A Manx hen harrier has been fitted with a satellite tracker as part of a scheme to monitor movement of the species and deter illegal persecution in the UK.
The juvenile female harrier, named Hetty, had the tag fitted by an RSPB bird ringer and an experienced local volunteer under a joint scheme run by Manx BirdLife and the RSPB’s Hen Harrier LIFE+ Project.
“The local population of hen harriers was considered to be doing well until recently,” Manx BirdLife Chief Operating Officer, Dora Querido said. “However a sudden decline of 49% was recorded on the island between 2004 and 2010, with numbers dropping from 54 to just 29 pairs.”
“Little is known about the reasons for decline of the Manx population and the satellite tagging will help us understand how juvenile hen harriers disperse and study their winter habits during the lifespan of the tag.”
“Given the wide-ranging nature of hen harriers, it is possible that there is some degree of movement between the Isle of Man, UK and Ireland.”
Hen harriers – in addition to their normal diet of small birds and mammals – sometimes eat grouse. This brings them into conflict with the driven grouse shooting industry. Scientific research shows that Illegal killing of hen harriers threatens their survival in some parts of the UK and that this persecution is principally associated with driven grouse moors
“Once fitted and while functioning, the satellite tag will transmit the location of the bird on a regular base” explained the local ringer responsible for the operation.
“However, should the bird stop moving for a set period of time, a “mortality switch” is triggered sending out a separate VHF radio signal which makes it easier to find the device and the bird.”
The public will be able to follow Hetty’s movements through an interactive map on the LIFE Project website and Manx BirdLife links.
However, for security reasons information will be shown with a two-week delay and at low map resolution making it impossible for the public to identify precise locations.
The bird was named Hetty by Lesley Cowin in memory of her late father Sydney Cowin who bequeathed an amount of money to the local charitable trust the Society for the Preservation of the Manx Countryside (SPMC). The society partly funded the costs of this procedure. Many thanks go to the SPMC for making this possible.
The experienced local RSPB volunteer followed and monitored the progress of an active hen harrier nest from April to determine likely hatching and fledgling dates and advised on the most suitable date for tagging. An RSPB UK volunteer came across to fit the solar-powered tag.
“One male and a female chick from the same nest were also color ringed” the local ringer said.
“All monitoring, ringing, and satellite tagging work was carried out under full appropriate licences from the relevant Manx and UK authorities and in strict accordance with the law”
Manx BirdLife are appealing to the public to help maintain the island’s population. If you see a hen harrier with a black plastic ring on their left leg please send the details to firstname.lastname@example.org.
Male hen harriers are a pale grey colour, females and immatures are brown with a white rump and a long, barred tail which give them the name ‘ringtail’. They fly with wings held in a shallow ‘V’, gliding low in search of food, which mainly consists of meadow pipits and voles.
Two more satellite tags will be fitted on young birds next year and an appeal for sponsorship of the project has been made by Manx BirdLife.