2. Monday 2/24 Pop Quiz #6 Review Prickly Pear math questions
See Salamanders and Lizards – Quiz M 3/3
Chapter 9 – L-P population estimates
Due today: all of Prickly Pear Case Study
Exam postmortem due Wednesday!!

3. Class Amphibia Class Reptilia Order Anura – frogs and toads
Order Caudata – salamanders and newts
Order Apoda – caecilians
Class Reptilia
Order Testudines - turtles, terrapins, and tortoises
Order Squamata - lizards and snakes
Order Crocodilia - crocodiles and alligators

4. Missouri Lizards and Salamanders
All images are from Wikimedia Commons, unless otherwise identified

6. Common mudpuppy Necturus maculosus

7. Hellbender Cryptobranchus alleganiensis

8. Ringed salamander Ambystoma annulatum

9. Tiger salamander Ambystoma tigrinum

10. Spotted Salamander Ambystoma maculatum

11. Eastern newt, red-spotted newt Notophthalmus viridescens

12. Broad-headed skink Plestiodon laticeps

13. American five-lined skink Plestiodon fasciatus

14. Little brown skink Scincella lateralis

15. Prairie lizard, eastern fence lizard Sceloporus undulatus

16. Not on quiz Axolotl Ambystoma mexicanum

17. Chapter 9 – Population Distribution and Abundance
What are some methods of counting populations?

18. Chapter 9 – Population Distribution and Abundance
What are some methods of counting populations?
What if the individuals are mobile?
Hidden/“cryptic”?
What if we only have a sample?

19. Required variables N = n1n2/m2 N = estimated population size
n1 = number of individuals marked in first sample.
n2 = number of individuals marked in second sample.
m2 = number of individuals captured in second sample, that were marked in the first.

20. This method only works IF:
Probability of survival is equal
Births and deaths are insignificant between release and recapture
Immigration and emigration are nonexistent or insignificant
Marked individuals re-mix randomly
The mark makes it no easier or more difficult to recapture
Marks are permanent

21. Practice
A biologist nets 45 largemouth bass from a farm pond, tags their fins, and releases them unharmed. A week later, she nets 58 bass from the pond, including 26 tagged. Based on the L-I index, estimate the size of the population.

22. Mark-Recapture m2 / n1 = probability that an animal will be captured.
So, how large is the population?
n2 is really the portion of N that we expect to capture.
This is N*p = n2 where p is m2/n1.

23. Population Density So, N*p = n2 N = n2 / p
N = n2 / (m2 / n1) = n1n2 / m2
But, this is only part of the problem. We also need some estimate of area since Density, D = N / A.

24. Population Density
Imagine we study rodents using a trapping grid w/ 15m trap spacing.
We trap the animals over a series of nights, always noting the identity and location of each animal.
Then, we can estimate how far each individual moved between captures.

25. Population Density
Now, if an organism can travel from one station to the next, we can assume that it could travel half the distance to the next station as well.
Thus, the ‘effective area’ of our sample is the area of our grid, plus a border region around the grid, with a width of half the distance between stations.

26. Population Density

27. Area? What is the area of the grid? Ag = W2
How about the 4 rectangles?
Ab = 4 * W * (0.5 * D)
How about the 4 corners?
This is essentially the area of a circle.
Ac = (0.5D)2

28. Population Density
Finally, density can be estimated as