The breeding season and reproductive cycle of the western red squirrel

1970 ◽  
Vol 48 (3) ◽  
pp. 471-473 ◽  
Author(s):  
John S. Millar
Keyword(s):  
British Columbia ◽  
North America ◽  
Breeding Season ◽  
Reproductive Cycle ◽  
Weather Conditions ◽  
Reproductive Organs ◽  
Tamiasciurus Hudsonicus ◽  
Eastern North America ◽  
Timing Of Breeding ◽  
Red Squirrel

Breeding in the red squirrel, Tamiasciurus hudsonicus (Erxleben), in southern British Columbia differed in some respects from that reported in eastern North America. The period during which males were capable of breeding varied from 2 to 6 months, and their reproductive organs showed only a single peak in size each year. All breeding females produced two litters in 1966, but only one litter in 1967. Females did not breed during the year of their birth, and, in 1967, some did not breed as yearlings. February appeared to be the earliest date for the onset of breeding in southern British Columbia. The timing of breeding may be influenced by weather conditions.

scholarly journals Do Barrow's Goldeneyes, Bucephala islandica, Breed South of the St. Lawrence Estuary in the Gaspé Peninsula, Eastern Canada?

2010 ◽  
Vol 124 (2) ◽  
pp. 179
Author(s):  
Jean-François Ouellet ◽  
Pierre Fradette ◽  
Isabel Blouin
Keyword(s):  
North America ◽  
Breeding Season ◽  
Breeding Habitat ◽  
Eastern North America ◽  
Eastern Canada ◽  
Lawrence Estuary ◽  
North Shore ◽  
The North ◽  
Bucephala Islandica ◽  
St Lawrence Estuary

We report the first observations of Barrow's Goldeneyes south of the St. Lawrence estuary in typical breeding habitat during the breeding season. Until recently, the confirmed breeding locations for the species in Eastern North America were all located on the north shore of the Estuary and Gulf of St. Lawrence.

scholarly journals Hemithea aestivaria (Hübner) (Lepidoptera: Geometridae), a Palaearctic moth new to eastern North America

2021 ◽  
Author(s):  
Christian Schmidt ◽  
Alexandre Anctil
Keyword(s):  
British Columbia ◽  
North America ◽  
Pacific Northwest ◽  
North American ◽  
Eastern North America ◽  
Urban Centers ◽  
Eastern Canada ◽  
Restricted Area ◽  
The Pacific ◽  
Geometrid Moth

The geometrid moth Hemithea aestivaria (Hübner, 1789) was introduced from Europe to North America, first detected in British Columbia in 1973. Until 2019, its North American range was limited to a restricted area of the Pacific Northwest. Here, we report on the first records of H. aestivaria for eastern North America from three widely separated urban centers in eastern Canada during 2019-2020.

scholarly journals The Leech Haemopis lateromaculata (Hirudinea: Haemopidae): Its North America Distribution and Additional Notes on Species Description

2006 ◽  
Vol 120 (4) ◽  
pp. 443 ◽  
Author(s):  
Peter Hovingh
Keyword(s):  
United States ◽  
British Columbia ◽  
North America ◽  
Coastal Region ◽  
Reproductive Organs ◽  
Geographic Range ◽  
Geographical Region ◽  
Species Description ◽  
Pleistocene Refugia ◽  
Specific Variation

The geographic range of Haemopis lateromaculata Mathers 1963 (Hirudinea: Haemopidae) is extended across North America. Its distribution in the coastal region of Alaska and British Columbia suggests a coastal Pleistocene refugia separate from the populations in the lower United States and suggests that H. lateromaculata and the Eurasian H. sanguisuga Linnaeus 1758 are sister taxa. Support of the identification and geography is based on the anatomical positions of the reproductive organs in H. lateromaculata and H. marmorata Say 1824. The variations within these species are described, noting that no specific variation was confined to a geographical region.

CHIRONOMIDAE (DIPTERA) ASSOCIATED WITH MYRIOPHYLLUM SPICATUM IN OKANAGAN VALLEY LAKES, BRITISH COLUMBIA

1983 ◽  
Vol 115 (11) ◽  
pp. 1545-1546 ◽  
Author(s):  
B.J. Kangasniemi ◽  
D. R. Oliver
Keyword(s):  
United States ◽  
Nineteenth Century ◽  
British Columbia ◽  
North America ◽  
Myriophyllum Spicatum ◽  
The United States ◽  
Eastern North America ◽  
Aquatic Weed ◽  
Okanagan Valley

Eurasian water milfoil, Myriophyllum spicatum Linnaeus, was introduced into eastern North America late in the nineteenth century. It has spread and developed into a major aquatic weed in many areas of the United states and Canada (Aiken et al. 1979; Reed 1977). In British Columbia, it was first observed in the Vernon Arm of Okanagan Lake in 1970 and had spread to all major 1,akes in the Okanagan Valley by 1976 (Newroth 1979).

scholarly journals Hemithea aestivaria (Hübner) (Lepidoptera: Geometridae), a Palaearctic moth, new to eastern North America

2021 ◽  
Vol 9 ◽  
Author(s):  
Christian Schmidt ◽  
Alexandre Anctil
Keyword(s):  
British Columbia ◽  
North America ◽  
Pacific Northwest ◽  
North American ◽  
Eastern North America ◽  
Eastern Canada ◽  
Restricted Area ◽  
The Pacific ◽  
Geometrid Moth

The geometrid moth Hemithea aestivaria (Hübner, 1789) was introduced from Europe to North America, first being detected in British Columbia in 1973. Until 2019, its North American range was limited to a restricted area of the Pacific Northwest. Here, we report on the first records of H. aestivaria for eastern North America from three widely separated urban centres in eastern Canada during 2019-2020.

Studies on the marsupial glider, Schoinobates volans (Kerr) I. Reproduction

1969 ◽  
Vol 17 (4) ◽  
pp. 625 ◽  
Author(s):  
RFC Smith
Keyword(s):  
Natural Population ◽  
Breeding Season ◽  
Reproductive Cycle ◽  
Reproductive System ◽  
Sexual Maturity ◽  
Field Data ◽  
Reproductive Organs ◽  
Female Reproductive System ◽  
Histological Changes ◽  
Second Year

Field data were obtained during the period September 1962-January 1965 from 710 greater gliders, S. volans, in a natural population. Histological changes were observed in the reproductive tracts of another 129 animals shot during this period. S. volans has a short breeding season in March, April, and May, after which involution of the reproductive organs occurs in both sexes. The species is monovular and polyoestrous. Sexual maturity is attained by both sexes in the second year, following which breeding probably occurs annually. The female reproductive system shows several primitive and anomalous features, among which is the retention of the Wolffian ducts in the adult. The histology of ovaries, uteri, and vaginae at various stages of the reproductive cycle is briefly described.

Structure, frequency of usage, and apparent learning in the primary song of the yellow-throated vireo, with comparative notes on solitary vireos (Aves: Vireonidae)

1984 ◽  
Vol 62 (3) ◽  
pp. 468-472 ◽  
Author(s):  
Ross D. James
Keyword(s):  
North America ◽  
Breeding Season ◽  
Eastern North America ◽  
Western North America ◽  
Breeding Range ◽  
Two Factors ◽  
Intraspecific Communication ◽  
Vireo Solitarius

The primary song of 27 yellow-throated vireos (Vireo flavifrons) from throughout their breeding range in eastern North America was examined spectrographically. Only 39 different song phrases were found, and each bird sang an average of only 5 phrases. There is, therefore, a great deal of overlap in the phrases sung by birds in any part of their range. Yellow-throated vireo primary song phrases are characteristically frequency modulated like those of the solitary vireos (Vireo solitarius) of western North America, but no phrases of the two species were identical. Male yellow-throated vireos sang a number of the same few song phrases at different times during the breeding season. Distinct changes in timing and the overall amount of singing, however, indicate the importance of these two factors for intraspecific communication. The discovery of a yellow-throated vireo singing primary song phrases characteristic of solitary vireo song seems to indicate that, to a large extent, primary song is learned, and that much of the learning takes place early in the bird's life.

scholarly journals VI. The Reproductive processes of certain mammals. Part VI. - The reproductive cycle of the female hedgehog

1934 ◽  
Vol 223 (494-508) ◽  
pp. 239-276 ◽  
Keyword(s):  
Breeding Season ◽  
Reproductive Cycle ◽  
Post Partum ◽  
Late Pregnancy ◽  
Reproductive Organs ◽  
Comparative Physiology ◽  
Ecological Data ◽  
Reproductive Processes ◽  
Period Of Gestation ◽  
Length Of Gestation

The hedgehog ( Erinaceus europceus ) is a common British and North European mammal, but no thorough investigation appears to have been made of the reproductive cycle of the female. The present account is designed to fill this gap and as a contribution to the comparative physiology of reproduction. Ecological data are not included. Hubrecht (1889), working at Utrecht on the embryology of the hedgehog, gives the breeding season as June to August and the number of foetuses as 4-8. He regards the hedgehog as a primitive type. Millais (1904) states that the hedgehog breeds twice a year in Great Britain, having its first litter in May or June and its second in August or September, the period of gestation being not more than one month. Five to seven young are born, which are blind at birth ; after about three weeks their spines harden and they assume adult coloration. The young are three-quarters grown by the time winter sets in. Barrett-Hamilton (1911) states that the earliest hedgehog pregnancies occur in April, but he does not include any records. Second litters are found between the middle of August and the end of September ; a late pregnancy is recorded on September 23 in Ireland and an early post-partum animal on September 28 in Scotland. There are generally four or five young, though they may vary in number from 2-9. The length of gestation is given as 4-7 weeks, but as most probably seven weeks on the authority of Lilljeborg (1874). Like Millais, Barrett-Hamilton states that the young are well grown in the same season. Both these writers describe the hedgehog as hibernating from late in November onwards ; the length and extent of hibernation are very variable, however, and the animal is not infrequently found walking about in the winter. In view of the restricted breeding season it seemed likely that the reproductive organs of the female, no less than of the male hedgehog (Marshall, 1911), would show marked changes between the anoestrous and breeding season conditions.

scholarly journals The reproductive processes of certain mammals. III.—The reproductive cycle of the male ferret

1932 ◽  
Vol 110 (767) ◽  
pp. 295-312 ◽  
Keyword(s):  
Breeding Season ◽  
Reproductive Cycle ◽  
Reproductive Tract ◽  
Reproductive Activity ◽  
Reproductive Organs ◽  
Interstitial Tissue ◽  
Quiescent Period ◽  
Cyclic Changes ◽  
Reproductive Processes ◽  
Periodic Changes

Cyclic changes in the reproductive organs of male mammals have been studied in a few forms only, but the information available reveals interesting differences in the duration of reproductive activity, and in the correlation between the various organs. Marshall (1911) has described the reproductive cycle in the male hedgehog. Regaud (1904), Tandler and Grosz (1911) and Lecaillon (1909) have studied the mole, but with conflicting results. Rasmussen (1917 and 1918) gives detailed information of the periodic changes in the interstitial tissue of the testis in the woodchuck, and more recently Courrier (1923) has investigated the reproductive cycle in various bats, in the mole, hedgehog, and marmot. The work of Marshall (1904), Robinson (1918) and Hammond and Marshall (1930) has established that in the female ferret the breeding season is restricted and lasts from April to August ; during the remaining months of the year the reproductive organs are in a state of quiescent anœstrus. The first mating occurs in March or April. The present investigation was undertaken in order to determine the duration of the quiescent period in the male ferret and to compare the changes in the testis tubules with those in the interstitial tissue and accessory organs. The condition of the reproductive tract has accordingly been studied at various times of the year, and an attempt has been made to assess the changes in the organs and in their constituent parts.

scholarly journals A taxonomic revision of the Paranoplocephala primordialis (Douthitt) complex (Cestoda: Anoplocephalidae) in voles and squirrels

Zootaxa ◽  
2007 ◽  
Vol 1548 (1) ◽  
pp. 51-68 ◽  
Author(s):  
VOITTO HAUKISALMI ◽  
HEIKKI HENTTONEN
Keyword(s):  
North America ◽  
Host Species ◽  
Related Species ◽  
Taxonomic Revision ◽  
Tamiasciurus Hudsonicus ◽  
Eastern Siberia ◽  
Red Squirrel ◽  
Myodes Rutilus ◽  
North Eastern ◽  
Specific Identity

This study redescribes Paranoplocephala primordialis (Douthitt) in the red squirrel, Tamiasciurus hudsonicus, describes two new, related species of Paranoplocephala Lühe from Microtus and Myodes (syn. Clethrionomys) voles, and summarizes the patterns of their host specificity and geographic distribution, particularly in Alaska and adjacent regions in Canada and north-eastern Siberia. Paranoplocephala nearctica n. sp. and Paranoplocephala alaskensis n. sp. are shown to be slightly, but consistently differentiated host-specific parasites of Myodes rutilus and Myodes gapperi, and Microtus miurus, respectively. The related Paranoplocephala sp. from Microtus oeconomus is also suspected to be specifically distinct, but the available material does not allow a description of a new species.Paranoplocephala primordialis-like cestodes occur widely in rodents in North America, ranging from California to Labrador and Alaska, but also in north-eastern Siberia. The specific identity of the few Eurasian specimens could not, however, be confirmed. Paranoplocephala primordialis-like species seem to be rare in all host species and regions, maximum prevalences being 8%, 3%, 6.5% and 5% for P. primordialis, P. nearctica n. sp., P. alaskensis n. sp. and Paranoplocephala sp., respectively.

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