Droevendaalsesteeg 10
6708 PB Wageningen
The Netherlands
About
I study long-distance range expansion in Pink-footed Geese as mechanism to cope with advancing spring by climate change in the Arctic.
Biography
My research at NIOO focuses on dispersal as mechanism to cope with climate change. In Svalbard, Pink-footed Geese (Anser brachyrhynchus) traditionally breed in the west, whereas nowadays also the east (Edgeoya) becomes snow-free early enough in the season to serve as breeding habitat. Pink-footed Geese have recently colonized this area, and we expect them to be better matched with the local food pulse than geese on traditional grounds, resulting in higher fitness. We also investigate to what extent the annual cycle differs between geese of both areas in terms of energy and time budgets and migration timing and routes, and whether geese of both areas are genetically differentiated. We will test aggression, docility and stress resistance during handling as measures of personality to see if personality may have played a role in the colonization process.
I did my Bachelor at Wageningen Universtiy focusing on Ecology and Biodiversity, with a thesis on Age- and density-dependent breeding success of Goshawks (at NIOO, A.J. van Noordwijk, and WUR, D. Kleijn). I moved to Groningen for the Topmaster Programme Evolutionary biology, with theses on Tidal migration of mobile benthic prey of Red Knots (at NIOZ, P.J. van den Hout and T. Piersma), the Relationship of personality with early-life body mass in Blue tits (at University of Turku, J.E. Brommer and B. Class), and Sex-ratio and sexual dimorphism in chicks of Honey Buzzard (at University of Groningen, C. Both and R.G. Bijlsma). After graduation I contiued working in Turku on the blue tit personalities.
Before and throughout my studies I have joined long-term breeding biology studies on raptors and meadow birds around my home-town Groesbeek, and assisted in fieldwork with Great Skuas on the Faroe Islands (University of Glasgow, S. Hammer), and with Arctic Skuas, Red-necked Phalaropes and Barnacle geese on Tobseda, Russia (NIOO, T.K. Lameris, and IMARES, R.S.A. van Bemmelen).
I am a keen fieldwork-based ecologist, valuing a holistic view and precise and standardised observations, also leaving room to respond to unexpected phenomena. Illustrative of such attitude is this quote by Tinbergen in the sixties:
"We did not tackle the problem by systematic experimentation but by collecting incidental evidence, which is not too difficult provided one has the problem continuously in mind during watching. As a rule, Nature makes numerous experiments for us and it is amazing how much evidence on can collect if one is continuously on the alert and appreciative of the possibilities." (N. Tinbergen (1960) The Herring Gull's World, p.99)
Publications not mentioned in publications tab:
International journals:
Schreven K.H.T. & Lehikoinen A.E. 2020. Arctic Terns attacking a leucistic Barnacle Goose near Longyearbyen, Svalbard: an explanation for the high local leucism frequency? Goose Bulletin 26: 2-6. https://www.blessgans.de/fileadmin/Dateien_Blessgans/GooseBulletin/Goos…
Schreven K.H.T. 2020. Can Starlings imitate a Blackbird's song upon seeing a silent Blackbird? Fróðskapparit 65-66: 163-166 (with Faroese summary). https://ojs.setur.fo/index.php/frit/article/view/123
Schreven K.H.T., Dooley J.L., Leafloor J.O. & Tijsen W. 2020. Records of a 'crested' Lesser Snow Goose and Brent Goose in the wild, and a discussion of previous records in relation to environmental pollution. Goose Bulletin 25: 6-10. https://www.blessgans.de/fileadmin/Dateien_Blessgans/GooseBulletin/Goos…
Schreven K.H.T. 2020. Lanceolated Warbler on Hornøya, Svalbard. Dutch Birding 42(3): 175-179. https://www.dutchbirding.nl/journal/42/3
Schreven K.H.T. 2020. Arctic Skuas caring for Common Eider duckling. British Birds 113(4): 235-238. https://britishbirds.co.uk/content/arctic-skuas-caring-common-eider-duc…
Schreven K.H.T. 2020. Blue Tit feeding a Great Tit brood. British Birds 113(3): 182. https://britishbirds.co.uk/content/blue-tit-feeding-great-tit-brood
Schreven K.H.T. & Hammer S. 2019. Primary moult of Great Skuas on the breeding grounds, with special attention to the Faroe Islands. Sula 27: 1-16. https://natuurtijdschriften.nl/pub/708250
Schreven K.H.T. & Lehikoinen A.E. 2019. A 'crested' Pink-footed Goose observed in Norway, and possible explanations why crested waterfowl are rare in the wild. Goose Bulletin 24: 4-7. https://www.blessgans.de/fileadmin/Dateien_Blessgans/GooseBulletin/Goos…
Schreven K.H.T. & Kangassalo K. 2019. Male Blue Tit feeding an injured female. British Birds 112(1): 49-50. https://britishbirds.co.uk/content/notes-1
National journals
Thissen J.B.M., Schreven K.H.T., van der Horst Y., Müskens G.J.D.M. & Zollinger R. 2023. Studies of home range of a female Goshawk (Accipiter gentilis) in the breeding season in Reichswald, Kleve with GPS telemetry. Charadrius 58: (in German with English summary)
Schreven K.H.T. & van der Horst Y.H.T.H. 2022. The road takes its toll: traffic victims in relation to characteristics of species, environment and a fauna passage. Limosa 95(1): 3-27 (in Dutch with English summary) https://limosa.nou.nu/limosa_samenvatting.php?language=UK&nr=5335
Schreven K.H.T. 2016. Predation by raptors and mammals on a large flock of Common Starlings Sturnus vulgaris at a night roost in a reedbed. De Takkeling 24(2): 102-110 (in Dutch with English summary) https://natuurtijdschriften.nl/pub/623888
Van Turnhout C., Nienhuis J., Majoor F., Ottens G., Schreven K. & Schoppers J. 2016. Breeding performance of Common Starlings Sturnus vulgaris in the Netherlands. Limosa 89(2): 37-45 (in Dutch with English summary) https://limosa.nou.nu/limosa_samenvatting.php?language=UK&nr=5156
Schreven K. & van der Horst, Y. 2016. A Sparrowhawk Accipiter nisus nestling without yellow carotenoid pigmentation. Limosa 89(2): 23-26 (in Dutch with English summary) https://limosa.nou.nu/limosa_samenvatting.php?language=UK&nr=5153
Müskens G.J.D.M., Thissen J.B.M., van der Horst Y., Schreven K.H.T., Visser D., Zollinger R. 2015. Extremely high raptor breeding densities in the Reichswald Forest near Kleve. Charadrius 51(2): 63-79 (in German with English summary) http://www.nw-ornithologen.de/index.php/publikationen/charadrius/charad…
Schreven K.H.T., Mooijman P.J.W. & Helder J. 2015. The parasitic nematode Synhimantus laticeps, identified using 18S rDNA sequencing, in the stomach of an emaciated Sparrowhawk Accipiter nisus. De Takkeling 23(2): 134-140 (in Dutch with English summary) https://natuurtijdschriften.nl/pub/603035
Klaassen R., Klaassen H., Berghuis A., Berghuis M., Schreven K., van der Horst, Y., Verkade, H. & Kearsley, L. 2014. Migration routes and wintering areas of Dutch Common Swifts Apus apus revealed using geolocators. Limosa 87(4): 173-181 (in Dutch with English summary) https://limosa.nou.nu/limosa_samenvatting.php?language=UK&nr=5101
Schreven K.H.T. 2014. An airgun pellet in the food of a Northern Goshawk Accipiter gentilis, in the context of hunting and lead poisoning. De Takkeling 22(3): 225-229 (in Dutch with English summary) https://natuurtijdschriften.nl/pub/595372
Schreven K.H.T. 2012. Egg-capping: a case in Common Buzzard Buteo buteo and evolutionary aspects. De Takkeling 20(2): 126-132 (in Dutch with English summary) https://natuurtijdschriften.nl/pub/547289
Local journals
Schreven K. 2022. De Veldleeuwerik als broedvogel in Groesbeek in 2009-2022. Groesbeeks Milieujournaal 45(2): 18-24 (in Dutch) https://www.wmg-groesbeek.nl/milieujournaal/Milieujournaal187.pdf
Thissen J., van der Horst Y. & Schreven K. 2017. Weidevogelbescherming in Groesbeek 2002-2017. Groesbeeks Milieujournaal 40(3): 8-14 (in Dutch) https://www.wmg-groesbeek.nl/milieujournaal/Milieujournaal169.pdf
Schreven K. 2017. Verspreiding en trends van de Veldleeuwerik als broedvogel in Groesbeek in 2009-2016. Mourik 43(1): 26-36 (in Dutch) https://vogelwerkgroepnijmegen.nl/?ddownload=2343
Schreven K. 2012. Staatssecretaris Bleker, de jagers, en de boeren. Groesbeeks Milieujournaal 35(1-2): 22-24 (in Dutch) https://www.wmg-groesbeek.nl/milieujournaal/Milieujournaal147_148.pdf
Schreven K. 2011. Viltkruiden en droogbloemen in Groesbeek. Groesbeeks Milieujournaal 34(4): 15-19 (in Dutch) https://www.wmg-groesbeek.nl/milieujournaal/Milieujournaal146.pdf
Schreven K. 2011. Helpgedrag bij het Waterhoen. Mourik 37(3): 103-106 (in Dutch) https://vogelwerkgroepnijmegen.nl/?ddownload=650
Schreven K. 2010. Bekentellingen in Groesbeek: watervogels in een glaciaal bekken in de winter. Mourik 36(3): 82-92 (in Dutch) https://vogelwerkgroepnijmegen.nl/?ddownload=708
Publications
Peer-reviewed publications
Intraguild predation and competition between avian top predators
https://doi.org/10.1007/s10336-026-02388-3Understanding species coexistence is central in ecology. Competition and predation mix during intraguild predation (i.e. predators eliminating competitors). After recovery from historical crashes caused by persecution and pesticides, raptor populations can now be studied in more natural assemblages. We studied two avian top predators in a Dutch-German forest during 1969–2024. Here, Northern Goshawks (Accipiter gentilis) first increased (from 4 to max. 61 pairs) but recently decreased (from 40 to 23 pairs), while Eurasian Eagle Owls (Bubo bubo) only established in 2019 and increased (to 9 pairs). We studied three aspects of their interaction: competition for territories and food, and intraguild predation. Diet was compared during 2019–2023 (Goshawks, n = 1649 prey; Eagle Owls, n = 655 prey). Diet overlap was moderate at species level (Pianka index, numbers: 0.5, biomass: 0.6). Goshawks ate mainly pigeons, while Eagle Owls mainly took pigeons, rats, and hares/rabbits. Whereas overall intraguild predation frequency was 5% (Eagle Owl) and 6% (Goshawk), predation of Goshawks by Eagle Owls was minimal (n = 1). Accordingly, distance to the nearest Eagle Owl nest did not affect Goshawk territory persistence and breeding success. Still, 3 out of 18 Eagle Owl nest sites were (old) Goshawk nests. The number of Goshawk fledglings per nest was higher further away from Eagle Owls, but this only played at larger distances, likely due to other factors (e.g. urbanisation). Further, Goshawk output was higher closer to the forest edge. Thus, we found no indication that Eagle Owls have contributed significantly to the Goshawk decline. Both currently coexist, but the nocturnal predator thrives while the diurnal predator struggles. Goshawks under pressure may have limited options to cope with increasing Eagle Owls in the future.
Neckband loss and its effect on apparent survival estimates in Greylag Geese (Anser anser): variation with season, sex and age
Mark-recapture studies enable us to estimate population parameters such as survival, if marks do not impact survival and if marks are not lost. Mark loss can result from external wear and damage, but also behavioural factors may be important and could explain differences between seasons or sexes. We studied Greylag Geese (Anser anser) in eastern Netherlands, ringed with neckbands, leg bands and metal rings (912 geese), observed weekly during 1997–2019 (131,625 observations). Given the double marking and high annual resighting probabilities (neckbands: 0.974, leg rings: 0.639), we quantified neckband loss and the effect of neckbands on apparent survival, using multistate mark-recapture models. Annual neckband loss was 0.038, was higher in males (0.056) than females (0.021) and increased with years since marking, up to 0.098 for males more than 8 years after marking. Neckband loss tended to be higher during December–May than June–November, with most losses occurring in March–April. Both the higher loss in males and the peak in spring in both sexes could result from intraspecific fighting (pulling each other’s neck and neckband). Survival was underestimated in Cormack-Jolly-Seber models that did not account for neckband loss, by up to 0.096 for adult males 6–7 years after marking. Thus, ignoring neckband loss may give erroneous survival differences between sexes and seasons, and overestimate the effect of ageing on survival (i.e. senescence). We did not detect an effect of neckbands on mortality, but statistical power for this test was limited. Neckband loss, although lower nowadays than in studies of decades ago, still impacts survival estimates and should be considered in mark-recapture studies.https://doi.org/10.1007/s10336-022-01993-2Brood Sex Ratio in European Honey Buzzards Pernis apivorus is Related to Spring Phenology
In sexually size-dimorphic bird species, rearing costs of sons and daughters usually differ and may be important in the evolution of offspring sex ratio adjustment. Raptors have reversed sexual size dimorphism and the smaller males are sometimes found to be overrepresented in food-poor territories or years. As a raptor with small reversed sexual dimorphism (6% in body mass), the European Honey Buzzard Pernis apivorus is expected to show little or no brood sex ratio bias in relation to environmental conditions. We molecularly sexed 311 chicks of 195 broods in and around The Netherlands, during 1996–2014. We examined which environmental factors explained brood sex ratio variation best. Overall, sex ratio was not biased (all nests pooled: 50.8% females) but more females were produced in years when on average Honey Buzzards bred earlier (32% sex ratio change over a ten-day range in annual mean laying date). Within-year laying date variation, hatching order, abundance of wasp (Vespinae) nests (main food source) and summer weather did not explain sex ratio variation. In the Veluwe and Drenthe (1974–2014), Honey Buzzards laid eggs earlier when the spring was warmer, which resulted in a c. 9-day advance in laying date over 40 years. As warm spring weather was also a predictor of a higher density of wasp colonies, we expected female chicks to benefit more from growing up in wasp-rich years than males, if the sex ratio biases were adaptive. However, this differential growth benefit was not noticeable in chick body mass; chick body mass was best explained by negative effects of relative laying date (within a year) and hatching order. The potential benefit for female nestlings (compared to males) of growing up in years with warm springs, when egg laying occurs early and wasp colonies are more abundant, remains unknown.https://doi.org/10.5253/arde.2022.a10Effects of capture and marking on the behaviour of moulting Pink-footed Geese Anser brachyrhynchus on Svalbard
Tracking of individuals is increasingly being used in waterfowl research. However, the effects of capture and tags on waterfowl welfare and ecology are poorly understood and too rarely reported. In this paper, time budget data are used to investigate the behavioural effects of capture and marking on moulting and brood-rearing Pink-footed Geese Anser brachyrhynchus on their arctic breeding grounds. The study compares the prevalence of self-maintenance and foraging time for unringed/uncaptured birds, male birds marked with standard neck collars and female birds marked with heavier GPS collars, and reports on the reduction through time in the pecking behaviour directed towards these markers. Results indicate that capture and marking substantially altered behaviour of marked birds in the days immediately after capture, but also that this effect faded quickly and was not discernible six days after marking. Proportions of time spent preening during foraging bouts indicated that, in the first six days, GPS-collared birds were significantly more affected (time preening c. 12%) than birds ringed with standard neck collars (c. 3%). Both groups showed higher proportions of self-maintenance type behaviours than unringed birds of the same sex (time preening < 1%). The probability of an individual goose pecking its marker during an observation period was initially high for GPS-collared birds (c. 65%), but decreased substantially to reach c. 2% by 11 days after capture. Our study indicates that, after an initial period of discomfort, neck collars and GPS collars are suitable for studying the behaviour of individual geese.Tail feather elongation in Great Skuas Stercorarius skua: a sexual ornament signalling individual quality?
Capsule – In breeding Great Skuas on Skúvoy, Faroe Islands, central tail feather elongation was longer in males than females and was related to head size, laying date, egg volume, diet composition, and only in males also the tendency to incubate the clutch.https://doi.org/10.1080/00063657.2021.1882936
Aims – Sexual ornaments, such as elongated tail feathers, allow birds to attract conspecifics of the opposite sex. In skuas, the smaller species have clearly elongated central tail feathers, while in the larger species, the elongation is marginal. We evaluate here if the modest elongation of the central tail feathers in Great Skuas is associated with ecological factors and thus could still function as a social signal.
Methods and results – We caught 47 breeding Great Skuas on their nests on Skúvoy, Faroe Islands in 2013 and found that the central tail feathers were more elongated in males (mean 15.2 mm, n=20) than females (11.3 mm, n=27). This sexual dimorphism persisted when corrected for body size, as males are smaller than females. In both sexes, longer tail feather elongation was associated with a shorter head, an earlier laying date, and a higher bird-based proportion in the pair’s diet, while no spatial patterns were found. Moreover, during our catching attempts, males with a longer tail feather elongation were quicker back at the nest to incubate the clutch. Egg volume, but not chick body condition, increased with parent tail feather elongation. In a model including laying date, head size, and diet, only laying date persisted as significant predictor of the tail feather elongation, as earlier laying birds had shorter heads and ate more birds.
Conclusion – We argue that the modest tail feather elongation in Great Skuas may signal individual quality for both sexes, and in males specifically also the nest attentiveness, even though this trait may seem ecologically irrelevant at first glance.Why do afternoon copulations mainly occur after the egg-laying peak date in a colony of Great Skuas on Skúvoy, Faroe Islands?
Abstract In Great Skuas Stercorarius skua, copulations are often preceded by courtship feeding and occur in the morning and afternoon.
We surveyed copulations in a colony of Great Skuas on Skúvoy, Faroe Islands during afternoons throughout the breeding
season of 2013. The afternoon copulation frequency peaked 2.5 weeks after the peak in laying dates. This is unexpected because
literature suggests that a pair copulates most frequently around a week before egg laying. As we were not able to link each copulation
to a specific pair, several explanations are possible. First, if these afternoon copulations were pre-laying copulations, they were
presumably mostly performed by pairs laying late in the season. A possible mechanism could be that young pairs and fish-eating
pairs, which breed later in the season, make longer foraging trips and therefore feed their mate, and thus copulate, later in the day.
These copulations may also reflect an increased copulation rate of young pairs, to strengthen the pair bond or compensate for low
copulation success. Alternatively, if these copulations were post-laying copulations, they may be a response to mate feeding that
continues during the incubation phase, and may strengthen the pair bond. We argue that potential individual and population differences
should be taken into account when describing copulation behaviour at the species level.
Popular-scientific publications
Wakker worden met ijsbeeralarm
Vogelonderzoeker Kees Schreven ging afgelopen juli mee op expeditie naar Spitsbergen. Hij bestudeert hoe de kleine rietgans omgaat met het veranderend klimaat in het poolgebied. Voor NEMO Kennislink hield hij een dagboek bij. Een reisverslag langs ganzenkeutels, gletsjermuren en nieuwsgierige ijsberen.
Projects & collaborations
Projects
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ArcticPinkfeet: Response of geese to climate warming in the Arctic
Climate is warming faster in the Arctic than elsewhere in the northern hemisphere. As a result, migratory Arctic-nesting birds may arrive too late to benefit from the Arctic growth pulse.
Outreach
Categories
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Featured in
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Symposium Migratory birds under pressure
On Thursday 7 September 2023 our Animal Ecology department is organising a symposium on migratory birds under pressure, followed by the PhD thesis defence of Kees Schreven the next day.
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PhD Thesis defence Kees Schreven: range expansion in Arctic-breeding geese
On Friday 8 September 2023, our colleague Kees Schreven will defend his PhD thesis "Geese colonising New Land: causes and mechanisms of range expansion in an Arctic-breeding migrant".
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Fireworks have long-lasting effects on wild birds
An international team of scientists has examined the long-term effects of fireworks on wild birds.