Monday, April 21, 2008

Joinery class, Spring, 08!


Tobias Ammon instructs older students about joining edges.

Wednesday, April 16, 2008

Spotted Frog Questions Answered!

My apologies for the slow response. See my answers intercalated below in capitals so you can

distinguish the lot.  Thank you for the tough questions. Let me know if you have any further questions.

Marc Hayes


How many Oregon biologists are studying them?


I CANNOT GIVE YOU A REALLY PRECISE ANSWER ON THIS BECAUSE THERE ARE AT

LEAST FOUR RESEARCH GROUPS (FRESC AT USGS IN, USFS FORESTRY SCIENCES

LAB, OSU ZOOLOGY DEPT ALL OF WHICH ARE IN CORVALLIS; and MICHAEL PARKER

AT SOUTHERN OREGON STATE UNIVERSITY IN ASHLAND) INVOLVED PLUS QUITE A

NUMBER OF BIOLOGISTS WITH SEVERAL STATE AND FEDERAL AGENCIES, BUT MOST

PROMINENTLY, THE DESCHUTES AND ROGUE-WINEMA NATIONAL FORESTS, THE BUREAU

OF LAND MANAGEMENT, AND OTHER COUNTY AND LOCAL AGENCIES.  THE RESEARCH

GROUPS DO BASIC OR MANAGEMENT-LINKED RESEARCH, WHEREAS THE OTHERS DO

MONITORING AND ARE WATCHDOGS FOR CONDITIONS THAT MAY BE UNFAVORABLE TO

OREGON SPOTTED FROGS.


How do they taste?


BITTER; LIKE MANY AMPHIBIANS, THEY HAVE GLANDS IN THEIR SKIN CALLED

GRANULAR GLANDS, WHICH PRODUCE DIFFERENCE COMPOUNDS THAT ARE DETERRENTS

TO SELECTED PREDATORS.


Are they poisonous?


SOME OF THE COMPOUNDS THAT HAVE BITTER TASTES ARE POISONS TO SOME

PREDATORS THAT VARY IN THEIR TOXICITY OR POTENCY. WE KNOW VERY LITTLE

ABOUT THE TOXINS ASSOCIATED WITH OREGON SPOTTED FROGS OR WHICH OF THEIR

PREDATORS THEIR ARE EFFECTIVE AGAINST.  BOTTOM LINE IS SOME OF THE

COMPOUNDS THAT OREGON SPOTTED FROGS PRODUCE ARE PROBABLY POISONOUS, BUT

BEING POISONOUS DEPENDS ON WHAT ANIMALS THEY ARE POISONOUS TO AND THAT

IS SOMETHING WE DO NOT KNOW AT THIS TIME. BY THE WAY, MANY POISONOUS

COMPOUNDS ARE BITTER TO SERVE AS A WARNING TO A POTENTIAL PREDATORS THAT

THE ANIMAL IS NOT GOOD TO EAT.


Why are frogs important?


FROGS ARE IMPORTANT BECAUSE THEY (AND THEIR LIFE STAGES) ARE KEY LINKS

IN FOOD WEBS IN MANY DIFFERENT HABITATS AND ECOSYSTEMS. FOR EXAMPLE,

ADULT AND JUVENILE FROGS (AFTER METAMORPHOSIS) ARE IMPORTANT PREDATORS

ON MANY AQUATIC AND TERRESTRIAL INSECTS. ADDITIONALLY, SOME PREDATORS

EACH MOSTLY FROGS OR SOME OF THEIR LIFE STAGES, SO WITHOUT FROGS (OR

THEIR LIFE STAGES), THE ANIMALS THAT DEPEND ON THEM ALMOST EXCLUSIVELY

FOR FOOD MIGHT NOT SURVIVE. FOR EXAMPLE, 95% OF THE DIET OF COMMON

GARTER SNAKES ARE AMPHIBIANS, ESPECIALLY FROGS.  ALSO, FROG AND TOAD

TAPOLES ARE GRAZERS IN STILLWATER OR POND TYPE AQUATIC HABITATS, BY

GRAZING ON ALGAE AND BIOFILMS OF BACTERIA, FROG AND TOAD TADPOLES KEEP

THESE PORTIONS OF PONDS SYSTEMS FROM TAKING OVER THOSE HABITATS TO

EXCESS AND THEIR WASTE MATERIALS ARE IMPORTANT IN NUTRIENT CYCLING,

PROVIDING NUTRIENTS FOR CERTAIN PLANTS AND OTHER ORGANISMS.  LASTLY,

FROGS ARE IMPORTANT BECAUSE THEIR ENRICH THE DIVERSITY OF ENVIRONMENTS

IN WHICH WE (HUMANS) LIVE; WITHOUT FROGS, THE ENVIRONMENTS IN WHICH WE

LIVE WOULD BE LESS DIVERSE.


Which animals, other than bullfrogs, eat Spotted Frogs?


MINK, RIVER OTTERS, GREATER SANDHILL CRANES ARE KNOWN PREDATORS OF

ADULTS. FROG EGGS HAVE FEW PREDATORS OF IMPORTANCE, BUT THIS HAS NOT BE

WELL STUDIED, BUT AT THE TIME EGGS ARE LAID, FEW PREDATORS MAY BE AROUND

TO PREY ON EGGS. LEECHES ARE ONE OF THE FEW DOCUMENTED PREDATORS OF

EGGS, BUT THEY ARE ALMOST NEVER ABUNDANT AT THE TIME EGGS ARE LAID, AND

ONE OR TWO LEECHES CAN ONLY EAT A FEW EGGS, SO THEY ARE NOT VIEWED AS

VERY IMPORTANT. THE TADPOLES HAVE MANY PREDATORS, INCLUDING COMMON

GARTER SNAKES, ADULT AND LARVAL DIVING BEETLES (LARVAL DIVING BEETLES,

ALSO KNOWN AS WATER TIGERS ARE IMPORTANT PREDATORS OF YOUNG (SMALL)

OREGON SPOTTED FROG TADPOLES), WATER SCORPIONS, SEVERAL WADING BIRDS

(LIKE GREAT BLUE AND LITTLE GREEN HERONS), AND PROBABLY A NUMBER OF

OTHERS.  WE ONLY KNOW ABOUT SOME OF THE PREDATORS OF FROGS; MANY ARE

UNDOCUMENTED OR WE SIMPLY ARE GUESSING THAT SOME SPECIES ARE PREDATORS

OF FROGS.


Do rough skin newts eat them?


ROUGH-SKIN NEWTS ARE RELATIVELY SLOW-MOVING, BUT THEY ARE WELL KNOWN

EGG PREDATORS OR PREDATORS OF TINY, JUST HATCHED TADPOLES OF OTHER FROG

SPECIES.  NEWTS COULD PREY ON OREGON SPOTTED FROG EGGS AND THEIR JUST

HATCHED TADPOLES IF THEY WERE ACTIVE AT THE TIME THAT OREGON SPOTTED

FROGS LAY EGGS, BUT NEWTS ARE ALMOST NEVER ACTIVE WHEN OREGON SPOTTED

FROG LAY EGGS, SO THEY DO NOT HAVE THE OPPORTUNITY TO PREY ON THEM....AT

LEAST NO ONE HAS EVER SEEN IT YET.


What did frogs look like a million years ago?


MOST OF THE FROGS AND FROG GROUPS THAT WE KNOW ABOUT TODAY EXISTED A

MILLION YEARS AGO. YOU HAVE TO GO FURTHER BACK IN TIME THAN A MILLION

YEARS TO UNDERSTAND HOW FROGS EVOLVED. THE FROG BODY PLAN WITH ENLARGED

(HOPPING OR LEAPING) BACK LEGS PROBABLY EVOLVED FROM SOME AN ANCESTOR

THAT LOOKED MORE SALAMANDER-LIKE DURING THE MESOZOIC (AGE OF THE

DINOSAURS). THAT ANCESTOR WHICH LOOKED MORE LIKE A SALAMANDER AND HAD

FRONT AND BACK LEGS OF APPROXIMATELY THE SAME SIZE AND MANY VERTEBRAE IN

ITS BACKBONE, SLOWLY CHANGED OVER TIME SO THAT ITS BACK LEGS BECAME

LARGER THAN ITS FRONT LEGS AND THE NUMBER OF VERTEBRAE IN ITS BACKBONE

SLOWLY DECREASED UNTIL YOU HAD THE BODY PLAN OF THE MODERN FROGS WE SEE

TODAY WITH ENLARGED BACK LEGS AND A SMALL NUMBER OF VERTEBRAE IN THE

BACKBONE (I.E., LESS THAN 10). 


Do caecilians live in groups or on their own?


THE SOCIAL STRUCTURE OF MOST CAECILIANS IS UNKNOWN. SOME OF THE AQUATIC

CAECILIANS HAVE BEEN FOUND IN SMALL GROUPS, BUT MOST CAECILIANS ARE

TERRESTRIAL BURROWERS, WHERE SINGLE INDIVIDUALS ARE USUALLY ENCOUNTERED

BY ACCIDENT WHILE DIGGING. SO, IN TRUTH, I CANNOT ANSWER THAT QUESTION

VERY WELL BECAUSE WE KNOW SO LITTLE.


Are caecilians edible?


I ASSUME THAT YOU MEAN EDIBLE TO PEOPLE. THERE IS VERY LITTLE MEAT ON A

CAECILIAN, BUT A FEW SPECIES ARE OCCASIONALLY EATEN BY SELECTED TRIBES

IN SOUTH AMERICA. HOWEVER, IT DOES NOT APPEAR TO BE AN IMPORTANT PART OF

THEIR DIET.


THANK YOU FOR ALL YOUR GOOD QUESTIONS!!!!!!!!


Monday, April 7, 2008

Homeschoolers at the Bite!


Gretchen Newcomb organized this art installation for Nora's Fish House in Hood River. The event where the art was displayed first was Columbia Gorge Art In Education's 2008 Bite of the Gorge. Big thanks to Olivia and Finney Newcomb and Erika and Blake Winner for producing these great paper fish with Gretchen!