development was completed in about two months.

AGE-SPECIFIC SURVIVAL, BREEDING SUCCESS, AND RECRUITMENT IN COMMON MURRES (URIA AALGE) OF THE CALIFORNIA CURRENT SYSTEM

The Auk ◽  
2008 ◽  
Vol 125 (2) ◽  
pp. 316-325 ◽  
Author(s):  
DEREK E. LEE ◽  
CHRISTINE L. ABRAHAM ◽  
PETER M. WARZYBOK ◽  
RUSSELL W. BRADLEY ◽  
WILLIAM J. SYDEMAN
Keyword(s):  
Breeding Success ◽  
Current System ◽  
California Current ◽  
Uria Aalge ◽  
California Current System ◽  
Common Murres

Ecological relationships between Common Murres, Uria aalge, and Thick-billed Murres, Uria lomvia, at the Gannet Islands, Labrador. III. Feeding ecology of the young

1987 ◽  
Vol 65 (7) ◽  
pp. 1638-1649 ◽  
Author(s):  
T. R. Birkhead ◽  
D. N. Nettleship
Keyword(s):  
Caloric Intake ◽  
Interspecific Difference ◽  
Uria Aalge ◽  
Uria Lomvia ◽  
Ice Breakup ◽  
Common Murre ◽  
Interspecific Differences ◽  
Daubed Shanny ◽  
Common Murres ◽  
Capelin Mallotus Villosus

A simultaneous comparison of the foods of Common Murre, Uria aalge, and Thick-billed Murre, Uria lomvia, chicks at the same location showed that the species composition of fish fed to chicks of the two murre species differed significantly. In both years of the study, Common Murre chicks were fed predominantly capelin, Mallotus villosus (78–80% by weight), whereas Thick-billed Murre chicks were fed mainly daubed shanny, Lumpenus maculatus (61–70% by weight). Thick-billed Murres tended to feed their chicks more frequently than Common Murres, probably because in both years the mean caloric value of their prey was lower than that of the Common Murre's. No other statistically significant interspecific differences were consistent between years. Prey lengths and weights overlapped considerably between the murre species, and the caloric intake of chicks showed no consistent interspecific difference. Marked interyear differences in feeding rate, prey size, and caloric intake occurred in both species. In 1982 ice breakup was late, and the murres' breeding seasons were delayed; this appeared to result in poor synchronization between the temporal pattern of food availability and the timing of each species' chick-rearing period, and the caloric intakes of chicks of both species were lower in that year than in 1983.

scholarly journals Thickness of Common Murre (Uria aalge) eggshells in Atlantic Canada

2014 ◽  
Vol 128 (1) ◽  
pp. 72 ◽  
Author(s):  
Donald W. Pirie-Hay ◽  
Alexander L. Bond
Keyword(s):  
Newfoundland And Labrador ◽  
Shell Thickness ◽  
Egg Size ◽  
Environmental Pollutants ◽  
Maternal Investment ◽  
Uria Aalge ◽  
Uria Lomvia ◽  
Common Murre ◽  
Common Murres ◽  
Nesting Material

Reported values for eggshell thickness in Common Murre (Uria aalge) are few, and even fewer since the decline in use of organochlorine pesticides and other environmental pollutants that caused significant thinning of shells. The eggshells of Common Murres and Thick-billed Murres (Uria lomvia) are among the thickest and heaviest, proportionately, of any bird and this represents a non-trivial maternal investment. We measured the length and breadth of Common Murre eggs collected from Machias Seal Island, New Brunswick, in 2006, and Gull Island, Newfoundland and Labrador, in 2012, and we measured the thickness of the eggshells. Shell thickness was not related to egg size or volume, and it varied in individual eggs. The shells of Common Murre eggs from Machias Seal Island (mean and standard deviation [SD] (0.767, SD 0.078 mm) and Gull Island (0.753, SD 0.057 mm) were significantly thicker than any previously reported value and among the thickest of all birds. Such thickness is likely a result of nesting on rock substrate with no nesting material and, perhaps, high breeding densities.

Nest site characteristics, duration of use and breeding success in the Guillemot Uria aalge

Ibis ◽  
1997 ◽  
Vol 139 (3) ◽  
pp. 468-476 ◽  
Author(s):  
M. P. HARRIS ◽  
S. WANLESS ◽  
T. R. BARTON ◽  
D. A. ELSTON
Keyword(s):  
Breeding Success ◽  
Nest Site ◽  
Uria Aalge ◽  
Site Characteristics
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