Put on your boots! Get set! Go!
Wednesday, July 15th. More and more tadpoles, more and more volunteers!
The SAT is looking for new trainees to complete the Brandon Ballengée « frog team ».
Trainees wanted!
Wednesday, July 15th. More and more tadpoles, more and more volunteers!
The SAT is looking for new trainees to complete the Brandon Ballengée « frog team ».
On the menu : bio-lab maintenance, amphibians experimentations, «frogs fishing» and «tadpoles catches» in wetlands… No specific knowledge is necessary.
To join the frog team, please send us an email : [email protected]
Put on your boots! Get set! Go!
Amphibians in wooded sites!
Monday, July 13th. On this monday, the team went near Mont Saint Grégoire. In the wooded small wetlands, tadpoles of various species were in large numbers : especially wood frogs, toads, and salamanders.
One albino tadpole has been collected during this field-trip. It’s actually under observation at the bio-lab ; and we’ve taken some photographs.
The Occurrence of Developmental Abnormalities in Amphibians
written by Brandon Ballengée
Tuesday, July 14th. The occurrence of abnormalities in natural populations of amphibians (mostly frogs and toads) has been a highly publicized environmental issue for more than a decade. The cause(s) for amphibian deformations remains scientifically controversial but the primary agents currently being investigated are parasitic trematode infection, chemical pollution, ultraviolet radiation and predation-induced injury, or a potential synergy between these.
The “normal” ratio for abnormalities in frogs and toads is generally considered to be less than 5% of the overall population. North American wetlands where amphibian populations exhibit a greater than 5% level of deformed individuals are often referred to as “hotspots”. Some researchers have suggested that such hotspots may be indicative of wetland ecosystem collapse.
Deformed frog hotspots in the Western regions of North America featuring young metamorphs with supernumerary hind limbs have been confirmed experimentally to be caused by infection by the trematode parasite Ribeiroia odontrae.
http://www.greenmuseum.org/malamp/trematode.php.
Deformity hotspots in Eastern north America featuring frogs with missing or truncated hind limbs or limb segments are more commonly reported but have been much more difficult to explain, and there have been few attempts to analyze them experimentally.
In 1997, a team of researchers reported several Southern Quebec wetlands with a greater than 5% malformed or deformed amphibian level. Although this study reported a small number of frogs with supernumerary limbs and a variety of other abnormalities (missing eyes for example), the majority featured missing limbs and limb segments (including toes).
The researchers found an increased incidence of deformities among frogs and toads at agricultural sites compared to sites with limited exposure to agro-chemicals. Although this correlation suggests chemical involvement, the water was not tested for the presence of specific chemical pollutants, and no definitive cause(s) or underlying mechanism resulting in abnormal development were established.
Currently Brandon along with the SAT Frog Team are collaborating with Dr. David M. Green (McGill University) and Dr. Stanley K. Sessions (Hartwick College) to study frog and toad populations in Southern Quebec for rates of abnormalities and what could be causing them.
So far, the team has sampled hundreds of frogs at several wetlands. Of these two wetlands have had a higher than 5% level of abnormality. Though it is important to remember that we will be sampling these sites throughout the summer so the ‘abnormality’ percentage may be lower as the season goes on.
These sites may have chemical pollutants but they also have lots of potential tadpole predators such as dragonfly nymphs, crayfish, fishes and even leeches! So far we have found a range of abnormalities in our sampled frogs which include fully missing limbs, truncated limbs, partial limbs, missing digits, missing eyes and ‘black’ eyes.
Last summer, Brandon found in his UK studies that hungry dragonfly nymphs would catch tadpoles and only eat portions of them such as limbs, eyes and tails. Many of the injured tadpoles survived and grew into young toads with permanent deformities. The results of these experiments where published with collegue Dr. Stanley K. Sessions of Hartwick College (Oneonta, NY) last month in the Journal of Experimental Zoology. http://www3.interscience.wiley.com/journal/122445444/abstract?CRETRY=1&SRETRY=0
The BBC reported on this finding last week! http://news.bbc.co.uk/earth/hi/earthnews/newsid8116000/8116692.stm
As of yet we do not know what is causing the abnormal frogs we have found so far in Quebec. We are running experiments in the SAT Lab and making new observations each day. Please check back or come visit us!
CALL FOR FROG PICTURES!
If you love frogs and want to photograph your local green friends email us a copy and we will potentially post it on our blog. Please send your name, date and place of photograph was taken. Also please send us permission to publish it along with your name on our blog!
IF YOU SEE ANY ABNORMAL FROGS! If you see any frogs that have abnormalities please report them to us. To do this send us a picture, the location and the date. Please do not collect the frog just the information! Thank you for your help!
Leeches in our fishing nets
Monday, July 6th. For its weekly field-trip, the team has casted its nets near Lake Champlain, once again. Many tadpoles, about an hundred of fishes, insects and leeches were caught in the fishing nets …. many and many leetches!
In the field, we have noticed that these parasites were attacking young fishes and tadpoles.
Could leeches be predators for frog tadpoles?
So far, we don’t have a clue, but we have to explore this new track!
Then, we brought back to the bio-lab about twenty leeches for more informations.
To be continued!
REPORT!
About 150 adult and young frogs have been examined during this field-trip.
The rate of deformations observed so far is above normal.
The main abnormalities are missing limb segments (such as toes) and missing eyes.
To see previous new
It’s raining…what a good day for frogs!
http://www.sat.qc.ca/post.php?id=40&post_id=1814&lang=en
