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Some introduced passerine species can cause considerable damage to arable crops in New Zealand. These crops are usually surrounded by hedgerows and, in Canterbury, these are commonly Monterey pine (Pinus radiata) and macrocarpa (Cupressus macrocarpa). The present study aimed to determine whether bird abundance and species composition differed among field margins bordered either by hedgerows of common species (pine and macrocarpa), mixed hedgerows (a variety of native and introduced plant species) or bare fence lines (no hedgerow). The numbers and species of birds along line transects traversing field margins were recorded on three different farms during spring and summer 2012. Generally, the same 12 introduced bird species were found along the different margins. However, a greater number of chaffinch (Fringilla coelebs), European goldfinch (Carduelis carduelis), European greenfinch (Carduelis chloris) and, to a lesser extent, house sparrow (Passer domesticus) were recorded in common hedgerows than in mixed species hedgerows and bare fence lines. This study indicates that composition of vegetation at field margins may influence the relative abundance of introduced birds.

The movement of managed alfalfa leafcutting bees (Megachile rotundata (F.)) in and around carrot flowers is compared with that of the honey bee (Apis mellifera L.) in a field trial to assess their relative efficacy as pollinators of hybrid carrot seed crops. Seed set is measured on carrot flowers inside cages with and without alfalfa leafcutting bees and compared with seed set in open field conditions in the presence of honey bees. Non-caged alfalfa leafcutting bees spend a similar amount of time on umbels and visit a similar number of umblets per umble as honey bees. Seed yield (number and weight of seeds) for flowers pollinated by caged alfalfa leafcutting bees is similar to that of flowers pollinated mainly by honey bees. However, it is not known how effective alfalfa leafcutting bees are compared with honey bees when not confined in cages (i.e. open pollination) under a range of commercial field conditions, particularly in the absence of plant species preferred by alfalfa leafcutting bees.