Browsing All Posts filed under »reproduction«

Fish life histories: filling in the gaps

July 5, 2018

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Estimates of life history parameters such as age at maturity, maximum body size and rates of growth and mortality play a crucial role in understanding and managing animal populations, but in the case of many species they’re lacking or poorly measured.  Fortunately however, compilations of existing estimates now exist, and these databases open up opportunities […]

A mature approach to growth data

March 25, 2018

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The age at which an animal matures is a key life history trait with implications for ecology, evolution and population dynamics, but data on maturation can be costly to collect. However, in many animals growth occurs in two phases, with a change-point at maturity, which means that it’s sometimes possible to estimate the maturation age […]

Male fish copy and mislead their rivals

December 13, 2016

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Because the numbers of sexually receptive females are relatively low in wild guppy populations, male fish incur a high cost in searching for suitable mates. However, such costs can be reduced if males are able to collect information on females by observing their sexual interactions with other males. To assess this possibility, preference experiments were […]

The dynamics of habitat choice: alien predators stifle amphibian breeding

June 1, 2016

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The way that animals select habitats reflects their need to balance the costs and benefits associated with factors such as food availability and predation risk. Therefore, habitat choices should vary in response to changes in these key factors. As an example, amphibians are expected to continually adjust the relative amounts of time that they spend […]

Cold water plankton are bigger

March 23, 2016

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Because large-bodied zooplankton species have higher grazing rates, take a wider size-range of food items, and evade predators more easily than small species, variations in zooplankton body size can have a strong effect on aquatic food webs. An international group of biologists looked at the influence of temperature on the size of planktonic crustaceans by […]

Sustaining turtles

March 23, 2016

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Freshwater turtle populations are very vulnerable to increases in adult mortality, such as those caused by the incidental capture of turtles in commercial fishing nets. Modelling of data from Canada’s Lake Opinicon (780 ha) indicates that the loss of just two additional adult female map or painted turtles per year will lead to population extinction […]

Cutting reed beds while protecting bird diversity

December 18, 2015

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The common reed (Phragmites australis) occurs throughout the world and provides habitat for a wide range of animal species, including a number of reedbed specialists. Although reeds are commonly cut for commercial reasons and to prevent plant succession to wet woodland, it’s been shown that large-scale cutting can reduce the feeding and breeding success of […]