scholarly journals Egg rejection behavior does not explain the lack of cowbird parasitism on an eastern North American population of Red-winged Blackbirds

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Justin J. Reel ◽  
Todd J. Underwood
Keyword(s):  
North America ◽  
Geographic Variation ◽  
Host Density ◽  
Nest Building ◽  
Host Community ◽  
North American Population ◽  
Eastern North America ◽  
Egg Rejection ◽  
Cowbird Parasitism ◽  
Red Wing

Abstract Background Red-winged Blackbirds (Agelaius phoeniceus), hereafter red-wings, are much less frequently parasitized by Brown-headed Cowbirds (Molothrus ater) in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania. Although hosts of Old World cuckoos (Cuculidae) often show geographic variation in egg rejection behavior, cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs. Thus, geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism. In this study, we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population, which may provide insight into low parasitism levels across eastern North America. Methods We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism. Nests were tested across three nest stages and compared to control nests with no manipulations. Because rejection differed significantly by stage, we compared responses separately for each nest stage. We also monitored other songbird nests to identify parasitism frequencies on all potential hosts. Results Red-wings showed significantly more rejections during the building stage, but not for the laying and incubation stages. Rejections during nest building involved mostly egg burials, which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg. Excluding these responses, red-wings rejected 15% of cowbird eggs, which is similar to rejection levels from other studies and populations. The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%. Conclusions Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population. Alternatively, we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism. Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.

Eastern North American Population at ca. A.D. 1500

2010 ◽  
Vol 75 (4) ◽  
pp. 707-726 ◽  
Author(s):  
George R. Milner ◽  
George Chaplin
Keyword(s):  
North America ◽  
Lower Bounds ◽  
Nearest Neighbor ◽  
Upper And Lower Bounds ◽  
North American Population ◽  
Eastern North America ◽  
American Population ◽  
Population Sizes ◽  
Local Densities ◽  
Nearest Neighbor Distances

Archaeologically documented population aggregates are used to estimate the population of eastern North America around A.D. 1500 and by extension the entire continent north of heavily populated Mesoamerica. Occupied areas plotted from archaeological and historical information were increased by buffer areas with widths determined by average nearest neighbor distances. Population sizes assigned to these areas were based on three compilations of historic sources, each handled in various ways. Local densities were calculated and then used to interpolate density surfaces for a ca. 3.1 million km2 area. The surfaces were further modified by assessments of data quality and overall occupation intensity to provide upper and lower bounds for each estimate. The procedure, designed to produce a range that was overly wide, resulted in an eastern population between .5 and 2.6 million and a continental total, north of Mesoamerica, of 1.2 to 6.1 million. These figures fall in the lower third of current authoritative estimates for the continent as a whole, which range from 2.4 to 18 million.

PARASITOIDS OF ENDEMIC AND EPIDEMIC POPULATIONS OF CHORISTONEURA OCCIDENTALIS FREEMAN AND CHORISTONEURA RETINIANA (WALSINGHAM) (LEPIDOPTERA: TORTRICIDAE) IN SOUTHERN OREGON

1991 ◽  
Vol 123 (5) ◽  
pp. 1095-1102 ◽  
Author(s):  
Willis C. Schaupp ◽  
W. Jan A. Volney ◽  
William E. Waters
Keyword(s):  
North America ◽  
Quantitative Estimation ◽  
Host Density ◽  
Population Trends ◽  
Eastern North America ◽  
Choristoneura Occidentalis ◽  
Parasitoid Species ◽  
Choristoneura Retiniana ◽  
Parasite Complex

AbstractParasitoid species attacking sparse, endemic populations of Choristoneura occidentalis Freeman and C. retiniana (Walsingham) are reported from 2 years of host collections at seven sites across southern Oregon. Results are compared with rearings from epidemic populations either from the same region or the same plot. Collections were designed to allow quantitative estimation of host density. Most of the parasitoid species present during epidemics across North America were recovered from the endemic and epidemic populations studied. The major difference is that at endemic host densities Glypta fumiferanae (Viereck) (Ichneumonidae) is rare to absent, whereas ichneumonids of the tribe Campoplegini, especially Tranosema (= Diadegma) interruptum (Ashmead), are common. This is the reverse of the situation at epidemic densities and consistent with results reported from eastern North America. It is suggested that the observed shift in the parasite complex with budworm density has the potential for predicting population trends.

CYTOTAXONOMY OF CONOPHTHORUS (COLEOPTERA: SCOLYTIDAE) IN EASTERN NORTH AMERICA

1990 ◽  
Vol 122 (6) ◽  
pp. 1131-1135 ◽  
Author(s):  
Peter de Groot ◽  
Terry J. Ennis
Keyword(s):  
North America ◽  
Geographic Variation ◽  
Distinct Species ◽  
Morphological Characters ◽  
Eastern North America ◽  
Supernumerary Chromosomes ◽  
Karyotypic Formula ◽  
Different Populations ◽  
Conophthorus Coniperda

AbstractThe male meiotic karyotypic formula of Conophthorus coniperda (Schwarz) (Coleoptera: Scolytidae) is 9AA + XY. This karyotype differs from C. resinosae Hopkins and C. banksianae McPherson, both of which have the karyotypic formula of 8AA + XY. Supernumerary chromosomes were found in different populations of C. resinosae and C. banksianae but were absent in C. coniperda. No geographic variation in the karyotypes of the three species was observed. The karyotypic formulae confirm the designations of C. coniperda and C. resinosae by morphological characters, but do not support the designation of C. banksianae as a distinct species.

scholarly journals Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini)

Zootaxa ◽  
2011 ◽  
Vol 3073 (1) ◽  
pp. 1 ◽  
Author(s):  
JASON GIBBS
Keyword(s):  
New Species ◽  
North America ◽  
Mississippi River ◽  
Nest Building ◽  
Eastern North America ◽  
Social Parasites ◽  
Identification Keys ◽  
Males And Females ◽  
Metallic Species ◽  
Subjective Synonym

Bees in the subgenus Lasioglossum (Dialictus) are commonly collected, behaviourally diverse and taxonomically challenging. The metallic species of Lasioglossum (Dialictus) occurring east of the Mississippi River are revised. Taxonomic treatments of all 97 species are provided with complete descriptions and illustrations given for the 40 species, which have not been recently described elsewhere. Identification keys for males and females are provided. The following eleven new species are described: Lasioglossum (Dialictus) arantium new species, L. (D.) ascheri new species, L. (D.) batya new species, L. (D.) curculum new species, L. (D.) furunculum new species, L. (D.) georgeickworti new species, L. (D.) gotham new species, L. (D.) izawsum new species, L. (D.) katherineae new species, L. (D.) rozeni new species, and L. (D.) trigeminum new species. Lasioglossum ascheri, L. curculum, L. furunculum, L. izawsum, and L. rozeni are believed to be social parasites or cleptoparasites of nest-building L. (Dialictus). Lasioglossum (D.) smilacinae (Robertson) is resurrected from synonymy with L. laevissimum (Smith). Lasioglossum (D.) nymphaearum (Robertson) is resurrected from synonymy with L. albipenne (Robertson).Lasioglossum rufulipes (Cockerell) and L. testaceum (Robertson) are removed from Evylaeus and placed in Dialictus. The following eleven new synonymies are proposed (junior subjective synonym listed second): L. (D.) flaveriae (Mitchell) = Dialictus tahitensis Mitchell; L. (D.) leucocomum (Lovell) = Dialictus otsegoensis Mitchell; L. (D.) lionotum (Sandhouse) = Paralictus asteris Mitchell; L. (D.) longifrons (Baker) = L. (Chloralictus) robertsonellum Michener; L. (D.) nigroviride (Graenicher) = Evylaeus pineolensis Mitchell; L. (D.) simplex (Robertson) = Halictus (Chloralictus) malinus Sandhouse; L. smilacinae (Robertson) = Halictus zophops Ellis, = D. philanthanus Mitchell; L. (D.) testaceum (Robertson) = Halictus (Chloralictus) scrophulariae Cockerell, = Lasioglossum (Chloralictus) sandhouseae Michener; and L. (D.) versans (Lovell) = Evylaeus divergenoides Mitchell. Lectotypes are designated for Halictus albipennis Robertson (1890), Halictus albitarsis Cresson (1872), Halictus cressonii Robertson (1890), Halictus disparilis Cresson (1872), Halictus hortensis Lovell (1905), Halictus nubilis Lovell (1905), Halictus pilosus leucocomus Lovell (1908), Halictus planatus Lovell (1905), Halictus stultus Cresson (1872), Halictus subconnexus rohweri Ellis (1915), Halictus tegularis Robertson (1890), Halictus versans Lovell (1905), and Halictus viridatus Lovell (1905).

Geographic Variation in Atlantic Cod, Gadus morhua, off Eastern North America: A Biochemical Systematics Approach

1978 ◽  
Vol 35 (1) ◽  
pp. 117-123 ◽  
Author(s):  
T. F. Cross ◽  
R. H. Payne
Keyword(s):  
North America ◽  
Geographic Variation ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Allele Frequencies ◽  
Fish Stock ◽  
Eastern North America ◽  
The North ◽  
Stock Discrimination ◽  
Significant Difference

Analysis of geographic variation in the frequencies of alleles at the Tf locus in Atlantic cod, Gadus morhua, indicates that it is possible to distinguish three major populations off eastern North America: (1) north of the Laurentian Channel, (2) south of the Laurentian Channel, and (3) Flemish Cap. The data also suggest that the north Laurentian stock may be further subdivided into a northern and southern component. The genetic distinction between the cod population on Flemish Cap and those on other areas of the continental shelf is confirmed by a significant difference in allele frequencies at the PGI-2 locus. It is suggested that the cod population on Flemish Cap may have persisted in isolation since the last glaciation. Key words: fish stock discrimination, transferrin, phosphoglucose isomerase, allele frequencies, genetic distance

The Identification and Study of Indian Shell Middens in Eastern North America: 1643–1861

1986 ◽  
Vol 6 (3) ◽  
pp. 227-243 ◽  
Author(s):  
Andrew L. Christenson
Keyword(s):  
Nineteenth Century ◽  
Civil War ◽  
North America ◽  
East Coast ◽  
Eastern North America ◽  
Shell Midden ◽  
Shell Middens ◽  
Work Done

Although the interest in shell middens in North America is often traced to reports of the discoveries in Danish kjoekkenmoeddings in the mid-nineteenth century, extensive shell midden studies were already occurring on the East Coast by that time. This article reviews selected examples of this early work done by geologists and naturalists, which served as a foundation for shell midden studies by archaeologists after the Civil War.

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