Pure Honey

Yesterday I posted on bees and the debate going on whether colony collapse disorder, a hot topic over the last decade had run its course and is no longer a concern.

Today on a related subject: One thing that everybody agrees on is that the price of honey has roughly doubled in the last 10 years. That price increase has led suppliers of honey to add other sweeteners to the honey to make it go further. This practice is illegal if not mentioned on the label.

Fresh, Pure Honey. Probably.

Honey always makes it near the top of the most counterfeited foods (Bon Appetit's list, a nutritionist's website list, mental floss' list, USAToday list). It's really tempting for some producers to add a little bit of cheap ingredients to make the honey go further. 

Honey has always been a favorite dish. Here's a recipe from Ancient Egypt for a dessert. The Romans knew Britain as the Isle of Honey and here's a mead recipe from 2,000 BC. Everybody, everywhere always liked honey.

Ancient Egyptian Instructions on Producing Honey

But here's the current problem in a nutshell. Honey sells for roughly $7 per pound today. High Fructose Corn Syrup (HFCS) costs about $.40 per pound. So adding a little HFCS to the honey is a gold mine if you can manage it.

So how can you choose a honey that's pure honey? There's not a test that you can do in the field that will give a good answer. The FDA has some pretty complicated tests they can run in the lab but they don't lend themselves to supermarket testing. But here are some rough guidelines that you can follow to help get real honey:

• Buy dark honey. HFCS and other sweeteners tend to lighten the color of the honey. Buying darker shades ensures that little or no sweetener has been added. However most people like the lighter colored honeys.

• Don't buy Chinese honey. About 40% of the US honey supply comes from other countries and about 1/3 of that comes from China. There have been lots of issues with the quality of honey from China because of sweetener additives. It should be labeled under country of origin laws. However the large honey distributors tend to mix honeys to get the consistency they want so it's not always on the label where every part of the mixture came from.

Do You Trust This Bear?

• The dissolve test. I haven't tried this but I've read that you can put a spoonful of honey in a glass of warm water it will sink to the bottom if it's pure but will dissolve quickly if it has a lot of other sweeteners. I may try this and report back.

• Deal with somebody you know and trust. Probably the best way to get unadulterated honey is to deal with a beekeeper you know and trust. Not everybody knows a beekeeper, but if you do that's the way to go.

So, it's harder than most people realize to get pure honey. The producer incentives to add cheaper artificial sweeteners are strong. For some people it doesn't matter much -- a sweet additive to their tea is just that. But to everybody buying an expensive product that is really much more cheaply made than you know can be both maddening and in the case of foods scary.

The Collapse of Colony Collapse Disorder

About a decade ago the idea of the extinction of honeybees was of concern. Colony Collapse Disorder (CCD) was the name it was given. The fear was that the number of bee colonies would continue to decline. Since bees are the primary pollinators of much of the US fruit and nut crop this was considered a really big deal.

Collapsing Colonies

Author Christopher Ingraham recently had an article in the Washington Post talking CCD. He points out that there are about 20% more colonies today than there were when CCD was discovered. He attributes the rise in colonies to more colonies being created. Lots of companies will now send beekeepers a new queen for $25 so they can split a colony and it will develop into 2 over the course of the next year. And with the price of honey doubling over the last l0 years beekeepers want to add the number of hives.

I want to go just a little deeper into the idea of colony collapse disorder and why Ingraham is both right and wrong at the same time.

CCD has many causes. The 2 most often cited are a parasitic mite called the varroa destructor mite and a virus that causes wing deformation. Other causes include increased travel by the beekeepers and new field pesticides. In reality it's not that well understood at this point. It seems like that many factors seem to occasionally come together to push a colony to oblivion.

The Speck in the Middle is a Varroa Destructor Mite

Ingraham's idea is that we're out of the woods on honeybee loss. The fact that the market has doubled both the price of honey and the pollination fees has made beekeepers more likely to continue to increase the number of hives. Increasing the number of hives offsets the increase losses during winter. But what he misses is just how precarious the beekeeping industry is right now.

CCD, at it's most basic was an increase in the number of colonies that die during the winter. The historic rate of colony death during winter was about 15%. In the early 2000's the rate of colony death doubled to around 30%. Ingraham is correct that beekeepers have been able cope with a string of losses in the range of 30% for more than a decade before falling to about 23% in the 2013-2014 year. A very distributed market with lots of small players has coped well by continuing to increase the number of new hives.

Bee Colony Loss by Year

That's probably not sustainable over the long term. By ordering a new queen and dividing the surviving colonies they're able to stay ahead of the colony deaths. The size of the average beekeeping operation is very small, averaging only 50 hives. If the rate of collapse increases further most small beekeepers will get out of the business.

Bees are very vulnerable to parasites, all social animals are. Parasites passed between individuals in the colony can kill the entire colony. Parasites are coming out of their home environments and moving to new hosts all the time. Modern transportation systems have allowed this fast spread worldwide. If CCD were caused by only a single source -- a parasite or virus solely causing the problem -- it would be easy to imagine the problems being behind us. Since the original CCD was a myriad of causes one or more new parasites or other stressors would be bad news, especially if the current stressors haven't yet been overcome.

But things seem to be getting better. The preliminary loss for the 2014-2015 year fell again to 22.3%. If it continues to fall or even further then Ingraham will be correct and the collapse of the industry will be averted. But if other factors will come into play the fact that the industry is dominated by small players can send it into a tailspin. Hopefully that doesn't happen.

Florida Georgia Line

The Florida-Georgia Line. Really good country music group but also a really good way to look at bear populations.

Not about these guys

I've written a couple of articles on the difference in the size of bears within Florida. Here's one about how the size of the bears killed by vehicle strikes varies with somewhat larger bears killed in South Florida. Here's another from an old Facebook post where I looked at the size even greater size differences of bears killed in the 2015 hunt.

The geographic Florida-Georgia line isn't much of a line. The plants don't change much. The forage for bears should be pretty similar on both sides of the line. Therefore the size of the bears on each side should be similar unless there are government policies in place that cause differences in the states. By looking at bears in both states that were killed within a week of each other we should be able to tell if the weights are substantially different.

For a while I've had the weights of bears killed in the 2015 Florida bear hunt. I asked the state of Georgia under their Open Records Law for similar numbers so I could compare them. At first they said no, then ignored my repeated requests. After I escalated to the Georgia's Department of Natural Resources top lawyer they finally gave me the data I wanted. Florida posts data online. Georgia fights release of data until they can't hold it anymore. Advantage Florida.

Big Bear, Probably Georgian

Once I got the data I restricted the data even more. In this analysis we're only looking at bears killed in the counties that border the other state. In Georgia the border counties where bears were killed are Charlton, Clinch, Echols and Ware counties. In Florida the counties that touch Georgia where bears were killed were Columbia, Hamilton, Jefferson, Leon and Madison counties. These counties line up rather well across the border from each other so differences between the bear populations should be predominantly as a result of policies in the given states.

The size differences were pretty stark.

Average Harvested Bear Weights, Fall 2015

The Georgia male bears were an average of 155 pounds or 52% heavier on average than the Florida male bears. With the females the Georgian bears were 47 pounds 31% heavier.

In statistics there are always lots of tests that can be run on data. In this case I wanted to see if the bear populations as shown in the hunts could have come from the same populations. The thought is that there could be some random variation fooling me into thinking that the populations were of much different weights.

In this case I used a couple of t-tests. A t-test will tell us what the probability of having identical populations and yet getting strange results just by random variation. In this case the probability of the males coming from the same population is about .1%. For the females it comes out even less likely as there's a .09% chance of this kind of outcome happening by chance. In other words there's roughly 1 in a thousand chance of random variation causing either of these weight differences.

Hungry in Florida

So, why the differences in weights of bears that are across a line on a map? My working thesis is that the differences are because of the bear hunt. Georgia has held an annual bear hunt in South Georgia for many years. Florida held their first bear hunt in 2015 since the 1970's. I think the North Florida bears have outstripped the available food supply. This stunts the growth of the bears in north Florida and is the cause of much of the bear-human interactions there.

It's always good when an idea gets support from an unexpected source. When I first started looking at sizes of bears killed in the 2015 bear harvest I only had Florida to look at. I could see that the bears in south Florida were much larger than the bears in North Florida. The vehicle strike data also confirmed that. But now looking at the differences between the bears that grow separated by a state line it becomes apparent to me that the population of bears in north and central Florida needs to be reduced. And the bear hunt is the best way to do it.

Bats

Bats are so cool. I wrote an earlier article on bats but there's just so much to bats that make it hard to do them justice in a single article. Huge populations living just barely out of our sight that have just so many stories to tell make it hard to do them justice in a single sitting.

The bats in the video below are <a href=http://www.arkive.org/brazilian-free-tailed-bat/tadarida-brasiliensis/>Brazilian free-tailed bats</a>. Also known as Mexican free-tailed bats they are the most common bat in Florida. If you see a bat there's a better than even chance it's a Brazilian free-tailed bat. If you look closely at one you can see the little "mouse tail" trailing as they fly.

Brazilian free-tailed bats are given more credit than deserved for eating mosquitos. Sure, they eat a few but the prefer larger insects like moths and flying beetles. Just not enough meat on mosquito body to go after them. Some surveys have found over 90% of their food to be moths.

I took pieces of the video above at a nearby bridge. I used a very weak light to shine into their crack and went by pretty quickly to get a video of them. Not a very good video but look closely and you can see a couple. Lousy video is the price of minimal disturbance. The last piece is some stock photos but the sound in the background is the bats that I recorded. In the daytime when you hear them it's a very high pitched squeak. As evening approaches they get more excited and start giving lower pitched squeaks that you hear at the end of the video. They know feeding time is near.

My what large ears you have!

The day we went to the bridge to watch them come out a Cooper's hawk joined us. He spend the evening sitting on an unused man-made bat house watching thousands emerge from the bridge, seemingly as fascinated as we were. He never tried to catch any of the emerging bats while we were there, but bats to make up a part of their diet. I think we may have intimidated him from trying on that day.

Bat on the menu?

Right now a vital time of year for the bats. The young were born in June so the mother is feeding the babies. All of the young in a colony are born in a period of 10 days. The males left just after the mating in March so the population of the bridge doubled when the babies arrived. They males fly to the south to give the mothers all of the insects in the neighborhood. As soon as the pups are able to hunt the mothers will fly away and leave the area to the young bats.

In some ways Brazilian free-tailed bats seem to be survivors. They depend on a variety of insects in their large range that extends from the south of Brazil to the south of the US. They can live in a large variety of homes -- caves, mines, bridges, old buildings and trees all fill the bill for habitat.

The bat signal is on

But they're not very resilient to pesticides. Agricultural pesticides are particularly hard on bats. Sprays frequently slow insects without killing them immediately. Bats feeding near a recently sprayed orchard or field can be devastated quickly. Bats eat many insects every night, and their body is very small. They take in a lot of pesticides compared to their body weight.

But I guess the reason I really like the Brazilian free-tailed bat is their ability to hide in plain sight. Bridges have become a favorite haunt but exceedingly few of the cars passing by know that thousands of bats may live in the bridge they just crossed. Nor do they realize the number of night insects that are consumed every night.

The Future of Zoos

So what is the function of a zoo today?

I was reading an article on the Brevard Zoo taking delivery of a new zebra. It brings to mind a bigger conversation that is happen around zoos now -- what is the function of a zoo going forward? That function is changing quickly and it's interesting to speculate on what a zoo will look like in a few decades.

Lauren, New Zebra at Brevard Zoo

Only 50 years ago zoos were a very different place than today. There were thousands of little roadside zoos (many in Florida) that had a few animals to show. The large city zoos still displayed animals in the "box with bars" environment. Many animals didn't thrive in either of these environments.

Over time the roadside zoos have largely closed. They still exist across the country (including Florida) but they are mostly gone, victims of stricter animal welfare rules and rising insurance premiums. The very large have been able to keep up with rising costs and the smallest are able to survive by keeping fewer animals. But thousands that once existed are now gone.

Gatorland, King of the Roadside Zoo

The larger zoos have changed their outlook considerably. In addition to their education and entertainment functions they have also taken on the role of providing for the future of threatened species. Once there was little cooperation between zoos to monitor bloodlines of their animals, resulting in animals with some serious inbreeding. They do a much better job of this now. Essentially they're changing their function to being a species sanctuary.

In the age of the internet people don't go to zoos with the regularity they once did. Anybody can do a quick search and find a zebra cam to check out the zebras. The National Zoo never recovered its attendance levels after the financial crash of 2008 (that's the only zoo I could easily find good data for). Zoos that have to charge admission are doing even worse financially.

National Zoo (Washington DC) Visitors

So, where do zoos go from here? Here's my guess. I think the days of the big displays at zoos are over. The elephants, gorillas, giraffes and other animals that need lots of space are probably going to be phased out of zoos. They're really expensive to maintain. A few very large sanctuaries per species will exist in areas with a similar climate to their native one. Zoos will remain but with smaller, more easily maintained exhibits with almost no large mammals. Aquariums will follow a similar path.

Another reason to phase out large animals is the bad publicity they can cause. The Cincinnati Zoo had to kill a lowland gorilla when a boy fell in. The resultant publicity they got was really bad even to the point of death threats coming from the internet. Few care if a gray squirrel or rat snake dies.

I think it's a high percentage guess that zoos will change considerably in the next 50 years. In the last 50 years they've changed from an emphasis on showing the animal to showing the animal in its habitat to helping preserve the species. Where the next 50 years will take them is hard to say. But they will be very different than they are today.

Cold Stun 2010

Cold Stun 2010.

Wasn't that a tour by a punk rock group? Or maybe a sequel to a Stallone action movie? If I recall correctly it may have been a professional wrestling pay-per-view event.

If only it were so benign. Cold Stun 2010 was a memorable event to any who were working with wildlife in Florida back in January of 2010. Temperatures across Florida dropped to 50 year lows and remained there for about 12 days. Florida hadn't seen such temperatures since the late 1940's. Pressure on many species of wildlife was extreme during this time.

Perhaps the hardest hit during the cold stun were reptiles. Reptile bodies tend to shut down when the temperature drops. This survival strategy does well for a cold snap of a few days. But 12 days is a killer, literally. Some say that up to 40% of the American Crocodiles in Florida were lost during those days. Most Americans think of South Florida as very hot but it's one of the coldest places that American Crocodiles can survive.

American Crocodile in warmer times

Sea turtles were another reptile hit hard. Roughly 4,500 sea turtles were rescued to be warmed up. Nine hundred were known to be killed and many more were probably never seen and died of the cold. Here's a video of the turtle rescue from the FWC.

Manatees were another hard hit animal. Over 200 died when the temperatures cratered and stayed there. Gives some perspective to the 8 that have died due to the algae bloom in Indian River this year.

Manatees staying warm at power plant

Manatees staying warm at power plant

I didn't live in Florida in January of 2010. I had vaguely heard of the cold stun of 2010 from a few wildlife managers. They talked of it with the awe older people in the north talk of The Great Winter of their childhood. But in the past few days I've been reading about snook to prepare yesterday's article. Virtually the entire year's young in the estuaries were killed by the cold stun. Shallow water estuaries get cold quicker than deeper waters. Lots of other fish in the estuaries were lost at the same time.

But the cold stun of 2010 did have a couple of good affects, at least from the point of view of native animals. The Florida Fish and Wildlife Commission estimates that half the Burmese Pythons in the Everglades died. Lakes in Central and Northern Florida became tilapia free for the first time in a decade as the water temperatures fell below where they could survive. Iguanas froze and dropped from the trees throughout the Southern Florida.

Too cold to climb trees today Too cold to climb trees today The reason this event was so severe is that many of the animals of Florida are tropical species. They exist in Florida at the extreme northern edge of their ability to survive. A cold snap can take them into territory that's just too difficult to make it.

Most of my articles are about me learning as much as telling. I had heard of the cold stun of 2010, but only a little. It was good to go back and read some of the newspapers of the time and watch the cold stun unfold. This was an unpredictable event that complicated the management of countless species.

And it shows just how fragile many species in Florida really are. The cold stun of 2010 was a remarkable event. Many don't remember how remarkable it was for the animal population and most of us who moved here since don't even know of it. That's unfortunate.

Snook

So, if a snook has to go to the bathroom in North Carolina, which one should it choose?

Snook are a species of fish that starts off as male then becomes female as they grow. They stay male for the first few years and then become female for the rest of their life.

Here's a video I took snorkeling at Caspersen Beach in Venice, FL. The snook are the longer fish with the yellow fins and lateral line down the side. Most of the smaller fish are greenbacks, a type of herring used in Florida as a bait fish. At the end there are a few sheepsheads. Sorry for the unclear video, but the surf was up a little that day.

The mating cycle is the really cool thing about the snook. The males spend their first year in the brackish estuaries before leaving for the saltwater. They stay males for a couple more years.

Mating happens during the summer. The females come in from the salt water during high tide and during the full moon. Mating occurs near the mouth of the estuary. Only the eggs that float into the estuary have a chance to survive since they need the lower salt content. The eggs float out with the tide then back in on the next high tide. Only a small percentage of the eggs will make it back to the estuary on the next tide.

They only get to participate as males in this ritual for a couple of years. Somewhere between years 3 and 5 the snook change into females. The next time when they come to the estuary it will be to release eggs for the smaller males to fertilize. Snook can live up to 25 years in the wild so she should have many years to propagate.

Young Man Dining Out

In an earlier article I talked about the issues in Florida Bay. Specifically since they're not able to release fresh water from into the bay Lake Okeechobee the salinity has increased considerably. The snook in the estuaries may be one of many victims of the increased salinity. They need water with low salt content for their first year. If the salinity in the estuaries increase, no more young snook.

But to end on a brighter note. The snook population has been increasing steadily over the last 20 years. There was a time they were found in Florida only off the southern half of the state numerous only in the keys. Now they're common statewide and even into Georgia and Alabama. 

And here's a way you can look like a genius next time you know somebody who brings home a snook. Bet them that it's a female. Since everybody assumes that there's a 50-50 chance it will be a female they'll take your bet at 2-1 odds. But any legal snook (28 -32 inches) will be female since the sex change happened much earlier. You'll look prescient when they clean it and pronounce it a female.

Gopher Tortoise, Part Deux

As Yogi Berra would say -- It's deja-vu all over again.

Many of you will remember that I posted a video recently (back when I was still using Facebook as a blogging platform) of a gopher tortoise getting all worked up about my GoPro Session 4 camera. I thought he mistook the camera for another male gopher tortoise and proceeded to try to intimidate it with head bobs. But with the tiny brain a gopher tortoise posesses the possibilities are pretty limited. Fight, mate, eat. That's about the extent of why he would approach anything.

Gopher Tortoise

I was hiking a few days ago and came upon another gopher tortoise beside the road. My immediate question was whether he would act the same way as the earlier tortoise or would he ignore the camera. My guess was that he would ignore it. This was too far away for it to be the same tortoise. So how would a different tortoise react?

So I put the 2 inch cube shape on the ground about 5 feet away from the tortoise as before and walked away to see what would happen. Well, from the fact that I'm posting it you've probably guessed the original tortoise behavior wasn't unique.

So what was going on? I spend an hour or so reading on gopher tortoise behavior to figure it out. I found lots of references and youtube videos of mating behavior where head bobbing starts the ball rolling. But I'm not finding any reference of it being used by one male to intimidate another. When fighting they keep their head tucked in tight to protect it. 

I'm pretty sure both tortoises in the videos are males from the bony projection from the bottom shell, also called a plastron.

Female Tortoise?

In the original post I guessed that the behavior was a male trying to intimidate another perceived male. I've changed my mind on that. I've come to the conclusion that he was probably looking for a date and the small, dark and boxy camera was about the best chance he had today. The tortoise equivalent of beer goggles.

I've posted the original video at the bottom. Note the similarities of the approach and head bobbing.

So does anybody have a scholarly reference to gopher tortoises using head bobbing to intimidate? I'm talking high quality reference -- post on facebook, youtube video, random musing in some corner of the internet or the like.

Any thoughts on the subject appreciated.

Likin' Lichens

Lichens are some of the most common organisms in the forest. About anywhere you look you can find lichens.

Lichen on Tree

But some would argue that lichen isn't really an organism. Not a single one, anyway. A lichen is made up of at 2 separate organisms. It's a relationship between an algae and a fungus. The algae provides the chlorophyll to make food for the lichen, the fungus provides structure and moisture. Living together the fungus and algae create something that is very different from either constituent part.

Here in Florida and much of the South one of the most beautiful lichens we have is the Christmas lichen.

Christmas Lichen

Christmas lichen is roughly circular and has a nice red outline that makes easy to identify. A few other lichens have some red coloring, but none has it just on the perimeter.

Another interesting Florida lichen is usnea. Unlike Christmas lichen usnea is very widespread, found throughout most of the world. Usnea was used by the Seminoles for wound treatment. Putting usnea in a wound was supposed to keep it from getting infected. Seriously folks, don't try this at home.

Usnea

Usnea was once thought to damage trees. Orchard owners would remove usnea from branches as it grew. But we now know that it doesn't hurt trees. Instead it tends to grow on trees that are already in ill health.

The relationship between the fungus and algae has been long understood. Or at least everybody assumed it was pretty well understood. A small nit in that understanding is scientists were never able to create a lichen in the lab. They could take the species of fungus and algae known to create the lichen but they couldn't make them combine to create the lichen.

But an earthquake in the lichen scientific world has been rumbling for the last few years. A researcher named Toby Spribille first proved that at least some lichens contain 2 different fungi. The amount of the 2nd lichen was so small that it was overlooked for a couple of centuries. The initial combination seems to be the 2 different fungi. Only after they combine can they take in the algae that completes the formation of the lichen.

Other previously unrealized fungi combinations are now being found, allowing creation of previously known lichens. Now that they know where to look creating lichens is much easier. Lots of science fiction novels deal with the creation of new life forms. Now knowing that there's a 2nd fungus involved in very small quantities makes it easy to create lichens from their fungus and algae parts. Not exactly a frankenstein lab, but life creation in its own way.

This will be an interesting area of research over the next few years. Better understanding of the over 20,000 species of lichen is coming. Labs across the world are finding fungi combinations core to the lichen. A large step in understanding such common organisms doesn't come every day.

One minor clarification:  There are a few lichens that are a combination of a fungus and cyanobacteria, and even fewer that are fungus, algae and cyanobacteria. I didn't go deeply into this because it can become quite complicated. Let's leave it as a combination of fungi and algae for simplicity.

Bats and Bridges

So what is it with bats and bridges?

Actually bridges are a prime habitat for bats these days. Once they lived in tree cavities or outside of Florida caves were always a prime roosting spot. But habitat destruction has greatly reduced their trees. Today the prime location to see bats is under a bridge. Small crevasses in the bridge joints can hold hundreds or even thousands of bats.

Brazilian Free-tailed bat

One of the many retirement hobbies I'm pursuing these days is bats. I'm currently volunteering with a group that's trying to map all of the bridges in Florida to tell which ones have bats and which don't.

I've included a couple of pictures of what to check for when looking for bats. First is the odor. A colony of bats puts out a lot of guano in a given day. It has a sour, musky odor. Unmistakable after you've smelled it. Bat guano is dry and dark, very different from a bird. Here's a video of the droppings of the Brazilian Free-tailed bat under a bridge (Just the thing to get everybody into their Friday).

Bat Droppings

Another thing to look for are dead bats. I saw several today.

Brazilian Free-tailed bat, RIP

I don't think the dead bats I saw today was cause for concern. It was just that it was a huge colony. On any given day a few are going to drop dead.

Another way to find the bats is to just listen. Brazilian Free-tailed make an audible chirping noise that you can hear if you stay quiet and they're nearby.

But a better question is why bats? Bats are important predators of about any insect in the air. They're also really cool animals that almost never actually turn into vampires. Yeah, they're creepy and smelly and everybody has heard a story about one that flew into somebody's hair. But they're really harmless.

So, I'll be posting a few updates when I can't think of any other subject for the day look at area bridges for bats. The last statewide survey of bridges was done in 2003 so we'll be looking to update that survey.

Black Bear Vehicle Strikes

A few weeks ago I wrote a piece on the Florida black bear hunt of 2015. I want to revisit that discussion with some new data that I've been able to find. To refresh, the small sizes of the bears in the northern 3 BMU's relative to the South BMU led me to think that there was a need for the bear hunt to control the population. The small sizes stemmed from a lack of food and a healthier population would be seen if it was smaller relative to the current food supply.

Bear in Woods

Here's a map of the 4 BMU's that had a bear hunting season in 2015:

Florida Bear Management Units

But with statistics there are always questions. All of the bear hunt data is collected in a couple of days. Would the earlier conclusions hold up if we look at bear deaths over a longer period of time?

Today I wanted to look at the data on bears that are struck by cars in Florida. Here's my thought: Maybe some of the information that I found was somewhat self selected. Maybe there's a reason I don't understand for the very small bears in the North Florida compared to the larger ones in the South Florida.

I decided I may be able to get information from the roadkill data. Every year in Florida a large number of bears are killed as a result of car strikes. Would that confirm my hypothesis that the bears in South Florida are larger?

Average Roadkill Bear Weight, 2014-2015

So here's a chart of all car strikes in Florida for 2014 and 2015. A couple of thoughts:

1> The bears here are smaller than the bears in the hunt data. That probably says that the hunters were staying away from the cubs during the hunt. However cars aren't able to avoid them as easily.

2> Overall the size ratios are about what I'd expect with the males being larger in 3 of the 4 BMU's. Only the North has larger females than males and this may be just a function random variation due to fewer data points in the north.

And speaking of few data points in the north here are the total bears killed by cars in the 4 BMU's with a significant bear population:

Roadkill Bears, 2014-2015

Interestingly the Central BMU has roughly the same bear population as the South BMU but has over 5 times as many car strikes. That's probably just a geographic feature. Bears in the South BMU are congregated around the Big Cypress area, a relatively unpopulated part of Florida. In the Central BMU they're found in more fragmented habitat and mixed in the human population much more. 

So, overall I went looking for confirmation that the bears in the northern BMU's were not getting enough food. I found some confirmation in the overall sizes but the smaller number in the roadkill data made for more variation in the numbers. Ah, the life of a statistician -- each new data point brings more questions.

I've just gotten my hands on some hunt data for 2015 from South Georgia that should shed some additional light on the subject. Stay tuned.

Bear Hunt 2015

Florida Bear Hunt -- Not happening this year.

For those who haven't heard the Florida Fish and Wildlife Conservation Commissioners voted yesterday to not have a bear hunt this year. The vote was 4-3 against the hunt. In 2015 the FWC allowed the hunt and 304 bears were killed statewide.

So today I wanted to see if I could look at the bear hunt and population and see what was going on. I retired about a year ago from my career as a statistician so it was good to get back to crunching data. Warning! Thar be numbers ahead.

The bear hunt occurred in 4 of Florida's 7 Bear Management Units, the South, North, East Panhandle, and Central BMUs. The first chart shows the estimated bear population of the BMUs. The figure that jumped out at me was the % increase of bears for the Central BMU was only 19% over the 12 years, or about 1.5% increase per year. That slow rate of population increase hints that the Central BMU has reached its carrying capacity -- the number of healthy bears it can support. The other annual percentage increases were 6.8%, 11.5%, and 4.9% for the East Panhandle, North, and South BMUs respectively. Those sound like they come from growing populations.

Bear Population Growth Rate

But that was an average growth over 11-12 years. What do the hunt numbers tell us about the bears that were killed in 2015? The 2nd graphic shows the statistics on the bears killed by sex and weight. In a population with room to grow I would expect the percentage of females to be slightly higher than that of males because males tend to kill other males when they can, especially in bad times. The South BMU again showed that it seems in good shape with 54% of the bears killed being female. The Central BMU is again the worst with 59% of the bears killed being female. The other 2 fall in between once more.

The last thing to look at is the weight of the bears killed in the hunt. In a normal bear population the male bears should be slightly larger than the females. MYFWC provides the data for this analysis. We see that in the South BMU the average male bear weighs in at 306 lbs and the females at 211 lbs for a ratio of 1.45. Once more a population with room to grow.

The other BMUs show a real problem. In all 3 the bears harvested were much smaller than in the South BMU. That comes from bears that don't have enough to eat. In each of the other BMUs the weight of the male bears ranged between 151 and 190 lbs. The females ranged between 167 and 204 lbs. Both were smaller than in the South BMU, but the males were very small especially in the East Panhandle where they were less than half the size of the males in the South BMU.

Also the females were roughly the same size as the males the last 3 BMUs and in 2 of the 3 the females were actually larger. This tells me that the bears are chronically short of food and the males that aren't killed by other bears are being forced out of their territories to areas that can't support them.

So I can see why the staff biologist recommendation was to continue the hunt with more restrictions. I'm guessing the big restriction would have been to discontinue the hunt in the South BMU since the population has sufficient forage to continue to grow. In the other 3 BMUs the population is hungrier than they would like and more males are being killed by other bears, car strikes and as nuisance bears in their search for food.

I know lots of people have a very emotional response to the idea of a bear hunt. Unfortunately there's not good pictures to show the issue of bears starving. But the numbers are telling me it's a very real issue.

But no to the hunt this year. I will hazard a guess that the case will grow stronger next year as male bears continue to go outside normal ranges in search for food. Also there will be more time to educate the commissioners and the public on the reasons for the hunt.

(This post was originally a facebook post on June 23, 2016. It was reformatted for Blogger).

Lake Okeechobee Temperature

I’ve written a couple of pieces on what caused the extreme amount of algae at Lake Okeechobee this year. Every year some algae forms in the lake (it’s in South Florida after all) but this year the amount was extreme. The first piece dealt with the history of Lake Okeechobee and how it took its current shape. The next piece dealt why the extreme amount of water in the lake this year (it’s about 3 feet above last year at this writing). This piece will deal with the temperature of Lake Okeechobee and why it’s so warm. I want to write another on the fertilizer load this year and a final one on options going forward.

Always remember that warm water rises.

Algae primarily grows on the surface of warm water. Since the outflows of Lake O primarily flow through gates it comes from surface water. Therefore the warmest, “algae-est” water is released. This lowers both the average temperature and the algae load in the lake.

This is primarily how the South Florida Water Management District (SFWMD) controls the temperature of the lake. Each summer when they start lowering the lake level to prepare for hurricane season they release the warmest water. In the attached graph you can see how that worked in past years. The red line is the average lake temperature of the past 10 years. Note how it increases until they start releasing warm water in June and then decreases. But this year (blue line) is different. The water temperature actually stayed cooler than average for the first half of the year. But the water releases slowed in June due to the algae and the temperatures continued to rise through June. Now the temperature is much warmer than it should be.

Lake Okeechobee Temperatures

Next question: This has been a very hot year. Why did the water temperature seem to stay below average for so long? That comes from 2 factors. The first is the heavy rainfall for this year. Normal rainfall for the lake is about 18 inches through the first 6 months of the year. This year we’re at about 29 inches. And rain water is cool as it enters the lake. That was the first factor that kept the lake cool.

Or maybe it just looked cooler to the temperature probes. The lake probes (sondes) are hanging from buoys, normally 1 meter above the bottom of the lake. As cool rain water enters it goes to the bottom. The sun heats the top. In this environment the difference between the top layer and bottom widens. As long as the level of the water is consistent the temperatures are comparable year to year. Since the lake is averaging about 4 meters this year vs 3 meters last they may be getting data further from the top than last year. I was unable to find exactly how the SFWMD placed their probes, but if they followed NOAA guidelines they were getting temps that were deeper than last year.

I think SFWMD didn’t fully realize how hot the lake surface was because of the dependence on sonde data. When the algae started forming they were behind the curve in releasing water. The downstream folks objected to pea soup coming their way and there was no Plan B.

I want to write one more piece on the current status of the lake. I’m looking at the fertilizer load but good data on the levels of phosphates is tricky. I’ll try to work through that. But if I don’t find the data I may skip that one. Between the high water levels and very warm water I now understand how the water levels and water temperatures got out of hand due to the combination of heavy rains, high surface temperatures reliance on sonde data. Those 2 factors are sufficient to explain the bad state of the lake without referencing fertilizer loads. But they exacerbated by high fertilizer loads.

Florida Bay

There are lots of bad things happening in the Florida environment right now. Many problems have their beginning in Lake Okeechobee. The papers are full of stories of algae invading beaches and of damage to the Indian River.

But if I had to choose the worst environmental issue right now linked to Lake Okeechobee it would be Florida Bay.

Map of Florida Bay