Archive for the Category ◊ Amphibians ◊

Author:
• Friday, March 11th, 2011

There is a magical event that happens in the early spring. No one knows what triggers it and no one knows exactly when it will occur. It’s a surprise. Don’t you just love surprises? It is a secret trek of the Spotted Salamanders to their breeding pools.

Vernal Pool in New Jersey

In what seems like impossibly cold weather, these amphibians have waited underground for the first warm evening spring rain. Warm being a relative term because it is still only about 45 or 50 degrees. But without fail, as the rain falls, spotted salamanders come up from their underground burrows and march sometimes by the hundreds, to vernal pools where they’ve been breeding for decades.

 

 

Vernal pools are shallow depressions in the earth where water collects in the spring but dries up by late summer or early fall. Salamanders will not breed in traditional ponds where predators such as fish loom.

Male spotted salamander. Spots are unique like finger prints.

Male salamanders migrate to their breeding pools and hang out in bachelor groups called congregations. But when the females arrive, the party really starts. 40-50 Spotted Salamanders gyrate, rub against each other and rotate their tail in hope of attracting a female’s fancy. If all this foreplay works, she’ll follow him out of the crowd as he swims away. He’ll then deposit a gelatinous sperm packet called a spermatophore. The female will trail him and pick up the spermatophore in her genital opening thus completing fertilization. Within a few days, she’ll deposit 2-3 jelly-like balls with 50-100 eggs in each. The egg sacs resemble snowballs that are attached to underwater sticks. After completing this task, both male and female adult salamanders leave the pool and return to their underground burrow until next spring.

The egg sacs remain underwater for 5-6 weeks when they hatch into tiny, gilled tadpoles. After feeding on small aquatic insects through the summer, the tadpoles metamorphose into miniature adults and leave the water by the fall.

 

 

Category: Amphibians, Seasons  | One Comment
Author:
• Monday, March 16th, 2009

It may not feel much like spring, and the calendar may say it is still a 5 days away, but spring has definitely sprung around here. Spring can be very subtle, and you need to be cued into the clues, but, if you look and listen carefully, you will soon discover that the seasons have changed.

On a recent trip to the bank, I noticed the branches of the silver maple lining the road had a distinct fuzzy appearance. I pulled over and discovered they were in fact blooming. Many people don’t realize trees bloom unless they are obvious like dogwoods, but maple trees are in full bloom now.

 

 

Another tip that spring is here has actually finished already. Just 5 days ago, the wood frogs were calling in the vernal pools of Five Mile Woods. With the first spring rain, the males make their way to these temporary pools and start calling. The females follow shortly after. You may have mistaken their calls for quacking ducks, but they are small woodland frogs that wake, call, mate, lay eggs and leave all within a two week period.

 

 

Thousands of jelly-like eggs are laid by the females while the male clasps her from behind and fertilizes the eggs as they come out. Also calling, and they will continue to do so for several weeks, are the spring peepers. These tiny tree frogs are no larger than a man’s thumb nail, but their loud whistling peep can be heard up to a mile away.

 

The last amphibian to wake from spring is a silent one. Along with the woodfrogs, the spotted salamander remains underground most of the winter. With the first “warm” spring rains, they migrate, sometimes in mass, to vernal pools. Males congregate first, followed by the females. Their courtship, though brief is very interesting, but hasn’t happened yet, so I’ll save it for another post.

Get outside and discover spring before it is too late.

Author:
• Friday, October 11th, 2002

“More than 100 new frog species have been discovered in the Sri Lankan rainforest.”
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