This week we detected the first evidence of Spotted Salamander breeding in Duck, Fairy, Buttonbush and Teardrop. WF known in Fairy, Buttonbush and Teardrop. With the rain, I expect there will be more activity in all the pools this weekend.
I will be gone from Friday afternoon to Sunday afternoon (to the Science March in NYC). Some of you have expressed interest in coming out this weekend but for safety reasons, I would prefer that you only come out when I am here. So, we could do this on Sunday afternoon.. Let me know if you want to do that. The next few weeks we will be attempting to count all the masses we can find and marking their locations.
We had a good outing yesterday, finishing SS egg counts in all the lower pools (not including Sugar pool). With marking stakes in place, we can follow the development of representative masses and estimate hatching success rates for SS in each pool. We will do the same for the upper pools tomorrow morning, starting at 9. Let me know individually if you will be coming. If you can only come in the afternoon, let me know. There are always useful things to do, e.g., monitoring for the arrival of non-obligate macrofauna like tree frogs and dragonflies, sampling for oligochaetes, stump surveys and the like. This may be your last chance to sit quietly by the side of a vernal pool and just watch, unmolested by mosquitoes. Yesterday we saw the dreaded pupae.
Obligate amphibians – WF and SS – are done breeding for the year. It is my impression that egg numbers for both are down but this is the first year we have accurate counts for most of the pools. It is too early to say what factors matter most in VP amphibian breeding success at Masson Ridge but having this complete data set will be very helpful as the study goes forward. We had weird weather – an overly warm February followed by some bitter cold and no well-timed warm rain to inspire a “Big Night” – so this could have interfered with the behavioral triggers for communal breeding. Although the worldwide phenomenon of amphibian decline is still being debated, a large impact is attributed to a fungal pathogen known to be deadly to frogs, Batrachochytrium dendrobatidis. There is a similar fungus species that kills salamanders. I am considering testing for their presence at Masson Ridge.
Analyzing Vernal Pool Data from 2015-2017.
One of the roles that I have decided to take upon myself was the analysis of the 2015-2017 data-sets that have come out of the vernal pool study. It is very important to get familiar with interpreting and analyzing data when it comes to working in any science-related field. With the overall organization of the data, you have to figure out what quantitative and qualitative values should be kept, trimmed, or completely left out so that other future researchers can use this data. For example, pH, air temperature, the quantitative estimated amount of spotted salamander and wood frog egg masses, shallow water temperature, deep water temperature, marker depth, weather, location, and date can tell us a lot.
Quantitatively, we can graphically measure the pH for each vernal pool over a span of time and see if there were any drastic dips during the month. Let’s take Buttonbush, for example. The May 2015 pH data for Buttonbush was pretty consistent and the average pH was 5.33. For the March-June 2016 pH data, the average pH was found to be at 4.99. So far, the average pH for the month of April (in 2017) has been recorded at 4.18. It is rather unusual how there has been a slight drop to Buttonbush’s pH. Perhaps it is a mechanical error with the pH probe, where it wasn’t calibrated properly and reported some obscure pH value. Equipment malfunctions and other mechanical errors can happen to the best of us, and so it is always in your best interest to make a note of it when recording the data in a spreadsheet.
With marker depth, you will be able to observe the fluctuations of the vernal pool’s water depth over time. Back in 2015, Buttonbush’s water depth for 4/16/2015 was measured at 105.5 cm and dropped to 63 cm by 5/23/2015, while data ranging from 4/8/2017-4/20/2017 started out at 110 cm and dropped to 103 cm. For 2017, the water level has increased by a few centimeters due to the amount of rainfall we have been getting (so far at least), although there has been a few drops in its depth in between the study.
We use the pH probe’s temperature sensor to obtain the shallow temperature measurements and a garden temperature probe to measure out the deep temperature. The shallow and deep temperature of the pools may vary on the weather and amount of shade. Weather tends to play a vital role in the changes in water temperature. Say the weather is cloudy on the day that you take a shallow or deep water temperature measurement. The sun can’t warm the vernal pool’s surface as quickly as it can on clear days. Shade provided by the trees can also keep the water temperatures cool. Removal of vegetation would otherwise increase evaporation rates and water temperatures.
A double-observer approach is used for estimating the egg masses of wood frogs and spotted salamanders found at each vernal pool. Two people count each egg mass individually, which is an effective system since one person may overlook some of the egg masses that are completely concealed by the pool’s reflective surface. For Buttonbush’s wood frog egg mass data, there were only 160 egg masses recorded in 2015, 1 raft (which is approximately 1,000 egg masses) of wood frog egg masses found in 2016, while only 74 wood frog egg masses were found this year. Spotted salamander egg mass data for Buttonbush revealed 200 egg masses for 2015, 64 egg masses for 2016, and 12 egg masses for this year.