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Up shit creek: new sampling method reveals foraging decisions of a specialised seabird

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Up shit creek : new sampling method reveals foraging decisions of a specialised seabird. / Courtens, Wouter; Stienen, Eric; Verstraete, Hilbran; Van De Walle, Marc; Vanermen, Nicolas.

Book of abstracts – VLIZ Marine Scientist Day. Brugge, Belgium, 12 February 2016. VLIZ Special Publication, 75. Vlaams Instituut voor de Zee - Flanders Marine Institute (VLIZ): Oostende. xii, 165 pp. ed. / Jan Mees; Jan Seys. Oostende, 2016.

Research output: Chapter in Book/Report/Conference proceedingConference Abstract

Harvard

Courtens, W, Stienen, E, Verstraete, H, Van De Walle, M & Vanermen, N 2016, Up shit creek: new sampling method reveals foraging decisions of a specialised seabird. in J Mees & J Seys (eds), Book of abstracts – VLIZ Marine Scientist Day. Brugge, Belgium, 12 February 2016. VLIZ Special Publication, 75. Vlaams Instituut voor de Zee - Flanders Marine Institute (VLIZ): Oostende. xii, 165 pp. Oostende, VLIZ Marine Scientist Day, Brugge, Belgium, 12/02/16.

APA

Courtens, W., Stienen, E., Verstraete, H., Van De Walle, M., & Vanermen, N. (2016). Up shit creek: new sampling method reveals foraging decisions of a specialised seabird. In J. Mees, & J. Seys (Eds.), Book of abstracts – VLIZ Marine Scientist Day. Brugge, Belgium, 12 February 2016. VLIZ Special Publication, 75. Vlaams Instituut voor de Zee - Flanders Marine Institute (VLIZ): Oostende. xii, 165 pp Oostende.

Author

Courtens, Wouter ; Stienen, Eric ; Verstraete, Hilbran ; Van De Walle, Marc ; Vanermen, Nicolas. / Up shit creek : new sampling method reveals foraging decisions of a specialised seabird. Book of abstracts – VLIZ Marine Scientist Day. Brugge, Belgium, 12 February 2016. VLIZ Special Publication, 75. Vlaams Instituut voor de Zee - Flanders Marine Institute (VLIZ): Oostende. xii, 165 pp. editor / Jan Mees ; Jan Seys. Oostende, 2016.

Bibtex

@inbook{82976814a96147519cbf81375a302820,
title = "Up shit creek: new sampling method reveals foraging decisions of a specialised seabird",
abstract = "Sandwich Terns are really picky when it comes to food. In Belgian and Dutch waters, they almost exclusively feed on two fish-groups: Clupeids and Sandeels. But this doesn’t mean that by knowing this, their ecology is completely unravelled! If we like to know why for example their chicks are dying or thriving, growing fast or rather slow, we have to conduct long term research. We’ve been studying their breeding and feeding ecology for the last 15 years and still learn exciting things each year!The study of the diet of the chicks is relatively straightforward. In a breeding colony, we place a hide and watch the adults feeding their chicks. We write down the species and length of each fish brought to the chicks and do this for several days, at least 8 hours a day... This way, we end up with a pretty good idea of what the chicks have been feeding on. On the other hand, it’s not so easy to study the diet of adult Sandwich Terns (and of most of the otherspecies of seabirds for all that matters). The foraging occurs far out at sea, out of sight except for themost intrepid of observers. As a consequence, not many studies of the adult diet of seabirds areavailable, especially not in combination with that of their chicks.Luckily, incubating adult Sandwich Terns have the habit of defecating next to the nest. As a result,after three to four weeks of incubation, a thick crust of faeces has formed around the nest. In there arethe remains of all prey eaten in four weeks (mainly otoliths or fish ear bones). This is why we went upshit creek. We collected this faeces crust just before the chicks hatched (end of May) to compare withthe chicks diet. Of this, we learned that while the species composition of the chick and adult diets isroughly the same, there is a profound difference between the fish sizes chicks and adults eat. Thechicks get the big fishes, while the adults eat the left-overs.We realised that the scientific problem with combining these two methods is that the samples of chickand adult diets are not taken within the same period of time: the adult sample in May, the samples ofthe chicks mainly in June. Especially because around the end of May, a shift in the size class of theClupeids in the North Sea occurs, with bigger fishes becoming more abundant, an innovation to thesampling method was necessary. We had to be able to take long series of consecutive samples of theadult diet during the breeding season. The solution was simple, but took some trial and error. We justhad to place clay plates between the nests of incubating adults and empty them every two to threedays. Now we had an exact idea of the time-frame of the adults’ faeces samples.We have been using this sampling method for three years now in the Dutch Delta area and learned thatafter the chicks have hatched, the adults keep on eating small fish and feed the big fish to their chicks.Also, by studying the adult diet in this way, we noticed it gives an indication of prey availability for thechicks and helps us to identify the prey-composition to species level. This way, a small adaptation insampling method helped to get a better insight in the ecology of this threatened seabird!",
author = "Wouter Courtens and Eric Stienen and Hilbran Verstraete and {Van De Walle}, Marc and Nicolas Vanermen",
year = "2016",
month = "2",
day = "12",
language = "English",
isbn = "ISSN 1377-0950",
editor = "Jan Mees and Jan Seys",
booktitle = "Book of abstracts – VLIZ Marine Scientist Day. Brugge, Belgium, 12 February 2016. VLIZ Special Publication, 75. Vlaams Instituut voor de Zee - Flanders Marine Institute (VLIZ): Oostende. xii, 165 pp",

}

RIS

TY - CHAP

T1 - Up shit creek

T2 - new sampling method reveals foraging decisions of a specialised seabird

AU - Courtens, Wouter

AU - Stienen, Eric

AU - Verstraete, Hilbran

AU - Van De Walle, Marc

AU - Vanermen, Nicolas

PY - 2016/2/12

Y1 - 2016/2/12

N2 - Sandwich Terns are really picky when it comes to food. In Belgian and Dutch waters, they almost exclusively feed on two fish-groups: Clupeids and Sandeels. But this doesn’t mean that by knowing this, their ecology is completely unravelled! If we like to know why for example their chicks are dying or thriving, growing fast or rather slow, we have to conduct long term research. We’ve been studying their breeding and feeding ecology for the last 15 years and still learn exciting things each year!The study of the diet of the chicks is relatively straightforward. In a breeding colony, we place a hide and watch the adults feeding their chicks. We write down the species and length of each fish brought to the chicks and do this for several days, at least 8 hours a day... This way, we end up with a pretty good idea of what the chicks have been feeding on. On the other hand, it’s not so easy to study the diet of adult Sandwich Terns (and of most of the otherspecies of seabirds for all that matters). The foraging occurs far out at sea, out of sight except for themost intrepid of observers. As a consequence, not many studies of the adult diet of seabirds areavailable, especially not in combination with that of their chicks.Luckily, incubating adult Sandwich Terns have the habit of defecating next to the nest. As a result,after three to four weeks of incubation, a thick crust of faeces has formed around the nest. In there arethe remains of all prey eaten in four weeks (mainly otoliths or fish ear bones). This is why we went upshit creek. We collected this faeces crust just before the chicks hatched (end of May) to compare withthe chicks diet. Of this, we learned that while the species composition of the chick and adult diets isroughly the same, there is a profound difference between the fish sizes chicks and adults eat. Thechicks get the big fishes, while the adults eat the left-overs.We realised that the scientific problem with combining these two methods is that the samples of chickand adult diets are not taken within the same period of time: the adult sample in May, the samples ofthe chicks mainly in June. Especially because around the end of May, a shift in the size class of theClupeids in the North Sea occurs, with bigger fishes becoming more abundant, an innovation to thesampling method was necessary. We had to be able to take long series of consecutive samples of theadult diet during the breeding season. The solution was simple, but took some trial and error. We justhad to place clay plates between the nests of incubating adults and empty them every two to threedays. Now we had an exact idea of the time-frame of the adults’ faeces samples.We have been using this sampling method for three years now in the Dutch Delta area and learned thatafter the chicks have hatched, the adults keep on eating small fish and feed the big fish to their chicks.Also, by studying the adult diet in this way, we noticed it gives an indication of prey availability for thechicks and helps us to identify the prey-composition to species level. This way, a small adaptation insampling method helped to get a better insight in the ecology of this threatened seabird!

AB - Sandwich Terns are really picky when it comes to food. In Belgian and Dutch waters, they almost exclusively feed on two fish-groups: Clupeids and Sandeels. But this doesn’t mean that by knowing this, their ecology is completely unravelled! If we like to know why for example their chicks are dying or thriving, growing fast or rather slow, we have to conduct long term research. We’ve been studying their breeding and feeding ecology for the last 15 years and still learn exciting things each year!The study of the diet of the chicks is relatively straightforward. In a breeding colony, we place a hide and watch the adults feeding their chicks. We write down the species and length of each fish brought to the chicks and do this for several days, at least 8 hours a day... This way, we end up with a pretty good idea of what the chicks have been feeding on. On the other hand, it’s not so easy to study the diet of adult Sandwich Terns (and of most of the otherspecies of seabirds for all that matters). The foraging occurs far out at sea, out of sight except for themost intrepid of observers. As a consequence, not many studies of the adult diet of seabirds areavailable, especially not in combination with that of their chicks.Luckily, incubating adult Sandwich Terns have the habit of defecating next to the nest. As a result,after three to four weeks of incubation, a thick crust of faeces has formed around the nest. In there arethe remains of all prey eaten in four weeks (mainly otoliths or fish ear bones). This is why we went upshit creek. We collected this faeces crust just before the chicks hatched (end of May) to compare withthe chicks diet. Of this, we learned that while the species composition of the chick and adult diets isroughly the same, there is a profound difference between the fish sizes chicks and adults eat. Thechicks get the big fishes, while the adults eat the left-overs.We realised that the scientific problem with combining these two methods is that the samples of chickand adult diets are not taken within the same period of time: the adult sample in May, the samples ofthe chicks mainly in June. Especially because around the end of May, a shift in the size class of theClupeids in the North Sea occurs, with bigger fishes becoming more abundant, an innovation to thesampling method was necessary. We had to be able to take long series of consecutive samples of theadult diet during the breeding season. The solution was simple, but took some trial and error. We justhad to place clay plates between the nests of incubating adults and empty them every two to threedays. Now we had an exact idea of the time-frame of the adults’ faeces samples.We have been using this sampling method for three years now in the Dutch Delta area and learned thatafter the chicks have hatched, the adults keep on eating small fish and feed the big fish to their chicks.Also, by studying the adult diet in this way, we noticed it gives an indication of prey availability for thechicks and helps us to identify the prey-composition to species level. This way, a small adaptation insampling method helped to get a better insight in the ecology of this threatened seabird!

M3 - Conference Abstract

SN - ISSN 1377-0950

BT - Book of abstracts – VLIZ Marine Scientist Day. Brugge, Belgium, 12 February 2016. VLIZ Special Publication, 75. Vlaams Instituut voor de Zee - Flanders Marine Institute (VLIZ): Oostende. xii, 165 pp

A2 - Mees, Jan

A2 - Seys, Jan

CY - Oostende

ER -

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