John L. Cummings

Blackbird Repellency of Selected Registered Pesticides

Abstract Bird depredation of agricultural crops is a worldwide problem. New strategies to include chemical repellents are needed to mitigate crop losses. We evaluated 3 preplant seed treatments (Apron XL® LS [Syngenta Crop Protection, Greensboro, NC], Dividend Extreme® [Syngenta], and Maxim® 4 FS [Syngenta]), one foliar insecticide (Karate® with Zeon Technology™ [Syngenta]), and one foliar fungicide (Tilt® [Syngenta]) as potential blackbird repellents in caged feeding trials and a field study. For all repellents tested, red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated and treated rice during preference testing in captivity. We observed a positive concentration–response relationship among birds offered rice treated with 25%, 50%, 75%, 100%, or 200% of the manufacturer label for Dividend Extreme, Karate, and Tilt. Relative to pretreatment, blackbirds ate 32% and 69% less rice treated with 100% and 200% Tilt label rates, respectively, during the concentration–response test. Maximum repellency of Dividend Extreme and Karate was 55% at 200% of their label rates. We observed no repellency of a combination of Apron and Maxim at 25–200% label rates during the concentration–response test. We subsequently measured rice crop consumption and propiconazole (active ingredient, Tilt) residues among 10 plots (i.e., netted enclosures) populated with red-winged blackbirds within a maturing rice field. Average mass of rice harvested between treated (Tilt) and untreated subplots did not differ. We recovered an average of 12.3 μg/g propiconazole immediately following the first application and 20.2 μg/g propiconazole immediately following the second application of Tilt. We recovered <0.1 μg/g propiconazole on 15 August 2006, just before populating plots with blackbirds. Thus, the label application of Tilt fungicide did not reduce blackbird consumption within a maturing rice field, and residues of the active ingredient were insufficient for repellent efficacy. Additional studies are needed to determine whether higher concentrations of Tilt repel blackbirds under field conditions and to evaluate other potential repellents for protection of newly planted and ripening crops.

Caffeine Formulation for Avian Repellency

Abstract Nonlethal management alternatives are needed to reduce avian depredation of agricultural crops. Caffeine has promise as an effective, economical, and environmentally safe avian repellent, yet formulation improvements are needed for field applications. We included sodium benzoate in subsequent formulations to enhance the solubility of caffeine. Red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated rice and rice treated with 250 ppm or 10,000 ppm caffeine and sodium benzoate in captivity. We observed a positive concentration–response relationship among birds offered rice treated with 250 ppm, 1,000 ppm, 2,500 ppm, 5,000 ppm, 10,000 ppm, or 20,000 ppm caffeine and sodium benzoate. Relative to the pretreatment of the concentration–response test, repellency was >85% for rice treated with our 2,500- to 20,000-ppm treatments. We conducted seed germination experiments and associated residue analyses to evaluate the potential phytotoxicity of various caffeine formulations under controlled environmental conditions. The optimized formulation enhanced the solubility of tank mixtures and ameliorated the negative impacts of seed treatments to germination. Our caffeine formulation provides an applicable, nonlethal alternative for managing blackbird impacts to agricultural production.

Registered Pesticides and Citrus Terpenes as Blackbird Repellents for Rice

Abstract Nonlethal management alternatives are needed to minimize bird depredation of agricultural crops. We conducted 8 caged feeding tests and 2 field studies to evaluate 2 registered fungicides (GWN-4770, Gowan Company, Yuma, AZ; Quadris®, Syngenta Crop Protection, Greensboro, NC), a neem oil insecticide (Aza-Direct®, Gowan Company), and a novel terpene formulation (Gander Gone, Natural Earth Products, Winter Springs, FL) as avian repellents. For all candidate repellents, red-winged blackbirds (Agelaius phoeniceus) discriminated between untreated and treated rice during preference-testing in captivity. We observed a positive concentration–response relationship among birds offered rice treated with 2,500 ppm, 5,000 ppm, 7,500 ppm, 11,000 ppm, or 22,000 ppm GWN-4770. Relative to pretreatment, blackbirds consumed 34% and 77% less rice treated with 11,000 ppm and 22,000 ppm GWN-4770, respectively, during the concentration–response test. Maximum repellency among other tested compounds was <40% during the concentration–response test. Blackbirds consumed 28% of rice seeds treated with 20,000 ppm GWN-4770 and 68% of untreated seeds broadcast within rice fields in southwestern Louisiana, USA. We observed 50% fewer unprotected seedlings than those treated with 10,000 ppm GWN-4770 within a drill-seeded rice field in southeastern Missouri, USA. The manufacturer subsequently applied for a United States patent for the active ingredient of GWN-4770 as an avian repellent. Although additional registration criteria and formulation optimization must be satisfied to enable the commercial availability of GWN-4770 as an avian repellent, additional efficacy studies of GWN-4770 and other promising repellents under extended field conditions are warranted for protection of newly planted and ripening rice.

Collision avoidance by migrating raptors encountering a new electric power transmission line

ABSTRACT Avian collisions with overhead power lines are of conservation concern, particularly in migration corridors. We studied potential collisions where an existing power line supported by towers 20–25 m tall was replaced by the Susquehanna-Roseland line (S-R line), a new line with towers 55–60 m tall. The S-R line crosses Kittatinny Ridge, a corridor for raptors migrating south through New Jersey and Pennsylvania, USA. We hypothesized that the S-R line, which on Kittatinny Ridge includes markers designed to increase its visibility to birds, would cause migrating raptors to react in 1 of 3 ways: (1) to not alter flight elevation, but to pass safely through the S-R wire zone; (2) to not alter flight elevation, and to not pass safely through the wire zone, leading to collisions; or (3) to alter flight elevation and to pass safely above or below the S-R wire zone. To evaluate these hypotheses, we recorded the flight elevations of migrating raptors in 2013 before construction of the S-R line and in 2014 postconstruction. Preconstruction, we recorded 3,698 raptor crossings. Most raptors (72%) crossed above the anticipated S-R wire zone. Some (24%) passed through the anticipated S-R wire zone, and a few (4%) passed below the anticipated S-R wire zone. Postconstruction, we recorded 4,482 crossings. Most raptors (92%) crossed above the S-R wire zone. A few passed through (5%) or below (3%) the S-R wire zone. Postconstruction, raptors responded to the new line by flying higher than they had when traversing the previous line. We did not observe any collisions. Altered flight elevations and the absence of observed collisions supported hypothesis 3. If similar patterns occur at other lines that cross diurnal migration corridors along ridges, then future monitoring may be better focused on potentially riskier settings, such as areas where migrating birds do not have deflected winds to assist with gaining elevation.

Effectiveness of AV-1011® to Reduce Damage to Drill-Planted Rice from Blackbirds

ABSTRACT n We determined efficacy of AV-1011® (a 50% anthraquinone product; Arkion® Life Sciences, New Castle, Delaware) on drill-planted rice seed to reduce blackbird damage and determine residue levels of anthraquinone (AQ) in rice seeds and seedlings and in the mature rice crop under field enclosures at the University of Missouri-Delta Center farm near Portageville, Missouri. Red-winged blackbird (Agelaius phoeniceus) damage was higher for untreated than AV-1011® treated rice seedlings at assessment period 3, 15 days postplanting (F 1,141 = 15.81, P < 0.001), and at assessment period 4, 19 days postplanting F 1,136 = 11.54, P = 0.001). Blackbird damage to AV-1011-treated seedling for assessment periods 3 and 4 was 8% and 7%, respectively, while blackbird damage to untreated seedlings during the same assessment periods was 52% and 44%. More blackbirds used untreated plots than AV-1011-treated plots during assessment periods 2–4 (F 1,17.8 = 20.02, P < 0.001). Overall concentrations of AQ on seeds averaged 5,993 µg/g or 0.59% during the test period. Concentrations of AQ in mature rice seed and plant collected at harvest averaged 1.22 µg/g and 0.10 µg/g, respectively. AV-1011 offers promise for reducing bird depredations to newly planted rice, but additional testing should be conducted to evaluate this repellent in a large-scale field setting.

Evaluation of Flight Control™ and Mesurol® as repellents to reduce horned lark (Eremophila alpestris) damage to lettuce seedlings

Abstract We conducted enclosure trials near Huron, CA in the San Joaquin Valley from 12 to 23 January 1999 to determine the efficacy of Flight Control™ (50% anthraquinone) and Mesurol ® (75% methiocarb) in preventing horned lark damage to lettuce seedlings. Flight Control™ (FC) and Mesurol ® were evaluated as foliar sprays at application rates of 2.79 and 2.27xa0kgxa0ha −1 , respectively. Horned lark damage to lettuce seedlings treated with antraquinone was greater ( p =0.015) than for methiocarb ® , 60 versus 20%, respectively, and seedlings in control plots were 100% destroyed. While this level of damage is probably unacceptable to lettuce growers, it should be remembered that the enclosure situation caused an artificially high bird pressure on the crop. Further studies in open fields under a more normal bird pressure are warranted.

Evaluation of a macro encapsulated repellent to reduce risk of white phosphorous ingestion by waterfowl foraging in a contaminated marsh

Abstract White Phosphorous contamination of a marsh at a U.S. Army artillery training range in Alaska is a causative agent for waterfowl mortality. We developed an encapsulated bird repellent containing the active ingredient, methyl anthranilate, and evaluated the formulations efficacy in reducing feeding activity by ducks, reducing mortality of ducks feeding in contaminated sediments, and the repellents ability to move ducks from contaminated areas. The formulation has a limited life span of about 4 days. However, in pen trials feeding activity of mallards can be reduced by up to 80%. Long term exposure to treated sediments confers a survival advantage to mallards tested in pens, and free-ranging mallards can be moved off of treated sections of marsh. This prototype formulation may have utility in the short-term remediation of contaminated sediments for the protection of waterfowl.

Polyurea Elastomer Protects Utility Pole Crossarms From Damage by Pileated Woodpeckers

Abstract Woodpeckers cause severe damage to utility poles and crossarms, resulting in substantial economic losses to utility companies. We evaluated effectiveness of a polyurea elastomer coating material for reducing damage by captive pileated woodpeckers (Dryocopus pileatus) to utility pole crossarms. Because woodpeckers inflicted essentially no damage to the fully coated crossarms, we infer that the coating material holds substantial promise for protecting utility pole crossarms. Additional research should be conducted to evaluate the coating under field conditions.

Dispersal of viable row-crop seeds of commercial agriculture by farmland birds: implication for genetically modified crops

To address some concerns about the expansion of genetically engineered pharmaceutical and industrial crops to outdoor plantings and potential impacts on the human food supply, we determined whether commercial agriculture seeds of maize or corn Zea mays L., barley Hordeum vulgare L., safflower Carthamus tinctorius L. and rice Oryza sativa L. are digested or pass viably through the digestive tract, or are transported externally, by captive mallard ducks Anas platyrhynchos L., ring-necked pheasants Phasianus colchicus L., red-winged blackbirds Agelaius phoeniceus (L.) and rock pigeons Columba livia Gmelin (with the exception of whole maize seeds which were too large to feed to the blackbirds). These crop seeds, whether free-fed or force-fed, did not pass through the digestive tract of these bird species. The birds nonetheless did retain viable seeds in the esophagus/crop and gizzard for several hours. For example, after foraging for 6 h, mallards had retained an average of 228 +/- 112 barley seeds and pheasants 192 +/- 78 in the esophagus/crop, and their germination rates were 93 and 50%, respectively. Birds externally transported seeds away from the feeding location, but in only four instances were seeds found attached to their muddy feet or legs and in no case to feathers. Risk of such crop seeds germinating, establishing and reproducing off site after transport by a bird (externally or internally) or movement of a carcass by a predator, will depend greatly on the crop and bird species, location, environmental conditions (including soil characteristics), timing, and seed condition.