Life-history theory suggests that iteroparous plants should be flexible in their allocation of resources toward growth and reproduction. Such plasticity could have consequences for herbivores that prefer or specialize on vegetative versus reproductive structures. To test this prediction, we studied the response of the cactus bug (Narnia pallidicornis) to meristem allocation by tree cholla cactu...

Nonadditive genetic variation and genetic disequilibrium are two important factors that influence the evolutionary trajectory of natural populations. We assayed quantitative genetic variation in a temporary-pond-dwelling population of Daphnia pulex over a full season to examine the role of nonadditive genetic variation and genetic disequilibrium in determining the short-term evolutionary trajec...

Energy allocation among somatic maintenance, reproduction and growth varies not only among species, but among individuals according to states such as age, sex and season. Little research has been conducted on the somatic (physiological) maintenance of long-lived organisms, particularly ectotherms such as reptiles. In this study, we examined sex differences and age- and season-related variation ...

With the increase in popularity of reptiles as personal pets, there is an increasing desire to inhibit reproduction and the associated, and often times undesirable, effects. In an attempt to develop a therapeutic treatment to induce a temporary inhibition of reproduction, we implanted time-released pellets of tamoxifen, an estrogen binding inhibitor, or indomethacin, a prostaglandin synthesis i...

Life-history theory proposes that organisms must trade-off investment in current and future reproduction. Production of ornamental display is an important component of reproductive effort that has rarely been considered in tests of allocation trade-offs. Male eastern bluebirds (Sialia sialis) display brilliant ultraviolet-blue plumage that is correlated with mate acquisition and male competitiv...

In Caeté Estuary, the decrease of larval abundance downstream was attributed to reduced retention, since ebb tide densities prevailed mainly in the middle and lower estuary during the rainy season due to increased freshwater outflow. Anchovia clupeoides, Stellifer microps and Guavina guavina were most abundant in the late dry season on flood tides in the upper estuary, whereas ebb tide densitie...

Overlapping moult and reproduction might be crucial for long-distance migratory birds, which are time-constrained to complete these energy-demanding functions before the onset of migration. However, proximate factors modulating the potential trade-off between moult and breeding, such as haemoparasite infection and stress, have not been studied in wild avian populations. We investigated the occu...

Many plant and animal species reproduce both sexually and asexually. These 2 reproductive modes are both likely to be costly and, in many species, they occur at different times of the year. Here, I present information on the sexual and asexual reproductive biology of the brittle star Ophiactis savignyi (Echinodermata, Ophiuroidea) in the Florida Keys, USA. Small brittle stars (less than 3 mm) a...