Evaluating an Alleged Mimic of the Monarch Butterfly: \u3ci\u3eNeophasia\u3c/i\u3e (Lepidoptera: Pieridae) Butterflies are Palatable to Avian Predators

Some taxa have adopted the strategy of mimicry to protect themselves from predation. Butterflies are some of the best representatives used to study mimicry, with the monarch butterfly, Danaus plexippus (Lepidoptera: Nymphalidae) a well-known model. We are the first to empirically investigate a proposed mimic of the monarch butterfly: Neophasia terlooii, the Mexican pine white butterfly (Lepidoptera: Pieridae). We used captive birds to assess the palatability of N. terlooii and its sister species, N. menapia, to determine the mimicry category that would best fit this system. The birds readily consumed both species of Neophasia and a palatable control species but refused to eat unpalatable butterflies such as D. plexippus and Heliconius charithonia (Lepidoptera: Nymphalidae). Given some evidence for mild unpalatability of Neophasia, we discuss the results considering modifications to classic mimicry theory, i.e., a palatability-based continuum between Batesian and Müllerian mimicry, with a quasi-Batesian intermediate. Understanding the ecology of Neophasia in light of contemporary and historical sympatry with D. plexippus could shed light on the biogeography of, evolution of, and predation pressure on the monarch butterfly, whose migration event has become a conservation priority

Detecting an Elusive Invasive Species: A Diagnostic PCR to Detect Burmese Python in Florida Waters and an Assessment of Persistence of Environmental DNA

Recent studies have demonstrated that detection of environmental DNA (eDNA) from aquatic vertebrates in water bodies is possible. The Burmese python, Python bivittatus, is a semi-aquatic, invasive species in Florida where its elusive nature and cryptic coloration make its detection difficult. Our goal was to develop a diagnostic PCR to detect P. bivittatus from water-borne eDNA, which could assist managers in monitoring this invasive species. First, we used captive P. bivittatus to determine whether reptilian DNA could be isolated and amplified from water samples. We also evaluated the efficacy of two DNA isolation methods and two DNA extraction kits commonly used in eDNA preparation. A fragment of the mitochondrial cytochrome b gene from P. bivittatus was detected in all water samples isolated with the sodium acetate precipitate and the QIAamp DNA Micro Kit. Next, we designed P. bivittatus-specific primers and assessed the degradation rate of eDNA in water. Our primers did not amplify DNA from closely related species, and we found that P. bivittatus DNA was consistently detectable up to 96 h. Finally, we sampled water from six field sites in south Florida. Samples from five sites, where P. bivittatus has been observed, tested positive for eDNA. The final site was negative and had no prior documented evidence of P. bivittatus. This study shows P. bivittatus eDNA can be isolated from water samples; thus, this method is a new and promising technique for the management of invasive reptiles

Nicarbazin bait reduces reproduction by pigeons (\u3ci\u3eColumba livia\u3c/i\u3e)

Development of effective methods for reducing populations of overabundant nuisance bird species continues to challenge wildlife biologists. Reproductive inhibition, although conceptually pleasing, has been difficult to implement because of the lack of a safe, approved avian contraceptive. Recently, however, nicarbazin received regulatory approval in the United States for use as a bait to decrease hatchability of resident Canada goose (Branta canadensis) and feral pigeon (Columba livia) eggs. In anticipation of the feral pigeon registration, we evaluated efficacy by exposing captive pairs of nesting pigeons to nicarbazin bait for 4 h daily. Egg production was unaffected, but only 9 of 22 eggs hatched, a 59% reduction from pre-treatment when each of the 11 test pairs produced 2 nestlings. In the recovery phase, when treated bait was removed, the 11 pairs produced 18 nestlings. All nestlings produced during the study appeared healthy and normal, and there was no mortality among the adult pairs. Nicarbazin is an effective and safe means of reducing hatchability of feral pigeon eggs that can be used within an integrated management plan to reduce feral pigeon populations

Detection and Removal of Invasive Burmese Pythons: Methods Development Update

The invasive Burmese python is a large constrictor snake that is now well established in south Florida. This invasive predator could have major detrimental impacts to native wildlife populations and is a perceived threat to human health and safety. Finding and removing this elusive predator in vast Everglades habitats of wet sawgrass prairies with interspersed hardwood hammocks poses many challenges for biologists and land managers in south Florida, and no single solution is likely to prevail. In ongoing research, we are exploring opportunities to improve detection of this cryptic species using such diverse approaches as environmental DNA, trained detector dogs, and thermal infrared imagery. In this paper we update the status of these efforts. Other research, using captive pythons in outdoor pens at our facility in Gainesville, has resulted in the development of a newly-patented live trap that is specific to large snakes. We are currently testing and evaluating techniques to complement this new trap design for effective python removal in concert with improved detection tools

Development of Nicarbazin Bait for Managing Rock Pigeon Populations

Effective methods for managing populations of rock pigeons and other overabundant avian species are limited. An alternative to lethal control is reproductive inhibition. Nicarbazin is a widely used additive in poultry feed that also reduces hatchability of eggs. It is the active ingredient in OvoControl®G, a bait product recently registered as a means for reducing hatchability of eggs of urban Canada geese. In a series of trials with captive pigeons, we evaluated the effectiveness of several nicarbazin bait formulations to determine effects on reproduction and to quantify levels of nicarbazin absorbed into the blood. Although pigeons readily accepted a scaled-down version of the OvoControl goose bait, this formulation did not adequately reduce hatchability because of insufficient absorption of nicarbazin into the blood. Other bait formulations that contained 2,500 ppm nicarbazin produced similar results. Only bait formulated with 5,000 ppm nicarbazin produced sufficient amounts of the active ingredient in blood plasma of test birds. Eventual registration of the nicarbazin pigeon bait will provide additional management options for limiting growth of unwanted pigeon populations

Development of Nicarbazin Bait for Managing Rock Pigeon Populations

Effective methods for managing populations of rock pigeons and other overabundant avian species are limited. An alternative to lethal control is reproductive inhibition. Nicarbazin is a widely used additive in poultry feed that also reduces hatchability of eggs. It is the active ingredient in OvoControl®G, a bait product recently registered as a means for reducing hatchability of eggs of urban Canada geese. In a series of trials with captive pigeons, we evaluated the effectiveness of several nicarbazin bait formulations to determine effects on reproduction and to quantify levels of nicarbazin absorbed into the blood. Although pigeons readily accepted a scaled-down version of the OvoControl goose bait, this formulation did not adequately reduce hatchability because of insufficient absorption of nicarbazin into the blood. Other bait formulations that contained 2,500 ppm nicarbazin produced similar results. Only bait formulated with 5,000 ppm nicarbazin produced sufficient amounts of the active ingredient in blood plasma of test birds. Eventual registration of the nicarbazin pigeon bait will provide additional management options for limiting growth of unwanted pigeon populations

Acetaminophen and Zinc Phosphide For Lethal Management of Invasive Lizards \u3cem\u3eCtenosaura similis \u3c/em\u3e

Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools, including toxicants. In Florida, using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis, we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species. Of the animals that received acetaminophen, none died except at the highest test dose, 240 mg per lizard, which is not practical for field use. Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard, equivalent to about 0.5% in bait which is lower than currently used in commercial baits for commensal rodent control. We conclude that zinc phosphide has potential as a useful tool for reducing populations of invasive lizards such as the black spiny-tailed iguana provided target-selective delivery methods are develope

Use of DiazaCon™ as a reproductive inhibitor for monk parakeets (\u3ci\u3eMyiopsitta monachus\u3c/i\u3e)

Feral monk parakeet (Myiopsitta monachus) populations have become established in the United States and other countries around the world, and can cause damage to electrical facilities. Because the monk parakeet is a highly visible species and there is often public opposition to lethal control measures, non-lethal methods, such as contraception, are being developed to help control the spread of feral populations. Two gavage studies and one ad libitum nesting study were conducted to assess the efficacy of DiazaCon™ as a potential contraceptive for the monk parakeet. The first gavage study compared daily dose levels of 0, 50, 75, and 100 mg DiazaCon™ (kg bodyweight)–1 administered for 10 consecutive days. Cholesterol concentrations decreased significantly concomitant with a significant increase in desmosterol concentrations in the treated groups, but did not vary between sexes. Cholesterol and desmosterol concentrations did not differ significantly among DiazaCon™ groups, and cholesterol remained significantly suppressed 12 weeks after treatment. On the basis of these results, the second gavage study compared 5 or 10 consecutive days of DiazaCon™ administration at 50 mg kg–1 bird–1 day–1. Cholesterol concentrations decreased significantly concomitant with a significant increase in desmosterol concentrations in the treated groups, but did not vary between sexes. Cholesterol and desmosterol concentrations did not differ significantly between DiazaCon™ groups, and cholesterol remained significantly suppressed 11 weeks after treatment. Parakeets in the nesting study were fed hulled sunflower seeds treated with a target dose of 50 mg DiazaCon™ kg–1 bird–1 day–1. Birds consumed enough to receive an average dose of 34 mg kg–1 pair–1 day–1, or 17 mg kg–1 bird–1 day–1. Birds in the treated group laid an average of 1.6 ± 0.7 eggs per clutch compared with 3.9 ± 1.1 eggs per clutch in the untreated control group. None of the eggs laid by treated birds hatched compared with 1.1 ± 0.6 eggs per clutch hatching in the control group. Reproductive inhibition was effective for the length of the breeding season, at which time the study was stopped and no more data were collected. DiazaCon™ is a promising avian oral contraceptive that should be further investigated in a field setting with monk parakeets

Development of Nicarbazin Bait for Managing Rock Pigeon Populations

Effective methods for managing populations of rock pigeons and other overabundant avian species are limited. An alternative to lethal control is reproductive inhibition. Nicarbazin is a widely used additive in poultry feed that also reduces hatchability of eggs. It is the active ingredient in OvoControl®G, a bait product recently registered as a means for reducing hatchability of eggs of urban Canada geese. In a series of trials with captive pigeons, we evaluated the effectiveness of several nicarbazin bait formulations to determine effects on reproduction and to quantify levels of nicarbazin absorbed into the blood. Although pigeons readily accepted a scaled-down version of the OvoControl goose bait, this formulation did not adequately reduce hatchability because of insufficient absorption of nicarbazin into the blood. Other bait formulations that contained 2,500 ppm nicarbazin produced similar results. Only bait formulated with 5,000 ppm nicarbazin produced sufficient amounts of the active ingredient in blood plasma of test birds. Eventual registration of the nicarbazin pigeon bait will provide additional management options for limiting growth of unwanted pigeon populations

Crow Pellets from Winter Roosts in Lancaster, Pennsylvania

Although crows cast pellets, there is little quantitative information on pellets from Corvus brachyrhynchos (American Crow), and none from C. ossifragus (Fish Crow). During a study of crow roost dispersal in Lancaster, PA, we collected samples of pellets from several locations. By mass, pellets consisted mostly of grit and other fi ne inorganic material, various seeds (principally Toxicodendron radicans [Poison Ivy] and Celtis occidentalis [Common Hackberry]), and vegetation remnants. Six pellets contained small-mammal bones. Because the Lancaster winter crow population included many Fish Crows, the source of the pellets was not certain. To clarify this, we compared the size of the Lancaster crow pellets to those produced by captive Fish Crows, and we provide the first quantitative description of pellets for either species. Our size comparisons suggest that \u3e90% of the pellets in our sample from Lancaster were produced by American Crows. Introduction Pellet-casting has been reported within at least 18 orders of birds (Below 1979). Pellets usually contain indigestible parts of prey items, so pellet analysis is a standard means for studying avian food habits (Coleman and Fraser 1987, Errington 1932, Glading et al. 1943). Among passerines, Corvus spp. (crows) regularly produce pellets (Berrow et al. 1992, Dean and Milton 2000, Kurosawa et al. 2003). Barrows and Schwarz (1895) described pellet production in Corvus brachyrhynchos Brehm (American Crow). They provided a sketch of a typical crow pellet, but included no measurements, nor did they characterize crow pellet contents except in a general way. We are aware of just two additional studies of crow pellets in the USA. Black (1941) collected 1214 pellets from 12 winter American Crow roosts in Illinois, but he combined all pellets from each site for analysis. Major food items identified by Black (1941) included corn, various common weed seeds, and small mammals (bones or teeth occurred in 178 pellets). He estimated that grit comprised 17.6% of the pellets, by volume. Platt (1956) collected 617 American Crow pellets year-round in south-central Kansas and examined them singly, although he quantified only the food items, “excluding sand and other extraneous material”, and he provided no measurements of pellet size. Field crops (wheat, sorghum, oats, sunflower, and corn) comprised 59% of the identifiable food residues, invertebrates comprised 26.5%, and mammal remains 2.6% (Platt 1956). Apparently, published information on pellets from Corvus ossifragus Wilson (Fish Crow) is lacking (McGowan 2001)