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Gerald D. Lindsey

Publications and source records attributed to Gerald D. Lindsey.

7 recordsLinked to original sources
USGS2015

Aerial-broadcast application of diphacinone bait for rodent control in Hawai`i: Efficacy and non-target species risk assessment

Introduced rats ( Rattus rattus, R. exulans , and R. norvegicus ) have been implicated in the decline or extinction of numerous species of plants and animals in Hawai‘i. This study investigated the efficacy of aerial-broadcast application of Ramik® Green baits containing 50 ppm (0.005%) diphacinone in reducing rat and mouse populations and the risk to non-target species. The study was undertaken in paired 45.56-ha treatment and non-treatment plots in Hawai‘i Volcanoes National Park. All 21 radio-collared rats in the treatment plot died within nine days of bait application, whereas none of the 18 radio-collared rats in the non-treatment plot died. There was a 99% drop in both the rat capture rate and percentage of non-toxic census bait blocks gnawed by rats in the treatment plot relative to the non-treatment plot three weeks after bait application. The only rat captured in the treatment plot three weeks after bait application was not ear-tagged (i.e., it was not a recapture), whereas 44% of the 52 rats captured in the non-treatment plot were ear-tagged. Most of the bait had disappeared from the forest floor within about one month of application. No birds likely to have eaten bait were found dead, although residues of diphacinone were found in the livers of three species of introduced seed-eating/omnivorous birds captured alive after bait application. No predatory birds were found dead one month or three months after bait application. The remains of a Hawaiian hawk (Buteo solitarius) were found six months after bait application, but it was not possible to determine the cause of death. This study demonstrated the efficacy of aerially broadcast diphacinone bait for control of rats and mice in Hawaiian montane forests, and was part of the dataset submitted to the U.S. Environmental Protection Agency for the national registration of a diphacinone bait for the control of rat populations in conservation areas.

Hawaii↗
USGS2013

Efficacy of hand-broadcast application of baits containing 0.005% diphacinone in reducing rat populations in Hawaiian forests

Introduced black rats ( Rattus rattus ), Polynesian rats ( R. exulans/i>), and Norway rats ( R. norvegicus ) impact insular bird, plant, and invertebrate populations worldwide. We investigated the efficacy of hand-broadcast application of Ramik® Green containing 0.005% diphacinone for rodent control in paired 4-ha treatment and non-treatment plots in both wet and mesic forest in Hawaiʽi. Radio telemetry of black rats, the predominant species, indicated 100% mortality in both treatment plots within about one week of bait application. Live trapping and non-toxic census bait block monitoring two to four weeks after each of 12 repeat bait applications in the wet forest, and three repeat bait applications in the mesic forest, indicated rat abundance was reduced on average by 84–88%. However, reinvasion could have occurred within this time. Rat populations in the treatment plots usually recovered to pre-poison levels within two to five months. House mice ( Mus musculus ), Indian mongooses ( Herpestes auropunctatus ), and feral cats ( Felis catus ) also ate bait or other animals that had eaten bait. This study demonstrates the efficacy of ground-based broadcast toxicant baits for the control of rats in Hawaiian montane wet forests.

Hawai'i↗
USGS2002

Palila ( Loxioides bailleui )

One of the last surviving of the extraordinary “finch-billed” Hawaiian honeycreepers (Drepanidinae), the Palila epitomizes specialization for seed-eating as it relies almost entirely on immature (soft) seeds, flowers, and other resources produced or supported by mämane ( Sophora chrysophylla : Fabaceae), an endemic dry-forest tree. Mämane seeds are highly nutritious, but a strong, sharp bill is necessary to remove and rip open the tough, fibrous pods that protect them. In addition, the seeds contain high levels of potentially toxic secondary compounds, which may also explain why they are eaten by so few other native or alien species. The Palila's close association with mämane influences not only its foraging behavior but also its distribution, abundance, dispersal, and breeding ecology. Like most drepanidines, the Palila produces small clutches, usually only 2 eggs. However, Palila embryos and chicks develop slowly, so eggs and nestlings are threatened by storms and predators for a longer time than many other small passerine species.

Birds of North America↗
USGS2002

Effectiveness of rodent control and monitoring techniques for a montane rainforest

Introduced black ( Rattus rattus ) and Polynesian ( R. exulans ) rats are damaging to native birds, insects, and plants in island ecosystems. We controlled rodent populations in a montane rainforest on the island of Hawaii to determine feasibility, cost, and effectiveness of ground-based rodent control in a rugged, remote rainforest habitat. Treatment was conducted 1996-99, from January to April each year, using rodenticide bait stations and snap-traps. We monitored rodent numbers in 48-ha treatment and reference areas before, during, and after control. As indexed by presence of rat sign in tracking tunnels or census blocks, rodent control reduced rodent abundance 58-90% each year 1 month after treatment began. There was an influx of rats into the treatment area, as shown by higher than expected numbers of rats snap-trapped on the treatment perimeter. Rodent numbers recovered to approximate pretreatment levels by the beginning of the following treatment year. Coast of equipment and supplies for rodent control for the first year was about \$7,000 for a 1-km 2 grid. After the first year, cost decreased to about \$2,000 for 1 km 2 per year. Rodent control applied continuously for 4 months each year during the breeding season may be effective in protecting nesting forest birds, but will not provide protection to plants and invertebrates vulnerable to predation throughout the year, and it is not likely to protect avian food resources.

Hawaii↗
USGS1997

Status and management of the PaliIa, an endangered Hawaiian honeycreeper, 1987-1996

A single, relictual population of Palila Loxioides bailleui, a Hawaiian honeycreeper, survives on the slopes of Mauna Kea volcano on the island of Hawai'i, where it feeds principally on flowers and green seeds of the mamane tree Sophora chrysophylla. The Palila was listed as an endangered species by state and federal governments because of continuing damage to its habitat by browsing Feral and Mouflon Sheep Ovis aries and O. musimon and Goats Capra hircus and because of the bird's restricted range and low numbers. Ecology of the Palila was studied from 1987 to 1996. Annual population estimates fluctuated between 1 600 and 5 700 and averaged 3 400 birds. Estimates varied with availability of mamane seeds, which are less abundant in drought years. In drought years, most birds did not attempt to breed, and survival rates were lower because of a shortage of food. Availability of mamane seeds also showed large seasonal variability. While some nests were preyed upon by Owls Asio flammeus, Cats Felis catus and Rats Rattus rattus, losses were high at the end of the season from unexplained death of eggs and chicks. Genetic studies did not implicate inbreeding depression. Neither avian malaria nor avian pox appeared at this site, where the mosquito vector was absent. However, weather and food shortage worsened towards the end of the nesting season. Availability of food and habitat remain the principal factors limiting increase in the Palila population. Recovery efforts now focus on reducing numbers of feral ungulates, fire management, removing mammalian predators, and developing techniques for captive propagation and introduction to currently unoccupied sites within the bird's former range. Reforestation adjacent to the Mauna Kea Forest Reserve would allow the Palila population to expand and grow.

Pacific Conservation Biology↗
USGS1991

Home range and movements of juvenile Puerto Rican parrots

We studied home range and movements of 15 radio-marked, juvenile Puerto Rican parrots ( Amazona vittata ) fledging from wild nests during summer and fall, 1985-87. When juvenile parrots remained in the nest valley, home ranges during 1986 ( x̄ = 32 ± 10 [SE] ha, n = 4) were larger ( P = 0.0079) than during 1987 ( x̄ = 13 ± 6 ha, n = 5). After radio-marked parrots integrated into adult flocks, home ranges during 1986 ( x̄ = 1,075 ± 135 ha, n = 3) were similar ( P = 0.10) to 1987 ( x̄ = 416 ± 62 ha, n = 2). Juvenile parrots restricted their movements to nest valleys an average of 58 ± 29 days following fledging. After joining adult flocks, juvenile parrots routinely flew between the east and west slopes of the Luquillo Mountains but did not exhibit a seasonal pattern of movement. We recommend that captive-raised, juvenile parrots used in release programs be ≥ 5 months old to ensure they are mature enough to integrate into wild flocks.

Luquillo Mountains, Puerto Rico↗