RE: {Disarmed} Re: [vernalpool] Re: Early spring migration

Very interesting discussion folks, thanks for sharing.

In NJ, my personal experience with both spotted salamander and wood frog movements (admittedly not well chronicled) is that since 2000, initial movements (so sometimes just males) was never observed earlier than March 5, and never later that March 24. Seems to me like on average, movement in NJ occurs the second week in March, is associated with relatively heavy rainfall, and often followed one or two previous nighttime rainfall events which had us wondering, but nothing ever happened (indicative of another relevant variable ~ such as the soil temps noted previously not having been suitable yet or - I used to wonder - simply "time of year"). I recall the March 5 event was a warm season like this year, and that year no precipitation event was involved, just ridiculously warm temps w/ thawed ground conditions. They got tired of waiting ...

Last week a consultant reported observing several spotteds already on the surface, beneath a log, and a few days later he had one crossing a road at a migration road closure site, under relatively unimpressive rainfall conditions. Wont be long ...

John H. Heilferty
Environmental Specialist 4
E&T Species/Vernal Habitat Unit
Division of Land Use Regulation
NJ DEP

>>> cdy3@cornell.edu 2/23/2012 1:14 PM >>>
Cliff's Notes version from Sexton's study:

Primary Condition
3 day mean temperature of 41.9° F / 5.5° C
Soil temperature @ 30 cm greater than 39.2° F / 2.13° C
At least 0.16 inches / 0.4 cm of rainfall
A reversal of the soil temperature profile (surface is warmer than sub-surface)

Secondary Condition
3 day mean temperature of 35.8° F / 2.13° C
Soil temperature @ 30 cm greater than 37.4° F / 3° C
At least 0.16 inches / 0.4 cm of rainfall

I tested Sexton's criteria in Upstate NY from 2003 through 2010 and the same conditions on my study population of spotted salamanders followed exactly in all years but one, which I think was 2005 where we never got any warm days in March. But the inversion of soil temps seemed to be the key. The 2005 exception was when we had equalization of soil temps at the surface and 30 cm. Oddly, rainfall was not always a necessary component. I was out one night that was dry and you could hear the rustling of leaves all over the forest surrounding the pool as salamanders made their way in. There had been heavy snowmelt the night before and a 75 degree sunny day preceding the influx of salamanders that night.

Sexton's criteria never worked with Jeffersons. Had some migration events that I couldn't figure how they got through frost, let alone ice cover on the pools.

For what it's worth, the average date for first migrants at my study pool from the last nine years is March 17 for Jefferson salamanders and March 29 for spotted.

Chris

-----Original Message-----
From: vernalpool@yahoogroups.com [mailto:vernalpool@yahoogroups.com] On Behalf Of matt burne
Sent: Thursday, February 23, 2012 12:04 PM
To: vernalpool@yahoogroups.com
Subject: Re: {Disarmed} Re: [vernalpool] Re: Early spring migration

Thank you. Leo responded off line with this link to the abstract:

http://www.mendeley.com/research/effects-temperature-precipitation-breeding-migration-spotted-salamander-ambystoma-maculatum-9/

Cheers,

Matt

2012/2/23 <Jessica.S.Veysey.00@alum.dartmouth.org>

> **
>
>
>
> Sure - it's:
>
> Sexton OJ, Phillips C, and JE Bramble. 1990. The effects of temperature
> and precipitation on the breeding migration of the spotted salamander
> (Ambystoma maculatum). Copeia 1990(3): 781-787.
>
> Jessica
>
> --- You wrote:
> Can you provide the citation? Attachments don't fly in this list.
>
> Matt
> --- end of quote ---
>
>
>

[Non-text portions of this message have been removed]

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