Peer-reviewed publications

Van Leeuwen, C.H.A., T. Dokk, T.O. Haugen, P.M. Kiffney and J. Museth (2017) Small larvae in large rivers: observations on downstream movement of European grayling Thymallus thymallus during early life stages
Journal of Fish Biology (online early)
Content: We investigated behaviour of early life stages of the salmonid European grayling Thymallus thymallus in large river systems by trapping of larvae moving downstream and electrofishing surveys. Larvae moved downstream predominantly during night, close to the substrate, and few young-of-the-year still resided close to the spawning areas in autumn. These observations advocate that there may be a deliberate, active component to downstream movement of T. thymallus during early life stages. This implies that human alterations of flow regimes and the construction of reservoirs for hydropower interfere with active movement behaviour of fish during critical early life stages. 
Gilioli G., Schrader G., Carlsson N., van Donk E., Van Leeuwen C.H.A., Martín P.R., Pasquali S., Vila M. and S. Vos (2017)
Environmental risk assessment for invasive alien species: A case study of apple snails afffecting ecosystem services in Europe 
Environmental Impact Assessment Review 65: 1-11 link
Content: We present a case study that illustrates how quantitative estimates of environmental risk assessment impacts can be used by decision makers and managers that have to balance the costs of control efforts against environmental and economic impacts of invasive species. The invasive apple snails omacea canaliculata and Pomacea maculata are used to demonstrate the application of an innovative procedure ssessing the potential impact of these species on shallow freshwater ecosystems with aquatic macrophytes in Europe. 
Van Leeuwen, C.H.A., J. Museth, O.T. Sandlund, T. Qvenild and L.A. Vøllestad. (2016)
Mismatch between fishway operation and timing of fish movements: a risk for cascading effects in partial migration systems 

Ecology and Evolution 6(8):2414-2425 pdf

Content: Fishways with restricted seasonal operation times were found to affect upstream spawning migrations of both spring and autumn spawning salmonid fish. We discuss possible effects of late opening and early closing of fish passages in a theoretical framework, in which we propose that movement restrictions of migratory individuals in partially migratory populations can also indirectly affect conditions for resident fish in the same river system. 

Van Leeuwen, C.H.A., R. BeukeboomB.A. Nolet, E.S. Bakker and B.J.A. Pollux (2016)
Locomotion during digestion changes current estimates of seed dispersal kernels by fish
Functional Ecology 30:215-225 pdf
Content: Physical activity during animal locomotion affects how their digestive system processes food, which has implications for their role as seed dispersers. We found that physically active fish retained ingested seeds longer than inactive fish, implying that modelling dispersal kernels using parameters from inactive fish underestimates potential dispersal distances of plants by endozoochory in aquatic systems.  
Kleyheeg, E. and C.H.A. van Leeuwen (2015)
Regurgitation by waterfowl: an overlooked mechanism for long-distance dispersal of wetland plant seeds
Aquatic Botany 127:1-5 pdf
Content: Seed regurgitation by waterbirds is an overlooked dispersal mechanism in wetlands. We found that regurgitation by waterbids can follow overfeeding or the ingestion of large indigestible seeds. As plant seeds are more likely to survive regurgitation than entire gut passage, regurgitation may make a suitable dispersal pathway for seeds that are unable to resist digestion during endozoochory.

Garcia-Álvarez, A., C.H.A. van Leeuwen, C.J. Luque, A. Hussner, A. Vélez-Martin, A. Pérez-Vázquez, A.J. Green, E.M. Castellanos (2015)
Internal transport of alien and native plants by geese and ducks - an experimental study
Freshwater Biology 60(7): 1316-1329 pdf
Content: Experiments on the transport of plant seeds by waterbirds revealed that: i) smaller ducks differ from larger geese in their role as dispersal vectors ii) invasive water primrose Ludwigia grandiflora has a greater dispersal potential than invasive cordgrass Spartina densiflora, which is consistent with its faster range expansion across Europe, and iii) maximum retention times of wetland seeds have been underestimated in previous experimental studies that lasted only 1–2 days, as intact seeds were retrieved from faeces for up to 4 days after ingestion. More attention should be paid to the role of waterbirds as vectors of alien plants and to the role of migratory geese as vectors of plants in general.

Kleyheeg, E., C.H.A. van Leeuwen, M.A. Morison, B.A. Nolet and M.B. Soons (2014)
Bird-mediated seed dispersal: reduced digestive efficiency in active birds modulates dispersal capacity of plant seeds
Oikos 124(7): 899-907 pdf
Content: Seed retrieval patterns of nine wetland plants were found to differ between resting and physically active mallards (Anas platyrhynchos). Physical activity increased the retrieval of intact seeds and modestly accelerated gut passage of seeds, however, in a plant species-specific way. Interactions between the digestion resilience of a particular seed species and the physical activity of an actively moving vector organism should be taken into account when constructing zoochoric dispersal kernels.

Van Leeuwen, C.H.A., J.M. Sarneel, J. van Paassen, W. Rip and E.S. Bakker (2014) 

Hydrology, shore morphology and species traits affect seed dispersal, germination and community assembly in riparian plant communities.

Journal of Ecology 102: 998-1007 pdf

Content: Seed dispersal and germination of plants on the shores of wetlands is influenced by water level fluctuations, shore morphology and seed characteristics. Active water level management and shore restoration can contribute to the creation of rich riparian plant communities.   



Van Leeuwen, C.H.A., N. Huig, G. van der Velde, T.A. van Alen, C.A.M. Wagemaker, C.D.H. Sherman, M. Klaassen and J. Figuerola (2013)

How did this snail get here? Multiple dispersal vectors inferred for an aquatic invasive species.

Freshwater Biology 58(1): 88-99 pdf

Content: Microsatellite analyses reveal how invasive aquatic snails (Physa acuta) can colonize isolated freshwater ponds in Doñana National Park (Spain) by using a multitude of passive dispersal vectors: water currents, waterbirds and large mammals.


Van Leeuwen, C.H.A., G. van der Velde, J.M. van Groenendael and M. Klaassen (2012)

Gut travellers: internal dispersal of aquatic organisms by waterfowl.

Journal of Biogeography 39(11): 2031-2040 pdf    supp1   supp2   supp3

Content: This is the first quantitative meta-analysis on internal transport of aquatic invertebrates and wetland plant seeds by waterbirds. Analysis of over 80 publications (which can be found in supplementary 1) indicates the state of the art on bird-mediated dispersal, and is used to present the first calculations on the quantitative and qualitative importance of endozoochory as a long distance dispersal mechanism.


Van Leeuwen, C.H.A. and G. van der Velde (2012)

Prerequisites for flying snails: external transport potential of aquatic snails by waterbirds.

Freshwater Science 31(3): 963-972 pdf

Content: This study experimentally addresses dispersal of snails on the outside of birds, known as ectozoochory. A large selection of aquatic snail species is highly tolerant to desiccation, will attach readily to the exterior of waterbirds, and can stay attached for over 8 hours in drying mud. Aquatic snails appear to have all the necessary prerequisites for successful zoochory by birds or other large animals.


Van Leeuwen, C.H.A., M.L. Tollenaar, and M. Klaassen (2012)

Vector activity and propagule size affect dispersal potential by vertebrates.

Oecologia 170(1): 101-109 pdf

Content: In this paper we describe how physical activity of mallards (Anas platyrhynchos), in the form of swimming, alters their digestive physiology. This has implications for the construction of seed dispersal kernels by zoochory, which have to date always been based on seed release patterns obtained from experiments with resting animals. We show for the first time that modelling dispersal kernels to predict seed dispersal distances by zoochory should incorporate potential digestive changes induced by the physical movement of animal vectors.


Van Leeuwen, C.H.A., G. Van der Velde, B. Van Lith, and M. Klaassen (2012) 

Experimental quantification of long distance dispersal potential of aquatic snails in the gut of migratory birds.

PLoS ONE 7:e32292 pdf

Content: This publication shows how aquatic snails can survive digestion of waterbirds. In a feeding experiment, snails were retrieved over five hours after ingestion, indicating for the first time that long distance endozoochory of aquatic snails is possible.


Dietz M.W., B. Spaans, A. Dekinga, M. Klaassen, H. Korthals, C.H.A. van Leeuwen, and T. Piersma (2010) 

Do red knots (Calidris canutus islandica) routinely skip Iceland during southward migration?

Condor 112(1): 48-55 pdf

Content: Stable isotope analyses of red knots (Calidris canutus islandica) reveal that these birds do not always use all available stopover sites on migration, but that direct migration from Greenland to Western-Europe occurs without a stopover in Iceland, even for juveniles.



Klaassen, R.H.G., B.A. Nolet, and C.H.A. van Leeuwen (2007)

Prior knowledge about spatial pattern affects patch assessment rather than movement between patches in tactile-feeding mallard.

Journal of Animal Ecology 76(1): 20-29 pdf

Content: This experiment with mallards (Anas platyrhynchos) reveals that birds searching for cryptic food items can make use spatial patterns to optimize their food intake over time.


Side project papers


Noback, M.L., E. Samo, C.H.A. van Leeuwen, N. Lynnerup, and K. Harvati (2016)

Paranasal sinuses: A problematic proxy for climate adaptation in Neanderthals

Journal of Human Evolution 97: 176-179 pdf

Content: We contribute to an online discussion on whether paranasal sinuse volume can be used as a proxy for climate adaptation in humans and Neanderthals. According to our data past inferences on this relation are problematic.


A list including citations is available viGoogle scholar