Sneakers and Guarders

As you can imagine we have a bunch of NEBRASKAland calendars hanging around the office, http://shopoutdoornebraska.ne.gov/AspDotNetStorefront/p-971-2012-nebraskaland-calendar.aspx .  Here is a scan of Eric Fowler’s bluegill picture which is the image for June 2012.

Who says fish do not have personalities?

I got to looking at all those calendar photos around the office and was thinking about that male bluegill on its spawn bed, staring down some weird creature that was down there trying to take its picture (sorry Eric, I do not think you are weird, but I am betting that bluegill was wondering what in God’s creation was swimming on the edge of its spawn bed?), and suddenly it dawned on me:  These simple fish that many of us caught as our first fish, these panfish that are the target species for many a beginning angler are really quite fascinating.  Of course a pointy-headed fish biologist would say something like that; keep reading and maybe you will come to the same conclusion.

A male bluegill on its spawn bed is the perfect calendar photo for June, should be on the NEBRASKAland calendar every June.  Bluegills do have an extended spawning period, in many populations a few of them may spawn throughout the summer, but in Nebraska by late May and on through June the bluegills will be spawning.  Even though some bluegills may spawn through the summer, the majority of spawning activity will take place during June in most parts of the state.

How do I know that is a male bluegill in the NEBRASKAland calendar photo?  Well, bluegills are one species of Nebraska fish in which the sex can be determined just by looking at the fish.  Male bluegills tend to be more colorful and have orange “chests”, the classic black tab at the back of the gill cover,and the characteristic blue edging of the gill cover (and that is why they are called bluegills).  Male bluegills build the spawn beds and defend their little realm around that bed.  The males that build nests will guard the eggs until hatching and even watch over the fry for a period after they hatch.  They are good parental, dads (wow, that reminds me, this coming Sunday is Father’s Day!).  Even though the males are very territorial when spawning, they do not go off and fan out beds in isolation; they typically spawn in colonies or close proximity to other male bluegills where the habitat, bottom substrate and depth, is perfect for bluegill spawning.  These beds and colonies are usually made in relatively shallow water and depending on water clarity can be easily spotted.

In all the photos I have, there was not a single example of a bluegill spawning colony, so I stole this one from the internet.

The fact that male bluegills tend to spawn in colonies creates some very interesting interactions.  For example, each male bluegill will defend its spawn bed from other male bluegills.  When you consider the fact that many beds can be built in close proximity to each other, bluegill spawning colonies are constant commotion.  Each male bluegill continuously circles around its spawn bed/territory and is quick to chase any neighboring males that tend to stray across the border.  If you watch a bluegill spawning colony you will see one skirmish after another, and as one male chases another out of its territory both bluegills may accidentally stray across the border into a third male’s spawning territory so then here he comes, and well it can be something like the chain reaction that occurs when an atom is split!

Did you know that bluegills make sounds?  No, I have not figured out how to communicate with the fish, still working on that, but I have seen and heard male bluegills make clicking noises while on their spawn beds.  The first time I noticed this was while holding a big male bluegill that I had just caught from a spawning colony.  As I prepared to release that fish it made a quick movement of its mouth, its jaws, and I heard a clicking sound.  Thinking that I had finally spent too much time with the fishes, I held the fish for a few seconds more and watched as it did it again.  When the fish got back in the water, back to its spawn bed, I could see it and recognized the same jaw movements as it circled its spawning territory and apparently warned other males to stay on their side of the line.  I have not seen much reference in the pointy-headed, fish biologist literature about bluegills producing sounds, but there is some mention of it (see, I am not crazy. . . well, at least I am not the ONLY crazy fish biologist).  There is some mention in the fisheries literature of male bluegills also making this sound to attract females in addition to warning other males.  Apparently they make this sound by clicking together the jaw pads at the back of their throats.

I will bet you did not know that.

But wait, there’s more!

Now, biologists can be very matter of fact and even somewhat crude in discussing and describing various “facts of life”.  I have already told you some things about bluegill spawning biology, but believe me, it gets a whole lot more interesting!  As I proceed, I promise that I will try to keep this “family friendly”.

OK, you know about the male bluegills building spawn beds and guarding these spawning territories.  Female bluegills tend to “stage” or hang around in deeper water adjacent to the spawning colonies.  I would imagine they sit out there and shake their heads at all the boys and their fussing, fighting, and noise-making!  Eventually though, eggs mature and it is time to spawn.  As a female casually swims into the spawning colony, every male bluegill hopes to prove to her that he is the biggest stud at the party.  Each male will try to herd a female onto his spawn bed.  Who knows what the females look for, and they may seem uninterested and unimpressed by it all, but eventually they will pair up and spawn.  There is some evidence that the biggest “bull” bluegills will occupy the best spawn beds within the colony and may be most likely to entice a female onto that spawn bed.  That makes sense, but this is where bluegill spawning biology goes clear off the modest, conservative path. . . .

I have described to you bluegill spawning behavior that is familiar and somewhat “normal”–what one would expect.  But there is a whole ‘nother part of the story, an alternative spawning behavior/alternative lifestyle!  Relatively large male bluegills are the fish that build spawn beds and guard them, and with that spawning strategy it is definitely an advantage to be the biggest, toughest male in the colony.  However, at the same time, in the same population of fish, there are these little male bluegills that go sneaking around spawning with females when they get the chance.  Those sneaky males accomplish this by mimicking the smaller females.  I already said that male bluegills tend to be more colorful and they tend to be larger than female bluegills, and that is true of the large males that build and guard nests.  The sneaky males are just the opposite as they try to spawn with as many females as possible by imitating a female in size and color.  When a female enters a spawn bed to spawn with a large, guarding male, one of the sneaky males will accompany that female and then spawn with her at the same time!  Here, the easiest way to explain that is to show you another photo I stole from the internet:

In that underwater shot you can see a large, nest-guarding, or parental, male on the left.  In the middle is a female that has entered the “nest” to spawn with that large, parental male.  Alongside that female, on the right, is one of the small, sneaky, female-imitating males.  The big parental male thinks he has scored big time because he has 2 females on his spawn bed!  What he does not know is that one fish is actually another male posing as a female, and as he spawns with the female that other phony male is sneaking his milt in there too!!!!

Wow, who knew?

Let me offer some commentary before I finish.  First of all, many anglers will tell you that the spawn period is one of the best periods of the year to catch bluegills.  I suppose that is true in that the bluegills are usually visible, can be spotted in the shallows, and once you find one you have found a bunch of them.  But, as a pointy-headed fish biologist I will tell you that the fishing for any species usually slacks off during the spawn period, because during that time, well, those fish have other things on their mind.  Fish will be feeding before and after the spawn, but during the spawn itself, spawning behavior, not feeding, dictates their actions.  Depending on the stage of the spawn, bluegills on or near the beds may still take baits.  In fact once the males start building beds, before actual spawning occurs, they may still move some distance to take baits.  But, the closer it is to actual spawning the more those fish are preoccupied with defending territories and attracting/herding females.  I have seen fishing on bluegill spawning colonies that was actually difficult because all the males were so concerned with defending their spawn beds from other males and hoping for a female to come swimming in that they never even saw a bait.

Typically, the best way to catch bluegills during the spawn is to use a presentation that will allow you to put a bait in the spawning colony, even right on individual spawn beds, and keep it there until a fish finally notices it and eats it.  One of the very best ways to do that is by using a fly rod and presenting some type of either dry fly, wet fly or nymph.  The nearly weightless fly-fishing presentation can be used to “hover” a relatively small, buggy, natural-looking fly in a bluegill’s face until it finally sips it in.  If you have been reading my blog for awhile you know that I am no fly-fishing purist; I will use whatever fishing gear or presentation is the best tool for the job.  During the spawn period a fly rod is often THE best tool.

If you do not fly-fish, well, I would recommend this system with a spin-cast or spinning rod,  http://outdoornebraska.ne.gov/blogs/2012/05/kids-system/ .  Use small floats to suspend small jigs right over the beds.  Bluegill spawn beds may be in only a few inches of water, so do not be afraid to suspend baits only inches below a small float.  The bluegills will not care.

Before I finish I must say a few words about the conservation of bluegills or more specifically the conservation of BIG bluegills.  I know some of you are thinking that bluegills are so prolific that they cannot be “over-fished” and in fact must be harvested to keep them from “stunting”.

“Not so fast, my friend”–Lee Corso

Bluegills become sexually mature at a young age, only a year, and at a small size.  They are sexually mature at a size much smaller than most anglers catch and certainly smaller than any anglers want to keep and clean.  The key to keeping bluegills from over-populating and the resulting slow growth rates or stunting is by having a healthy population of predators, typically largemouth bass, to eat small, young bluegills.  If they are not thinned before they are a few years old, it is too late.

Anglers tend to harvest the largest individuals from a population, especially from panfish populations.  When bluegills are on their spawn beds, it can be quite easy to “cherry pick” the largest individuals from a population.  Now go back to the complicated spawning biology of bluegills that I just told you about:  As anglers we like to have bluegill fisheries that offer big bluegills, populations that have a lot of the large, nest-guarding, parental males.  It is a competitive advantage for a bluegill, especially a male bluegill, to grow fast and become one of the big bulls that can build and guard a nest.  But, if anglers come along and harvest all of those big males off their spawn beds, suddenly the competitive advantage swings to the little, female imitating, slow-growing, sneaky males.  If those small, sneaky males are not harvested like their faster-growing parental, nest-guarding counterparts, then their slow-growing, “stunted” growth characteristics will actually be promoted in that population of fish!  Anglers actually are more likely to encourage stunting in bluegill populations than they are to solve it!  Anglers are often a part of the problem rather than part of the solution!

Venture out and enjoy some bluegill fishing during the spawn period, absolutely!  In fact, maybe you will have even more appreciation and enjoyment for those fish knowing more about their spawning biology.  But, I hope you can understand why I am such a big fan of selective harvest, catch & release, even of panfish!  Harvest some panfish for a meal of fresh fish; panfish are species that tend to be more abundant and can withstand some harvest, but I hope you see why it can be so important to selectively harvest the small and medium-size fish while turning the big ones loose!  Those big bluegills need to be released!  It is necessary if you want big, parental, guarding males like this:

And smiles like this!