The Pied Currawong's role in avian nest predation: a predator removal experiment

2001 ◽  
Vol 7 (3) ◽  
pp. 154 ◽  
Author(s):  
Graham R. Fulton ◽  
Hugh A. Ford
Keyword(s):  
Nest Predation ◽  
Bird Species ◽  
Artificial Nests ◽  
Predator Removal ◽  
Rural Landscapes ◽  
Before And After ◽  
Eucalypt Woodland ◽  
Avian Nest ◽  
High Level

Pied Currawongs Strepera graculina have been implicated as a major threat to the persistence of small passerines in urban and rural landscapes through their intense nest predation while raising their young. Pied Currawongs have recently increased in abundance and colonized new areas, due to the planting of exotic berry-bearing trees and shrubs. In association with habitat fragmentation, this may have intensified their predatory impact. We measured the rate of predation on 416 artificial nests, using quail and plasticine eggs, in a 240 ha remnant of eucalypt woodland. Nests were placed in one grid from which Pied Currawongs were removed and in one control grid. The level of predation was monitored before and after Pied Currawong removal. Overall, nest predation was extremely high with 91 % of all nests preyed upon in seven days. Moreover, nest predation decreased significantly following Pied Currawong removal, thus identifying them as significant nest predators. However, imprint evidence from plasticine eggs and the remains of real eggs indicate that other animals, particularly other birds, are also important predators. If this high level of nest predation is reflected in real nests and occurs over a number of years, it may lead to low recruitment of open-nesting birds at this site. If it occurs regionally, it could contribute to long term declines of these species. Our findings suggest that even quite large woodland fragments may be too small to sustain many declining bird species.

Plasticity in incubation behaviour under experimentally prolonged vulnerability to nest predation

Behaviour ◽  
2013 ◽  
Vol 150 (14) ◽  
pp. 1767-1786 ◽  
Author(s):  
Chiara Morosinotto ◽  
Robert L. Thomson ◽  
Erkki Korpimäki
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Parental Perception ◽  
Nest Boxes ◽  
Incubation Behaviour ◽  
Before And After ◽  
Entrance Hole ◽  
And Control

Nest predation is the main cause of nest failures in many bird species. To counter this, birds have evolved different behavioural strategies to decrease the visibility of their nests, thus reducing the probability of nest detection. We manipulated the long-term perception of nest predation risk in pied flycatchers (Ficedula hypoleuca) by experimentally increasing the nest vulnerability to predators. We placed treatment and control nest-boxes for breeding pied flycatchers that appeared identical during the initial phase of breeding. But after the removal of a front panel, treatment boxes had an enlarged entrance hole, almost twice the initial diameter. This treatment increases actual predation risk and presumably parental perception of risk. Control boxes presented instead an entrance hole of the same size both before and after the manipulation. When breeding in enlarged entrance holes, females doubled the vigilance at the nest while males reduced the time spent at the nest, compared to pied flycatchers breeding in control boxes. Increased vulnerability of the nest site to predation risk, thus, induced pied flycatcher parents to increase nest vigilance while reducing their activity at the nest. These results highlight the existence of plasticity in incubation behaviours under long-term experimentally increased nest predation risk.

Predation of artificial Xantus's murrelet (Synthliboramphus hypoleucus scrippsi) nests before and after black rat (Rattus rattus) eradication

2005 ◽  
Vol 32 (4) ◽  
pp. 320-325 ◽  
Author(s):  
HOLLY P. JONES ◽  
R. WILLIAMHENRY ◽  
GREGG R. HOWALD ◽  
BERNIE R. TERSHY ◽  
DONALD A. CROLL
Keyword(s):  
Nest Predation ◽  
Life Stage ◽  
Deer Mouse ◽  
Rattus Rattus ◽  
Small Population ◽  
Eradication Programme ◽  
Artificial Nests ◽  
Black Rat ◽  
Before And After ◽  
Synthliboramphus Hypoleucus

Introduced rats depredate every life stage of island nesting seabirds, but the extent of predation is rarely quantified. Introduced black rat (Rattus rattus) and native deer mouse (Peromyscus maniculatus anacapae) predation on Xantus's murrelet (Synthliboramphus hypoleucus scrippsi) nests was experimentally quantified using artificial nests before and after rat eradication on Anacapa Island (California). The staged rat eradication programme provided experimental treatments: in 2002 rats were eradicated on one island (East Anacapa Islet) and remained on two islands (Middle and West Anacapa Islets), providing a control comparison, and, in 2003, rats were eradicated from the remaining islands (Middle and West Anacapa Islets). In 2002, 96% of artificial nests were depredated on control islands (rats present) with rats accounting for most predation. Nest predation on the treatment island (rats eradicated) in 2002 was significantly lower: 8% of artificial nests were depredated, mostly by endemic deer mice. In 2003, following rat eradication on the remaining islands (Middle and West Anacapa Islets), nest predation was reduced from 96% in 2002 to 3% of total nests in 2003. Predation of nests on East Anacapa Islet (rats eradicated in 2002) increased significantly due to reintroduction and recovery of native deer mouse populations, with 23% of artificial nests depredated. The inference is that rat predation on real Xantus's murrelet nests was responsible for the historically low nesting success and small population sizes of breeding murrelets on Anacapa Island. With rats removed, the hatching success of Xantus's murrelet chicks and the number of individuals nesting on Anacapa Island will increase dramatically. Artificial nest studies are particularly well suited to quantifying introduced rat impacts on hole and crevice nesting seabirds and can simultaneously serve as an effective monitoring tool to detect the presence of rats and the recovery of native nest predators.

scholarly journals Observed heterospecific clutch size can affect offspring investment decisions

2011 ◽  
Vol 8 (3) ◽  
pp. 341-343 ◽  
Author(s):  
Jukka T. Forsman ◽  
Janne-Tuomas Seppänen ◽  
Inka L. Nykänen
Keyword(s):  
Clutch Size ◽  
Bird Species ◽  
Investment Decisions ◽  
Optimal Investment ◽  
Migratory Bird ◽  
Lifetime Reproductive Success ◽  
Egg Mass ◽  
Artificial Nests ◽  
Fine Tune

Optimal investment in offspring is important in maximizing lifetime reproductive success. Yet, very little is known how animals gather and integrate information about environmental factors to fine tune investment. Observing the decisions and success of other individuals, particularly when those individuals initiate breeding earlier, may provide a way for animals to quickly arrive at better breeding investment decisions. Here we show, with a field experiment using artificial nests appearing similar to resident tit nests with completed clutches, that a migratory bird can use the observed high and low clutch size of a resident competing bird species to increase and decrease clutch size and egg mass, accordingly. Our results demonstrate that songbirds can discriminate between high and low quantity of heterospecific eggs, and that social information can have long-term physiological consequences affecting reproductive strategies. Such behaviour may help animals to better adapt to changing environments and lead to convergent traits with competitors.

An experimental approach to understanding the use of mistletoe as a nest substrate for birds: nest predation

2008 ◽  
Vol 35 (1) ◽  
pp. 65 ◽  
Author(s):  
Stuart J. N. Cooney ◽  
David M. Watson
Keyword(s):  
Site Selection ◽  
Nest Predation ◽  
Nest Site ◽  
Nest Site Selection ◽  
Artificial Nests ◽  
Bird Populations ◽  
Nest Sites ◽  
South Wales ◽  
Eucalypt Woodland ◽  
Substrate Variation

Recent research has documented an unprecedented diversity of birds using mistletoes as nest-sites, and a strong preference for nesting in mistletoes has recently been demonstrated for some species. The consequences and underlying reasons for this behaviour have not been evaluated, and it is unclear whether nests in mistletoes confer advantages compared with other available substrates. Nest predation is often cited as the most important factor regulating many bird populations and is thought to influence all aspects of nest-site selection. To evaluate whether nest predation may play a role in the widespread use of mistletoe as a nest-site, we conducted an artificial nest predation experiment in a eucalypt woodland in southern New South Wales, Australia. Artificial nests were modelled on noisy friarbird (Philemon corniculatus: Meliphagidae) nests, baited with a single quail egg and checked after four days. We used logistic regression to model the rate of depredation between plant substrates, and demonstrate that, in this experiment, mistletoe nests experienced a lower proportion of predation than eucalypt nests (51.5% versus 63.8% respectively). This finding suggests that predation may influence the widespread use of mistletoe as a nest-site in a range of habitats and regions. In addition to clarifying priorities for further work on mistletoe nesting, this finding has implications for studies of nest-site selection generally, with researchers encouraged to supplement between-substrate comparisons with direct measurements of within-substrate variation.

Planning and Health Policy in Finland

1972 ◽  
Vol 2 (1) ◽  
pp. 23-34 ◽  
Author(s):  
A. S. Härö ◽  
T. Purola
Keyword(s):  
Social Background ◽  
Point Of View ◽  
Decision Makers ◽  
Present System ◽  
Centralized Control ◽  
Related Information ◽  
Before And After ◽  
Health Related ◽  
High Level

The health services system in Finland is analyzed from the point of view of planning–oriented activities. Society has traditionally been the main provider of services in this country, and executive responsibilities of local autonomous authorities are balanced with the centralized control carried out by legislative measures and subsidies. An organized information system is a prerequisite to planning (this is especially true in a country with Finland's type of organizational structure). The Finnish system is based on problem–oriented data banks. Health interview surveys which link social background data with health–related information have a key role in this system; these surveys are well suited to before and after comparisons. Information is capable of producing action only if it is properly analyzed and timed. In order to obtain information about actual goal expectations of the decision–makers, the special–purpose planning departments are located at a high level of government in Finland. Typical methods of implementation, such as financial subsidies, are described in this paper, and economic estimates and long–term budgeting are given as examples of guides for the central authorities. The use of before and after studies to measure the effect of the policies is described, and some observations on the weaknesses in the present system are presented.

scholarly journals Artificial Nest Predation and Abundance of Birds Along an Urban Gradient

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 838-847 ◽  
Author(s):  
Jukka Jokimäki ◽  
Esa Huhta
Keyword(s):  
Nest Predation ◽  
Predation Rate ◽  
Forest Area ◽  
Urban Gradient ◽  
Artificial Nest ◽  
Artificial Nests ◽  
Avian Predators ◽  
Avian Nest ◽  
Town Center ◽  
The Town

Abstract We studied nest predation pressure on birds along an urban gradient in urban parks in three Finnish towns. Artificial ground nests with Japanese Quail (Coturnix coturnix japonicus) eggs were depredated more in the urban area than in the adjacent forest area. Within each town, the nest predation rate was higher in the town center than in the less urbanized area of detached houses. Predation rates did not vary from year to year or between study towns. Abundances of generalist avian predators were higher in the town center than in the area of detached houses and in the surrounding forest area. Most of the nests in the town center were destroyed by avian predators. Predation rate of artificial nests in each of the town areas was higher in managed parks than in unmanaged parks, presumably due to the less dense vegetation in the managed than the unmanaged parks. A test involving covering nests revealed that artificial nests covered by adjacent vegetation survived better than nests with less cover. In our study, artificial nest loss reflected the distribution of avian nest predators. Ground nesters were present at lower abundances in areas where concealing vegetation was missing and avian nest predation was high. Apparently, nest predation is one of the several possible mechanism affecting urban bird assemblages.

scholarly journals Zika virus seroprevalence declines and neutralization antibodies wane in adults following outbreaks in French Polynesia and Fiji

2019 ◽  
Author(s):  
Alasdair D Henderson ◽  
Maite Aubry ◽  
Mike Kama ◽  
Jessica Vanhomwegen ◽  
Anita Teissier ◽  
...  
Keyword(s):  
Latin America ◽  
Zika Virus ◽  
French Polynesia ◽  
Cross Sectional ◽  
The Pacific ◽  
Before And After ◽  
Dynamics Of Population ◽  
High Level ◽  
Antibody Levels

SUMMARYBackgroundSerosurveys published following major outbreaks of Zika virus (ZIKV) have so far shown a high level of seroprevalence from samples collected within 12 months of the first confirmed case. A common assumption is that ZIKV infection confers long-term protection against reinfection, preventing ZIKV from re-emerging in previously affected areas for many years. However, the long-term immune response to ZIKV following an outbreak remains poorly documented.MethodsWe compared results from eight serological surveys, with sample sizes ranging from 49 to 700, before and after known ZIKV outbreaks in the Pacific region: five from cross-sectional studies of schoolchildren and the general population in French Polynesia over a seven-year period; and three from a longitudinal cohort in Fiji over a four-year period.FindingsWe found strong evidence of a decline in seroprevalence in both countries over a two-year period following first reported ZIKV transmission. In the cohort in Fiji, there was also a significant decline in antibody titres against ZIKV. However, the decline in seroprevalence was concentrated in adults, while high seroprevalence persisted in children.InterpretationThe observed patterns of long-term anti-ZIKV antibody levels following outbreaks in the Pacific could be an early indication of the dynamics of population immunity in Latin America. Given that ZIKV antibody levels can wane substantially over time, follow-up seroprevalence studies and prospective clinical trial designs in Latin America may need to be revised, and assumptions about the potential for ZIKV to re-emerge may need to be revisited.FundingPacific Funds, ANR, MRC, Wellcome, Royal Society.

Does vestibular habituation still have a place in the treatment of benign paroxysmal positional vertigo?

2000 ◽  
Vol 114 (7) ◽  
pp. 501-505 ◽  
Author(s):  
G. K. Banfield ◽  
C. Wood ◽  
J. Knight
Keyword(s):  
Benign Paroxysmal Positional Vertigo ◽  
Response To Treatment ◽  
Positional Vertigo ◽  
Spine Pathology ◽  
Before And After ◽  
Traditional Therapies ◽  
High Level ◽  
Term Response ◽  
Paroxysmal Positional Vertigo

Particle repositioning procedures such as the Epley manoeuvre have become popular in the management of benign paroxysmal positional vertigo (BPPV) at the expense of more traditional therapies such as vestibular habituation.We prospectively analysed the response of consecutive patients presenting with BPPV to treatment with vestibular habituation exercises using a symptom score sheet before and after treatment. This same patient group was then followed up, on average three years, eight months after discharge, to determine their long-term response to treatment.The results of the study demonstrated an excellent short-term response rate to treatment but a high level of recurrence after discharge. Most patients who experienced further symptoms following discharge were however self-reliant and were able to return to their habituation exercises without the need for further medical input.The aim in the management of these patients must be to provide long-term self reliance as well as shortterm cure and it may be that this has not yet been well demonstrated with the Epley manoeuvre. It must also be remembered that particle repositioning manoeuvres cannot be used in all patients for example those who suffer with cervical or thoracic spine pathology and that some will fail to respond at all.We believe that vestibular habituation retains a useful role in the treatment of BPPV.

scholarly journals Nesting Success and Nest Predators in Forest Fragments: A Study Using Real and Artificial Nests

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 445-454 ◽  
Author(s):  
Liana Zanette ◽  
Bert Jenkins
Keyword(s):  
Nest Predation ◽  
Agricultural Land ◽  
Fragment Size ◽  
Nesting Success ◽  
Forest Fragments ◽  
Artificial Nests ◽  
Area Sensitivity ◽  
Avian Nest ◽  
Nest Predator ◽  
Nest Predators

Abstract Area sensitivity in songbirds is commonly attributed to increased nest predation in forest fragments. In 1995 and 1996, we tested whether the nest predators and nesting success of an area-sensitive forest bird, the Eastern Yellow Robin (Eopsaltria australis), varied with fragment size, and we also conducted an artificial nest experiment. The study occurred in two small (55 ha) and two large (>400 ha) forest fragments in a matrix of agricultural land in New South Wales, Australia. Predation accounted for 95% of all failures of 282 robin nests, and the survival of robin nests was negatively correlated with how frequently we observed avian nest predators near nests (i.e. nest-predator activity). Of 461 artificial nests, 84% were depredated, nearly all (99%) by birds. Thus, birds were important predators of nests. The abundance, species richness, and activity of avian nest predators were not related to fragment size. Survival of robin nests averaged 19%; nests in small fragments had a 22% chance of producing at least one fledgling compared with 15% in large fragments, but the difference was not significant. Survival of artificial nests averaged 12% in both small and large fragments. Nest-predator activity accounted for the most variation (68%) in the fate of robin nests, followed by the cumulative density of open-cup nesters (16%). The placement of robin nests had no influence on nest fate. We conclude that nest predation was not area dependent and propose food supply as an alternative hypothesis to explain area sensitivity. We suggest that, rather than being related to fragment size, nest predation increases with decreasing forest cover in a landscape. Increased nest predation in fragmented compared with contiguous landscapes may lower the population viability of songbirds in a region, and hence regional numbers. Therefore, the spatial scale at which fragmentation influences nest predation and songbird populations must be considered carefully.

Effect of the level of oestradiol on oxytocin-induced prostaglandin F2α release in the cow

1995 ◽  
Vol 145 (1) ◽  
pp. 175-180 ◽  
Author(s):  
G E Mann ◽  
G E Lamming
Keyword(s):  
Luteal Phase ◽  
Plasma Concentrations ◽  
Prostaglandin F2α ◽  
Normal Group ◽  
Plasma Samples ◽  
High Group ◽  
Before And After ◽  
Prostaglandin F ◽  
High Level

Abstract We have investigated the effects of oestradiol-17β on the development of the luteolytic signal (prostaglandin F2α (PGF2α) release to an oxytocin challenge) using a steroid-treated ovariectomised cow model. Long-term ovariectomised cows were pre-treated with progesterone for 14 days followed by oestradiol-17β for 2 days to induce oestrus (day 0), and were then treated for a further 16 days with physiological doses of progesterone and oestradiol-17β to simulate a luteal phase. On day 11 oestradiol was either withdrawn (low group; n=4), maintained (normal group; n=4) or increased (high group; n=4), generating mean (± s.e.m.) plasma concentrations of oestradiol from days 12–16 of 0·9±0·1, 2·3±0·4 and 3·7±0·3 pg/ml respectively. Basal and oxytocin-stimulated PGF2α secretion was monitored by measuring concentrations of the principal metabolite of PGF2α, 13,14-dihydro-15-keto PGF2α (PGFM), in plasma samples collected before and after daily i.v. injection of 50 IU oxytocin from days 12–16. Basal PGFM was unaffected by the level of oestradiol treatment. In the normal group significant rises in plasma PGFM were seen following oxytocin on days 12, 13 and 14 (P<0·05) as well as days 15 and 16 (P<0·01). In the low group significant elevations in PGFM were only seen on days 15 and 16 (P<0·05), and were smaller (P<0·05) than those seen in the normal group. In the high group two cows showed no elevation in PGFM on any day while in two cows a rise was seen on all days which by day 16 was 84% greater than that seen in the normal group. The results demonstrate that a low level of oestradiol over the second half of the luteal phase leads to a weaker luteolytic signal, while a high level can be stimulatory or inhibitory. Journal of Endocrinology (1995) 145, 175–180

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