Tag Archives: San Diego Safari Park – San Diego

Ridgway’s Rail (Rallus obsoletus)

Ridgway's Rail (Rallus obsoletus)

This is a bad photo of a Ridgway Rail. It is, however, perhaps the best photo I’ll ever get as their population declined by 51% between 2007 and 2008.

The question I ask myself a lot though, is “does it really matter?” I mean, there are lots of rails. I’ll be posting about a Guam rail in a few weeks or so. The Guam rail is interesting because it’s story is similar to the Wake Island rail. This was a bird that died out sometime between 1942 and 1945. Why? Well, there was a war on, there was an island and some abandoned soldiers. Basically, it was eaten to extinction … by humans … in living memory.

This is the pattern we’re seeing. On islands, in estuaries, and on mountaintops (or hilltops), animals are restricted in terms of both movement and resources. If something happens to the environment, then they run out escape room and, eventually, die out. When soldiers were stations on Wake Island, they liked the little birds, until they ran out of things to eat. This Ridgeway Rail lives in a very small area that is being developed and, where buildings are built, nests can’t be.

Today, we are seeing a massive extinction rate on these sorts of islands. It makes sense. Not only are humans building into the places that these animals live, but the creatures we bring with us, like rats, cats, and dogs, move into the remaining area and start eating eggs and whatever else they can get ahold of.

The problem is that we are also making new islands. As cities expand, and roads are constructed, we are basically carving up the remaining surface of the planet into a whole lot of little islands. Some animals don’t care. Birds can fly over highways. Deer can cross them. But some can’t. Jaguars won’t cross large roads because it means leaving their woodland, where they are safe. Small butterflies won’t fly across roads because they can eaten by birds if they’re in the open that much. Larger mostly-flightless birds won’t leave their little area because there’s guarantee of what they’ll find.

So as their living space shrinks, the genetics of each population start to homogenize. Thus, in addition to indirect threats like habitat loss/degradation and direct threats like invasive species, there is an internal threat from the species itself. If you cut any species into enough pockets (or islands) it’s not going to survive. We’re seeing this today with the rails. They live on islands and along coasts, so they’re bound to the land. They don’t really fly, so the populations stay static and vulnerable.

So really, we run the risk of losing the Ridgway’s rail just like we lost the Wake Island rail (1940’s), the Chatham rail (1900), the Hawkin’s rail (1900), both species of red rail (mid 18th century), the ascension crake (late 17th century), the Saint Helena swamphen (16th century), the Antillean cave rail, Haitian cave rail, and Cuban cave rail (all in human pre-history).

Will the world survive the loss of the Ridgeway rail or the Guam rail? Yes. They are a niche species and something will come along to fill that niche. However, I think the real question is, how many more species do we have to lose before we hit that one that can’t be replaced, and what do we do then?

Addra Gazelle (Nanger dama)

Addra Gazelle (Nanger dama)_16

The addra gazelle (aka dama gazelle or mhorr gazelle) is critically endangered. But those words are used a lot. What do they really mean?

The last assessment was in 2008. This is what they had to say:

“The sustained decline due to uncontrolled hunting and habitat loss has continued and is now estimated to have exceeded 80% over 10 years. Extensive field surveys have been made since 2001, but all subpopulations encountered are very small, with all at risk from unmanaged large-scale hunting, and the total population certainly numbers well less than 500 individuals. Decline is expected to continue based on ongoing hunting and unpredictable arrival of large hunting parties with high destructive potential from the Gulf states. The Dama Gazelle is following the same trail into extinction in the wild as the Scimitar-horned Oryx.”

In the early 1970’s, the species assessment presumed 10,000-12,000 … so that’s not only a drop of 80% in ten years … that’s a loss of over 95% over less than four decades.

So where is this happening (Facebookers, go here: http://maps.iucnredlist.org/map.html?id=8968 ) ?

Africa - Dama Gazelle

So, at under 500 individuals in the wild, each of those orange blobs likely represents less than 100 individuals. If drought or hunting happens to hit in one of those areas, the population can drop by 25% alone. If the 80% loss rate continues, it could happen anyway.

This is why it is important that places like San Diego Safari Park do the breeding work they do. It’s not great that a species accustomed to roaming hundreds of miles be constrained to a handful of acres. But it’s much worse to let them die out completely.

Deer

DSC_8904

One thing about about having so much space is that animals are free to engage in more natural behaviors … such as a male deer doing his “chase after the female until she’s ready to mate” approach. I’d seem similar techniques used in high school but, frankly, it seems to work better for the deer.

Giraffe (Giraffa camelopardalis)

Giraffe (Giraffa camelopardalis)_23

At the park, you get to drive out with a group (or on your own if you pay enough) and actually be out where the animals are. What’s interesting is that groups of animals stay together just like they were in a smaller enclosure. So, while the giraffes were free to roam wherever they like, they all seem to roam together.

Up in the back, you can see the big balloon ride and the lodges, neither of which I’ve used personally.