Locally abundant, endangered Mariana swiftlets impact the abundance, behavior, and body condition of an invasive predator.

Invasive predators are known to have negative consumptive and non-consumptive effects on native species, but few examples show how the abundance of native prey may influence an established invasive predator. We compared invasive brown treesnakes (Boiga irregularis; BTS) found in caves occupied by endangered Mariana swiftlets (Aerodramus bartschi) to snakes found in nearby forests and caves without birds to quantify how the abundance of native avian prey impacts BTS abundance and behavior on Guam. From 2011 to 2017 we removed 151 BTS in caves occupied by swiftlets and never observed BTS in caves without birds.

comparison of treatments and commercially available solutions on mortality of third-stage larvae.

On Hawai'i Island, an increase in human neuroangiostrongyliasis cases has been primarily associated with the accidental ingestion of Angiostrongylus cantonensis L3 in snails or slugs, or potentially, from larvae left behind in the slug's slime or feces. We evaluated more than 40 different treatments in vitro for their ability to kill A. cantonensis larvae with the goal of identifying a safe and effective fruit and vegetable wash in order to reduce the risk of exposure.

Vertical foraging shifts in Hawaiian forest birds in response to invasive rat removal.

Worldwide, native species increasingly contend with the interacting stressors of habitat fragmentation and invasive species, yet their combined effects have rarely been examined. Direct negative effects of invasive omnivores are well documented, but the indirect effects of resource competition or those caused by predator avoidance are unknown. Here we isolated and examined the independent and interactive effects of invasive omnivorous Black rats (Rattus rattus) and forest fragment size on the interactions between avian predators and their arthropod prey.

Brown tree snake (Boiga irregularis) population density and carcass locations following exposure to acetaminophen.

Mass aerial delivery of dead mouse baits treated with acetaminophen has been evaluated as a means to reduce brown tree snake (Boiga irregularis) populations over large areas, increasing the likelihood of wide-scale eradication on Guam. Given the high density of snakes in some areas of their invasive range, eradication efforts could result in a resource pulse that may influence food web dynamics and the indirect transport of acetaminophen among trophic levels. We evaluated abundance, habitat type, and snake size (i.

Detection of Angiostrongylus cantonensis in the Blood and Peripheral Tissues of Wild Hawaiian Rats (Rattus rattus) by a Quantitative PCR (qPCR) Assay.

The nematode Angiostrongylus cantonensis is a rat lungworm, a zoonotic pathogen that causes human eosinophilic meningitis and ocular angiostrongyliasis characteristic of rat lungworm (RLW) disease. Definitive diagnosis is made by finding and identifying A. cantonensis larvae in the cerebral spinal fluid or by using a custom immunological or molecular test.

Capillaria hepatica infection in black rats (Rattus rattus) on Diego Garcia, British Indian Ocean Territory.

Rats (Rattus spp.) are among the most damaging invasive species worldwide. The accidental introduction of rats has caused significant detriment to native flora and fauna, crops, structures, and human livelihoods.

Potential citric acid exposure and toxicity to Hawaiian hoary bats (Lasiurus cinereus semotus) associated with Eleutherodactylus frog control.

We examined potential exposure of Hawaiian hoary bats (Lasiurus cinereus semotus) to citric acid, a minimum risk pesticide registered for control of invasive Eleutherodactylus frog populations. Hoary bats are nocturnal insectivores that roost solitarily in foliage, federally listed as endangered, and are endemic to Hawaii. Oral ingestion during grooming of contaminated fur appears to be the principal route by which these bats might be exposed to citric acid.

Longevity of rodenticide bait pellets in a tropical environment following a rat eradication program.

Invasive rodents (primarily Rattus spp.) are responsible for loss of biodiversity in island ecosystems worldwide. Large-scale rodenticide applications are typically used to eradicate rats and restore ecological communities.

Assessing spatial variation and overall density of aerially broadcast toxic bait during a rat eradication on Palmyra Atoll.

Baits containing brodifacoum rodenticide were aerially applied to eradicate invasive black rats from Palmyra Atoll, an important biodiversity center. Bait application must be sufficient to be effective, while minimizing environmental hazards by not exceeding designated label rates, prompting our bait density assessments for two aerial drops. With few physical or human resources on this remote, uninhabited atoll, assessments were particularly challenging, requiring observations within 30 min of aerial application to avoid bait loss to rats, crabs, or elements.

The effect of cooking on diphacinone residues related to human consumption of feral pig tissues.

We examined feral pig tissues to determine whether the potential hazard of consuming meat from pigs previously exposed to diphacinone rodenticide baits was reduced by cooking. Residue levels were measured in cooked and uncooked tissues of feral pigs exposed to sub-lethal quantities of the anticoagulant rodenticide. Pigs were provided large amounts of baits or untreated food to consume, then euthanized prior to the onset of symptoms indicative of rodenticide poisoning or sickness.

Efficacy of rodenticide baits for the control of three invasive rodent species in Hawaii.

We tested the efficacy and palatability of nine commercial rodenticide bait formulations on Polynesian rats (Rattus exulans), roof rats (R. rattus), and house mice (Mus musculus). Efficacy varied by rodenticide tested and rodent species.

Isolation of microsatellite loci from the coqui frog, Eleutherodactylus coqui.

Thirteen microsatellite loci were isolated from the coqui frog (Eleutherodactylus coqui) and optimized for future research. The loci were screened across 37 individuals from two Puerto Rican populations. Loci were variable with the number of alleles per locus ranging from three to 38.

Determination of diphacinone residues in Hawaiian invertebrates.

A reversed-phase ion-pair liquid chromatographic analysis combined with a solid-phase extraction clean-up method is used to assess the quantity of diphacinone residue found in invertebrates. Three invertebrate species are exposed to commercially available diphacinone-fortified bait used for rat control. The invertebrate samples are collected, frozen, and shipped to the laboratory.

Probabilistic risk assessment for snails, slugs, and endangered honeycreepers in diphacinone rodenticide baited areas on Hawaii, USA.

Three probabilistic models were developed for characterizing the risk of mortality and subacute coagulopathy to Poouli, an endangered nontarget avian species, in broadcast diphacinone-baited areas on Hawaii, USA. For single-day exposure, the risk of Poouli mortality approaches 0. For 5-d exposure, the mean probability of mortality increased to 3% for adult and 8% for juvenile Poouli populations.

Coyotes (Canis latrans) are definitive hosts of Neospora caninum.

Four captive-raised coyote pups consumed tissues from Neospora caninum-infected calves. Faeces were examined from 4 days before to 28 days after infection. One pup shed N.