Assessing the Negative Impact of Edible Frogs on European Tree Frogs: A Potential Conservation Issue in Southern Sweden
(2024) BIOM02 20222Degree Projects in Biology
- Abstract
- Since habitat loss has been a major threat to the European tree frog, conservation efforts are primarily focused on increasing the pond area by constructing new ponds and restoring the existing ones. However, emerging threats within the breeding habitats, such as the presence of highly competitive species, is important to consider. One such highly competitive species for the European tree frog in Scandinavia might be the edible frog, which is expanding in Sweden. This study aims to investigate the potential impact of the expanding edible frog population on the European tree frog in southern Sweden. In this study, breeding habitats of tree frogs were mapped, and data from Artportalen from 2005-2023 were utilized to assess the edible frog's... (More)
- Since habitat loss has been a major threat to the European tree frog, conservation efforts are primarily focused on increasing the pond area by constructing new ponds and restoring the existing ones. However, emerging threats within the breeding habitats, such as the presence of highly competitive species, is important to consider. One such highly competitive species for the European tree frog in Scandinavia might be the edible frog, which is expanding in Sweden. This study aims to investigate the potential impact of the expanding edible frog population on the European tree frog in southern Sweden. In this study, breeding habitats of tree frogs were mapped, and data from Artportalen from 2005-2023 were utilized to assess the edible frog's impact on the European tree frog. Results indicate a significant impact of the edible frog on the abundance of European tree frogs in shared breeding ponds. Habitats shared by both species exhibit lower tree frog populations compared to those without edible frogs. Additionally, waterbody connectivity becomes increasingly important for tree frog abundance in the presence of edible frogs, possibly facilitating colonization. One possible explanation is that the predatory edible frog, which is typically found in large numbers along the shore of wetlands, consume a substantial amount of newly metamorphosed and emerging tree frogs. Another possible explanation is that juvenile edible frogs, possibly sharing dietary preferences with tree frogs due to their similar body sizes and shared preference for shallow waterbodies, could potentially outcompete the tree frog. The results from this correlative study highlights the need for further experimental and field studies focusing on identifying mechanisms behind the patterns found. These findings may inform conservation strategies aimed at safeguarding the European tree frog in southern Sweden. (Less)
- Popular Abstract
- Trouble in the Pond: Edible Frogs Threaten European Tree Frogs
In the tranquil ponds of southern Sweden, European tree frogs (Hyla arborea) have long thrived, peacefully going about their lives. However, a new threat has emerged in the form of the edible frog (Pelophylax esculentus), which is expanding in southern Sweden, inhabiting more and more ponds where other amphibians live such as the European tree frog. Their expansion predicts trouble for the European tree frogs.
European tree frogs are already facing a big problem: their ponds are disappearing. To help them out, conservationists are working hard to make more ponds and restore the ones that already exist. But there is a new threat emerging within the pond: the edible frog.... (More) - Trouble in the Pond: Edible Frogs Threaten European Tree Frogs
In the tranquil ponds of southern Sweden, European tree frogs (Hyla arborea) have long thrived, peacefully going about their lives. However, a new threat has emerged in the form of the edible frog (Pelophylax esculentus), which is expanding in southern Sweden, inhabiting more and more ponds where other amphibians live such as the European tree frog. Their expansion predicts trouble for the European tree frogs.
European tree frogs are already facing a big problem: their ponds are disappearing. To help them out, conservationists are working hard to make more ponds and restore the ones that already exist. But there is a new threat emerging within the pond: the edible frog. These guys are moving into the ponds of the European tree frog, and they are not very friendly. Therefore, I wanted to find out how much trouble these edible frogs were causing. I checked out where the tree frogs lived and where they co-lived with the edible frog. And indeed, the tree frogs are disappearing when the edible frog is present, throughout various pond sizes. But there’s a twist: when there are a lot of ponds connected, the tree frogs seem to have a better chance of surviving, even when the edible frog is around. They probably colonize other ponds where the European tree frog is less abundant in order to get away from the competition with the edible frog.
Thus the much bigger edible frog is causing trouble for the much smaller European tree frog. The generalist feeder that can be in various habitats, might be trouble for the tree frog that has less of a diet diversity palette. But how are the edible frogs causing trouble for the European tree frog? One possibility is that the edible frog eats the young tree frogs the moment they emerge. Another possibility could be that the juvenile edible frog eats all the prey that is meant for the European tree frog.
Conservation
A conservation recommendation is to focus on creating temporary, shallow ponds. The European tree frog thrives in shallow waters, while the edible frog prefers deeper waters. Besides, the edible frog is more dependent on permanent ponds since they metamorphose in August when the temporary pond is dried up, not having enough time to finish the life cycle of metamorphosis. The European tree frog can still finish this cycle in time before temporary ponds dry up at the end of July.
This study shows that we need to do more research to understand what is really going on. By figuring out why the edible frogs are causing trouble, we can come up with better ways to protect the European tree frogs in southern Sweden.
Master’s Degree Project in Conservation Biology, 30 credits, 2024
Department of Biology, Lund University
Supervisors: Dr. Ola Olsson, Dr. Per Nyström
Lund University and Ekoll AB (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9153892
- author
- Brandsen, Samara
- supervisor
-
- Ola Olsson LU
- Per Nyström LU
- organization
- course
- BIOM02 20222
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9153892
- date added to LUP
- 2024-05-23 14:32:58
- date last changed
- 2024-05-24 03:41:23
@misc{9153892,
abstract = {{Since habitat loss has been a major threat to the European tree frog, conservation efforts are primarily focused on increasing the pond area by constructing new ponds and restoring the existing ones. However, emerging threats within the breeding habitats, such as the presence of highly competitive species, is important to consider. One such highly competitive species for the European tree frog in Scandinavia might be the edible frog, which is expanding in Sweden. This study aims to investigate the potential impact of the expanding edible frog population on the European tree frog in southern Sweden. In this study, breeding habitats of tree frogs were mapped, and data from Artportalen from 2005-2023 were utilized to assess the edible frog's impact on the European tree frog. Results indicate a significant impact of the edible frog on the abundance of European tree frogs in shared breeding ponds. Habitats shared by both species exhibit lower tree frog populations compared to those without edible frogs. Additionally, waterbody connectivity becomes increasingly important for tree frog abundance in the presence of edible frogs, possibly facilitating colonization. One possible explanation is that the predatory edible frog, which is typically found in large numbers along the shore of wetlands, consume a substantial amount of newly metamorphosed and emerging tree frogs. Another possible explanation is that juvenile edible frogs, possibly sharing dietary preferences with tree frogs due to their similar body sizes and shared preference for shallow waterbodies, could potentially outcompete the tree frog. The results from this correlative study highlights the need for further experimental and field studies focusing on identifying mechanisms behind the patterns found. These findings may inform conservation strategies aimed at safeguarding the European tree frog in southern Sweden.}},
author = {{Brandsen, Samara}},
language = {{eng}},
note = {{Student Paper}},
title = {{Assessing the Negative Impact of Edible Frogs on European Tree Frogs: A Potential Conservation Issue in Southern Sweden}},
year = {{2024}},
}