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Biology subjects

Howard, C. E.

Publications and source records attributed to Howard, C. E..

2 recordsLinked to original sources

Differential effects of farming practice on cuckoo bumblebee communities in relation to their hosts

O_LIBees are important for vital pollination of wild and crop plants, but are in decline worldwide. Intensification of agriculture is a major driver of bee decline. Organic farming practices are designed to limit environmental impacts of agriculture and can increase bee abundance and species diversity. However, studies have been heavily focused towards some guilds of bees, overlooking others. This includes social brood parasites, cuckoo bumblebees, an understudied bee lineage. Little is known about bumblebee host and cuckoo population dynamics, and the effects of farming practice on cuckoo bumblebees have never previously been evaluated.\nC_LIO_LITo compare the effects of farming practice (organic vs conventional) on the abundance, species diversity, and community dissimilarity of cuckoo bumblebees and their hosts, we compared host and cuckoo community metrics across ten matched pairs of organic and conventional farms in Yorkshire, UK.\nC_LIO_LIAs found by many previous studies, host bumblebees were more abundant on organic farms than on conventional farms. Despite this, cuckoo bumblebees were equally abundant on both farm types. Contrary to prediction, community dissimilarity and species diversity were unaffected by farm type for both host and cuckoo communities.\nC_LIO_LISynthesis and applications: Results suggest that cuckoo bumblebee community metrics are not solely driven by host community metrics, and that cuckoos may respond differently from their hosts to differences among farming practices. This could, in turn, indicate that a unified management practice is not sufficient to conserve all bumblebee species.\nC_LI

ecology↗

Serotonergic modulation of walking in Drosophila

To navigate complex environments, animals must generate highly robust, yet flexible, locomotor behaviors. For example, walking speed must be tailored to the needs of a particular environment: Not only must animals choose the correct speed and gait, they must also rapidly adapt to changing conditions, and respond to sudden and surprising new stimuli. Neuromodulators, particularly the small biogenic amine neurotransmitters, allow motor circuits to rapidly alter their output by changing their functional connectivity. Here we show that the serotonergic system in the vinegar fly, Drosophilamelanogaster, can modulate walking speed in a variety of contexts and in response to sudden changes in the environment. These multifaceted roles of serotonin in locomotion are differentially mediated by a family of serotonergic receptors with distinct activities and expression patterns.

neuroscience↗