Species Up­date

De­spite mil­lions of Red-legged Par­tridges re­leased into the coun­try­side ev­ery year, their breed­ing num­bers have de­clined

Bird Watching (UK) - - Contents -

Kate Risely throws the spot­light on Red-legged Par­tridges

NA­TIVE TO FRANCE and Spain, Red-legged Par­tridges were first in­tro­duced to Suf­folk in 1770 as game birds, and fol­low­ing years of re­leases they are now com­mon in low-ly­ing farm­land across the coun­try. When ap­proached, they pre­fer to run, and will burst from cover into fast flight at the last minute. Red-legs have white heads fea­tur­ing a black stripe through the eye, while the now less com­mon na­tive Grey Par­tridges have or­ange faces. In the two years I have lived in my vil­lage, in the prime par­tridge coun­try of East Anglia, I have only en­coun­tered one Grey Par­tridge in the lo­cal fields, but ev­ery fast-re­treat­ing Red-legged Par­tridge is checked in the hopes of see­ing an­other. More than six mil­lion Red-legged Par­tridges are re­leased into the coun­try­side ev­ery year by shoot­ing es­tates, and while many thou­sands are shot or oth­er­wise per­ish, th­ese re­leases sus­tain a sub­stan­tial breed­ing pop­u­la­tion of around 82 thou­sand pairs. While it may be tempt­ing to blame the in­tro­duced Red-legged for the de­cline of the na­tive Grey, there ac­tu­ally ap­pears to be lit­tle di­rect in­ter­ac­tion be­tween the two species. Both Red-legged and Grey Par­tridges feed on farm­land seeds, the avail­abil­ity of which has been greatly re­duced by agri­cul­tural in­ten­si­fi­ca­tion, re­sult­ing in the sig­nif­i­cant de­clines seen in Grey Par­tridge. Ac­cord­ing to the Breed­ing Bird Sur­vey, num­bers of breed­ing Red-legged Par­tridges have also de­clined since their peak num­bers in the 1970s, de­spite in­creas­ing num­bers be­ing re­leased, pos­si­bly be­cause cor­re­spond­ingly more are shot. While the two species do not ap­pear to di­rectly af­fect one an­other, there is ev­i­dence that shoot­ing op­er­a­tions based on high num­bers of Red-legged Par­tridges can lead to lo­cal ex­tinc­tion of the now red-listed Grey Par­tridge. When the first breed­ing bird at­las was pub­lished in the 1970s, Red-legged Par­tridges were mainly found in the drier south­ern and east­ern ar­eas of Eng­land, and had not been es­tab­lished in Scot­land or Wales de­spite re­peated at­tempts to in­tro­duce them. The ex­pla­na­tion given at the time was that th­ese parts were too wet for this south­ern Euro­pean species, but since then they have suc­cess­fully been in­tro­duced into Wales, the north of Eng­land, and Scot­land, though they are still most com­mon in the low­lands of East Anglia and around the Wash. We know rel­a­tively lit­tle about how far Red-legged Par­tridges move un­der their own steam, since there are no ring­ing re­cov­er­ies; the spurs on their legs make it un­safe to fit num­bered metal rings. How­ever, the sim­i­lar­ity of their sum­mer and win­ter dis­tri­bu­tions sug­gests that th­ese birds are not prone to mov­ing large dis­tances, and it seems likely that the in­crease in range is driven by birds spread­ing short dis­tances from re­lease sites. Their in­tro­duced Bri­tish dis­tri­bu­tion rep­re­sents a sub­stan­tial in­crease in the global range of this species, which oth­er­wise con­sists of the Iberian penin­sula, cen­tral and south­ern France, and a small part of Italy. The pop­u­la­tion has de­clined in their na­tive lands, partly due to over-hunt­ing, loss of habi­tat and hy­bridi­s­a­tion. It is per­haps ironic that the pres­sure of main­tain­ing a stock for sport, which has driven the huge in­crease of the species in this coun­try, has also caused them to de­cline in their orig­i­nal range. While all bird pop­u­la­tions are in­flu­enced by man to a greater or lesser ex­tent, per­haps the most af­fected are those des­ig­nated and ex­ploited as game birds.

Kate Risely is the Bri­tish Trust for Or­nithol­ogy’s Gar­den Bird­watch Or­gan­iser

We know rel­a­tively lit­tle about how far Red-legged Par­tridges move un­der their own steam, since there are no ring­ing re­cov­er­ies

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