The P50 of whole blood [30 ̊C, PCO∑=2.08kPa (15.6mmHg)] decreases during embryonic development from approximately 6.7kPa (50mmHg) at 15 days to about half this value at hatching (86 days), paralleling a decrease in ATP from 100 to 5–10 mmol g21 Hb. There is also a progressive changeover from embryonic to adult haemoglobin (HbA). A pulse of 2,3-diphosphoglycerate (2,3-DPG) (18 mmol g21 Hb) occurs...

In altricial birds, the nestling period is an important part of the breeding phase because the juveniles may spend quite a long time in the nest, with associated high energy costs for the parents. The length of the nestling period can be variable and its duration may be influenced by both biotic and abiotic factors; however, studies of this have mostly been undertaken on passerine birds. We stu...

Female insects have a limited energy budget to invest in reproduction. Clutch size and egg size are two traits typically involved in energy budget trade-offs, and an optimum clutch size is generally predicted. This trade-off, however, is influenced by many factors including the probability of egg parasitism. We studied this possibility in the pine processionary moth (Thaumetopoea pityocampa), w...

Many experiments require early determination of offspring's sex as well as early marking of newborns for individual recognition. According to animal welfare guidelines, non-invasive techniques should be preferred whenever applicable. In our group, we work on different species of song birds in the lab and in the field, and we successfully apply non-invasive methods to sex and individually mark c...

These experiments are part of a larger study designed to investigate the influence of husbandry parameters on the life history of the apple snail, Marisa cornuarietis. The overall objective of the program is to identify suitable husbandry conditions for maintaining multi-generation populations of this species in the laboratory for use in ecotoxicological testing. In this article, we focus on th...

Prostaglandins participate in a variety of female reproductive processes, including ovulation, fertilization, embryo implantation and parturition. In particular, maternal prostacyclin (PGI(2)) is critical for embryo implantation and the action of PGI(2) is not mediated via its G-protein-coupled membrane receptor, IP, but its nuclear receptor, peroxisome-proliferator-activated receptor δ (PPARδ)...

I examined the role of vibrations in predator-induced early hatching of red-eyed treefrogs, Agalychnis callidryas. The arboreal eggs of A. callidryas hatch up to 30% early if attacked by egg-eating snakes. This induced hatching is a behavioural response that occurs once snakes begin physically disturbing the clutch, and is sufficiently rapid to allow most embryos to escape. Other intense but be...

Maternal yolk androgens in avian eggs have been shown to affect numerous offspring traits. These changes in offspring phenotype represent examples of maternal effects and are thought to adjust offspring development to the posthatching environment. When studying the functional consequences of yolk hormones it is, therefore, crucial to manipulate the yolk androgen concentrations as well as the en...

One of the major challenges in ecological research is the elucidation of physiological mechanisms that underlie the demographic traits of wild animals. We have assessed whether a marker of plasma oxidative stress (TBARS) and plasma haptoglobin (protein of the acute inflammatory phase response) measured at time t predict five demographic parameters (survival rate, return rate to the breeding col...

The effect of exposing the lymnaeid snail Fossaria cubensis to the trematode Fasciola hepatica on the snail population's life-history traits was studied under laboratory conditions. Exposed individuals showed a lower survival rate than control snails, although from week 7 onward a slower decrease of this parameter in relation to the control group was observed. There were higher values of fecund...