scholarly journals Nesting Biology of Lesser Canada Geese, Branta canadensis parvipes, along the Tanana River, Alaska

2008 ◽  
Vol 122 (1) ◽  
pp. 29
Author(s):  
Craig R. Ely ◽  
John M. Pearce ◽  
Roger W. Ruess
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Branta Canadensis ◽  
Haliaeetus Leucocephalus ◽  
Canada Geese ◽  
Red Foxes ◽  
Nesting Biology ◽  
Bald Eagles ◽  
Nest Sites ◽  
Nest Initiation

Lesser Canada Geese (Branta canadensis parvipes) are widespread throughout interior regions of Alaska and Canada, yet there have been no published studies documenting basic aspects of their nesting biology. We conducted a study to determine reproductive parameters of Lesser Canada Geese nesting along the Tanana River near the city of Fairbanks, in interior Alaska. Fieldwork was conducted in May of 2003, and consisted of locating nests along the riparian corridor between Fairbanks and Northpole, Alaska. Nests were found on gravel islands and shore habitats along the Tanana River, and were most commonly observed among driftwood logs associated with patches of alder (Alnus spp.) and willow (Salix spp.). Peak of nest initiation was 3-8 May, with a range from 27 April to 20 May; renesting was likely. Clutches ranged in size from 2 to 7 eggs and averaged 4.6 eggs. There was a negative correlation between clutch size and date of nest initiation. Egg size (mean mass = 128 g) was similar to other medium-sized Canada Geese. A positive correlation between egg size and clutch size was likely related to female age. Nineteen of 28 nests (68%) were active when visited; nests located on islands with nesting Mew Gulls (Larus canus) were more likely to be active than nests located elsewhere. Evidence at nest sites implicated Bald Eagles (Haliaeetus leucocephalus) and Red Foxes (Vulpes vulpes) as nest predators.

Measurements and weights of eggs of the Canada goose, Branta canadensis, analyzed and compared with those of other species

1978 ◽  
Vol 56 (4) ◽  
pp. 676-687 ◽  
Author(s):  
T. H. Manning
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Branta Canadensis ◽  
Published Data ◽  
Canada Goose ◽  
True Density ◽  
Fresh Weight ◽  
Coefficients Of Variation ◽  
Branta Canadensis Interior ◽  
The Mean

The length and breadth of 334 eggs (82 clutches) of Branta canadensis interior were measured and 125 eggs (30 clutches) were weighed. Published and unpublished data for eggs of Branta canadensis maxima, hutchinsi, moffitti, and minima were also used and comparisons made with published data on 31 other species from seven ordersMeasurements of full clutches rather than of one egg per clutch proved advantageous. The means for length (L) and breadth (B) were 83.87 ± 0.366 mm and 56.60 ± 0.126 mm; those for the indices of volume (LB2), shape (100B/L), and density (100W/LB2), 268.98 ± 1.897 cm3, 67.34 ± 0.248, and 55.21 ± 0.190; that for weight (W), an estimated 1.5 days after the commencement of incubation, 150.02 ± 1.718. The clutch variances were significant and accounted for about half the total variance. The lightest egg weighed 68% of the heaviest and the coefficients of variation varied from 2.48 (breadth) to 7.17 (weight). The last eggs were significantly lighter and smaller than earlier eggs, owing to their lesser breadth. Correlations between egg size and clutch size were not constant. Correlations between length and breadth were generally positive, those between volume and shape generally negative. The mean true density of the eggs was estimated to be 1.085, the mean true volume 137.74 cm3, the mean fresh weight 150.95 g, and the mean of the factor k for the correction of the ellipsoidal volume, 0.9780. All differences between the five races for length, breadth, and volume were significant. Joint non-overlaps varied from 64 to 100%.

Intraclutch variation in egg size of Canada geese

1987 ◽  
Vol 65 (12) ◽  
pp. 3044-3047 ◽  
Author(s):  
Yves Leblanc
Keyword(s):  
Egg Size ◽  
Branta Canadensis ◽  
Western Canada ◽  
Canada Geese ◽  
Hormonal Changes ◽  
Egg Formation ◽  
Laying Sequence

Variation in egg size relative to laying sequence was examined for clutches of captive and wild western Canada geese (Branta canadensis moffitti). Eggs laid in the middle of a sequence were very similar in size and were larger than the first and last eggs of a clutch, which did not differ. Intraclutch variation in egg size in Canada geese may be caused by hormonal changes during egg formation and at the onset of incubation.

NEsting by the hawsbill turtle (Eretmochelys imbricata) on Milman Island, Great Barrier Reef, Australia

1995 ◽  
Vol 22 (2) ◽  
pp. 241 ◽  
Author(s):  
KA Loop ◽  
JD Miller ◽  
CJ Limpus
Keyword(s):  
Clutch Size ◽  
Carapace Length ◽  
Average Diameter ◽  
Average Weight ◽  
Nesting Biology ◽  
Eretmochelys Imbricata ◽  
Nest Sites ◽  
Emergence Success ◽  
Incubation Temperatures ◽  
Hawksbill Turtles

Nesting biology of hawksbill sea turtles (Eretmochelys imbricata) is described with morphometric and meristic measurements collected from 365 turtles over 76 nights of beach patrols on Milman I. The nesting season was already in progress when the study began in January and continued after the research team left in March 1991. Average renesting interval was 14.2 days, and the hawksbill turtles laid an average of 2.6 clutches during the study period. Nest sites were located most commonly under trees (67.2%). Average curved carapace length was 81.7 cm, width was 70.6 cm, and weight after laying was 50.3 kg. Mean clutch size was 124 eggs. Eggs had an average diameter of 3.48 cm and an average weight of 25.7 g. Emergence success rate was 79.9% for hawksbill hatchlings, which had an average straight carapace length of 3.96 cm and weight of 13.3 g. Incubation temperatures were monitored and sex ratios determined in four clutches, two in shaded and two in unshaded sand. The sexes of 25 hatchlings from each clutch were identified. Two unshaded clutches produced 92% and 100% female hatchlings while two shaded clutches produced 64% and 44% female hatchlings. Statistical differences were not found between the presented hawksbill turtle curved carapace length, weight after laying and clutch size and those collected elsewhere in Queensland by earlier studies.

scholarly journals Optimizing Nest Survival and Female Survival: Consequences of Nest Site Selection for Canada Geese

The Condor ◽  
2007 ◽  
Vol 109 (4) ◽  
pp. 769-780 ◽  
Author(s):  
David A. Miller ◽  
James B. Grand ◽  
Thomas F. Fondell ◽  
R. MICHAEL Anthony
Keyword(s):  
Nest Site ◽  
Nest Survival ◽  
Negative Relationship ◽  
Nest Site Selection ◽  
Site Quality ◽  
Adult Survival ◽  
Canada Geese ◽  
Bald Eagles ◽  
Nest Sites ◽  
Female Survival

Abstract We examined the relationship between attributes of nest sites used by Canada Geese (Branta canadensis) in the Copper River Delta, Alaska, and patterns in nest and female survival. We aimed to determine whether nest site attributes related to nest and female survival differed and whether nest site attributes related to nest survival changed within and among years. Nest site attributes that we examined included vegetation at and surrounding the nest, as well as associations with other nesting birds. Optimal nest site characteristics were different depending on whether nest survival or female survival was examined. Prior to 25 May, the odds of daily survival for nests in tall shrubs and on islands were 2.92 and 2.26 times greater, respectively, than for nests in short shrub sites. Bald Eagles (Halieaeetus leucocephalus) are the major predator during the early breeding season and their behavior was likely important in determining this pattern. After 25 May, when eagle predation is limited due to the availability of alternative prey, no differences in nest survival among the nest site types were found. In addition, nest survival was positively related to the density of other Canada Goose nests near the nest site. Although the number of detected mortalities for females was relatively low, a clear pattern was found, with mortality three times more likely at nest sites dominated by high shrub density within 50 m than at open sites dominated by low shrub density. The negative relationship of nest concealment and adult survival is consistent with that found in other studies of ground-nesting birds. Physical barriers that limited access to nest sites by predators and sites that allowed for early detection of predators were important characteristics of nest site quality for Canada Geese and nest site quality shifted within seasons, likely as a result of shifting predator-prey interactions.

Bald Eagle Nesting Habitats in the Upper Mississippi River National Wildlife and Fish Refuge

2013 ◽  
Vol 4 (2) ◽  
pp. 362-376 ◽  
Author(s):  
Neal D. Mundahl ◽  
Anthony G. Bilyeu ◽  
Lisa Maas
Keyword(s):  
Land Cover ◽  
Mississippi River ◽  
The United States ◽  
Bald Eagle ◽  
Haliaeetus Leucocephalus ◽  
Upper Mississippi River ◽  
Human Disturbances ◽  
Bald Eagles ◽  
Land Cover Types ◽  
Nest Sites

Abstract This study examined habitat variables associated with 53 active bald eagle Haliaeetus leucocephalus nest sites in the Winona District of the Upper Mississippi River National Wildlife and Fish Refuge, Minnesota and Wisconsin. The Refuge is the most heavily visited refuge in the United States, where breeding eagle populations have been increasing dramatically. During February–April 2009, nest trees were identified and measured, nest heights were determined, distances to nearest water bodies were assessed, and forest inventories were conducted for the standing timber surrounding the nest trees. Nest densities and spacing were assessed within each navigation pool, and land cover types were examined within 100- and 1,000-m radii around known eagle nest sites and random points within the Refuge. Ninety-three percent of nest sites had supercanopy eastern cottonwoods Populus deltoides and silver maples Acer saccharinum as the nest trees. Potential human disturbances from highways, railroads, and commercial barge and recreational boat traffic were present within 400 m of 90% of known nest sites. Eagle nest sites were located an average of 1.52 km from the next nearest nest, with nest densities ranging from 0.32 to 9.72 nests/100 km2 among the four navigation pools of the Winona District. Land cover types around known nest sites and random points differed significantly at both 100- and 1,000 m scales, with wet forest and open water significantly more abundant and agricultural and developed lands significantly less abundant than around randomly selected points. Successful nests that fledged at least one young were spaced significantly further away from other active nests and were located in areas with lower tree density than were unsuccessful nests. Floodplain-nesting bald eagles tended to select the tallest, dominant trees for nest sites, placing nests near the height of the surrounding canopy. Human presence within the Refuge does not appear to be limiting the expansion of nesting bald eagles in this riverine habitat.

scholarly journals Nest Survival in Dusky Canada Geese (Branta Canadensis Occidentalis): Use of Discrete-Time Models

The Auk ◽  
2006 ◽  
Vol 123 (1) ◽  
pp. 198-210 ◽  
Author(s):  
James B. Grand ◽  
Thomas F. Fondell ◽  
David A. Miller ◽  
R. Michael Anthony
Keyword(s):  
Nest Survival ◽  
Survival Rates ◽  
Branta Canadensis ◽  
Canada Geese ◽  
Ecological Processes ◽  
Nonparametric Models ◽  
Daily Survival ◽  
Calendar Dates ◽  
Nest Initiation ◽  
Nesting Season

Abstract The Dusky Canada Goose (Branta canadensis occidentalis) population that breeds in the Copper River Delta, Alaska, has declined substantially since the late 1970s. Persistent low numbers have been attributed to low productivity in recent years. We examined patterns in survival rates of 1,852 nests to better understand ecological processes that influenced productivity during 1997-2000. We compared 10 nonparametric models of daily survival rate of nests (DSR) that included variation among years, calendar dates, nest initiation dates, and nest ages with equivalent models based on parametric functions. The unequivocal best model included patterns of DSR that varied among discrete periods of years, calendar dates, and nest ages. Generally, DSR was low early in the nesting season and higher midseason. Across years, patterns in DSR were most variable early and late in the nesting season. Daily survival rates of nests declined between the first and second week after initiation, increased until the fourth week, and then declined during the last week before hatch. Nest survival probability estimates ranged from 0.07 to 0.71 across years and nest initiation dates. Mean rates of nest survival ranged between 0.21 and 0.31 each year. We suggest (1) considering models that do not limit estimates of daily nest survival to parametric forms; (2) placing greater emphasis on sample size when nests are rare, to obtain accurate estimates of nest survival; and (3) developing new techniques to estimate the number of nests initiated. Supervivencia de los Nidos en Branta canadensis occidentalis: Uso de Modelos de Tiempo Discreto

Influence of Nesting Characteristics on Health of Wild Bee Communities

2020 ◽  
Vol 65 (1) ◽  
pp. 39-56 ◽  
Author(s):  
Alexandra Harmon-Threatt
Keyword(s):  
Climate Change ◽  
Nest Site ◽  
Site Conditions ◽  
Wild Bees ◽  
Nesting Biology ◽  
Habitat Disturbances ◽  
Wild Bee ◽  
Growth Development ◽  
Bee Communities ◽  
Nest Initiation

Nest site availability and quality are important for maintaining robust populations and communities of wild bees. However, for most species, nesting traits and nest site conditions are poorly known, limiting both our understanding of basic ecology for bee species and conservation efforts. Additionally, many of the threats commonly associated with reducing bee populations have effects that can extend into nests but are largely unstudied. In general, threats such as habitat disturbances and climate change likely affect nest site availability and nest site conditions, which in turn affect nest initiation, growth, development, and overwintering success of bees. To facilitate a better understanding of how these and other threats may affect nesting bees, in this review, I quantify key nesting traits and environmental conditions and then consider how these traits may intersect with observed and anticipated changes in nesting conditions experienced by wild bees. These data suggest that the effects of common threats to bees through nesting may strongly influence their survival and persistence but are vastly understudied. Increasing research into nesting biology and incorporating nesting information into conservation efforts may help improve conservation of this declining but critical group.

Parental Investment in Clutch Size and Egg Size in the Ural Owl Strix uralensis

1986 ◽  
Vol 17 (4) ◽  
pp. 309 ◽  
Author(s):  
Hannu Pietiainen ◽  
Pertti Saurola ◽  
Risto A. Vaisanen
Keyword(s):  
Clutch Size ◽  
Parental Investment ◽  
Egg Size ◽  
Ural Owl

scholarly journals Ecological interactions and habitat modification in nesting Common Murres, Uria aalge

1996 ◽  
Vol 6 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Julia K. Parrish ◽  
Robert T. Paine
Keyword(s):  
Reproductive Output ◽  
Habitat Modification ◽  
Haliaeetus Leucocephalus ◽  
Uria Aalge ◽  
Ecological Interactions ◽  
Bald Eagles ◽  
Predator Removal ◽  
Common Murre ◽  
Corvus Caurinus ◽  
Common Murres

SummarySeabird populations suffer from a variety of natural and human-induced sources of mortality and loss of lifetime reproductive output. On the outer coast of Washington State, Common Murre Uria aalge populations have been in decline for approximately the last decade and are currently reproductively active only at Tatoosh Island. These murres nest in two basic habitat types: crevices (25% of the population) and larger cliff-top subcolonies (75%). Murres in cliff-top subcolonies have suffered dramatic reductions in reproductive success in recent years relative to conspecifics nesting in the crevices, primarily due to egg predation by Glaucous-winged Gulls Larus glaucescens and Northwestern Crows Corvus caurinus, facilitated by the presence of Bald Eagles Haliaeetus leucocephalus. Because predator removal is not feasible and creation of additional crevice habitat is difficult, expensive and potentially ineffective, we have designed a temporary habitat modification (the “silk forest”) which replaces the natural vegetation cover and modifies the interaction between murres and eagles. Within the test subcolony, murres nesting under and immediately adjacent to the silk forest produced nearly twice as many eggs per square metre as their conspecifics nesting in adjacent exposed-ground areas.

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