A day with the bears (2)

Myself with a live research bear that had been processed and was moments from being put into the culvert trap to come out of the effects of the drugs safely.

In my last entry, “A day with the bears (1) I introduced you to my internship at the NYSDEC main office in Albany. I also shared an amazing day I was allowed to participate in at a wildlife rehabilitation facility in Western, NY.

If you’re new to my blog, please check out the previous entry (and all the others!) to get the back story.

In this entry I’ll explain what “processing” a bear means, and walk through all the steps with pictures taken that day.

Once a bear is chemically immobilized, and it’s deemed safe for DEC staff to enter the enclosure we start to move quickly. The clock immediately starts ticking backwards and we only have about 20-30 minutes to get everything done before the bear becomes mobile again.

The checklist of what needs to be done will vary from handling to handling of the bears. Generally the same things are accomplished each time a bear(s) is handled, which I will detail below.




Black bear with a unique ear

tag used for identification at a distance.

A data sheet is kept with the bears ID which is assigned the first time he is handled. The bear gets a unique set of ear tags that are often colored and are have large numbers so the bear can be identified at a distance. The time of chemical immobilization is noted as well as a temperature of the bear. Which is taken…non-orally. The temperature can indicate if the bear is in any kind of distress. If the temperature spikes or drops, steps can be taken to reverse the effects of certain chemicals and allow the bear to come out of the effects. Heart and breathing rate is also monitored for these same reasons. One time, not this time, I was in charge of listening to the bear’s breathing. There is something about listening to a “sleeping” bear breathing deep and slow that was so intriguing. THAT is the stuff that makes me love my job!

 

Matt taking down data being called out by others working on the bear.

A tattoo is usually also added to the inside of the bear’s lip. This number is the same as the ear tags, in case the tags get pulled out or fall off. If this bear is handled again for whatever reason in the future, the biologist can look up her number and know “who” she is.

Region 3 Biologist Matt Merchant tattoos the first bear’s lip, as Main office big game technician Matt Walters looks on.

Sometimes a bear is fitted with a collar that allows DEC staff to keep tabs on the bear. Some collars are a bit more “old fashioned” and one has to go out with a receiving device, and look for a signal given off from the collar. Other (much more expensive) collars can output live updates at predetermined intervals. This is neat, because we can plot those GPS points on a map and see where the animal is moving about. These bears though, did not receive collars.

Sometimes also a PIT (passive integrative transponder) tag is inserted into the bear. This is essentially the same thing as having your pet “micro-chipped”. Information is saved on the tag, and can be read with a scanner at a later date. It’s about the size of a large grain of rice, and is inserted with a large gauge needle above the shoulders between the skin and muscle. But we also did not do this, this time.

Photo credit: NYSDEC Black bear tooth collection

In the case that age is not known, a premolar tooth is extracted, and age can be read on rings found in a cross section of the tooth. Similar to how you can read the age of a tree. This tooth is not a dominant tooth, and studies have shown little ill effects from this tooth being extracted. Because we knew these bears were yearlings, a tooth did not need to be extracted.

A weight was taken of the bears that day, using a spring weight. We wrapped the bear up in the net, then all lifted and hooked him or her up to the scale. Gravity pulled the bear down and a weight was read. To hoist the bear up, and then to hold the scale took the whole team!



NYSDEC staff taking measurements from a live research bear.

In this case, measurements were also taken of the bear. I don’t recall this happening other times I’ve assisted with bears. Matt and Christie set to taking length and girth of the bear and recording the measurements on the data sheet. Perhaps in the future, these measurements can help staff determine what kind of condition the bear is in, if it’s handled again.

The other team there that day, from Region 5 (Adirondacks) were also taking foot measurements (width and length). I was interested to know why, but didn’t have a chance to listen in and ask questions. They had their own set of bears they were bringing back to the ADKs for release!

At this point, the bear is still immobilized, so entering such a tight space was deemed “safe”. The clock was ticking though, and the biologist had to get him tucked away quickly and the door shut so he could begin work on the other two girl bears.

Once everything was complete, the bear was loaded into the culvert trap on the trailer. The first bear was Brother (who remember weighed 175#). Maneuvering an animal like that in a tight space is hard work! They are completely limp under the effects of the drugs. But eventually he was nestled in there, and we went back to work on the sisters.

One of the first things to

do is to cover the bear’s

eyes to protect them from

light and debris.

You may have noticed in the pictures that the bear’s faces are almost always covered. This is done because under the influence of the drugs, they can not blink. To keep them moist, Jean put an ointment in their eyes, and then we cover them to protect them and keep the light out. This may also help keep the animal calm. Sometimes when you remove one of the senses, an animal will calm right down. And the entire time, we kept our voices low and calm. We strive to make the whole experience the least stressful it possibly can, given the circumstances.

I was able to take a quick tour with Jean of the rest of the facility and get to know her a bit. She is truly an inspirational woman for her care and handling of wild black bears. She is known across our state for the ethic she and her husband hold and maintain while working with these wild animals.
Their respect of the animals challenges me to keep in mind that they ARE wild. While I love a cute animal as much as the rest of us, they are strong, powerful, intelligent, and not to be reckoned with. Practicing good “bear aware” behaviors while living or visiting bear country is something we all must be vigilant to do. Bears inhabit three main zones of NY: the Northern Zone (Adirondacks), Southern Zone (Catskills), and the Western Zone (Allegany and Southern Finger Lakes). More and more of us are finding black bears in places they haven’t lived in decades, but we must adapt to each other to find a healthy balance.

I encourage you, if you are to cross paths with a black bear, to educate yourself on how to potentially avoid that crossing to begin with, or to prevent a repeat meeting, and to safely maneuver out of the situation. I love to photograph wild animals just as much as anyone, but I respect the animals too much to chase them down or lure them in for that perfect shot, which many of us are tempted to do, regardless if it’s a rabbit or bear.

Anyway, the day ended with us hitting the road and heading back. I was dropped off in Albany, and the bears and their “chaperones” kept going to their final destination. I spent the drive home and that night ruminating about this day. I wanted to share this experience with my blog readers, because it was such a great day, and it’s such important work. I got to meet great people, I got to handle my all time favorite animal, and it was a very happy ending for “The Jumbos” who spent that first night on their own. Can you imagine what they got up to that night?!

Here’s my final glimpse at the bears before we parted ways!

 

Black bear den season: part IV

This is my third and final installment of black bear den visits for the spring 2013 season. I had a good run with the NYS DEC Region 8 wildlife biologists and technicians. Their invitation allowed me a truly unique experience that many, including those "in the field", may not get to experience. I'm aware of that, and VERY grateful!

To catch up on my other black bear den experiences from this year and in the past, check out those entries here.

My first entry this season focused on the protocol of handling bear cubs, and what data is taken from them. My next entry was all about Mama Bear. Every piece of information that can be taken, seems to be written down. And why not? We have the time and the access to the bears while the mother is chemically immobilized. In this entry, I'll show you what this den actually looks like. Not all bear dens are created equal, keep that in mind.



The township of den visit #3 was in Cameron, NY.
Click to enlarge the image.

Often, when people think of a bear den, they think of a cozy, sheltered rock cave. This is rarely the case. I've not seen enough dens to know what the majority of black bear dens look like in New York. I've visited and seen with my very own eyes 5 black bear dens. All of them broke "convention", or what I made convention to be in my mind.

I think it's safe to say that all of them have some sort of protection from vegetation. In a couple of cases, it was thick, dense thorny branches. In one case, it was dead Christmas trees in a brush pile. In another, the den was underneath a blown-down dead tree. The bears seem to be way more exposed to the elements than is preconceived they would be.



Region 8 Wildlife Biologist Art Kirsch (left),
and Fish and Wildlife Technician Ron Newell (right).

The location of this den was in the township of Cameron, NY. This town seems to be in the middle of nowhere, and really to close to anything. Except maybe the Pennsylvania border!

We drove down a road (dirt, seasonal, 2-track) for a few miles and ended at a dead end which had one house at the end, and was surrounded by agricultural fields. The den was down a bit of a hill, and about 50 yards into the woods at the edge of the field. Standing at the edge of the field, I could see the den, once I knew what I was looking for, so it really wasn't far from the field.

Both of the above images were taken at the same spot. The top picture was taken to my left, looking into the woods.
The red arrow shows approximately where the bear den was located.
The bottom image was taken to my right, looking out at the agricultural field.

The whole process went smoothly- the team went in a successfully and safely chemically immobilized the mother, and the rest of us came in to handle cubs and take data down from them.

There were triplets at this den, but I could only get my hands on 2 at a time!
Photo credit: Marty DeLong

Meanwhile, the mother was under the case of the veterinarian, Dr. Jeff Wyatt, and vet tech Robin English.

I was invited over to get my hands on the mother bear. It was a really neat experience...most of the group was off to the side with the cubs, obviously preoccupied. But Art, and the vet staff were working on the mother. I kind of meandered over, and they invited me to listen to her heart beat. I'm not a mother, so I haven't heard the first sounds of my child's heartbeat. But, listening to that bear's steady heart beating was awe-inspiring.
Photo credit: Art Kirsch

At this den visit, the FLCC students and faculty did not attend. They had to get back to the college for classes, but since I was there on my own, I stayed for the entire day (this was the second den visit we did that day). They asked if I would be OK with taking down some data for them, in their absence. Of course I said I would, but really it was for selfish reasons. HAVING to take down data only gave me more access to the fun stuff. And this time it was data off any of the bears, it was the characteristics of the bear den.

When I was a student at Finger Lakes Community College, during my first full time semester, John (my professor) tasked me with revamping the "den data sheet". It's not in my nature to turn something down, so I started working on it. Looking back, in the fall of 2010, I had never USED a data sheet and had actually never even seen one. I hadn't experienced a den visit, or met any of the biologists. I really had no idea what I was doing. I had the old, out of date data sheet to guide me, as well as a 3" binder stuffed full of journal articles related to bear dens. "Have at it" I was told.

I distinctly remember sitting at a computer in the Conservation Department equipment room at FLCC in tears because I had been asked to do this, and I didn't want to disappoint, but I was lost. It seems so trivial and silly now, since I've created that new data sheet, and used many, many of them since for various projects. But at the time, it was very overwhelming.

So, to be able to take "my baby" into a bear den, alone, and use the protocol I wrote and take down the measurements, and read my own phrasing...it was a "moment". Nothing too profound, but cool.

Here's the den!

Instead of a rock cave, this is more likened to Bird Bird's nest! In the middle of the den is a digital thermometer reading the in-den temperature. To the right of that is some one's camera that fell out of a pocket when they were removing the bear from the den.

This is the view from laying inside the den looking straight up. As you can see, there isn't a whole lot of cover.
Precipitation comes right in...

Don't judge me! I'm in a BEAR DEN, people! You'd take a picture like this too!

Below are a few snippets from the data sheet, so you can get an idea of what types of information FLCC students are interested in. A current student of the Black Bear Management class at FLCC, just presented the class's findings of bear dens in the Finger Lakes at a national conference. It was really well received, and very interesting to see all of the data collected!

And so, another fantastic experience was coming to a close. Envious classmates of mine, current and past, keep telling me how lucky I am. I am a lot of things: grateful, appreciative and fortunate mostly, but not lucky. Luck would have been if I woke up that morning snuggled in with the bears in the den! The opportunities I've been presented were made with forged relationships (with generous, patient people), and persistence on my part. It's been number one on my bucket list to visit a bear den and handle a cub. And by the time I was at the 3rd den, handling cubs was not old news by any means, but I was comfortable enough to meander around the scene, taking in different aspects of the science taking place, and enjoying the wonder on everyone's faces.

After everything was wrapped up, the cubs were placed back with their mother. There are 3 in there, although just one little guy, probably only 6-7 weeks old, peeked back at me.

I lingered JUST long enough to get this shot of this bear family.



Black bear den season: part III

It's been awhile since I've been able to write. I had a busy weekend in DC at a conference, and also my power cord for my laptop shorted out and stopped working. BUT I'm back from DC and I'm all powered up!

If you want to get caught up on my 2013 bear den experiences, check out this link: bear dens.



Site of Den #2. Click to enlargen.

On March 14 and 15, I was invited to hang out with some NYSDEC biologists and technicians while they did some bear den checks. In this entry I'll outline my experience at den #2!

Den #2 was interesting because it was located about 80 yards from the landowner's house. It was just about in plain sight from the back of the house, although it was shielded a little bit by the thick brush it was in.

If the home owner's were outside talking, or their dog barked, the bears I'm sure could easily hear them. But, the sow (or mother bear) apparently wasn't bothered, and chose that spot to have her triplets.


FLCC student Judi McDougall attempts to access the bear den to take measurements.

In the last entry I focused mostly on what happens with the cubs during a visit. This entry I'll focus on mom. She really is what the biologists are most interested in I think. How the bear team finds the den is from tracking down mom, who is wearing a collar. This collar does sometimes need maintenance, or a battery change, so while the bears are semi-stationary in the den is the perfect time to do it.

On our lunch break, Wildlife Biologist Art Kirsch prepares the chemicals (a mixture of Ketamine and Xylazine) for the next den visit. The chemicals are then put into a dart which is loaded into a low velocity pistol or a rifle powered by compressed air, a CO2 cartridge or a .22 blank. The biologists aim for the bear's hip, which has a

Accompanying us on these visits are Rochester, NY Seneca Park Zoo staff: a veterinarian Dr. Jeff Wyatt DVM, and veterinary technician Robin English. Both are there with the animal's health and safety as their first priority.

A select few members of "the bear team" approach the den first. Art, technicians, and the vets go first. It's a tense few moments as they're trying to chemically immobilize the adult bear. Bears do not truly hibernate (see this blog entry: The true NY hibernators), so if spooked, and so inclined, they can get up and run away. So the team has to move in stealth mode until he/she is darted, and they've given it time to set in. If all goes to plan, the whole process should take about 20 minutes. Then the clock starts ticking. There's approximately 1 hour of time to work while the animal is immobilized.



From left to right: Robin (with her back turned),
Dr. Wyatt, Jeb (a Fish and Wildife Technician), and Art.

Dr. Wyatt and Robin are responsible for watching the bear's vital signs. This includes heart rate, breathing rate, temperature, and maintaining good oxygen levels.

Meanwhile, the DEC team is busily checking the collar, tagging the bear (if it hasn't been already), extracting a tooth for aging (if it hasn't been already), tatooing an ID number on the gum (if it hasn't been already), and gathering other data points. If some or all of these things have been done already, as was the case this time, "processing" the adult moves fairly quickly.

You might notice that the bear is laying on a silver space blanket. This provides a buffer between the animal and the cold ground. While under "the drugs", it cannot thermoregulate, or maintain a constant internal temperature. An animal can quickly become hypthermic if this step isn't observed. Also, between Art's hands is a red and green piece of fabric. This is a fleece sleeve that they slide over the face to protect the eyes. One of the chemicals in the cocktail paralyzes all muscles, so the bear can't blink. So to keep the bright light and debris out of the eyes, they use this sleeve or sometimes I've seen them place large band-aids over the eyes too.

I once got to take the temperature of a large male bear. Not orally. :)

 

 

The little gadget see above, is a pulse oximeter. If you've spent anytime in the hospital, you may have had this thing clipped to your index finger. It measures the concentration of oxygen in the bloodstream, and this one also monitored the pulse. Without this tool, the vet must keep his fingers on an artery almost constantly to make sure the pulse is steady and strong. He also kept pressing on a mucous membrane (commonly the gums). If they're bright and pink, there's a healthy oxygen level in the blood. If the gums are ashy and gray, we've got problems. So, this pulse oximeter is not an "instead of" tool, but an "addition to" tool. It also beeps outloud in time with the pulse, so you can listen instead of totally concentrate while pressing on an artery through the skin. They've never used one before, and weren't sure if it would work. There was a strong enough pulse in the tongue though, and all were pleasantly surprised with how well it all worked out.

While the bear is "out", they allowed me to explore her a little bit. When else will I get to look so closely at a bear paw?

Because this mother bear was mom to triplets, I believe (all the visits are blending together!), she was engorged with milk. Bear nipples are set up a bit differently than our domestic pets. She only has 6 nipples. Two are down low on her abdomen, and the other 4 are up high on her chest.

Her claws were beautiful. Not made for slashing prey, but more for digging. Bears are also extremely dextrous with their digits, and can pluck berries from a vine with their paws and their lips.

Jeb (on left) is now a DEC Fish and Wildlife Technician, but he got his start at Finger Lakes Community College and SUNY Cobleskill, just as I am. Jeb is fitting the new collar with fresh batteries. The "old" collar is at right on the ground. The collar's band is leather, but does have a canvas tab on it. If for some reason, the bear team can't get their hands on this bear again in the next year to change it out, and the bear happens to be on the loose and growing, that canvas tab can be torn away and the collar removed. It's always a risk when putting a multi-thousand dollar piece of equipment on a wild animal.

Danika Van Niel (my professor's daughter) hands a bear cub to Fish and Wildife Technician Ron Newell to be placed back in the den with mom. Once all of the "work" is done, the cubs MUST go back, although we may not want them to!
Photo credit: John Van Niel

A parting shot of the happy family, back in the den.
Photo credit: John Van Niel 

Yet another FANSTASTIC experience in the field with these people. I can tell you that it doesn't get old, and I feel so very fortunate to be included. Making connections with the right people, and a little persistence certainly pays off. Stay tuned for at least one more bear entry to come!

Black bear den season: part II

In my previous post, I shared with blog readers that I was afforded a very unique opportunity. I was invited to attend 3 black bear den visits where biological information is taken, and live bears are handled. I am VERY fortunate and very happy to share what I learned.

I’ll begin by explaining WHY we want to visit black bear dens and handle the bears. I had a very outdoorsy and wildlife saavy friend write to me and say “Not trying to be a buzz kill but this is a wild animal. Why are we handling them like a child or a pet? makes no sense to me that they are exploited to human touch and then hunted, killed skinned and eaten!” I will admit that at first, I got hot. Here’s a man who sticks out in my mind as a conservationist, and a life-long hunter and trapper…and yet he can’t understand that what I’m participating in is important to conserving wildlife?


Den #1 was located within the township of Almond, NY

Click to enlargen

In Western, NY and specifically the Finger Lakes region, black bears are moving Northward from Pennsylvania. Over the past 10-12 years they’ve really made a comeback. A combination of factors have influenced this. Many farms are being abandoned, and land is reverting back to how it was historically wooded instead of wide open agricultural fields. This is allowing the bears, and other animals, more cover and suitable habitat. I also think that bears are particularly adaptable. They are similar in feeding and human interaction habits to raccoons. Many people have preconceived notions that bears are vicious. ALL wild animals have tendencies to be vicious. Deer mice can act vicious, cottontails, foxes, and yes bears can act vicious. But black bears don’t TEND to be vicious, unless they are sick, wounded, or given reason to be defensive. I liken them to raccoons because often the most they are to humans are annoying. There are a lot of summer homes and hunting camps in the Finger Lakes that are seasonally used. Bears looking for a place to hunker down may break into these camps. And they love bird feeders, grills, garbage, cars with coolers, and all sorts of other treats that people living in this newly reclaimed “bear country” forget to put away. They’re really just like a 200 pound raccoon. Of course bears are capable of greater damage, so they’re often feared more than ‘coons.

Ok, so all that being said, since bears are moving back into “our” territory, the biologists of the Department of Environmental Conservation Wildlife Division strive to learn as much about their habits and movements as possible. The easiet and least invasive way of doing this, is to place a collar of sorts on certain bears. In Region 8, for example (which is where I visited dens), the biologists are monitoring approximately a total of 7-15 adult bears. Also, with some of those adults are cubs or yearlings…but those are not individually monitored. There are a lot of human-bear interactions, and also there is an interest in hunting black bears in New York State. They are considered “big game” , and to help control the population, there are hunting seasons, which you can view here: Deer and Bear Hunting Seasons.

To address a word that my friend used…”exploiting” the bears. I do not look at handling these bears and cubs as exploiting. Yes, we take pictures with them. But for them, it’s a moment in time. As Art Kirsch, Senior Region 8 Wildlife Biologist, told me that “the science obtained from monitoring these bears, far outweighs the inconvenience they experience”, which is very true. The adults are always immobilized with a cocktail of drugs. There is no safe way to handle the adults without them being immoblized. The cubs though this time of year are quite small and easy to handle. There is no reason to impose unnecessary risk (there's always risk with use of chemical immobilizers- bear, dog, cat, human) by immobilizing the cubs. The largest cub I think I handled was just around 6 pounds, and the smallest was 3.2 pounds. If any memories of these interactions with the bear biologists are remembered, it’s not of terror and panic. The animals are treated with respect, voices are kept low, and the adult bear’s eyes are covered to further keep it calm. Cubs are kept in fleece bags to keep them warm and secure.

A question I’ve been asked since I shared that I handled bear cubs is “Won’t the mother reject them with your scent on them?”…no! Please keep in mind that the protocol for these visits has the bear's health and safety as the first priority. The mother is handled the same as the cubs, her den is entered by biologists when she’s removed, and so everything and the whole bear family have human scent. Everyone is required to wear gloves, and “nuzzling” is prohibited. The team does not want the other people at the den visits, to "Disney-fy" the bears. Really there is nothing cuter than a 2 month old bear cub, but these are wild animals who are returning to the wild. They are not pets or cartoons. We do not name them, or kiss them, and hugging is ONLY allowed to keep them warm.We are handling these cubs to obtain data from them, as well as keep them warm while mom is being processed. They've never been out of then den before, and have never been away from mom's side. If for some reason the mother can not be handled (she runs off, for example), the cubs are not handled. It’s all of them or none of them. That way, everyone smells the same.

The whole experience takes less than 1 hour, as that is how long we have for the drugs to keep a hold on the adult. This is not a process that drags on for several hours, but is done efficiently and safely for all involved.

Now I know if you clicked on this post, you don’t REALLY care about all that I’ve written. You came for the pictures. I will describe my experience of den #1 through the captions. Also, all people mentioned by name are from Finger Lakes Community College (unless otherwise noted) where there is a Black Bear Management course offered. John Van Niel is the professor of that course.

 

In this massive brush pile of dead Christmas trees and other debris, a mother bear and 3 cubs are in a cozy den. Region 8 Wildlife technician Jeb McConnell along with Region 8 Wildlife Biologist Art Kirsch and Region 9 Wildlife Biologist Tim Spierto are searching for an access point to shoot the chemical immobilizer into the mother bear. Once the drugs are administered, they must wait 15-20 minutes for it to take effect.

After the sow was stabilized, I was invited to climb up on top of the brush pile (10-12 feet off the ground) to see the entrance of the den.

The veterinarian on hand, Dr. Jeff Wyatt DVM, of the Seneca Park Zoo, went 8 feet down into the den to watch the sow's vitals. She maintained a strong and steady heartbeat, and was breathing normally through out. She was not removed from the den, due to how precarious the brush pile was to maneuver. Jeff mentioned to me while I was taking this picture that he was almost 'hot' down in the den. Lucky, we were freezing out on top!



Art Kirsch, Senior Wildlife Biologist, has the second best seat in the house. Art held his post just outside the den monitoring all that was going on, and recording data from the sow still in the den.



When cubs are first removed, the are placed into a fleece sack as seen here. This helps contain them (they are wiggly) and keep them warm. Weights are taken for each cub, as seen here. Alicia Walker is reading the scale, as John Van Niel holds it. Ben Williams and Julia Lampman record data in the background.

Here John Van Niel removes the cub from the bag for a moment so that the cub can be sexed. I think in this case, it's a girl! Grasping the cub by the scruff of the neck is not painful, this is something the mother, like many other mother animals, do to move their babies when they are too young to move on their own.



Here, I am holding the cub as Alicia continues to take measurements. There is a hair length (from the top of the head) to ear length ratio that can be plugged into an equation, which can give a fairly accurate date of birth. Jon Muller and Kevin Skryzinski watch on, while Ben records the data.

Here John is readying me for the insertion of the Passive Integrated Transponder (PIT) tag. This is very similar to a 'micro chip' you may have put in your cat or dog. It is not an active means of tracking the animal, but if the animal is handled again in the future, a receiver can be waved over the location of insertion (between shoulder blades under skin), and the unique ID

number can be read.



Cubs are born with blue eyes, as many mammals seem to be. I do not know why this is, but with age the eyes will likely darken to brown.

Once all data was collected from cubs and the mother bear, we formed a bit of a 'bucket brigade' from the ground up and over the brush pile to get the cubs back into the den. It was easier and safer than trying to hold your balance and keep your footing while holding onto a squirming cub. Photo credit: Julia Lampman

 

 

In total, the experience was around an hour and a half. That includes walking time from the road to the den, and the time it took the team to immobilize mom, wait for the drugs to kick in, and then for all of the data collection. It was one of those experiences that I could not WAIT to partake in, and then in a blink, it was over. BUT, fortunately I had 2 more dens to look forward to. I will be blogging about those experiences soon. Hope you enjoyed!

A Lesson: Aging Fish Scales

Earlier this week we had a very rainy, miserable day, and temps barely topped 50 degrees. After going out the the Funny River to check the weir, and getting thoroughly soaked, I was offered the chance to sit in the office for the rest of the afternoon and learn to age fish scales. I jumped at this, not just to get out of the weather, but because I'm interested in checking out scales a bit closer.

In the Wetland Mammals class I took a couple of years ago, we found otter scat and rinsed it out so that we just had the hard bits left over. We attempted to ID the species of fish that the otter had been eating by looking at the scales. It's tedious and difficult...and as I remember, we were not successful in IDing the species.

Anyway, when I had the chance to do this again,  I was interested to actually LEARN what I'm looking at rather than just trying to compare an itty-bitty scale to a picture in a book.

I got kind of a crash course in aging scales, but this paper is very comprehensive. If you're a Fish Head, you should read it. Not only comprehesive, but written fairly "layman", so it's easy to understand. Sometimes these things are written with ONLY peers in mind, and that's not always the audience.

This is a scale card. It's kind of sticky once it gets wet, and the scales stick to it pretty well. The way it's organized is from right to left, top to bottom. SO, fish #1 that we sample goes from 1 down to 31. We take 4 scales/fish. Not sure WHY it's done this way, there's got to be a reason. Seems too odd to not have a reason. These were not the scales I would be learning to age from though. These still needed to be pressed into acetate making a permanent, hard record of the scales.

The scales I was to abe ging were in these little envelopes.

Not sure how many are in here...but way more than is considered "fun"...Also, the scales in these envelopes are no where near the size on the above card. Those scales, to give a frame of reference, are like the size of a pencil eraser. Below are the size of the scales I was working with.

Can you see them? I circled them because otherwise I don't think you'd be able to see them. They are tiny, and also very silvery/translucent. These scales came from coho and chinook smolts, which were probably finger-length, if that. And I realize that you probably can't see the scales too well, but I didn't want to write this post without sharing HOW small they are.

So what I was looking for was to determine if these fish were "0" in age (hatched that year, haven't had a chance to add a annuli ring), or a "1" year old in age (between 1 full year and 2 years of age). All of those rings you see above are not annuli, but circuli. Annuli rings are added on after a year, and are a bit more pronounced than the others. The image above points this out with an arrow, although to me, they all look the same in these drawings. Actually looking at the scales under the dissection scope seemed (or maybe I thought I was doing better than I actually was...) to be easier to pick out.

All of these fish have yet to live in salt water, they've just been hanging out in the rocks and vegetation eating inverts and growing.  At the same time of the scales being taken, they were also implanted with a PIT tag.

Q.

What is a PIT tag?

A.

A Passive Integrated Transponder tag is a radio frequency device that transmits a unique individual code to a reader where it is displayed in a numeric or alphanumeric form. The tag has no internal battery, hence the term “passive". The reader powers or excites the tag circuitry by radio frequency induction and receives the code back from the tag. Radio frequency identification does not require line of sight, tags can be read as long as they are within the range of a reader. Biomark - Specialists in Electronic Identification

I'd speak more on that above, if I had enough information to explain with. Simply, I assume half of you that are reading have worked with these tags in the field, and need little explanation. The other half of you, you know those little microchips your vet can put in the cat/dog? Same thing! The tag is actually about the size of a grain of rice- it's very, very small.

I may have the opportunity to implant some in fish later this season, and of course if that happens I'll be sure to share.

And this is the data sheet I was recording the ages on. That length is in milimeters, just to give you an idea. Above I said finger-length and 91mm is long, but that was one of the larger fish that I recorded.

I sat here for 3 hours or so, staring at these little scales, through a microscope. When I walked out of work that day, I could barely see straight. I've always had an issue looking through binoculars and microscopes, even though I have 20/20 vision. I'm not sure if that's me misusing the equipment or truly having an issue. Regardless, it was interesting to do, just will remember to take breaks next time.

I have a few blog entries in mind to write soon, and I wanted to share a picture of what was going on outside my window as I was writing this. I would like to write a full entry on these guys eventually.

Common Raven (Corvus corax)

There was a group of 4-5 Ravens hopping around the tree tops squawking very loudly...not sure what was going on but it disturbed me enough to go out on the porch and look for them!