Archive | April 2019

Chutes and Otters

otters

A “romp” of river otters seen on a Snapshot Wisconsin camera in 2015.

Within the scientific field of animal behavior, research topics such as parental care, natural selection, and feeding tendencies seem to arise far more frequently than animal play.  After all, a life in the wild tends to revolve less around play and more around survival.  For some animals, however, play is an integral part of their lifestyles and ultimately their perseverance.  River otters, for example, are social animals with a playful and charismatic reputation.  As their name suggests, river otters do not typically stray far from waterways, and some Snapshot Wisconsin cameras are perfectly positioned to capture interesting otter behavior.  We have observed otters grooming together, wrestling with one another, and – perhaps most amusingly for our staff and volunteers – sliding across the snow.  At the bottom of this post there is a compilation of otter slide photos.

otter_door017_4.15.18a-e1551379448343.pngUndeniably, sliding across snow or mud is an effective method for locomotion when you compare it an otter’s normal gate – a cylindrical body bounding on short legs.  It’s the kind of body shape that glides effortlessly through the water but doesn’t demonstrate the same sort of grace on land.  Those proportions make it especially tough to traverse snow, just take it from the otter pictured on the right.

Is sliding truly just an efficient way to travel, or does the otter’s seemingly spirited nature play a role in this behavior as well?  2005 paper published in the Northeastern Naturalist suggests that it could be both.  The study analyzed 5 minutes and 49 seconds of video of wild otters in Pennsylvania.  The otters were observed sliding 16 times, an excessive number for the sake of conserving energy.

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A Snapshot Wisconsin otter on what may be a latrine site.

The term “otter slide” doesn’t just refer to a mode of transportation, however.  It can also refer to the marks near riverbanks that are left when otters slide in and out of the water.  Often repeated otter sliding will occur near latrine sites, where the animals will go to deposit and read scent-coded messages from other otters in the area.  The slides are such a great indicator of otter presence, that the Wisconsin DNR conducts aerial surveys in the winter to help determine population trends.  Whatever the motivation is behind the sliding behavior, we certainly enjoy watching it on our trail cameras.

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Snapshot Saturday: April 27th, 2019

It’s that time of year again when black bears begin making their appearances on Snapshot Wisconsin cameras. Have you spotted a bear yet on your trail camera this year?

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Did you know you can view and classify photos collected from Snapshot Wisconsin cameras across the state at www.SnapshotWisconsin.org? It’s a fun activity for the whole family!

April Science Update: Time-lapse Photos

The Snapshot Wisconsin team is often asked why we accept data only from our Snapshot-specific cameras. While there are several reasons, the reason that was highlighted in the April 2019 newsletter was because Snapshot Wisconsin cameras are programmed to take a single photo at 10:40 a.m. each day.  Although 10:40 may seem like an arbitrary time, this corresponds to the approximate time that a NASA satellite flies over Wisconsin and collects aerial imagery. (More information on how NASA data and Snapshot data are complementary can be found in this blog post.)

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An example of a motion-triggered photo and a time-lapse photo from the same site in Sawyer County, September 2017.

It may be difficult to recognize the value of a blank photo in wildlife research, but a year-long series of these photos allows us to examine something very important to wildlife: habitat condition. For each camera site, the time-lapse photos are loaded into the statistical software, “R,” where each pixel in the image is analyzed and an overall measure of greenness is summarized for the entire photo. That measure, called the Green Chromatic Coordinate, can be used to identify different “phenophases,” or significant stages in the yearly cycle of a location’s plants and animals. These stages can be delineated on a graph, called a phenoplot, where a fitted curve reveals the transition day-by-day. The 2018 phenoplot for one Snapshot Wisconsin camera site is seen below.

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PhenoPhases

Time-lapse photos from the corresponding phenophases as identified by the phenoplot above.

In 2018, 45 camera sites had a complete set of 365 time-lapse photos, but we expect many more sites to be included in the 2019 analyses. The relatively small sample size for 2018 is due in part to many counties not being opened for applications until partway through the year, but also because time-lapse data are rendered unusable if the date and time are not set properly on the camera. This may happen when the operator accidentally sets the time on the 12-hour clock instead of the 24-hour clock, or if the hardware malfunctions and resets the date and time to manufacturer settings—this is why we ask our volunteers to verify the camera’s date and time settings before leaving the site each time they perform a camera check.

The information derived from these analyses will be integrated into wildlife models. For example, the objective of one ongoing DNR research project is to understand linkages between deer body condition and habitat, which includes what’s available to deer as forest cover and food resources, as well as weather-related factors, such as winter severity or timing of spring greenup. The project currently uses weather data collected across the state to estimate snow depth, temperature, and winter severity, and creates maps based off this information.

Snapshot’s time-lapse cameras offer a wealth of seasonal information regarding type of forest cover and food sources, as well as weather-related information. In the future, phenological data obtained from Snapshot cameras could be used to create “greenup maps” that provide estimates of where and when greenup is occurring, and potentially test that information as a means of better understanding how environmental factors affect deer health, such as whether an early spring greenup improved deer body condition the next fall.

Snapshot Saturday: April 20th, 2019

Check out this hawk captured on a Columbia County Snapshot Wisconsin camera. Happy Snapshot Saturday!

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Interested in hosting your own Snapshot Wisconsin camera? Visit our webpage to find out how to get involved: https://dnr.wi.gov/topic/research/projects/snapshot/.

The Process of Deer Antlers

Did you know that white-tailed deer (Odocoileus virginianus) antlers are one of the fastest growing tissues known to man? For instance, human fingernails grow between 1 to 10 centimeters a year whereas white-tailed antlers grow several centimeters each day during the growing stage! Unlike human fingernails, deer antlers are composed of veins, arteries, vessels, and cartilaginous tissue. Many hunters believe that the bigger the rack the older the buck. Yet, the inspection of teeth is the only accurate indication of a deer’s age. The greatest antler size within a buck’s life is from age five to seven. Factors sure as age, genetics, and nutrition of the buck determines the magnitude of antler size. Keep reading below to learn how antlers grow and change throughout the year!

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Pedicles, the area attaching the antler to the skull, are first formed on top of a buck’s head during late winter and spring and can reach up to ¼ of the ear-length. Snapshot Wisconsin asks volunteers to classify any deer with formations less than ¼ of the deer’s ear-length as antlerless, while reserving the antlered classifications for more than ¼ of the deer’s ear-length.

To create antlers in early spring, minerals in the ribs and shoulders of the buck are redistributed in his body. Velvet (pubescent skin) covers the antler and provides nutrients through the flow of blood. These nutrients cause antler growth. During the velvet stage, the antlers are very sensitive. Any impact will be painful and could, due to the fragile state, cause breakage. Nevertheless, this sensitivity allows the buck to comprehend the size of its antlers and, eventually, the buck will move through the forest with ease.

By late summer, the antlers are fully grown. Blood flow becomes constricted, causing gradual hardening and calcification. The velvet dies off in response and, like a sunburnt human, the buck becomes annoyed and wants to peel the excess skin off. The buck rubs his antlers on trees to rid himself of the velvet, exposing glabrous antlers. This rubbing strengthens the buck’s neck, which will come in handy during the rut where the buck will compete with other bucks’ antlered attacks.

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Due to reduced sunlight and testosterone, white-tailed bucks’ antlers fall off around January and February. Their body absorbs the calcium between the antler and pedicle, which weakens the antler, causing it to eventually fall off. If you’re looking for a hobby this time of year, check out shed hunting! Shed hunting is the pastime of searching for antlers that have been naturally shed by antlered bearing mammals. Another great hobby for this time of year is checking out the trail camera photos captured by the Snapshot Wisconsin project! Start viewing and classify photos today!

For more information, please visit these sources:

Snapshot Saturday: April 13th, 2019

Each spring greater prairie-chickens congregate on leks, or mating grounds, to show off their ornate displays. Male birds use their orange air sacs to create a distinctive booming sound that can be heard from across the prairie.

Snapshot Wisconsin paired up with DNR Wildlife Management staff to start a pilot project last spring using trail cameras to monitor greater prairie-chickens, and we think it has been a “booming” success! Check out these two male greater prairie-chickens caught on camera.

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Did you know you can view and classify photos collected from Snapshot Wisconsin cameras across the state at www.SnapshotWisconsin.org? It’s a fun activity for the whole family!

Citizen Science Day 2019

Are you ready to celebrate Citizen Science Day?

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Before we dive into the details, let’s start with what is citizen science? There are many definitions for citizen science, which may also be referred to as community science, crowd-sourced science or volunteer monitoring. The Oxford English Dictionary defines citizen science as,

“Scientific work undertaken by members of the general public, often in collaboration with or under the direction of professional scientists and scientific institutions.”

Citizen scientists partaking in Snapshot Wisconsin monitor trail cameras across to state to gather year-round data about wildlife. Data collected from the project help inform wildlife management decisions at the WDNR, and also engage the public in learning about the state’s natural resources. Snapshot Wisconsin has over one thousand volunteers hosting trail cameras across the state, and hundreds more from around the globe helping to identify the wildlife caught on camera on Zooniverse.

Citizen Science Day is hosted annually to celebrate and recognize the projects, researchers, and dedicated volunteers that contribute to citizen science all over the world. Mark your calendars for April 13th, this year’s Citizen Science Day kick-off! The Citizen Science Association and SciStarter have teamed up to promote events in celebration of citizen science. Are you interested in celebrating Citizen Science Day this year? Check out SciStarter’s project finder to find Citizen Science Day events near you!

You can celebrate citizen science any day of the year by participating in Snapshot Wisconsin, whether you are interested in hosting a trail camera or identifying the exciting critters captured on camera (which can be done from anywhere!)

Snapshot Saturday: April 6th, 2019

The charismatic red fox are ubiquitous in Wisconsin, although they are found most commonly in the southern, central, and western parts of the state. A Snapshot Wisconsin trail camera deployed in northeastern Wisconsin captured this red fox on a particularly snowy day last winter.

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Interested in hosting your own Snapshot Wisconsin camera? Visit our webpage to find out how to get involved: https://dnr.wi.gov/topic/research/projects/snapshot/.

April Volunteer of the Month

April’s Volunteer of the Month is
Mark and Sue from Columbia County!

April’s Volunteer of the Month goes to Mark and Sue from Columbia County! Before retirement, Mark and Sue spent their careers as Conservation Biologists for the DNR Natural Heritage Conservation Program. For the past 40 years they have served as resident managers at the Madison Audubon Society’s Goose Pond Sanctuary. Goose Pond Sanctuary, located near Arlington, is comprised of 660 acres including restored tallgrass prairie, wetlands, some cropland and a one-acre oak savannah. In addition to hosting two Snapshot Wisconsin cameras, Mark and Sue are also involved in trapping and releasing black-footed ferrets in South Dakota to vaccinate them against Sylvatic plague.

Mark and Sue were motivated to join Snapshot Wisconsin because they enjoyed viewing and surveying wildlife and wanted to use the project to help Madison Audubon members to learn about the wildlife at the Goose Pond Sanctuary. The project provides them a way to view the wildlife responses to habitat restorations on the property, and to see how populations change over time. A few previously absent species they were intrigued to find in their photos were coyote and red fox. Mark and Sue also capture a great diversity of avian life including Cooper’s hawk, snowy owl, ring-necked pheasants, northern harrier and more. Check out a glimpse of what Mark and Sue are finding below!Mark and Sue birds

Thank you, Mark and Sue! Thank you to all our trail camera hosts and Zooniverse volunteers for helping us discover our wildlife together.

March #SuperSnap

This month’s #SuperSnap features an Oneida County pair of North American porcupine (Erethizon dorsatum) nominated by Zooniverse volunteer cjpope!

Did you know that a baby porcupine is referred to as a “porcupette”? Porcupine give birth to a single porcupette. Porcupettes enter the world with soft quills, which harden within an hour. Contrary to popular belief, porcupine cannot shoot their quills – although they still come in handy for defense!

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Continue classifying photos on Zooniverse and hashtagging your favorites for a chance to be featured in the next #SuperSnap blog post. Check out all of the nominations by searching “#SuperSnap” on the Snapshot Wisconsin Talk boards.