Seasonal constraints and reproductive performance in female Common hamsters (Cricetus cricetus)

Abstract

a b s t r a c tCommon hamsters (Cricetus cricetus) are hibernators and therefore show a pronounced seasonal breeding behaviour. Previous studies suggest that an early onset of reproduction after vernal emergence can be crucial for reproductive success in the current year. In Vienna, the winter 2005/06 was exceptionally cold and snow cover lasted until late March. This enabled us to investigate the effects of harsh winter conditions on seasonal timing and reproductive success in female Common hamsters. We investigated differences in the timing of the active season, reproductive performance and physical condition before hibernation between 2006 and previous years (2003-05) to determine potential environmental effects. Hamsters were live-trapped throughout the active period, weighed, individually marked and reproductive status was determined. The number of litters per season and litter size were determined in individual females. Vernal emergence in 2006 was considerably delayed and females mated significantly later than in 2003-05. Reproductive output in 2006 was about half that of the preceding years. This was particularly pronounced in the size of the females' first litters per season. The number of litters per female was similar in all periods. Almost 90% of the females in 2006 mated shortly after parturition and overlapped lactation of the first and gestation of the second litter. In 2003-05, only about one-third of the focal females successfully produced a litter after a postpartum oestrus. The time delay in spring 2006 led to a shorter active season compared to previous years reflecting the time constraints in this species. In conclusion, the results demonstrate that environmental factors can affect seasonal timing, reproductive output and preparation for hibernation in female Common hamsters.

Genetic rescue and the increase of litter size in the recovery breeding program of the common hamster (Cricetus cricetus) in the Netherlands. Relatedness, inbreeding and heritability of litter size in a breeding program of an endangered rodent

“…We therefore tested several non‐genetic factors like age of the father, breeding location and breeding year for possible effects on litter size, but no clear effect of non‐genetic factors on litter size was found, with exception of parity of the mother. First parity mothers had larger litters, which is in line with a study from Vienna where first litters were bigger than second litters, probably as a result of energetic constrains (Hufnagl et al 2011).…”

“…The common or European hamster ( Cricetus cricetus canescens ) is a small medium sized rodent, which inhabits cultivated fields and farmland on loss and loamy soils across Europe (Mitchell‐Jones et al 1999), although the species can also be found in urban areas in some countries (Franceschini‐Zink and Millesi 2008). Hamsters can produce two, sometimes three litters in the wild during one reproduction season, which last from May till August (Franceschini‐Zink and Millesi 2008; Hufnagl et al 2011). Males in the wild rarely survive longer then one year, while females have a better survival and can survive up to two years in the wild (Kuiters et al 2007).…”

“…Moreover, it is important to maintain genetic variation in litter size as litter size in the wild will have an optimum depending on the environment. Too large litter sizes cannot be maintained in environments where and in years when food is scarce ( HUFNAGL et al 2011).…”

“…although the species can also be found in urban areas in some countries ( FRANCESCHINI-ZINK and MILLESI 2008). Hamsters can produce two, sometimes three litters in the wild during one reproduction season, which last from May till August ( FRANCESCHINI-ZINK and MILLESI 2008;HUFNAGL et al 2011). Males in the wild rarely survive longer then one year, while females have a better survival and can survive up to two years in the wild ( KUITERS et al 2007).…”

Decreasing litter size of marmots over time: a life history response to climate change?

“…On the other hand, we expected earlier springs and improved spring conditions to increase litter size of Alpine marmots. Indeed, as reported in yellow-bellied marmots (Ozgul et (Hufnagl et al 2010), earlier springs should enable foraging females to increase body mass, which, in turn, should increase mean litter size.…”