Female Receptiveity, Embryonic Diapause, and Superfetation in the European Badger (Meles Meles: Implications for the Reproductive Tactics of Males and Females

Unique biphasic progestagen profile in parturient and non-parturient giant pandas (Ailuropoda melanoleuca) as determined by faecal hormone monitoring

The luteal phase of the giant panda has been exclusively assessed by studying urinary hormone patterns in a very few individuals. To better understand hormonal dynamics of protracted progestagen excretion in this endangered species, we monitored hormonal metabolites in the fibrous faeces of multiple females in the USA and China. Giant pandas that were anoestrual during the breeding season excreted baseline progestagen throughout the year. In contrast, there were two distinctive periods when progestagen excretion increased in females that experienced behavioural oestrus, the first being modest, lasting for 61–122 days, and likely reflecting presumptive ovulation. This increase was far surpassed by a secondary rise in progestagen excretion associated with a rejuvenated luteal capacity or hormone production from an extra-gonadal source. The duration of this ‘secondary’ rise in progestagen excretion averaged ∼45 days and terminated in a decline to baseline coincident with parturition or the end of a non-parturient luteal interval. Data revealed that, even with a complex, biphasic progestagen profile, the longitudinal patterns produced by giant pandas were relatively consistent among animals and across years within individuals. However, progestagen excretion patterns throughout this period could not be used to discriminate among non-pregnant, pregnant or pseudopregnant states.

Fitness measures in selection analyses: sensitivity to the overall number of offspring produced in a lifetime

Age at first (alpha) and last (omega) breeding are important life-history traits; however, the direction and strength of selection detected on traits may vary depending on the fitness measure used. We provide the first estimates of lifetime breeding success (LBS) and lambda(ind) (the population growth rate of an individual) of European badgers Meles meles, by genotyping 915 individuals, sampled over 18 years, for 22 microsatellites. Males are slightly larger than females, and the opportunity for selection was slightly greater for males, as predicted. lambda(ind) and LBS both performed well in predicting the number of grand-offspring, and both detected selection for a late omega, until the age of eight. Differential selection (S'(alpha)) for an early alpha, however, was only detected using LBS, not with lambda(ind). In declining populations (lambda(ind) < 1) selection favours reproduction later in life, whereas early reproduction is selected in increasing populations (lambda(ind) > 1). As 41% of badgers were assigned only one offspring (lambda(ind) < 1), whereas 40% were assigned more than two (lambda(ind) > 1), this cancelled out S'(alpha) measured by lambda(ind).

Conservation of the European mink (Mustela lutreola): focus on reproduction and reproductive technologies

The European mink (Mustela lutreola) is a small mammal, which belongs to the Mustelidae family (Carnivora). Earlier, the range of distribution of this species encompassed much of the European continent. During the 20th century, the numbers of European mink declined and the range of its distribution became reduced to three fragmented populations; today this species faces extinction. The urgent necessity for effective conservation efforts to protect the European mink is accepted by the governmental organizations as well as scientific communities of most European countries. In this paper, the reasons for the disappearance of European mink are reviewed and results of past conservation efforts based on captive breeding and reintroduction programmes are critically evaluated in the broad context of modern concepts of conservation genetics and reproductive biology. The data recently obtained on the reproduction and pre-implantation development of European mink and the prospects of incorporation of modern reproductive technologies into the conservation programme of this species are discussed.