Divergent mitochondrial lineages arose within a large, panmictic population of the Savannah sparrow ( Passerculus sandwichensis )

2019 ◽  
Vol 28 (7) ◽  
pp. 1765-1783 ◽  
Author(s):  
Phred M. Benham ◽  
Zachary A. Cheviron
Keyword(s):  
Passerculus Sandwichensis ◽  
Panmictic Population ◽  
Savannah Sparrow

Effects of agriculture upon populations of native passerine birds of an Alberta fescue grassland

1973 ◽  
Vol 51 (7) ◽  
pp. 697-713 ◽  
Author(s):  
R. A. Owens ◽  
M. T. Myres
Keyword(s):  
Passerine Birds ◽  
Passerculus Sandwichensis ◽  
Disturbed Areas ◽  
Native Grassland ◽  
Savannah Sparrow ◽  
Anthus Spragueii ◽  
Agricultural Use ◽  
Horned Lark ◽  
Sprague's Pipit ◽  
Avian Populations

The effects of several forms of agricultural use of native fescue (Festuca scabrella) grasslands upon populations of native passerine birds were studied in the Hand Hills of southern Alberta in 1970.Censuses of avian populations were carried out on twelve 40-acre (16.2 ha) study plots as well as on two 10-mi (16.1 km) long roadside routes. The vegetation on the study plots and along the roadside routes was described.Native fescue grasslands, undisturbed for 3 years, supported a passerine community consisting of Baird's sparrow (Ammodramus bairdii), Sprague's pipit (Anthus spragueii), savannah sparrow (Passerculus sandwichensis), clay-colored sparrow (Spizella pallida), and western meadowlark (Sturnella neglecta). Incomplete disturbance of fescue grasslands, by mowing for hay or grazing by cattle, reduced or eliminated Baird's sparrow and Sprague's pipit but permitted the ingress of horned lark (Eremophila alpestris) and chestnut-collared longspur (Calcarius ornatus). Total elimination of the native grassland, by ploughing and cultivation for cereal crops, eliminated all passerine species except the horned lark. Peripheral disturbed areas resulting from cultivation, such as held boundaries and roadside ditches, may have benefited several species that tend to occur in ecotonal habitats: savannah sparrow, clay-colored sparrow, and vesper sparrow (Pooecetes gramineus).

Nestling foods of the savannah sparrow

1984 ◽  
Vol 62 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Marie Meunier ◽  
Jean Bédard
Keyword(s):  
Breeding Season ◽  
Temporal Changes ◽  
Prey Abundance ◽  
Large Prey ◽  
Passerculus Sandwichensis ◽  
Main Prey ◽  
Savannah Sparrow ◽  
Close Relationship ◽  
Males And Females ◽  
Prey Items

The diet of savannah sparrow (Passerculus sandwichensis) nestlings was monitored at Îsle Verte, Québec, during the 1980 breeding season. Adults carried exclusively arthropods to the nest. The main prey types found were Lepidoptera and Hymenoptera larvae, larval and adult Diptera and Homoptera. The proportion of different prey types in the diet varied during the season but there was no close relationship between temporal changes in the indices of prey abundance in the habitat and the type of prey chosen by the adult birds. Both the type and size of prey brought to the nest changed with the age and number of nestlings (aged 4–10 days). The proportion of Homoptera in the diet decreased sharply with age while that of Lepidoptera and Diptera increased. Adults feeding broods of four brought a larger proportion of large prey items (Lepidoptera and Hymenoptera larvae) than those feeding broods of a lesser size; to these they brought a larger proportion of smaller items such as Diptera and adult Lepidoptera. Males and females brought the same major prey types to the nest but not in the same proportions.

Breeding Biology of the Savannah Sparrow on Kent Island

The Auk ◽  
1978 ◽  
Vol 95 (2) ◽  
pp. 235-246 ◽  
Author(s):  
Clara L. Dixon
Keyword(s):  
New Brunswick ◽  
Clutch Size ◽  
Breeding Season ◽  
Breeding Population ◽  
Nesting Success ◽  
Breeding Biology ◽  
Passerculus Sandwichensis ◽  
Herring Gulls ◽  
Savannah Sparrow ◽  
The Mean

Abstract I studied the breeding biology of the Savannah Sparrow (Passerculus sandwichensis) on Kent Island, New Brunswick, Canada from 1964 through 1968. I estimated the breeding population to be 125-135 pairs $(412-445\ \text{individuals}/{\rm km}^{2})$. The mean number of nests produced per female, including those destroyed by predators, was 2.97. Clutch size ranged from 2 to 5. The mean clutch size based on 1,142 eggs in 284 nests of known clutch size was 4.02. Not only was the four-egg clutch most numerous but a greater percentage of eggs in the four-egg clutches hatched and the mean number of young fledged per nest was also highest. The mean incubation period was 12.2 days, the mean duration of nestling life was 9 days, and the approximate length of the breeding season as 52 days. The daily mortality rate of eggs was 11.9% and of nestlings 2.1%. Predation was the major factor affecting reproductive success; 50.5% of all nests located were destroyed by predators. The main nest predators were Common Crows and Herring Gulls. Of the nests destroyed by predators, 87.8% contained eggs rather than nestlings. The intense predation necessitated high nest replacement. The mean interval between the termination of one nest and the appearance of the first egg in the succeeding nest was 6.3 days. If successive nests are destroyed on the day incubation begins, it is hypothetically possible for a pair to produce four nests during a single breeding season; many birds in the population produce at least three. Although enough time was available for birds to fledge two broods in a season, few of them fledged more than one. Thus, the nesting success was low (success from egg to hatching 18.1%). High nest replacement compensated for high egg mortality, and an average of 2.16 young per pair were fledged per season.

Parental care in the savannah sparrow

1983 ◽  
Vol 61 (12) ◽  
pp. 2836-2843 ◽  
Author(s):  
Jean Bédard ◽  
Marie Meunier
Keyword(s):  
Parental Care ◽  
Dry Weight ◽  
Food Delivery ◽  
Male And Female ◽  
Passerculus Sandwichensis ◽  
Short Period ◽  
Savannah Sparrow ◽  
Gross Energy ◽  
Males And Females ◽  
Prey Items

The apportioning of parental care by male and female during the nestling stage was studied in the savannah sparrow (Passerculus sandwichensis). Brooding by both parents amounted to 66% of the daylight period during the first 2 days after hatching and decreased to 12% toward the end of the nestling stage. Broods of two received more brooding care than broods of either three or four nestlings during the last 2 days of rearing. We monitored the identity, size, and number of all the prey items (exclusively arthropods) brought by 32 nesting pairs during 628 h of observation. These estimates were later converted to estimates of dry weight of food transported (in milligrams per nestling per hour) by using weight measurements of standard prey items. The number of food deliveries increased steadily with nestling age. Males and females contributed nearly equally in this respect, with some exceptions. Estimates of gross energy carried to the nestlings peaked markedly on days 5 and 6 and decreased afterwards. During this short period, the male contributed significantly more than the female in terms of gross food energy transported. We conclude that the birds can tune their feeding contribution to the nest in subtle ways that the monitoring of food delivery rates alone cannot adequately describe.

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