Klug et al., 2019 Rose-ringed Parakeet Control Tools Critical Review of Potential Control Tools for Reducing Damage by the Invasive Rose-ringed Parakeet (Psittacula krameri) on the Hawaiian Islands Page E. Klug1†, William P. Bukoski2, Aaron B. Shiels3, Bryan M. Kluever4, and Shane R. Siers5 15 June 2019 1 USDA APHIS Wildlife Services National Contents Wildlife Research Center, North Dakota Field Station, Fargo, ND Executive Summary 2 Aims and Goals . .2 2 USDA APHIS Wildlife Services, Hawaii State Recommendations and Conclusions . .2 Office, Kauai, HI Legal and Regulatory Status 3 3 USDA APHIS Wildlife Services National Legal Aspects . .3 Wildlife Research Center, Rodents Project, Disclaimer . .3 Fort Collins, CO Rose-ringed Parakeets 4 4 USDA APHIS Wildlife Services National Physical Description . .4 Wildlife Research Center, Florida Field Vocalizations and Hearing . .6 Station, Gainesville, FL Distribution and Range . .6 5 USDA APHIS Wildlife Services National Population Growth and Spread . .8 Wildlife Research Center, Hawaii Field Reproduction . .9 Station, Hilo, HI Survival and Mortality . 11 Habitat . 11 † Study director, corresponding author: Flocking and Roosting . 12 [email protected] Food Habits and Feeding Behavior . 12 Sponsor: Effects of Rose-Ringed Parakeets 13 State of Hawai‘i, Department of Land and Natural Economic Effects . 13 Resources, Honolulu, HI Ecological Effects . 13 Suggested Citation: Human Health and Safety and Wildlife Klug, P. E., W. P. Bukoski, A. B. Shiels, B. M. Disease . 15 Kluever, and S. R. Siers. 2019. Critical review of potential control tools for reducing damage by the Current and Potential Management Practices 16 invasive Rose-ringed Parakeet (Psittacula krameri) Population Reduction and Population on the Hawaiian Islands. Unpublished Final Report Monitoring . 16 QA-2836. USDA APHIS WS NWRC. Fort Collins, CO. 52 pp. Chemical Control . 17 Lethal Shooting . 18 Capture Devices . 20 Fertility Control . 21 Exclusion Techniques . 22 Physical Exclusion . 22 Auditory Exclusion . 23 QA-2836 USDA APHIS Wildlife Services National Wildlife Research Center 1 Klug et al., 2019 Rose-ringed Parakeet Control Tools Repellents . 23 for immediate action. However, uninformed Tactile Repellents . 23 reactionary measures may not be cost-effective Chemical repellents . 24 and may worsen the problem (e.g. shooting Frightening Devices . 25 at roosts may simply disperse roosting birds to Auditory . 26 inaccessible areas). Thus, our objective was to Visual . 27 complete a comprehensive, critical review of bird Habitat Modification . 29 damage management tools and their potential use Vegetation Management . 29 for controlling parakeet damage on the Hawaiian Crop Management and Alternative Islands. Specifically, we reviewed, summarized, Food . 30 and interpreted existing information to evaluate the potential effectiveness of damage management Human Dimensions 31 tools for RRPA and the best strategies for deploy- ment. We used the behavior and ecology of RRPA Conclusions 31 to inform our tool recommendations and their potential efficacy under various damage scenarios Acknowledgements 31 (e.g., urban, agricultural). We identified candidate tools for further evaluation in lab and field studies Literature Cited 32 and provided guidelines for actions that can be taken to protect stakeholder assets at this time. Executive Summary Recommendations and Conclusions Aims and Goals We recommend an integrated pest management Rose-ringed parakeet (Psittacula krameri, Scopoli; strategy including lethal and non-lethal tools hereafter RRPA) are present on the Hawaiian specific to the damage problem and surrounding Islands of Kaua‘i, O‘ahu, and Hawai‘i. The environment. The effects of non-lethal tools RRPA is an invasive bird that can cause economic are temporary given RRPA learn quickly and damage and is a threat to natural resources and habituate to threats without a negative stimu- human health and safety. A single pair of RRPA lus. Thus, success with non-lethal tools requires were introduced on Kaua‘i in the 1960s. The combining multiple techniques and changing or current population estimate is 6,800 birds as of moving them regularly. Lethal removal of birds 2018 with documented exponential growth. RRPA in local damage situations is not effective for are major pests of agricultural crops world-wide population control. To alleviate damage through and in Kaua‘i and O‘ahu have been shown population reduction, a well-funded, coordinated, to negatively impact seed crops including corn and sustained lethal campaign is required at broad (Zea mays) and soybeans (Glycine max) as well scales. Future research should include an adaptive as fruit crops including lychee (Litchi chinensis), management plan for population suppression in longan (Dimocarpus longan), rambutan (Nephelium addition to lab and field-based tests of non-lethal lappaceum), and many others. Invasive parakeets tools and their effectiveness at reducing RRPA pose a risk to natural resources through the damage on the Hawaiian landscape. dispersal of invasive plant seeds, destruction of The primary management tools for population native seeds, and competition with and aggression reduction of RRPA include shooting with limited toward native wildlife. Invasive parakeets are use of trapping at foraging sites and hand net a potential threat to human health and safety capture at roosting sites (Table 1). We recommend through unsanitary conditions and the risk of shotguns for moving birds and air rifles for precise disease transmission to livestock and humans removal of birds perched in crops or roosting in agricultural fields or urban roosts. The trees. Shooting strategies should be applied in alarming increase in invasive RRPA on the island a manner that does not simply disperse birds, of Kaua‘i, and the damages they cause, has compromising the ability of managers to access compelled multiple stakeholder groups to appeal nesting and roosting sites. Further research is QA-2836 USDA APHIS Wildlife Services National Wildlife Research Center 2 Klug et al., 2019 Rose-ringed Parakeet Control Tools needed on fertility control via contraceptives given devices used in combination and reinforced with functionality on Kaua‘i may be limited by inability a negative stimulus (shooting). In areas with high to establish feeding stations due to abundant human density, auditory devices are not practical alternative food resources and potential nontarget due to noise pollution. Promising hazing tools consumers. Currently, no toxicants are approved include lasers and water devices to cause reflexive by regulatory agencies for RRPA. withdraw or make the roost undesirable. The primary management tools for reducing RRPA damage at agricultural sites include 1) modifying the crop and surrounding habitat, 2) Legal and Regulatory Status exclusionary devices, and 3) frightening devices Legal Aspects (Table 2). Habitat suitability for RRPA can be reduced by altering the timing, siting, spacing, and RPPA are nonnative and not protected by the crop varieties used in agricultural practice. We United States Migratory Bird Treaty Act. RRPA recommend a) growing sensitive crops away from are not listed as an injurious species under the RRPA flight routes, loafing sites, and night roosts, US Lacey Act (18 U.S.C. 42), but are listed by the b) eliminating early and late-maturing crops in State of Hawai‘i (http://dlnr.hawaii.gov/dofaw/ the same locality to avoid birds establishing a files/2013/09/Chap124a.pdf). This designation feeding site, c) advancing harvest date to limit the prohibits the release, transport, or export of damage period, d) delaying disking or destruction RRPA with importation restricted by the Hawai‘i of unused crops to provide alternate forage, and State Department of Agriculture. All wild birds e) using large plots and reducing space between including introduced species are protected under plots due to damage being greater at field edges. Hawai‘i Revised Statues (HRS183D and HAR124), Habitat suitability can be reduced by altering the thus a nuisance wildlife control permit must surrounding landscape by a) removing loafing be obtained through the Hawai‘i Department of areas near the crop to be protected and b) Land and Natural Resources to lethally take RRPA. providing alternative forage by planting lure crops Various avian repellents are registered by the US in extra tillable space and not harassing birds in EPA and State of Hawai‘i with label specifications the lure crop. Exclusionary devices can deter for various habitats. Follow all state and local RRPA from entire crop fields and orchards (e.g., regulations for firearm discharge (HRS-134; netting over entire trees and plots) or simply limit https://web.archive.org/web/20111129064310 / access to the part of the plant to be protected http://www.honolulupd.org/info/gunlaw.htm) (e.g., bags, netting, or plastic over fruiting bodies and laser use under Hawai‘i Revised Statues only). We recommend multiple visual and (HRS-136; lasers https://www.laserpointersafety. auditory frightening devices used in combination com/rules-general/uslaws/uslaws.html). and reinforced with a negative stimulus (i.e., lethal shooting). Promising tools include lasers Disclaimer due to parakeets visually perceiving laser lines as startling, drones due to the ability to access Wildlife can threaten the health and safety of hard-reach areas for hazing, and bioacoustics due you and others in the area. Use of damage to noises that occur naturally in the environment prevention and control