Internship End

My Conservation and Land Management Internship experience was amazing! I really couldn’t have asked for a better opportunity. The San Diego Zoo Institute for Conservation Research has an annoyingly long name, but it offered a glimpse into multiple fields of scientific study, all of which I found interesting. There are seven different divisions within the Institute: Applied Animal Ecology, Behavioral Biology, Conservation Education, Genetics, Applied Plant Ecology, Reproductive Physiology, and Wildlife Disease Laboratories. I mostly worked on projects within the applied ecology divisions, but I still learned about some of the other research being conducted. For someone like me, who is curious about all aspects of conservation biology, but has no idea how to narrow it down in order to choose an area of study for graduate school, this internship was invaluable.

I’ve learned all about seed banking and herbariums; how to collect vouchers, monitor and eventually gather the seeds from plant populations. I’ve learned how to clean and store seeds, and how to bring them out of dormancy . I’ve learned how to recognize the song of Coastal Cactus Wrens, and how to catch endangered Stephens’ Kangaroo Rats. I’ve learned about habitat restoration, and acquired a healthy respect for cacti and its spines. I was able to explore many remote areas in San Diego County, and I got to call hunting for wild flowers “work”.

I’m excited for what comes next, but I am also very grateful for everything I got to experience in my ten months here.

The endangered Stephens’ kangaroo rat

One of the studies that I have been lucky enough to participate in at the San Diego Zoo Institute for Conservation Research is the Stephens’ kangaroo rat project. The Stephens’ kangaroo rat (SKR) is one of 19 species of kangaroo rat in the genus Dipodomys in the family Heteromyidae. It as listed as endangered by both the federal and state governments. The main threat to the species is loss of habitat due to urban development in its native range. Of the available habitat that remains to the SKR, much of it is unsuitable due to invasive grass species. These exotic grasses form a thick mat on the ground that restricts the movement of the nocturnal rodent and doesn’t allow them to sand-bathe, which is a behavior they need for healthy pelts and social interaction. This project was the first to establish a viable population of SKR via trans location.
Six circular experimental plots were set up on the Southwestern Riverside County Multi-Species Reserve. Each plot was divided into six slices, two slices per treatment. Two slices from each plot were mowed, grazed by sheep, and burned to see which treatment was most effective in removing the thick layer of exotic grasses. Of the two slices per treatment, one was left as an control and the other was planted with native bunch grasses to see which method prevented the establishment of the exotic grasses best. The arrangement of the different treatment slices within each circular plots were randomly chosen. Ten thousand grasses were planted in 2011, and again in 2012 for a total of 20,000 grass seedlings. Each seedling was planted in a shallow basin to maximize the benefits of rainfall and supplemental watering. For the first year that the seedlings were planted they were protected by a blue plastic tube that minimized the effects of detrimental weather and offered extra protection. The seedlings were also given extra water once a month during the dry parts of the year.
On the animal side of the project, 200 SKR were caught and trans-located to the experimental plots. They were divided into four groups, with 50 individuals per treatment (mowed, burned, grazed and control). Trans-locations are fairly complicated, they tend to be more successful when there are social bonds between the individuals that are moved, and there must already be artificial burrows in place before they are released.
I had never participated in a restoration project prior to this internship and I had no idea how much time and energy would be required. It took us almost three full weeks to plant all of the seedlings, and that was with volunteers and the extra help of prison work crews. Because we were in the second year of the project we were able to see how successful the first year had been, and it was really encouraging! The plots where the native grasses had been planted were much more open, with hardly any invasive species present. Many of the slices were also dotted with SKR burrows and there were patches of cleared soil where sand-bathing could occur. Next month I will be going out with a team from the Applied Animal Ecology Department to trap the SKRs. I’ll get to see them up close! Its really interesting to connect the science behind both the plant and animal sides of big studies like the SKR project, and I feel very lucky to have had this unique experience.



San Diego County is the most botanically diverse area in the U.S. with nearly 2,000 species, many of which are endemic. The county has the coast to the West, the desert to the East, and is bisected from North to South by the Peninsular Ranges. The elevation ranges from sea level to over six thousand feet. This varied landscape allows for an exceptionally high level of plant diversity.
The desert transition habitat is found down the east side of the Peninsular Ranges and this was the area where we went last week. The weather forecast looked ominous, but we were optimistic. To get to our site, we had to drive up and over the Cuyamaca Mountains and out into the lower elevations beyond.
The drive over the Cuyamucas was relatively uneventful, with very little rain. When we finally reached our site we saw a mix of cacti, shrubs and huge granite boulders. It was freezing cold and very windy. At certain points the wind became so strong it was difficult to open the truck doors to identify plants. Despite the rough conditions, it was a beautiful place to explore. We saw Desert Apricot (Prunus fremontii), Golden Gooseberry ( Ribes quercetorum), and Grape-Soda Lupine (Lupinus excubitus) in bloom.
As the day wore on the weather only got worse. When we tried to collect a sample of Apricot Mallow (Sphaeralcea ambigua) the rain turned to hail and we decided to admit defeat for the day. On the drive back up and over the Cuyamucas the hail turned to snow! It was so much fun to watch everything turn white throughout the course of our drive. We followed a snow plow most of the way down the mountain. (I never would have imagined experiencing something like that in Southern California.) As we dropped in elevation, the snow slowly changed back into rain and everything turned green again. It was odd to realize that we had only been a half an hour away from the ocean.
There are not many places where you can experience the ocean, the snow, and the desert within a couple hours. San Diego is truly a remarkable place, and I couldn’t ask for a better area to study plant diversity.

Germination Fun

One of the projects I get to work on involves germination studies. Germination can be defined differently in an experiment. Some scientists define it as the emergence of the radical (the first root), but for the seed bank here at the safari park it is defined as the emergence of the radical and the emergence of at least one cotyledon (first leaf). This is because some seeds may have enough energy to produce the tip of a root but then lack the ability to develop further.

When seeds are placed into a long term cold storage facility they can remain viable for decades, but when they go dormant for that length of time it can be a very difficult to get them to “wake up” again. In nature seed germination is triggered by a variety of factors; fire, water, and temperature changes are some of the main contributors to germination. To test the germination ability of seeds that have been placed into storage we have to try different triggers on them. In order to determine which triggers are effective, scientists look at a things like the natural habitat of the species and what triggers have worked on closely related species. Coming up with the correct combinations can be a time consuming, yet fascinating puzzle. The process is further complicated by the fact that species require different combinations depending on how long they have been in storage. For example, a trigger that works for seeds that have been stored for ten years may not work for seeds that have been stored for fifty years. Another complicating variable is that even within the same species different populations may be reproductively isolated enough that their seeds have different requirements, and just to add insult to injury, the same population of individuals may differ slightly year to year due to environmental conditions. Despite all these frustrating details that have to be taken into account, germination testing is an extremely important area of study, because whats the point of seed banks if we are unable to use the seeds?

At the Safari Park, seeds that are to be tested are chosen based on the length of time the have been in cold storage. Twenty or so seed lots that have been placed into storage around the same time period are removed and soaked in water over night before different triggers are tested on them. For some seed lots this initial soaking is the only stimulus they need. Some of the other tests we perform include:

Smoke Water:
In nature, one environmental condition that triggers germination is fire. Either heat, the chemicals released by burned plant matter, or a combination of the two causes seeds to come out of dormancy. To mimic the chemicals released by burned plants we collect samples of different chaparral species and turn them into charcoal, which is then mixed in water to give us “smoke water”. In some cases, when this water is absorbed through the seed coat it triggers the seed to grow.

Running Water:
For some species, especially those that live in very dry areas like the desert, being triggered by only water can be a bad thing. For example, if rain fell for too short of a time period and triggered the germination and growth of a species, that species would not have enough resources to reach maturity. One way that seeds measure the amount of rainfall is by the amount of small abrasions they receive. When there is enough water to tumble them over rocks and sand (which cuts up their seed coats and causes small abrasions), seeds “know” that there is enough of the resource to sustain them through their life cycle so that they can reproduce. The small abrasions allow the water to penetrate the seed coat. To replicate this process we run water over seeds and gravel so that they rub together in a similar way.

Cold Stratification:
One of the other tests we do is expose the seeds to different temperatures. Seeds “know” when it is time to grow by measuring the changes in the seasons. The passage of time is determined by the changes in temperature. Winter exposes the seeds to a long cold period and plants will germinate in expectation of the Spring that is to follow. The length and degree of the gold snap varies buy the theory behind it remains the same.
The whole process of germination testing is really interesting and really annoying, but I’m glad I got to learn about it in my internship.

Seed Banking

When I tell people I collect seeds for seed banking, the first question I’m asked is if the collections are stored in the Svalbard Global Seed Vault, which is located on the Norwegian island of Spitsbergen. While it’s awesome that so many people know about that bank, it is used primarily for agricultural species. Native plant species, especially those that are not threatened or endangered, receive much less attention. There are very few native seed banks around the world, and San Diego County happens to have one.

The seed bank here at the Safari Park houses more than five hundred different
plant populations. It is a straw bale, solar-powered structure that has all sorts of interesting contraptions used for seed processing. The seed bank is located at the back of the park and is the first permitted straw bale building in San Diego County. Cleaning and storing seeds is time consuming and often tricky, but it can also be very rewarding. Our goal is to collect multiple populations of the same species because each population may have adaptations unique to its
location. San Diego County is home to over 1,500 different plant species, so that adds up to a lot of seed collections!

When we first find a population that we want to collect we take clippings of the plant and press them to preserve the specimens (herbarium vouchers). It is best to take a sample that has both flowers and leaves so that the species can be verified by a specialist. Our herbarium vouchers are sent to the San Diego Natural History Museum for verification. Data on the location, soil color, slope, habitat, and associated species are also collected. After theses initial steps are taken we monitor the population until enough of the seeds ripen for a collection. We often have to compete with herbivores and rough weather to collect the seed before it is lost.

Once the collection is made, it is taken back to the seed bank and processed. The steps involved in processing the seed lots are generally dependent on each particular species. The seed and plant material is often rubbed over screens of various sizes until the seed is separated from its various shells, pods, leaves, pappi, and stems. Once separated, it is run through air separators so that lighter material is blown off and/or the seeds are lifted away from the heavier debris.
Even after all of these techniques are used, we are often left with seed that is still mixed with extra plant material. When this happens, our only option left is to clean the seed lot by hand.  With larger seeds this can be fairly easy, but with the small seeds it often involves a microscope, tweezers, and a lot of patience.

Clean seed lots are placed in the drying room in order to lower their moisture level. Once the seeds reach a moisture content between 5 and 9 percent, they can be placed in long-term storage. Five hundred of the seeds are counted out into groups of one hundred and then weighed. The entire seed lot is then weighed and we estimate the total number of seeds. At least ten thousand seeds are placed in storage at a time. If there are extra they are set aside for future
restoration and research. The seed is sealed in double-layered foil bags and frozen. It has been proven through germination testing that frozen seeds remain viable for decades.

Amaranthus fimbriatus

Desert Trip

Pretty much from day one at the institute I’ve heard people talk about how beautiful Anza-Borrego Desert is. This year’s Seeds of Success collections focused more on the areas surrounding Ramona. While the properties we scouted in the Ramona area were very diverse and interesting, they were all composed of the same types of plant communities. This was the first week we’ve been able to make it out to the desert transition areas leading into Anza-Borrego. When planning to explore a new property, the first step is to find one that has access. For our internship, we are only allowed to make collections on BLM land, which doesn’t always have roads. We look at layers of BLM land on GIS and then choose one that looks reasonable. To do this we mostly use images from Google Earth. The only problem with this is that it can be difficult to determine if something is a dry creek or a road… but we were fairly sure that we could get within walking distance of the site. Another part of scouting that is always fun is navigating back roads. The first dirt road we turned off on was well kept, the second one was less so, and on the third road I felt the tires sink a few inches into soft ground. We managed not to get the truck stuck, which was a very good thing since we didn’t have cell reception. The site itself was a combination of hills and dry wash ravines with an amazing number of different plant species. After exploring for a couple of hours we determined that we could make three collections starting next week, which was really exciting!

Cactus Wren Surveys

For the last three weeks we have been doing avian point counts in the preserve around the Safari Park. We listen and look for two bird species in particular, the California Cactus Wren and the California Gnatcatcher. The wren is a subspecies that is found only in a limited area within California and because of habitat loss it has become endangered. The gnatcatcher is believed to be in decline as well. When identifying these two birds we use a combination of visual and audio techniques. All birds have a unique call and/or song, and we use these sounds to identify them and estimate the distance they are from the point we’re at. The wren can be difficult to figure out because the mocking birds in the area tend to mimic its song.
The point counts start at six in the morning and has to end before 10am so that all of the surveys are as standardized as possible. It has been a great opportunity to observe these birds in their natural habitat and learn different bird call in San Diego county.

Safari Park Adventures

It’s an amazing experience to work at the Safari Park here in San Diego. Last week we got to see the Cheetah Run which is a 150 yard stretch of lawn on which a cheetah chases a stuffed animal and can run up to 70 mph. The cheetahs are always accompanied by their dog partners who are raised with the cheetah cubs. The dogs go with the cheetah everywhere and provide them with a security blanket. It’s so much fun to be able to walk in the park after work and look at all of the animals. The Safari Park itself is 900 acres with an additional 900 acres of land preserved in back of it. The additional 900 acres is primarily coastal sage scrub where there are many ongoing experiments. These studies include Herp arrays which monitor the reptile biodiversity and restoration plots for the threatened cactus wren. We have been able to help out on both of these studies. While doing the Herp arrays I saw lizards, small mammals, scorpions, and even a tarantula. While monitoring the cactus wren plots I almost stepped on a red diamondback rattlesnake, which was very exciting. I enjoy the seed collections and exploring San Diego County, but I am also very grateful for all the other opportunities that the park provides. It’s always an adventure!

San Diego

My first three weeks here have been amazing. I get to travel to beautiful locations all around the county, work at the Safari Park, and live close to the beach. It really could get much better. Its surprising to me that that there are so many new plant species here, I wouldn’t have expected there to be so much variation just a few hours south of where I first took field botany. I never thought I would find the dry desert areas interesting, but the more I look the more there is to see. I am even more excited for the next five months than when I first started. There are multiple projects going on at the park and I hope I can find time to learn a little bit about all of them.

It was halfway done eating a bunny when we found it. It was the least intimidating snake I have even seen. It couldn't even rattle.