scholarly journals Unexpected involvement of a second rodent species makes impacts of introduced rats more difficult to detect

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Lambert ◽  
S. Carlisle ◽  
I. Cain ◽  
A. Douse ◽  
L. Watt
Keyword(s):  
Breeding Success ◽  
Late Summer ◽  
Wood Mouse ◽  
Rodent Species ◽  
Negative Effects ◽  
Norway Rat ◽  
Wood Mice ◽  
Control Programmes ◽  
Manx Shearwater ◽  
Norway Rats

AbstractRodent predators are implicated in declines of seabird populations, and removing introduced rats, often, but not always, results in the expected conservation gains. Here we investigated the relationship between small mammal (Norway rat, wood mouse and pygmy shrew) abundance and Manx shearwater breeding success on the island of Rum, Scotland, and tested whether localised rodenticide treatments (to control introduced Norway rats) increased Manx shearwater breeding success. We found that Manx shearwater breeding success was negatively correlated with late summer indices of abundance for rats and mice, but not shrews. On its own, rat activity was a poor predictor of Manx shearwater breeding success. Rat activity increased during the shearwater breeding season in untreated areas but was supressed in areas treated with rodenticides. Levels of mouse (and shrew) activity increased in areas treated with rodenticides (likely in response to lower levels of rat activity) and Manx shearwater breeding success was unchanged in treated areas (p < 0.1). The results suggest that, unexpectedly, negative effects from wood mice can substitute those of Norway rats and that both species contributed to negative impacts on Manx shearwaters. Impacts were intermittent however, and further research is needed to characterise rodent population trends and assess the long-term risks to this seabird colony. The results have implications for conservation practitioners planning rat control programmes on islands where multiple rodent species are present.

scholarly journals Field trials of flocoumafen against warfarin-resistant infestations of the Norway rat (Rattus norvegicus Berk)

1986 ◽  
Vol 96 (3) ◽  
pp. 467-473 ◽  
Author(s):  
A. P. Buckle
Keyword(s):  
Rattus Norvegicus ◽  
Field Trials ◽  
Anticoagulant Rodenticide ◽  
Complete Control ◽  
Norway Rat ◽  
Norway Rats ◽  
Farm Buildings

SUMMARYThe anticoagulant rodenticide flocoumafen was tested against warfarin-resistant Norway rats (Rattus norvegicus Berk.) infesting farm buildings. Complete control was obtained in 10–21 days (mean 14·2 days) in six treatments in which baits poisoned with 0·005% flocoumafen were maintained, in surplus, until rats ceased to feed from them. A further six treatments, in which the application of poisoned bait was restricted to periodic placements of 50 g, were also completely successful in 15–30 days (mean 21·0 days). Less poisoned bait was used in the restricted flocoumafen treatments than in the unrestricted treatments but the time taken to control the rat infestations was significantly longer.

scholarly journals Poaching vs. patrolling: effects on conservation of Cory’s Shearwater Calonectris diomedea borealis colonies

2011 ◽  
Vol 21 (3) ◽  
pp. 342-352 ◽  
Author(s):  
MARTA LOPEZ-DARIAS ◽  
JAVIER LUZARDO ◽  
RAFAEL MARTÍNEZ ◽  
DANIEL GONZÁLEZ ◽  
EDUARDO A. GARCÍA ◽  
...  
Keyword(s):  
Canary Islands ◽  
Breeding Success ◽  
Conservation Status ◽  
Negative Consequences ◽  
Negative Effects ◽  
Seabird Species ◽  
Cory’S Shearwater ◽  
Final Population ◽  
Calonectris Diomedea ◽  
Government Surveillance

SummaryNegative effects of poaching on seabird populations are not usually evaluated quantitatively when assessing seabird colony conservation status, nor are they generally considered a major concern. We demonstrate that poaching is still intense in the Canary Islands, and has negative consequences for the conservation of seabird colonies. We quantified the effects of poaching of Cory’s Shearwater fledglings on breeding success on different islands in the Canaries, comparing colonies that suffer from intense, medium, or no poaching. Poaching reduced the breeding success of affected colonies to almost a third, potentially causing the future extinction of the colony. Only colonies with intense wardening campaigns reached high values of reproductive success, showing that government surveillance in conjunction with volunteers from different NGOs is a very effective approach in reducing poaching. A population sensitivity analysis was also conducted to provide data on the factors that most affect the performance of the model. Although population growth and mean final population size varied with increases and decreases in mortality and carrying capacity, only harvesting resulted in a probability of 100% of extinction in 20–40 years. To promote seabird conservation in regions such as the Canary Islands, a core archipelago for seabird species in the Atlantic, poaching control should be elevated by society to a level of urgency, requiring dedicated funding and mobilisation of experts and volunteers to adequately address it through education, prevention and enforcement.

scholarly journals Earth observation for monitoring and mapping of cyanobacteria blooms. Case studies on five Italian lakes

2016 ◽  
Vol 76 (s1) ◽  
Author(s):  
Mariano Bresciani ◽  
Claudia Giardino ◽  
Rosaria Lauceri ◽  
Erica Matta ◽  
Ilaria Cazzaniga ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Algal Blooms ◽  
Remote Sensing Data ◽  
Late Summer ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
Landsat 8 ◽  
Negative Effects ◽  
Eutrophic Lakes ◽  
Chl A

Cyanobacterial blooms occur in many parts of the world as a result of entirely natural causes or human activity. Due to their negative effects on water resources, efforts are made to monitor cyanobacteria dynamics. This study discusses the contribution of remote sensing methods for mapping cyanobacterial blooms in lakes in northern Italy. Semi-empirical approaches were used to flag scum and cyanobacteria and spectral inversion of bio-optical models was adopted to retrieve chlorophyll-a (Chl-a) concentrations. Landsat-8 OLI data provided us both the spatial distribution of Chl-a concentrations in a small eutrophic lake and the patchy distribution of scum in Lake Como. ENVISAT MERIS time series collected from 2003 to 2011 enabled the identification of dates when cyanobacterial blooms affected water quality in three small meso-eutrophic lakes in the same region. On average, algal blooms occurred in the three lakes for about 5 days a year, typically in late summer and early autumn. A suite of hyperspectral sensors on air- and space-borne platforms was used to map Chl-a concentrations in the productive waters of the Mantua lakes, finding values in the range of 20 to 100 mgm-3. The present findings were obtained by applying state of the art of methods applied to remote sensing data. Further research will focus on improving the accuracy of cyanobacteria mapping and adapting the algorithms to the new-generation of satellite sensors.

scholarly journals Late Summer and Fall Nesting in the Acorn Woodpecker and Other North American Terrestrial Birds

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 334-350
Author(s):  
Walter D. Koenig ◽  
Justyn T. Stahl
Keyword(s):  
Global Warming ◽  
North American ◽  
Breeding Success ◽  
Population Studies ◽  
Late Summer ◽  
Substantial Fraction ◽  
Melanerpes Formicivorus ◽  
Summer Temperatures ◽  
Total Productivity ◽  
Acorn Woodpeckers

Abstract Acorn Woodpeckers (Melanerpes formicivorus) at Hastings Reservation in central coastal California exhibit a bimodal peak in annual breeding activity. One peak occurs in spring during which the majority of breeding takes place, while a second is centered in late August as the new acorn crop matures. These latter nests are mostly initiated in late summer but often do not fledge until at least late September and are thus referred to here as ‘fall’ nests. Fall nests occur in about one-third of all years, taking place when the acorn crop is large and summer temperatures are relatively high. Fledglings from fall nests constitute 4.3% of the population's total productivity and survive and recruit to the population at levels comparable to spring fledglings. Fall nesting is less likely in groups in which either the male or female breeding adults have undergone a change from the prior year, but groups are otherwise indistinguishable. Ecologically, fall nesting is closely tied to the acorn crop and thus to breeding success in the following, rather than the prior, spring. Among North American terrestrial birds in general, fall breeding has been reported in 16% of all species and is significantly more common among residents and colonially nesting species, in which the frequency exceeds 25%. Furthermore, fall nesting is likely to have been underreported in the literature. Thus, this phenomenon is at least an irregular part of the breeding biology of a substantial fraction of North American birds and should be considered a possibility in population studies of temperate-zone species. This is especially true given that fall nesting is likely to increase as global warming takes place.

Negative effects of acorns on the wood mouse Apodemus speciosus

2003 ◽  
Vol 45 (1) ◽  
pp. 7-17 ◽  
Author(s):  
Takuya Shimada ◽  
Takashi Saitoh
Keyword(s):  
Wood Mouse ◽  
Negative Effects ◽  
Apodemus Speciosus

scholarly journals Detection of Wood Mice (Apodemus sylvaticus) Carrying Non-Tuberculous Mycobacteria Able to Infect Cattle and Interfere with the Diagnosis of Bovine Tuberculosis

2020 ◽  
Vol 8 (3) ◽  
pp. 374
Author(s):  
Lucía Varela-Castro ◽  
Olalla Torrontegi ◽  
Iker A. Sevilla ◽  
Marta Barral
Keyword(s):  
Small Mammals ◽  
Mycobacterium Tuberculosis Complex ◽  
Previous History ◽  
Wood Mouse ◽  
Abundant Species ◽  
Apodemus Sylvaticus ◽  
Tuberculosis Complex ◽  
Wood Mice ◽  
History Of ◽  
Cattle Farms

Mycobacterial infections caused by the Mycobacterium tuberculosis complex (MTC) and non-tuberculous mycobacteria (NTM) are of great medical and veterinary relevance. The aim of this research was to study whether small mammals play a role in the epidemiology of mycobacterioses. Four samplings of 100 traps were performed in each of three cattle farms with previous history of tuberculosis or NTM between 2017 and 2018. A total of 108 animals belonging to seven species were trapped, classified, and necropsied, and tissues were submitted to microbiological and molecular methods for mycobacteria identification. The wood mouse (Apodemus sylvaticus) was the most abundant species (87%). No MTC was detected but six different NTM were identified (M. intracellulare, M. avium subsp. paratuberculosis, M. gordonae, M. celatum, M. fortuitum, and a not determined Mycobacterium sp.), showing a prevalence of 6.5%. No significant association was found between mycobacteria prevalence and the analyzed factors. Although a role in the epidemiology of MTC could not be attributed to small mammals, A. sylvaticus carries NTM that could be pathogenic or interfere with the diagnosis of tuberculosis. According to our results, there is a risk of NTM transmission at the wildlife–livestock interface through potential indirect contacts between small mammals and cattle.

scholarly journals Using the Data-Compression Method for Studying Hunting Behavior in Small Mammals

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 368 ◽  
Author(s):  
Zhanna Reznikova ◽  
Jan Levenets ◽  
Sofia Panteleeva ◽  
Anna Novikovskaya ◽  
Boris Ryabko ◽  
...  
Keyword(s):  
Data Compression ◽  
Prior Experience ◽  
Common Shrew ◽  
Rodent Species ◽  
Compression Method ◽  
Hunting Behavior ◽  
Adult Rats ◽  
Norway Rat ◽  
Different Types ◽  
The Common

Using the data-compression method we revealed a similarity between hunting behaviors of the common shrew, which is insectivorous, and several rodent species with different types of diet. Seven rodent species studied displayed succinct, highly predictable hunting stereotypes, in which it was easy for the data compressor to find regularities. The generalist Norway rat, with its changeable manipulation of prey and less predictable transitions between stereotype elements, significantly differs from other species. The levels of complexities of hunting stereotypes in young and adult rats are similar, and both groups had no prior experience with the prey, so one can assume that it is not learning, but rather the specificity of the organization of the stereotype that is responsible for the nature of the hunting behavior in rats. We speculate that rodents possess different types of hunting behaviors, one of which is based on a succinct insectivorous standard, and another type, perhaps characteristic of generalists, which is less ordered and is characterized by poorly predictable transitions between elements. We suggest that the data-compression method may well be more broadly applicable to behavioral analysis.

Tourism and little penguins: a comparative study of survival and reproductive parameters

2020 ◽  
Vol 47 (4) ◽  
pp. 349
Author(s):  
Philippa Agnew ◽  
David M. Houston
Keyword(s):  
Breeding Success ◽  
Survival Rates ◽  
Monitoring Program ◽  
Public Access ◽  
Environmental Damage ◽  
Negative Effects ◽  
Nest Sites ◽  
Research Activities ◽  
Management Procedures ◽  
Wildlife Viewing

Abstract ContextTourism operations that provide the opportunity for wildlife viewing can support conservation management through public education, habitat protection, population management, research activities and revenue generation. However, alongside these potential benefits there can be negative effects on the species that include the possibility of reduced breeding success, survival and, subsequently, population growth. AimWe sought to establish whether a tourism operation affected little penguins Eudyptula minor by comparing reproductive and survival parameters of two managed populations in Oamaru, New Zealand. One population was the focus of a tourism operation, whereas the other (located nearby) did not provide any public access. The tourism operation implemented strategies to reduce human disturbance, including the reduction of noise, light and movement from visitors during viewing, and by ensuring that visitors were restricted to designated viewing areas. MethodsNesting boxes were installed at both colonies that facilitated weekly monitoring of the populations. The monitoring program (1993–2017) included weekly checks of every nesting box in the colony for the presence of eggs, chicks and adults. Chicks were weighed before fledging, and both fledglings and breeding adults were individually marked. Key resultsLay dates, breeding success, chick fledge mass and survival rates were not measurably different between the two populations, indicating that there was little evidence of negative effects on the penguins at the tourist site. ConclusionsThe slight differences observed between the colonies during the time series were attributed to environmental damage sustained at the non-tourist site and a difference in the proportion of un-monitored nest sites available to the penguins when the study was initiated. ImplicationsNotwithstanding the present findings, long-term and consistent monitoring of wildlife populations facing increasing pressure from tourism is essential to ensure effects are detected and that management procedures implemented to reduce potential effects.

Effects of salbutamol and Ro-20-1724 on airway and parenchymal mechanics in rats

1999 ◽  
Vol 87 (4) ◽  
pp. 1373-1380 ◽  
Author(s):  
Ferenc Peták ◽  
Janet L. Wale ◽  
Peter D. Sly
Keyword(s):  
Steady State ◽  
Airway Resistance ◽  
Brown Norway ◽  
Wave Tube ◽  
Norway Rat ◽  
Airway Caliber ◽  
Brown Norway Rat ◽  
Phosphodiesterase Type ◽  
Induced Changes ◽  
Norway Rats

We investigated the effects of a selective β2-agonist, salbutamol, and of phosphodiesterase type 4 inhibition with 4-(3-butoxy-4-methoxy benzyl)-2-imidazolidinone (Ro-20-1724) on the airway and parenchymal mechanics during steady-state constriction induced by MCh administered as an aerosol or intravenously (iv). The wave-tube technique was used to measure the lung input impedance (Zl) between 0.5 and 20 Hz in 31 anesthetized, paralyzed, open-chest adult Brown Norway rats. To separate the airway and parenchymal responses, a model containing an airway resistance (Raw) and inertance (Iaw), and a parenchymal damping (G) and elastance (H), was fitted to Zl spectra under control conditions, during steady-state constriction, and after either salbutamol or Ro-20-1724 delivery. In the Brown Norway rat, the response to iv MCh infusion was seen in Raw and G, whereas continuous aerosolized MCh challenge produced increases in G and H only. Both salbutamol, administered either as an aerosol or iv, and Ro-20-1724 significantly reversed the increases in Raw and G when MCh was administered iv. During the MCh aerosol challenge, Ro-20-1724 significantly reversed the increases in G and H, whereas salbutamol had no effect. These results suggest that, after MCh-induced changes in lung function, salbutamol increases the airway caliber. Ro-20-1724 is effective in reversing the airway narrowings, and it may also decrease the parenchymal constriction.

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