Reproductive physiology of the Grey squirrel (<i>Sciurus carolinenis</i>)

Webley, G. E.; Johnson, Elizabeth

doi:10.1111/j.1365-2907.1983.tb00275.x

Cited by 14 publications

(22 citation statements)

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“…Early pregnancy is indicated by a metoestrous vaginal smear. 21 A serum progesterone level of >10 ng mL −1 is indicative of mid to late (∼day 30) pregnancy 22 (Forest Research, unpublished). For each blood sample, 25 µL of plasma was analysed for progesterone using IBL Progesterone ELISA kit (RE52231; BioSupply UK Ltd), and OD was read at 450 ± 10 nm on a Dynatech MR250 plate reader.…”

Section: Reproductive Successmentioning

confidence: 99%

“…Seven progesterone standards (0-40 ng mL −1 ) were provided, and the coefficients of variation were given as 5.4-6.99% for intraassay and 4.34-9.96% for interassay variation. 23 ELISA assays were used to identify whether progesterone levels were within specific ranges indicative of pregnancy, rather than to determine absolute values, and were carried out in a temperature-controlled (18)(19)(20)(21)(22)(23)(24) • C) environment. Cross-reactivity levels with 11 other steroids were given as 1.1 to <0.02%.…”

Section: Reproductive Successmentioning

confidence: 99%

“…30 In Britain, Webley and Johnson 21 found that 30% of female grey squirrels have two litters, with peak litter production in March/April and June/July, but Gurnell 2,31 suggests that peak litter production is in July/August. Ferryman et al 4 also found that peak matings in their study occurred in April and June in 2002 and in May and June in 2003.…”

Section: Effect Of Diazaconmentioning

confidence: 99%

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Home Ranges of the Nilgai Antelope (Boselaphus tragocamelus) in Texas

Moczygemba

Hewitt

Campbell

et al. 2012

The Southwestern Naturalist

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BACKGROUND: The grey squirrel, Sciurus carolinensis Gmelin, is an invasive alien species introduced into Great Britain in the late nineteenth century and into Northern Italy during the early twentieth century. Grey squirrels have displaced the native European red squirrel, Sciurus vulgaris L., throughout much of Great Britain and have a significant impact on trees and woodlands through bark-stripping activity. In Britain, eradication is no longer an option at a regional scale, but fertility control offers a non-lethal approach to reducing negative impacts. The cholesterol mimic DiazaCon  has been successfully used to inhibit reproduction in some species. These studies aimed to evaluate whether DiazaCon  is effective in inhibiting reproduction in grey squirrels. RESULTS: DiazaCon reduced serum cholesterol levels in female grey squirrels at a range of doses. The period of effect increased with increasing dose. Reproduction rate was not significantly different between treatment and control groups owing to a lack of breeding in controls. CONCLUSIONS: DiazaCon has potential to reduce serum cholesterol levels enough and for a sufficient period to reduce fertility in female grey squirrels. Information on baseline physiology and blood chemistry of grey squirrels is required to inform interpretation of the level of significance of the effect.

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Section: Reproductive Successmentioning

confidence: 99%

Section: Reproductive Successmentioning

confidence: 99%

Section: Effect Of Diazaconmentioning

confidence: 99%

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Home Ranges of the Nilgai Antelope (Boselaphus tragocamelus) in Texas

Moczygemba

Hewitt

Campbell

et al. 2012

The Southwestern Naturalist

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“…Esta também deve ser a provável explicação de não ter sido observado cópula durante o período de estudo, apesar das tentativas feitas pelos machos. WEBLEY & JONHSON (1983) sugerem que a reprodução dos esquilos em cativeiro, pode ser di ficultada por fatores como espaço dos recintos e o período de adaptação dos animais ao novo ambiente, entretanto, estes problemas parecem não ter sido tão marcantes para S. ingrami, pois após o período de observações, durante o mês de dezembro de 1995, ocorreu o nascimento de três tilhotes de serelepes no "criadouro científico" do Museu de História Natural Capão da Imbuia (R.R. Lange e T.C.C.…”

Section: Comportamento Reprodutivounclassified

Comportamentos e atividade diária de Sciurus ingrami (Thomas) em cativeiro (Rodentia, Sciuridae)

Bordignon

Filho

1997

Rev. Bras. Zool.

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ABSTRACT. BEHAV IOUR ANO OIARV ACTlVITV 01' SCIUIIUS ISGRAAI/ (THOMAS) lN CAPTIVITV (ROOENTIA, SCIURIDAE). Frorn October 1994 to Novcmber 1995 the behaviour, postures and diurnal activity of tive captive squilTels Scillrlls illgromi were observed and registered. Four basics postures, tive grooming behaviours, displacements and face wiping behaviour were identified. Based on behavioural observations, the diurnal activity was divided into four categories: resting, disp!acement, feed ing and maintenance. The time spent in each category varied seasonaJ\y and the sq uirrels spent more time resting during winter and spring. However, more time was spent feeding during autum and summe r and was reduced the displacement in autum. Two types of breeding behaviour were identilied: sex ual trailing and mating chase of females by males. However copulatori behaviollr was not recorded during the studied period. We also verified that S. illgromi prescnts thenn orregulati on behaviour during winter, remaining resting in the nest to conserve energy in heath maintenance. During the hottest seasons, the squirrels remain resting out of the nest. placed on the branchs to decrease their body heat to normal tcmpcrature. The behaviours observed in thi s study were similar to those dcscribed in the literatllre. as well as the mating behaviour, which was vely similar to S. (HORW ICI-I 1972).

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“…Oestrus occurs on one day only and is asynchronous among the females in a population (Webley andJohnson 1983, Gurnell 1987). This creates a temporally and spatially limited resource that is contested by males, and provides the potential for dominant males to monopolise the matings within local populations.…”

Section: Introductionmentioning

confidence: 99%

Estimating the relatedness in a population of grey squirrels Sciurus carolinensis, using DNA fingerprinting

David-Gray

Gurnell²,

Hunt³

1999

Acta Theriol.

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. 1999. Estimating the relatedness in a population of grey squirrels Sciurus carolinensis, using DNA fingerprinting. Acta Theriologica 44: 243-251.Studies on the behaviour of grey squirrels Sciurus carolinensis Gmelin, 1788 and other species belonging to the same genus, suggest they exhibit dominance hierarchies among both males and females, and their mating strategy is promiscuous or polygynous. However, there is little information available on how dominance translates into reproductive success or on the levels of genetic variation or genetic substructuring within a population. To address these questions, we used multilocus DNA fingerprinting to quantify genetic diversity and estimate relatedness amongst individuals in a free--ranging population of grey squirrels. Background band-sharing values revealed a high degree of genetic diversity existed. The frequency distribution of band-sharing values between known first order relatives and presumed unrelated animals was significantly different. Estimates of relatedness between individuals were therefore based on threshold levels of genetic similarity and used as a tool to infer close kinship. Possible kinship groups were identified using the spatial distribution of the home ranges of adults and juveniles. Levels of relatedness between neighbouring adults was low with five family units identified comprised of putative parents and their offspring. Several juveniles from the single cohort revealed levels of relatedness intermediate between first order relatives and unrelated animals, suggesting possible second order relationships (eg half siblings) existed. The implications of these relationships are discussed.

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Reproductive physiology of the Grey squirrel (Sciurus carolinenis)

Cited by 14 publications

References 0 publications

Home Ranges of the Nilgai Antelope (Boselaphus tragocamelus) in Texas

Home Ranges of the Nilgai Antelope (Boselaphus tragocamelus) in Texas

Comportamentos e atividade diária de Sciurus ingrami (Thomas) em cativeiro (Rodentia, Sciuridae)

Estimating the relatedness in a population of grey squirrels Sciurus carolinensis, using DNA fingerprinting

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