Shrill carder bee  (Bombus sylvarum)

The loss of unimproved flower-rich grasslands, unploughed and unsprayed field headlands and hedge banks, as a result of agricultural improvement and intensification, has been the major cause for the decline of this and many other species of bumblebee. Heavy and continued grazing of flower-rich sites also poses a threat, and the existing populations along the Thames corridor are presently being threatened by proposed development.

The shrill carder bee is listed in the UK Biodiversity Action Plan (UKBAP) and is included on English Nature's Species Recovery Programme. It is one of several species of bee that is threatened in Britain, and in 1998, the UKBAP Bumblebee Working Group was set up to discover more about the status of many endangered bees. The group consists of seven conservation bodies, including three of the UK statutory bodies; English Nature, Countryside Council for Wales and Scottish Natural Heritage.

Survey work has begun to establish the true numbers and ranges of several species of bumblebee, and the working group has published a series of recommendations for restoring the bee's populations. These include encouraging the practice of leaving field margins undisturbed and free from herbicide and pesticide treatment, the re-creation of herb-rich meadows, and the modification of grazing regimes on existing grassland. They also suggest modifying the grazing patterns on existing grassland, and erecting artificial nest boxes to encourage queen bees to start a colony.