It's Hatch Week at the EagleCam
So, will there be chicks?
It is “hatch
week” in our beloved eagle’s nest. Will we see chicks?
Unfortunately, inconsistent
incubation and wet, cool spring temperatures are unfavorable conditions for a
successful hatch. We know that eggs are composed of mostly fluid and many factors affect
hatchability. Just like in humans, there
are genetic, nutritional, physiological, and behavioral features of the incubation
process that all need to transpire in order for the eggs to hatch into healthy
eagle chicks. Temperature and humidity
are important environmental conditions that have not been consistent at the
nest. Prolonged absence from the eggs we
have witnessed make it likely the remaining two eggs will not hatch. Thirty-three to thirty-five days from laying
is average hatch date. Monday the 26th
of March was 35 days from the first egg lay.
While the
female continues to incubate, she is not doing so consistently, as most of you
have noted. The inconsistent incubation
eggs does not bode well for proper development of the chicks. On 3-28, one of the eggs appeared to be
missing. We have seen egg fragments in
the nest, so we assume one egg has broken and will not hatch.
At this
point it is very unlikely the female would lay another egg, even if both
remaining eggs don’t hatch. She has laid
three eggs and has expended her calcium and energy reserves in her body for the
nesting season. The male has not been
providing much needed support to the eggs or the female. This suggests this new male may be young and
inexperienced in nest brooding.
Frequent
close-up images of the eggs do not provide reliable insight into the viability
of the eggs. There are some spots on the
eggs that appear to be a pip. Wind,
grass in the nest and other factors make it difficult to tell a dirt spot from
a true pip, but we remain watchful.
We hope
you continue to watch with us and share the exciting tale of life in a bald
eagle nest! Thank you for all of your
continued support on Facebook and emails.
Donations
keep our program afloat and help us to continue providing this viewing for
you. If you forgot to donate on your
taxes, or if you are not a Minnesota taxpayer, please consider a donation
to our program. The important work of
protecting wildlife in Minnesota is broad and severely under-funded. Any donation you provide is helpful and so
appreciated. Not only that, but ALL
donations are matched one-to-one from the Critical Habitat License Plate
fund! Making a double
donation knowing you are personally helping bald eagles, trumpeter swans,
loons, blue birds and other species thrive is a gift that rewards for future
generations! We thank you, and our family
of eagles thanks you!
It’s Officially
Spring!
Get excited! Snow
piles are melting, temperatures are rising, and day length is increasing! Now
that spring is just around the corner, it’s time to break free from our
seasonally dormant lifestyle and embrace the pending vernal changes.
Speaking
of dormancy, did you know that wildlife species practice multiple types? For
example, there’s hibernation, brumation, diapause, quiescence, torpor, and
aestivation! Many of these terms get used loosely and synonymously, but each
has a specific meaning and describes a specific type of dormancy.
Hibernation is
specific to endotherms, like mammals, and is characterized by inactivity,
lowered body temperature, and reduced breathing, heart, and metabolic rates.
Hibernation was traditionally defined relative to body temperature reduction;
however, the term has been redefined and is now based on seasonal metabolic
depression concurrent with food scarcity and cold temperatures.
Brumation is similar
to hibernation but is specific to ectotherms, like reptiles, and involves
different metabolic processes. For example, reptiles accumulate high levels of
glycogen in their tissues and blood, allowing them to tolerate lower oxygen
levels than hibernating mammals. And unlike true hibernators, brumators will
periodically “awake” and drink water to avoid dehydration.
Diapause is a period
of developmental arrest initiated in response to a stimulus (e.g., reduced day
length) prior to predictable, seasonally recurring environmental conditions
(e.g. low winter temperatures). Diapause facilitates survival, synchronizes
life history traits with seasonal cycles, and cannot be interrupted until the physiological
process has ended. Diapause is typically associated with insects and other
arthropods, as well as the embryos of certain fishes.
Comparatively, torpor
and quiescence are immediate and relatively short-term responses to unpredictable
environmental conditions (e.g., food scarcity). These physiological processes
are not seasonally dependent and may last for one day to multiple weeks. Generally,
torpor is applied to birds and mammals, whereas quiescence is applied to
insects.
Like hibernation and
brumation, aestivation is characterized by inactivity and reduced metabolic rates;
however, this physiological process is a response to arid conditions and high,
rather than low, temperatures. Typically, aestivating species burrow in the
soil to avoid heat damage and desiccation; however, some species have evolved
clever supporting mechanisms. For example, lesser sirens, which occupy portions
of the Mississippi River Valley and the Atlantic and Gulf Coast Plains, survive
week- to year-long droughts by retreating deep into crayfish burrows and
secreting mucus that hardens into a cocoon and prevents dehydration.
Looking
for a way to get outside and be less dormant? Check out the Minnesota State Parks
and Trails event calendar for maple syrup workshops, group hikes, wildlife
photography classes, and more!
The EagleCam and
associated technology are paid for and maintained by the DNR’s Nongame Wildlife
Program, which is largely supported by voluntary
contributions. Recognized as one of the most successful programs of
its kind in the United States, the Nongame Wildlife program helps hundreds of
Minnesota species through habitat restorations, surveys and monitoring,
technical guidance, and outreach and education – critters such as bees,
butterflies, songbirds, loons, frogs, turtles and bats, as well as eagles. Donations
to the Nongame Wildlife Program are matched dollar for dollar by the
Reinvest in Minnesota (RIM) license plate fund. They’re also tax-deductible.
Learn more at http://www.dnr.state.mn.us/eco/nongame/index.html.
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