Double-crested Cormorant Population not at Biological Carrying Capacity

Double-crested Cormorant Population not at Biological Carrying Capacity

Labeling Double-crested Cormorant Population as Overabundant is “Inappropriate”

Scientists Linda Wire and Francesca Cuthburt, of the University of Double-crested cormorantMinnesota’s department of Fisheries, Wildlife and Conservation biology, find that describing the population of Double-crested Cormorants as overabundant is “inappropriate” given historical evidence that this fish-eating bird has  previously been very abundant.

Biological Carrying Capacity vs. Wildlife Acceptance Cpacity

Ecologists often describe the biological carrying capacity as the population limit that a particular ecosystem can support.  Wire and Cuthburt instead discuss the “wildlife acceptance capacity” as the population number desired or tolerated by human society.  They stress that society should aim to maintain bird Double-crested cormorant wings stretchedpopulations at historic levels, and not set population goals based on how they are perceived to help us reach our fisheries goals. Perhaps we need to take a step back and evaluate the contribution of the double-crested cormorant’s activities versus our own activities that impact the fisheries. The cormorants were abundant long before the demise of fish populations.  This is evident upon inspection of the historical records that Wires and Cuthburt have included in their study.   At the very least, we should not claim that this bird is overabundant if there is no evidence that it is at its true carrying capacity.

Human Activities and the Double-crested Cormorant Population

Cormorants have had a reputation as a competitor of humans for fish as far back as 1634.  Wire and Cuthburt cite that there are only a few locations double-crested cormorant swimmingwhere a decline of natural resources have been directly linked to double-crested cormorant populations and that the perceived overabundance is due to the double-crested cormorant populations rebounding closer to their historic levels after recent declines.  The double-crested cormorant population dropped due to the use of DDT from the 1940s to 1970s, combined with population control by humans (legal and illegal methods) and habitat change.    While it may be perceived that the cormorant population has increased, the perceived increase is really a population rebound after a decline due to human activities.  The population along the Atlantic Coast and in the interior of the United States and Canada has rebounded from 32,000 breeding pairs (early 1970s) to more than 226,000 breeding pairs (late 1990s).


Future Population Goals

The core issue here is that we need to decide if we should keep our bird populations at historic levels (keep common birds common) or try to reduce population sizes if they compete with us for the same food source.   At the very least, we should not misrepresent their population size to the public as “overabundant” if the historic population size was equal or greater than the current population size.  We need to be honest about the difference between the biological carrying capacity and the “wildlife acceptance capacity”, which is the number that certain human populations think should exist.  That number may have little to do with scientific evidence about how a particular population size affects the rest of the ecosystem.

Find the full study on historic Double-crested Cormorant population sizes here.


Invasive Beetles of New England

Invasive Beetles of New England

Oriental Beetle

Anomala orientalis Waterh,

 Oriental Beetle Anomala orientalisThis invasive beetle might not be much of a pest as an adult, but the larvae can do a number on your turf grass.  This individual was found in early July on a King George Day Lily in Scituate, MA.

 Lily Leaf Beetle

Lilioceris lilii

The Lily Leaf Beetle is an invasive pest species that is very commonly found on most (if not all) Asiatic Lilies throughout New England.    It is a very distinguishable bright red beetle on an Asiatic Lily with black head, under-body, legs, and long antennae. This LILIOCERIS LILII individual was photographed feeding on the leaves of our Asiatic Lilies in Massachusetts after their blooming period.  In the last few years, we checked on the plants almost daily and killed any adults we could find.  A few vacations early in the season this year meant that we were not as vigilant, and our lilies paid the price.  We did get to see the beautiful orange blossoms, but with a few holes in the petals and damaged leaves.  One of them even fell over while still in bloom.

Now for lilyleafbeetlethe gross part.  If you notice these critters munching on your lilyleafbeetle larva2lilies, and then notice what looks like mud stuck to the leaves elsewhere, it is really the larva stage that has covered their bodies with their own feces.  Your best bet is to kill as many of these invaders by hand as you can find.  Remember that they are invasive and have not had the chance to co-evolve with natural predators.  You are the only predator available.


Best Late July Daylily

Best Late July Daylily

And the winner goes to…..King George.  We are fortunate to have some of the most beautiful late July daylilies in our garden.  All survived the harsh New England winter with record breaking snowfall.  These are our absolute favorites.  If I had to recommend one, it would be King George for its enormous flowers, but you should try to get them all and you’ll be rewarded year after year.


New England Turtles

New England Turtles and Turtles of Atlantic Canada

Try to guess the species common name of the New England turtles and then hover your mouse/cursor over the image to see the answer.

Blanding’s Turtle (Emys blandingii or Emydoidea blandingii)
Eastern Painted Turtle Chrysemys picta (Pond and Box Turtle Family)
Plymouth Red-bellied Turtle (Pseudemys rubriventris)
Red-eared Slider Turtle Trachemys scripta elegans (not native to New           England but found due to pet releases)
Snapping Turtle Chelydra serpentine
Spotted Turtle Clemmys guttata (Pond and Box Turtle Family)
Wood Turtle Clemmys [Glyptemys] insculpta
Musk Turtle Sternothaerus odoratus (Musk and Mud Turtle Family)

Not Shown:
Common Box Turtle (Pond and Box Turtle Family)
og Turtle Clemmy muhlenbergi

Sea Turtles (not shown)

Loggerhead Caretta caretta
Green Turtle Chelonia mydas
Leatherback Dermochelys coriacea


Eastern Newt

Eastern Newt

(aka Red-Spotted Newt)

Notophthalmus viridescens 

(Subspecies: Red-spotted N.v. viridescens)

Notophthalmus viridescens
Notophthalmus viridescens

Red Eft Eastern Newt Sighting

The Eastern Newt is the first New England species added to by our 2-year old daughter.  The sighting occurred on a late afternoon hike in Pawtuckaway State Park, New Hampshire after a midday rain shower.  Our 2-year old had to be carried up a rocky trail a mile into our hike, and while she was being carried in my husband’s arms, she excitedly shouted, “Look, an orange lizard!”.

None of us saw it.

My husband, who has a sixth sense for spotting any “herp”, had to put her down and have her point to where this “orange lizard” was among the beach leaves and thick vegetation covering the forest floor.  Of course, we already knew what we were looking for – not a reptile, but the unmistakable dayglow-orange terrestrial juvenile form of the (very common) Eastern Newt (aka the Red Eft form).

Further up the trail, we spotted two more (Red Eft) Eastern Newts.  The conditions were ideal for such a sighting – the forest floor was damp after a midday downpour.  However, the conditions for rock climbing (the purpose of our trip) were far from ideal.  We did manage to top-rope at the Upper Cliff area, and enjoyed wet rock on the Great Chimney (climbing route).  We also spotted countless numbers of Spring Peepers (Pseudacris crucife) jumping away from our feet along Pawtuckaway’s amazing Boulder Trail (a true gem!).

Eastern newts have 3 distinct life stages.  The “Red Eft” stage is the most conspicuous, with its bright orange coloration and 10-12 well defined reddish spots.   The bright color serves to warn potential predators, and easily attracts the hiker’s eye.  They hatch in water (i.e., lakes, small ponds, backwaters, swamps, ditches, etc.) and have gills during their larval stage.  They venture away from their hatching grounds .

Larval Stage

The young  Eastern Newt larval stage emerge from eggs attached to submerged vegetation.  They are 8mm at birth, and after a period lasting around 50 days (late summer) they lose their gills and turn into the Red Eft.

Red Eft:

The Red Eft is the juvenile life stage.  The most notable differences are the absent gills, and the bright orange coloration with red spots outlined in black.  Some sources report that they turn more reddish brown as they mature.  Many field guides report that this Red Eft Stage lasts for 1-3 years, but current research studies reference this terrestrial woodland period lasting 3-7 years.

Adult Eastern Newt:

The adult (6.5-14cm)returns to live in water where it will breed and spend the rest of its days.  Adults of the Red Spotted subspecies are aquatic lunged adults, but other subspecies can skip the Eft Stage and become a gilled aquatic adult without metamorphosis (paedomorphsis). The  dorsal side (back)vis yellowish brown to olive-green to dark brown, and the ventral  side (underside) is yellow.  Adults have black spots on dorsal and ventral side.  The adult tail is shaped like a paddle with a prominent keel . Adults do not return to Eft Stage.

Visit our Eastern Newt Species Page to Learn More about the Eastern Newt’s Life History and  Current Research.

My New Friend – The Carolina Wren

My New Friend – The Carolina Wren

Thryothorus ludovicianus
Thryothorus ludovicianus

Recording Backyard Bird Songs

A picnic on the lawn with my 2 and 4 year-old  today was filled with sounds of backyard birds chirping, squawking, and calling, but there was one call in particular that gave me an idea.  “Hey kids, do you want to try to record that bird sound?”  I later discovered it was the song of the Carolina Wren.

In a few moments, the kids and I were lying on the picnic blanket plugging in a microphone and headphones into my laptop.  After, the initial disciplining to get the kids to stop tugging back and forth at the microphone and headphones, our recording adventure began….but wait….no bird calls anymore.

I was saddened to think that in the few minutes I had left to go inside, that the bird left too…but then I heard it again.  After playing with the audio device settings on the laptop, and trying to entertain the kids away from the microphone, I successfully recorded our first bird call.

Bird Behavior: Response to Hearing Their Song

The kids and I played it over and over again.  I told them they were biologists and ornithologists today – they were thrilled.  Then, the most amazing thing happened.  This little bird kept flying back and forth over our picnic blanket, sometimes coming within feet of us.  It flew from a tree branch to our shed, from our neighbors shed, to our rooftop, from another branch to our nearby lawn chair…stopping every now and then to repeat it’s song back to us.  Every time we played the song back to the little bird, it flew over us again, daring to fly closer and closer to us with each pass.  We were communicating somehow.

Species Identification: Carolina Wren Song

Later on that evening, thumbing through my favorite field guides, I discovered that my new friend was the Carolina Wren, a native bird to Connecticut, Rhode Island, and Southern Massachusetts that is expanding its range northwards.  Many sources claim that it is a shy bird that is more often heard than seen.  It’s true that I first heard the wren, but once I started playing back its tune, it was anything but shy – truly amazing.

Try at Home: Attracting Songbirds – The Carolina Wren Song

Try playing this bird call in your own backyard to see if any Carolina Wrens come to visit you.  I played it again the next day for my husband and without fail 2-3 Carolina Wrens came to visit us.  They flew back and forth always passing near to us and stopped to perch on nearby branches to sing us their song.  If this works for you, please leave a comment below to let us know.

Garden or Garter Snake?

Garden or Garter Snake?

Thamnophis sirtalis

Yes…I said it….”garden snake”.  I was one of those who thought Common Garter Snake Thamnophis sirtalisthat this species was called a garden snake when I was growing up before I knew better.  However, it seems most people that dislike all snakes in general wrongly misjudge the docile nature of this species; these same people call them “garden” or “gardener” snakes to further support the fact that they are misinformed about this beautiful snake.  Garter snakes should be revered as a garden protector since they almost exclusively eat bugs, which are more detrimental to ones valued flowers/plants.  This species is a perfect example of a biological control for insect nuisances in the garden. I, for one, get excited to find a garter snake making a home in my garden. However, one snake may not be enough to keep all insects at bay from destroying your prized summer gardens.

My grandmother was one such person that fiercely hated snakes, and insisted that the snake in her yard was a garden snake.  I of course asked what species?  She would then tell me to listen better since the species had already been disclosed as a “GARDEN” snake.  My grandmother also loved planting marigolds in her garden beds along the foundation of her cape-style summer cottage, and my grandfather admired her green thumb.  Therefore, he had to obey her orders to discard  any snake immediately upon discovery since she would refuse to return to her garden until the snake had been exiled. In the same breath, my grandmother would also curse the slugs that devoured her precious, softball-sized marigolds.  I tried explaining to her that she was creating an environment where the (also mutant-large) slugs could thrive: a garden filled with marigolds, which had no natural predators (i.e. garter snakes) to the slugs.  Instead, my grandmother spent a sizeable amount of money on salt for the slugs (not in a nice way).


This little common garter snake (pic above), approx. 18″ in length, was well camouflaged alongside Beech Mountain Trail, which is on the “quieter” side of Acadia National Park.  Garter Snakes are extremely common throughout New England and Atlantic Canada, and can often be found in residential gardens; hence the similar-sounding nickname (i.e. misnomer) “garden” snake.  I have also heard of people referring to  black racer snakes (also a very common type of non-venomous colubrid) as garden snakes as well; I suppose any snake found in a residential setting may be incorrectly referred to as a garden snake. Garter snakes vary in color (from black, brown, grey, and/or olive), and some darker phases may make distinguishing marks, such as (typical) three light stripes that run along the length of their body,  imperceptible.  Garter snakes range in size from approximately 1.5′ to 4′ at maturity.  These snakes are usually docile in nature, but be warned that they will protect themselves by releasing a putrid-smelling fluid from their postanal glands.

We were lucky to observe two garter snakes on the side of the Beech Mountain Trail (at Acadia National Park) slithering between the last few patches of snow during spring melt.  These snakes had just emerged from hibernation (most likely), and were trying to soak up the warmth of the sun.  They were still cold to the touch, and much slower in trying to evade our capture.  Snakes, like all reptiles, are endothermic; this means that they must absorb energy/heat from their surroundings.  Therefore, they will sun themselves in the heat of the day, and will retreat within stonewalls (or under rocks), which retain heat.


Goutweed (aka. Bishop’s Weed)

Aegopodium podagraria L.


Family: Carrot Family

Gout Weed Leaves 2

Goutweed invades coreopsis

Do not ever plant Goutweed Invades English IvyGoutweed intentionally.  I’ve read that some people like it as a ground cover…..not a good idea.

We’ve been fighting Goutweed in our garden for the last 6 years since we’ve moved in.  You can’t just pull it up, you have to carefully follow the rhizomes (underground stems) as you remove it, otherwise it will just pop right back up.

It is especially hard to remove around large boulders or other objects that it’s rhizomes can hide under.

You can see that it has grown right through some landscape fabric that we put down to help control weeds.  This fabric was in our garden for 3 years.  The benefit of pulling the landscape fabric out this year was that we pulled out a lot of goutweed with it.

goutweed runner length Goutweed runner through landscape fabric goutweed runners

Great Blue Heron

This Great Blue Heron was filmed and photographed on an après work canoe paddle at Jacob’s Pond in Norwell, MA. The Great Blue Heron has great size and stature at 4’ tall. I highly recommend this pond for anyone looking to see wildlife by canoe or kayak.

Despite the heron being so large, it easily takes off from the water and doesn’t seem to care that it’s 6’ wide wingspan is pushing though tree branches. They wait motionless on their stick-like legs in the water or slowly stalk their prey before they ambush them. They swallow their prey whole, rather that be fish, frogs, or even rodents. You may find that they show up at your backyard koi pond so beware..

There is no sexual dimorphism, meaning that the males and females look the same. Their backs and wings are a bluish-grey. Their neck is brownish-cream and has a scruffy appearance. Their face is white. They’ve got two black stripes above their eyes, and the middle of their crown is white.

This bird can be found around freshwater or brackish water habitats all over New England and into Atlantic Canada. The Great White Heron in Florida was thought to be a separate species, but it is now accepted that they are the same species with different coloration.

I hope that all of you can also add the Great Blue Heron to your own species list. Please visit and click on Blue Heron to add your own sightings to our range maps or tell us about them in our comment section. Check our other pages on species from around New England and Atlantic Canada.

Balsam Poplar Catkin (not a cocoon) on Balsam Fir

Balsam Poplar Catkin (not a cocoon) on Balsam Fir Tree

If you see these strange structures on a Balsam Fir tree, it may at first look like an insect cocoon or egg case, but the structure in the photo is of a Balsam Poplar catkin  (Populus balsamifera) that has fallen onto a Balsam Fir tree.   The part that looks like a fuzzy caterpillar is the catkin/flower of the Balsam Poplar tree and the Reddish-brown structure, that looks like a smaller version of a moth cocoon, is the bud scale.  These structures are adapted for wind dispersal and often land on trees together, making them look sometimes like they are physically connected to the tree.   The attachment is aided by a sticky substance the buds are covered with that smells like balsam — perhaps the source of the name.

These pictures were taken on Memorial Day weekend in Spruce-Fir Northern Hardwood Forest in Northeast Vermont.


unknown species on fir

unknown species on fir 2 unknown species on fir 3

Biodiversity Exposed