Rose-Ringed Parakeets

Rose-ringed parakeets (Psittacula krameri; hereafter RRPA; Figure 1) are an invasive species in the United States, present in Alabama, Louisiana, Texas, and Virginia, and with established populations in California, Florida, and Hawaii. They are also the most successful species of invasive parakeet, worldwide. RRPA can cause significant damage to agriculture, including grains, oilseeds, fruits, and ornamental plants. Large flocks of RRPA roost near human infrastructure resulting in concerns about human health and safety (e.g., collisions with aircraft, disease transmission, feces accumulation, and noise complaints). The population growth and spread of RRPA is of conservation concern given the potential impact on native wildlife, spread of invasive plant seeds, and destruction of native plants. RRPA are an agricultural pest with a generalist diet and feeding behaviors that increase the severity of crop damage (Figure 2). RRPA damage corn by feeding on the anthers and pollen of the inflorescence, the tender cob stage, and the milky cob stage up until maturity. RRPA perch on sunflower heads and access the seeds that are hulled prior to consumption. Damage to tree fruits is greater on the top branches compared to the side and bottom branches. RRPA attack stored grains and eat unripe fruit, extending the damage period. RRPA often discard partially-eaten food. Crop damage varies with some fields experiencing more damage due to the timing of crop maturity or location (e.g., field or orchard edges have greater damage than interior). RRPA strip roosting trees (e.g., royal palms in Kauai) of their leaves. A long-term management plan that involves sustained lethal control is necessary to reduce invasive RRPA populations and their damage. In the meantime, the following damage management methods may provide short-term relief from RRPA damage

Evaluation of roost culling as a management strategy for reducing invasive rose‑ringed parakeet (\u3ci\u3ePsittacula krameri\u3c/i\u3e) populations

Rose-ringed parakeets (Psittacula krameri) are one of the most widespread invasive avian species worldwide. This species was introduced to the island of Kaua‘i, Hawai‘i, USA, in the 1960s. The rapidly increasing population has caused substantial economic losses in the agricultural and tourism industries. We evaluated the efficacy of a roost culling program conducted by an independent contractor from March 2020 to March 2021. We estimated island-wide minimum abundance was 10,512 parakeets in January 2020 and 7,372 in April 2021. Over 30 nights of culling at four roost sites, approximately 6,030 parakeets were removed via air rifles with 4,415 (73%) confirmed via carcasses retrieval. An estimated average of 45 parakeets were removed per hour of shooter effort. The proportion of adult females removed in 2020 was 1.9 × greater when culled outside of the estimated nesting season. Of the four roosts where culling occurred, the parakeets fully abandoned three and partially abandoned one site. Of the three fully abandoned roosts, an estimated average of 29.6% of birds were culled prior to roost abandonment. The roost culling effort was conducted during the COVID-19 pandemic, when tourist numbers and foot traffic were greatly reduced. It is unknown how public perception of roost culling in public areas may impact future efforts. Findings suggest roost culling can be utilized for management of nonnative roseringed parakeet populations when roost size is small enough and staff size large enough to cull entire roosts in no greater than two consecutive nights (e.g., if two shooters are available for three hours per night, roost culling should only be attempted on a roost with ≤ 540 rose-ringed parakeets)

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Diets of Kauai’s invasive rose-ringed parakeet (\u3ci\u3ePsittacula krameri\u3c/i\u3e): evidence of seed predation and dispersal in a human-altered landscape

Rose-ringed parakeets (Psittacula krameri) are the world’s most successful introduced parrots, and[2000 individuals reside on Kauai, Hawaii. These birds destroy crops, but impacts to other native and non-native species are largely unknown. Our study objectives on Kauai were to determine: (1) diets of rose-ringed parakeets at five sites (n = 9–25 per site), by sex, through crop and gizzard analysis and carbon and nitrogen stable isotope analysis, and (2) whether birds are dispersing or depredating seeds. We found 100% of birds (n = 64) were eating plant material and 80% of their diet was seed; males had more food in their crops and gizzards than did females. Corn (Zea mays) was eaten by 67% of birds and averaged 31% of mass in crops and gizzards. Invasive yellow guava (Psidium guajava) was eaten by 97% of birds and averaged 30% of their diet. Parakeets are potentially dispersing yellow guava seeds, as 66% of birds had intact guava seeds, and each bird had an average of three intact seeds. Diets differed statistically among sites. Parakeets from Lihue Airport did not have any corn, and isotopic carbon values also supported low feeding on corn by birds at Lihue Airport. No seeds of native plants were identified in rose-ringed parakeet diets. Our findings of a diverse plant diet, frequent seed predation, and potential to disperse invasive species’ seeds implies that land managers in agricultural, urban, and natural areas should be concerned with the current expansion of these invasive birds on Kauai and elsewhere

Rose-Ringed Parakeets

Rose-ringed parakeets (Psittacula krameri; hereafter RRPA; Figure 1) are an invasive species in the United States, present in Alabama, Louisiana, Texas, and Virginia, and with established populations in California, Florida, and Hawaii. They are also the most successful species of invasive parakeet, worldwide. RRPA can cause significant damage to agriculture, including grains, oilseeds, fruits, and ornamental plants. Large flocks of RRPA roost near human infrastructure resulting in concerns about human health and safety (e.g., collisions with aircraft, disease transmission, feces accumulation, and noise complaints). The population growth and spread of RRPA is of conservation concern given the potential impact on native wildlife, spread of invasive plant seeds, and destruction of native plants. RRPA are an agricultural pest with a generalist diet and feeding behaviors that increase the severity of crop damage (Figure 2). RRPA damage corn by feeding on the anthers and pollen of the inflorescence, the tender cob stage, and the milky cob stage up until maturity. RRPA perch on sunflower heads and access the seeds that are hulled prior to consumption. Damage to tree fruits is greater on the top branches compared to the side and bottom branches. RRPA attack stored grains and eat unripe fruit, extending the damage period. RRPA often discard partially-eaten food. Crop damage varies with some fields experiencing more damage due to the timing of crop maturity or location (e.g., field or orchard edges have greater damage than interior). RRPA strip roosting trees (e.g., royal palms in Kauai) of their leaves. A long-term management plan that involves sustained lethal control is necessary to reduce invasive RRPA populations and their damage. In the meantime, the following damage management methods may provide short-term relief from RRPA damage

A novel parakeet‐selective feeder for control of invasive psittacines

Over 40 species of parrots, members of order Psittaciformes, have established nonnative populations globally. Monk parakeets (Myiopsitta monachus) are among the most invasive bird species worldwide. In their introduced range, populations of monk parakeets have caused negative impacts on native species, habitats, economies, and human safety. Lethal population management has been complicated by the intelligence of monk parakeets, as they quickly alter behavior to avoid risks. Further, lethal control programs have been halted due to public controversy, as parakeets are highly charismatic. The contraceptive DiazaCon has been demonstrated to effectively reduce fertility in monk parakeets and other psittacines. In field applications, chemical control agents (e.g., toxicants and contraceptives) must be delivered in a manner that prohibits access by nontarget species. We developed and tested a parakeet‐selective feeder. The feeder allows access by parakeets and limits access by nontarget bird species by lowering a wire exclusion curtain around the feeder, requiring a zygodactyl toe arrangement to access food. We tested the parakeet‐selective feeder in trials with captive and freeranging monk parakeets and nontarget species in Florida, USA. Monk parakeets successfully accessed food from the parakeet‐selective feeder throughout the study. The mean number of daily feeder uses by nontarget species decreased from a high of nearly 16 uses per day when the exclusion curtain was not implemented to \u3c1 use per day when implemented. Our findings suggest the parakeet‐selective feeder is a promising tool for delivery of bait treated with chemical control agents to manage monk parakeets and other nonnative parakeet populations, but implementation success will likely vary by target species, location, local faunal diversity, and availability of alternative forage

A novel parakeet‐selective feeder for control of invasive psittacines

Abstract Over 40 species of parrots, members of order Psittaciformes, have established nonnative populations globally. Monk parakeets (Myiopsitta monachus) are among the most invasive bird species worldwide. In their introduced range, populations of monk parakeets have caused negative impacts on native species, habitats, economies, and human safety. Lethal population management has been complicated by the intelligence of monk parakeets, as they quickly alter behavior to avoid risks. Further, lethal control programs have been halted due to public controversy, as parakeets are highly charismatic. The contraceptive DiazaCon has been demonstrated to effectively reduce fertility in monk parakeets and other psittacines. In field applications, chemical control agents (e.g., toxicants and contraceptives) must be delivered in a manner that prohibits access by nontarget species. We developed and tested a parakeet‐selective feeder. The feeder allows access by parakeets and limits access by nontarget bird species by lowering a wire exclusion curtain around the feeder, requiring a zygodactyl toe arrangement to access food. We tested the parakeet‐selective feeder in trials with captive and free‐ranging monk parakeets and nontarget species in Florida, USA. Monk parakeets successfully accessed food from the parakeet‐selective feeder throughout the study. The mean number of daily feeder uses by nontarget species decreased from a high of nearly 16 uses per day when the exclusion curtain was not implemented to <1 use per day when implemented. Our findings suggest the parakeet‐selective feeder is a promising tool for delivery of bait treated with chemical control agents to manage monk parakeets and other nonnative parakeet populations, but implementation success will likely vary by target species, location, local faunal diversity, and availability of alternative forage

Differences in Feeder Visitation by Invasive Rose-Ringed Parakeets (\u3ci\u3ePsittacula krameri\u3c/i\u3e) Between Hawaiian Islands

Rose-ringed parakeets (Psittacula krameri; parakeets) are among the most invasive bird species worldwide. In their introduced range, populations of this species have caused negative effects on native species, natural environments, economies, and human safety. Lethal population management has been complicated by the intelligence of the birds, as they quickly alter behavior to avoid risks. Further, lethal control programs have been halted due to public opposition, as parakeets are considered to be charismatic by animal welfare advocates. The contraceptive DiazaCon has been demonstrated to effectively reduce fertility in captive parakeets. In field applications, any chemical control agents (e.g., toxicants or contraceptives) must be delivered in a manner that prohibits access by non-target species. Parakeets are known to feed from bird feeders throughout their native and introduced range, suggesting contraceptivetreated bait may be a useful management strategy. However, our 24-week trials with free-ranging parakeets using platform, hopper, and tube feeders on the island of Kaua‘i did not result in any parakeet visitation and thus precluded further testing of using feeders to selectively deliver fertility control products. Nonetheless, multiple citizen science reports and other documentation indicate parakeets using feeders on the island of O‘ahu over a period of \u3e10 years, and recently on the island of Maui. Our findings suggest the chemical control of nonnative parakeet populations is a promising technique, but implementation success will likely vary by target population acceptance, location, local faunal diversity, and availability of alternative forage