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After a very dry summer, rains have started to fill up part of the rivers we are studying. In some cases this has led refuge pools to connect with previously dried-up sections of river, as has happened in the Riera de Escales in the photo, a very dry stream in the Garrotxa. Interestingly enough, a day or so after the rain the pools have disconnected again, and we found fish in the newly created pools, meaning they must have come from the bigger original pool. How they got there, e.g. passive by strong flow of the rain or by actively swimming, is something to be determined, but interestingly it only seems to be fish of certain size-classes. These fish may be safe for now in their new pool, but if it does not rain enough in the coming weeks, the pool may still dry up and the fish will die

#drought #freshwater #freshwaterecology #riuscatalans #sequera #aigua

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After a very dry summer, rains have started to fill up part of the rivers we are studying. In some cases this has led refuge pools to connect with previously dried-up sections of river, as has happened in the Riera de Escales in the photo, a very dry stream in the Garrotxa. Interestingly enough, a day or so after the rain the pools have disconnected again, and we found fish in the newly created pools, meaning they must have come from the bigger original pool. How they got there, e.g. passive by strong flow of the rain or by actively swimming, is something to be determined, but interestingly it only seems to be fish of certain size-classes. These fish may be safe for now in their new pool, but if it does not rain enough in the coming weeks, the pool may still dry up and the fish will die #drought #freshwater #freshwaterecology #riuscatalans #sequera #aigua

1 year ago

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1/9

In the field with my amazing field technician @galdric98, exploring our study streams after the rain and documenting how some fish may manage to escape the refuge pools that enabled them to survive the dry summer months

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In the field with my amazing field technician @galdric98, exploring our study streams after the rain and documenting how some fish may manage to escape the refuge pools that enabled them to survive the dry summer months

1 year ago

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2/9

Something different to share today! The PhD defence of Apu Ramesh at the RUG in Groningen, where I was one of the members of the PhD examination committee and it was my role to ask detailed questions about her thesis. Apu did a wonderful job and successfully defended her thesis "animal personalities on the move" about the movement strategies of migrating and resident sticklebacks. It was a shame to miss some of the official procedures and customs that we have in the Netherlands as I could not attend in person, but great to be able to still do it (dressed-up) from the lab abroad!

#phddefense #rijksuniversiteitgroningen #gelifes #science #sciencedegree

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Something different to share today! The PhD defence of Apu Ramesh at the RUG in Groningen, where I was one of the members of the PhD examination committee and it was my role to ask detailed questions about her thesis. Apu did a wonderful job and successfully defended her thesis "animal personalities on the move" about the movement strategies of migrating and resident sticklebacks. It was a shame to miss some of the official procedures and customs that we have in the Netherlands as I could not attend in person, but great to be able to still do it (dressed-up) from the lab abroad! #phddefense #rijksuniversiteitgroningen #gelifes #science #sciencedegree

1 year ago

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3/9

There is large temperature variation in the refuge pools we are sampling, with many actually keeping a moderate temperature due to sufficient cover, but others heating up to well over 30C. This large pool ranged between 29C and 33C, which, so far, the Mediterranean barbel still seem to be able to withstand

#freshwaterecology #freshwaterstream #environmentalchange #fieldbiology #fieldresearch #riversampling #lagarrotxa #riuscatalans

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There is large temperature variation in the refuge pools we are sampling, with many actually keeping a moderate temperature due to sufficient cover, but others heating up to well over 30C. This large pool ranged between 29C and 33C, which, so far, the Mediterranean barbel still seem to be able to withstand #freshwaterecology #freshwaterstream #environmentalchange #fieldbiology #fieldresearch #riversampling #lagarrotxa #riuscatalans

1 year ago

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4/9

Just had a fantastic week in Stockholm, attending and presenting at #ISBE2022, the bi-annual conference of the International Society for Behavioural Ecology. So great to see and chat with so many colleagues from around the world and see a week full of highly diverse and inspiring talks at such a great location!

#scienceconference #ecology #behavioralecology #sciencetalk

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Just had a fantastic week in Stockholm, attending and presenting at #ISBE2022, the bi-annual conference of the International Society for Behavioural Ecology. So great to see and chat with so many colleagues from around the world and see a week full of highly diverse and inspiring talks at such a great location! #scienceconference #ecology #behavioralecology #sciencetalk

1 year ago

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5/9

Besides fish, frogs, and snakes, we also occasionally find turtles in our refuge pools! Including this native species, the Tortuga de rierol (Mauremys leprosa)

#turtle #tortoise #tortuga #tortugarierol #herpetologia #catalunya_natura

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Besides fish, frogs, and snakes, we also occasionally find turtles in our refuge pools! Including this native species, the Tortuga de rierol (Mauremys leprosa) #turtle #tortoise #tortuga #tortugarierol #herpetologia #catalunya_natura

1 year ago

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6/9

An intermittent stream in the pyrenean foothills in the midst of the dry season with only some small pools with increasingly warm water on the blank bedrock remaining.. Photo by @galdric98, Riera d'Escales, Garrotxa

#drystream #garrotxa #riusdecatalunya #intermittentstream

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An intermittent stream in the pyrenean foothills in the midst of the dry season with only some small pools with increasingly warm water on the blank bedrock remaining.. Photo by @galdric98, Riera d'Escales, Garrotxa #drystream #garrotxa #riusdecatalunya #intermittentstream

1 year ago

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7/9

Aquatic snakes are one of the main predators of fish of the freshwater habitats in the region. In intermittent streams refuge pools may offer a safe haven from droughts but are an ideal location for snakes and other predators to come for a snack. Indeed, almost every day out in the field we saw at least one snake and often multiple individuals looking out for an easy meal. Here you can see the Iberian Grass Snake (Natrix astreptophora), curiously coming towards me while a school of Mediterranean Barbel hurries past. It is larger (up to 125cm) and less common than the Viperine water Snake (Natrix maura), and tends to be less aquatic, so I was really happy to see this individual swimming from up close!

#watersnake #natrix #natrixastreptophora #natrixnatrix #herpetologia #swimmingsnake #grasssnake #altagarrotxa #catalunya_natura #reservafluvial

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Aquatic snakes are one of the main predators of fish of the freshwater habitats in the region. In intermittent streams refuge pools may offer a safe haven from droughts but are an ideal location for snakes and other predators to come for a snack. Indeed, almost every day out in the field we saw at least one snake and often multiple individuals looking out for an easy meal. Here you can see the Iberian Grass Snake (Natrix astreptophora), curiously coming towards me while a school of Mediterranean Barbel hurries past. It is larger (up to 125cm) and less common than the Viperine water Snake (Natrix maura), and tends to be less aquatic, so I was really happy to see this individual swimming from up close! #watersnake #natrix #natrixastreptophora #natrixnatrix #herpetologia #swimmingsnake #grasssnake #altagarrotxa #catalunya_natura #reservafluvial

1 year ago

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8/9

My field technician @galdric98 exploring the Llierca river to document the distribution of fish and location of refuge pools. Here are some of the deepest parts of the river. That is, when there is water. Now it is almost completely dry already and it feels more like walking on the moon #dryriverbed #rivergorge #sadernes #fieldwork #freshwaterfish #freshwaterecology #natgeoexplore #moonwalk

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My field technician @galdric98 exploring the Llierca river to document the distribution of fish and location of refuge pools. Here are some of the deepest parts of the river. That is, when there is water. Now it is almost completely dry already and it feels more like walking on the moon #dryriverbed #rivergorge #sadernes #fieldwork #freshwaterfish #freshwaterecology #natgeoexplore #moonwalk

1 year ago

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9/9

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While snorkelling in the Bodensee, I found a large number of pikes stalking juvenile fish in the reeds along the shores. The pikes here can easily get 1m and are actually quite easy to approach to within 2m when quiet. Beautiful to see these hunters up close in the wild.

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Jolle Jolles

Behavioral Biologist, PhD, National Geographic Explorer

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