Action: Use buffer zones to reduce the impact of invasive plant control
A study from the USA found that having buffer zones around snail kite Rostrhamus sociabilis nests, where no herbicides were sprayed, resulted in no nests being lost during a vegetation control programme.
Control efforts for invasive or problematic species can be very destructive and if not performed carefully may damage native species. We captured one study attempting to reduce the impact of invasive water plant control on snail kite Rostrhamus sociabilis nests, which are built above water in cattail Typha spp. and bulrush Scripus validus and are therefore vulnerable to herbicide applications, which can kill supporting vegetation, collapsing the nests.
Supporting evidence from individual studies
A study from March-July in 1988 in one wetland area in Florida, USA (Rodgers 1998), found that creating ‘no-spray’ buffer zones extending 68 m around the perimeter of kite colonies and 23-46 m around individual nests resulted in none of the 19 snail kite nests monitored being adversely affected by an aquatic plant control program: nests averaged 0.73 fledglings/nest and no nests collapsed. This fledging rate was similar to the overall rate of 0.74 fledglings/nest recorded in other regions of Lake Okeechobee during 1987–1993. Buffer zones were used in the breeding season, whilst water hyacinth Eichhornia crassipes and water lettuce Pistia stratiotes control measures were ongoing. The initiative was expanded to other lakes supporting kite nests in March 1989.