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Janske van de Crommenacker

Janske van de Crommenacker
Birdlife Netherlands · Science & Conservation Evidence

PhD in Animal Ecophysiology

About

38
Publications
6,308
Reads
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614
Citations
Citations since 2017
17 Research Items
314 Citations
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201720182019202020212022202301020304050
Introduction
Island ecologist and ornithologist with a strong background in both academia and applied conservation. Key words: Ecology | Birds | Island biology | Conservation | Physiology | Environmental awareness | Phylogenetics.
Additional affiliations
November 2018 - November 2020
University of Groningen
Position
  • PostDoc Position
June 2013 - December 2014
University of Kent
Position
  • PostDoc Position
Description
  • Assessing evolutionary distinctiveness and hybridization patterns of Aldabra's landbirds using molecular methods.
January 2006 - March 2011
University of Groningen
Position
  • Hard times in paradise? Oxidative status, physiology and fitness in the tropical Seychelles warbler
Description
  • oxidative status, natural population, Seychelles warbler, trade-offs

Publications

Publications (38)
Article
Full-text available
Changes in marine ecosystems from human stressors, and concerns over how species will respond to these changes have emphasized the importance of understanding and monitoring crucial demographic parameters for population models. Long-lived, migratory, marine vertebrates such as sea turtles are particularly vulnerable to changes. Life-history paramet...
Preprint
Full-text available
Changes in marine ecosystems from human stressors, and concerns over how species will respond to these changes have emphasized the importance of understanding and monitoring crucial demographic parameters for population models. Long-lived, migratory, marine vertebrates such as sea turtles are particularly vulnerable to changes. Life-history paramet...
Article
Full-text available
Around the world, declines in the mean size of nesting sea turtles have been reported with concerns of a concomitant decrease in the reproductive output of populations. Here, we explore this possibility using long-term observations of green turtles (Chelonia mydas) at Aldabra Atoll, Seychelles. Based on > 4500 individual measurements over 21 years...
Article
Full-text available
We report on the sighting of a nesting hawksbill with a carapace length of 94.0 cm encountered during the 2016-17 nesting season at Fregate Island, Seychelles. The turtle was bearing flipper tags that had been applied to her in January 2005 at Cocos (Keeling) island located 4,600 km east of Fregate Island. It turns out that she had been tagged at C...
Article
Full-text available
Environmental conditions experienced during early life may have long‐lasting effects on later‐life phenotypes and fitness. Individuals experiencing poor early‐life conditions may suffer subsequent fitness constraints. Alternatively, individuals may use a strategic “Predictive Adaptive Response” (PAR), whereby they respond—in terms of physiology or...
Article
Full-text available
Plastic pollution affects marine ecosystems worldwide and poses risks for seabirds. Most recorded impacts on organisms are negative but, in some cases, the constructive use of plastic fragments or objects by birds has also been recorded. Small blue and green plastic fragments are found scattered among nests in a large (c.500,000 pairs) Sooty Tern O...
Article
Full-text available
Seabirds, being long-lived top-level marine predators, are often considered to be valuable environmental indicators. With growing evidence of seabird declines worldwide, it is essential to monitor changes in populations and determine drivers of change. The Seychelles Archipelago supports the greatest abundance of seabirds in the tropical Indian Oce...
Article
Common Myna Acridotheres tristis is considered to be among the world’s most damaging invasive species through disturbance, predation, competition pathogen introduction to native birds and other taxa. Claimed impacts on native birds have often been based on anecdotal reports. More substantive evidence of interference with small-island endemic birds...
Preprint
1.Environmental conditions experienced during early life may have long-lasting effects on later-life phenotypes and fitness. Individuals experiencing poor early-life conditions may suffer subsequent fitness constraints. Alternatively, individuals may use a strategic ‘Predictive Adaptive Response’ (PAR), whereby they respond – in terms of physiology...
Article
Birgus latro, the largest terrestrial arthropod in the world, has undergone a substantial decline globally over the last decades, with only a few healthy populations remaining where they are actively protected. We aimed to quantify demographic and spatio-temporal dynamics of a protected population of B. latro on Aldabra Atoll (Seychelles). Based on...
Article
Full-text available
[This corrects the article DOI: 10.1371/journal.pone.0226064.].
Article
Full-text available
Flight loss has evolved independently in numerous island bird lineages worldwide, and particularly in rails (Rallidae). The Aldabra white-throated rail (Dryolimnas [cuvieri] aldabranus) is the last surviving flightless bird in the western Indian Ocean, and the only living flightless subspecies within Dryolimnas cuvieri, which is otherwise volant ac...
Article
Full-text available
Aldabra Atoll’s marine protected area was expanded in April 2019 from 71, 612 km2 to 177, 447 km2, which provides greater protection to the marine mammal populations that use these waters. Opportunistic observational data on marine mammals sighted around Aldabra were collected between 2008 and 2018. Patterns in their location and over time were ass...
Conference Paper
Full-text available
Management and eradication techniques for invasive alien birds remain in their infancy compared to invasive mammal control methods, and there are still relatively few examples of successful avian eradications. Since 2011, five separate eradication programmes for invasive birds have been conducted on three islands by the Seychelles Islands Foundatio...
Conference Paper
Full-text available
The Seychelles was one of the first tropical island nations to implement island restoration resulting in biodiversity gain. In the 2000s a series of rat eradication attempts was undertaken in the inner Seychelles islands which had mixed results. Three private islands with tourist resorts successfully eradicated rats: Frégate (2000), Denis Island (2...
Article
Full-text available
Feral goats Capra hircus, considered among the world’s most destructive invasive mammals, were introduced to Aldabra Atoll, a UNESCO World Heritage site in the Seychelles, before 1878. An eradication programme to remove goats from Aldabra was initiated in 1987, after severe ecological impacts were recorded. Eradication and control efforts continued...
Article
1.Oxidative damage, caused by reactive oxygen species during aerobic respiration, is thought to be an important mediator of life-history trade-offs. To mitigate oxidative damage, antioxidant defence mechanisms are deployed, often at the cost of resource allocation to other body functions. Both reduced resource allocation to body functions and direc...
Data
Figure S1. Seasonal variation in rainfall at the research station on Picard, Aldabra. Figure S2. Recapture and survival rates of marked animals on Grand Terre East (gte), Grand Terre West (gtw) and Malabar (mal). Figure S3. Size‐dependence of survival.
Data
Table S2. Mark‐recapture analysis of apparent survival rates.
Article
Full-text available
Long-term survey data can provide important information on temporal and spatial changes in bird populations and are needed for conservation management. We investigate population indices of seven landbird species using an 11-year dataset from the UNESCO World Heritage Site of Aldabra Atoll. We analysed the associations of location, season and habita...
Article
Full-text available
Understanding the extent of morphological variation in the wild population of Aldabra giant tortoises is important for conservation, as morphological variation in captive populations has been interpreted as evidence for lingering genes from extinct tortoise lineages. If true, this could impact reintroduction programmes in the region. The population...
Article
Senescence – the progressive age-dependent decline in performance – occurs in most organisms. There is considerable variation in the onset and rate of senescence between and within species. Yet the causes of this variation are still poorly understood, despite being central to understanding the evolution of senescence. Long-term longitudinal studies...
Article
AimBiological invasions are a major threat to island biodiversity and are responsible for a large proportion of species declines and extinctions worldwide. The process of hybridization between invasive and native species is a major factor that contributes to the loss of endemic genetic diversity. The issue of hybridization is often overlooked in th...
Article
Full-text available
The global range of the Aldabra white-throated rail Dryolimnas cuvieri aldabranus, the last surviving flightless bird in the Indian Ocean, was restricted to only three islands of Aldabra Atoll in 1998. It was extirpated on the islands of Grand Terre (before the late 1800s) and Picard (soon after 1910), mainly due to the introduction of feral cats b...
Article
Full-text available
We report the results of a survey of breeding Greater Frigatebird Fregata minor and Lesser Frigatebird F. ariel on Aldabra Atoll, a UNESCOWorld Heritage site in the Seychelles archipelago, which hosts the largest breeding population of frigatebirds in the Indian Ocean. All four colonies across the atoll were surveyed in 2011 and 2012 by counting ad...
Article
Full-text available
Parasites can have detrimental effects on host fitness, and infection typically results in the stimulation of the immune system. While defending against infection, the immune system generates toxic oxidants; if these are not sufficiently counteracted by the antioxidant system, a state of oxidative stress can occur. Here, we investigated the relatio...
Data
Investigation of associations between social status, breeding stage and physiological indices for each sex separately. If non-significant, the status*breeding interaction was eliminated to investigate the main effects of status and breeding stage. The models further included all explanatory variables were left in the final models of Tables 1 and 2....
Data
Post-hoc tests: patterns throughout the breeding season per status group and for each sex. Significance levels were adjusted for multiple comparisons using the False Discovery Rate (FDR) procedure. (DOC)
Data
Post-hoc tests: status differences in physiological indices per breeding stage and for each sex. Significance levels were adjusted for multiple comparisons using the False Discovery Rate (FDR) procedure. (DOC)
Article
Full-text available
In cooperatively breeding species, helping close relatives may provide important fitness benefits. However, helping can be energetically expensive and may result in increased generation of reactive oxygen species. Consequently, an oxidant/antioxidant imbalance can lead to higher oxidative stress susceptibility. Given the potential costs of helping,...
Article
Aggression often shows large inter-individual variation, but high intra-individual consistency. Although the physiological basis and direct costs of aggression are generally well known, less is known about the physiological costs such as increased oxidative stress (OS). This can occur via increased leakage of oxidants during high metabolic demands...
Article
Full-text available
The use of oxygen for energy generation results in the continuous production of reactive oxygen species (oxidants) that can damage body molecules. Organisms attempt to reduce this harm by use of their antioxidant defence barrier. Yet, when more oxidants are produced than can be neutralized by this protective barrier, a state of oxidative stress may...
Article
Full-text available
1.Fluctuations in the quality of the habitat in which an animal lives can have major consequences for its behaviour and physiological state. In poor-quality habitat with low food availability, metabolically intensive foraging activity is likely to result in increased generation of reactive oxygen species, while scarcity of food can lead to a weaken...
Article
Full-text available
One route to gain insight into the causes and consequences of ecological differentiation is to understand the underlying physiological mechanisms. We explored the relationships between immunological and oxidative status and investigated how birds cope physiologically with the effects of immune-derived oxidative damage. We successively implemented t...
Article
Full-text available
In male birds, testosterone (T) plays an important role in aggressive and mate-attraction behaviour. In the cooperatively breeding Seychelles warbler, Acrocephalus sechellensis, extra-group copulations (EGCs) occur frequently, but are not accompanied by sexual courtship displays as in within-pair copulations. Paternity is nearly always gained by pr...
Article
Full-text available
Water tables in the Netherlands have been greatly lowered in recent decades, largely in order to favour agricultural activities. Drought and increased nitrate (NO3-) leaching from agricultural land lead to oxidation of iron-sulphide (FeSx) in the subsoil, resulting in increased sulphate (SO42-) concentrations in the groundwater. In addition, increa...
Article
Chapter7 Chapter 7 160 Oxidative stress is repeatedly suggested to be an important mediator of life-history trade-offs. To avoid accumulation of oxidative damage, costly antioxi-dant defence mechanisms are needed. Both direct oxidative damage and the allocation of resources towards antioxidant defences may decrease an indi-vidual's fitness by lower...

Questions

Questions (3)
Question
I'm using MLwin version 3.02. In older versions it was very easy to paste my dataset from Excel, and click ''use first row as names'' to make my upper row from Excel the column headers.
Now, I use edit-paste to import the dataset, but when I just click the ''use first row as names'' button (it's not a tickbox anymore), the data are imported but the column names are empty! If I don't click this button and click the paste button in the paste view window the column names are imported but the dataframe is empty!
It's something really simple probably, but so far I can't get it done and it's really frustrating. I hope any of you has the golden hint.
Question
I'm performing a Discriminant Function Analysis. I have three subspecies, which are grouped through the analysis in a canonical function plot, showing function 1 and 2. Now I want to show the male and female subjects of the dataset with different symbols in the figure, but I can't find an option to do this. Or alternatively, I can't seem to find back which data point in the graph matches with which datapoint in the original dataset so I can adjust the symbols manually. Many thanks!
Question
I try to run a Beast analysis on 2 genes: cytb and CR. I have run the analysis multiple times, and once the analysis has run, ESS and convergence look good in Tracer. However the output tree is odd. When opened in Figtree I can only view the tree if I convert it to a cladogram and I can’t obtain node ages or a scale axis.
When opening the file in Genious the same problem comes up. On scrutinising the tree file in a text editor, it seems that the source of the bug is that Beast hasn’t written the tree file correctly. The tree file begins with “(((“, but then no other “(“ nor “)” symbols appear at all! For most formats I know, we’d expect this to be full of such symbols (depicting the branches) and, critically, the number of “(“ symbols must be exactly balanced with the same number of “)” symbols.
What's wrong, and how to solve it? Many thanks!

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