The California spotted owl (Strix occidentalis occidentalis) is a threatened subspecies of the endangered northern spotted owl (Strix occidentalis caurina). It occurs in southern California as a group of discrete populations within the San Bernardino Mountains of southern California. Their habitat is discontinuous in part because of human development activities. Individual populations have shown recent declines, which currently are attributed to increased isolation of habitat patches and natural environmental stochasticity. Dispersal between these populations is important for maintaining both the individual populations as well as the metapopulation.
Below is a list of the 23 populations in the model some of which have abbreviations.
| Number | Full name | Abbreviated name |
| 1 | Northern Monterey: | N. Monterey |
| 2 | Southern Monterey: | S. Monterey |
| 3 | Cerro Alto: | C. Alta |
| 4 | Southern Santa Lucia: | S. Lucia |
| 5 | Sierra Madre: | S. Madre |
| 6 | San Rafael: | S. Rafael |
| 7 | Santa Ynez: | S. Ynez |
| 8 | Pinus: | Pinus |
| 9 | Tecuya: | Tecuya |
| 10 | Cobblestone: | Co. |
| 11 | Tehachapi: | Tehachapi |
| 12 | Pelona: | Pelona |
| 13 | San Gabriel: | S. Gabriel |
| 14 | San Bernardino: | S. Bernardino |
| 15 | San Jancinto: | S. Jancinto |
| 16 | Thomas: | Thomas |
| 17 | Santa Ana: | S. Ana |
| 18 | Palomar: | Palomar |
| 19 | Black: | B. |
| 20 | Volcan: | V. |
| 21 | Cuyamaca: | Cu. |
| 22 | Laguna: | Laguna |
| 23 | Sierra Nevada: | Sierra Nevada |
Use METAPOPW (K:\WLF\448\PRE2004\RAMAS\) to explore the metapopulation and population dynamics of the California spotted owl using the cal-owl.mp model. See the In-class exercise for information on how to use the program. Please answer the following questions.
1. Run the model with the default values. Print out the Trajectory Summary and the Metapopulation Occupancy graphs. Compare these results. You may also want to look at the numerical results. Based on the Trajectory Summary what will happen to these populations of spotted owls in 20 years? Based on the Metapopulation Occupancy? How and why are these results different? (5 points)
2. What sort of change in survival rates and/or number of adults producing juveniles would it take to change the mean number of extant populations to 12 and improve this metapopulation’s chances for persistence over the next 20 years? Clearly explain what you changed and why. Print out any relevant results to show how you achieved your objective. (4 points)
3. What is different about the Sierra Nevada population compared to all the other populations? (2 points)
4. Which populations would be most influential to stabilize and why? (3 points)
5. If you decided to test the possibilities of an artificial augmentation program to stabilize this metapopulation how would you simulate that? Can you come up with a way to simulate such an augmentation program or to mimic it using changes in vital rates, etc? (4 points)
6. Provide 2 examples of other species that you think might have a metapopulation structure and why. (2 points)
Turn in the following (due next week at the beginning of lab):
Read directions carefully!
Answers to the 6 discussion questions listed above (20 points). REMEMBER: answers must be typed and double-spaced. Points will be deducted for improper grammar, spelling errors, and poor organization. Make sure your name and lab-section number are on the front page. Place your figures or model output after your answer page(s). Please staple your pages with 1 staple in the upper-left corner. We are not responsible for the loss of pages that are turned in loose.
