Thursday, November 30, 2017

Noxubee from New Angles

I’ve written before about the fascinating place that is Sam D. Hamilton Noxubee National Wildlife Refuge.  The two afternoons that my family and I spent there this November definitely attest to the refuge’s uniqueness.  Our first excursion this month occurred on the 4th.  The daytime temperature was in the mid-70s, so it was hardly surprising that we saw three alligators almost right off the bat.  Being ectothermic, these reptiles can’t internally regulate their body temperatures, and instead rely on the external environment for heating and cooling.  The first two gators of our day were in the shallows of Bluff Lake, basking in the afternoon sun.
Large alligator
Larger alligator!
This smaller alligator, which was basking in the spillway, looked like a silvery bit of debris or a half-submerged log in the calm, murky water.
I like how the cypress foliage in this photo reflects on the water's surface, adding rusty hues to the muddy green.
A quarter-sized (including the leg span) orb-weaver spider seemed to float in midair as it built its web between a road sign and some nearby vegetation.
Great Blue Herons and a couple of Great Egrets foraged in Bluff Lake.  Hopefully, they were wary of the alligators!
It was nearly dark by the time we arrived at Goose Overlook, an observation platform over part of Bluff Lake, but there was still light enough for us to watch a very large cottonmouth wind its way through the shallow water.  Unlike the nonvenomous water snakes, which swim with their bodies submerged and their heads sticking out of the water, cottonmouths swim with their bodies parallel to the water’s surface.
In addition to the various chirps and chips of forest and marsh songbirds and the barking of the Canada Geese that were settling in for the night, we heard the sonorous Hoo hoo hoo hooooo hoo of two Great Horned Owls.  Visitors are not allowed to be on the refuge trails after dark, so we made the most we could of the waning daylight before packing up and heading out.  Only a few minutes before we left, I attempted a Barred Owl impression (Who cooks for you?  Who cooks for YOU-all?) and was delighted when a real one called from deep in the swampy woods.  Had the owl really responded to my noise, or was it just coincidence?  I suspect the latter, but it was nevertheless a fun incident.  Remember the Barred Owl—it will be significant later on.
Goose Overlook, November 4
Here is a picture of Goose Overlook on a different date: November 22.  Obviously, it was a different time of day, as well, and the forest birds—including Red-bellied Woodpeckers, Northern Cardinals, Carolina Chickadees, and Golden-crowned Kinglets—chattered away much more noisily.
One of my sisters drew my attention to a Wilson’s Snipe feeding in the mud.  This chunky shorebird is commonly found in marshy areas during the winter in Mississippi.
There were other good birding spots on this day at Noxubee, including Cypress Cove, where we saw a Belted Kingfisher.  The rust-red band across the belly marked this one as a female.  The male lacks the reddish band, but, like the female, it has the blue chest band.  True to their name, kingfishers are master hunters, diving into lakes and ponds to catch fish with their spear-like bills.
An American Kestrel darted up to the top of a cypress snag at the Cove.  This was a male kestrel, as you can tell from the slate-blue wings and the prominent dark bar near the end of the tail.  Kestrels tend to bob their tails when perched, and that is exactly what this bird was doing.  I noticed that most of the songbirds in the area became very quiet when this small falcon made its appearance.  Kestrels feed primarily on small birds, rodents, and insects.
We greatly enjoyed our visit.  As we headed out of the refuge at about 4:00 p.m., a Barred Owl flew in front of our van and landed in an oak tree on the side of the road.  Wow!  This was even more interesting than the aural encounter with an owl of the same species during the last visit.  The owl seemed nonchalant about our presence, sitting still and allowing us to take several photographs.  Eventually, we had to leave, but our afternoon could not have ended on a better note.  Of course, days like this are the normal state of things at the fascinating Noxubee NWR.

Monday, October 30, 2017

Sharp-shinned and Cooper's Hawks


It’s a good thing that we birders are not songbirds ourselves.  If we were, the great admiration that we have for hawks, eagles and falcons would be replaced by feelings of fear and dread at the smallest glimpse of one of these magnificently fierce predators.  And no other raptors strike fear in songbirds so much as the accipiters, a family of long-tailed, agile, mostly bird-eating hawks of which there are three species in North America.

In the southeastern parts of the United States, most of us have the chance to see at least two of the three accipiter species found in North America—the common and widespread Sharp-shinned and Cooper’s Hawks.  The larger Northern Goshawk strays only rarely into Mississippi.  It is typically an elusive bird of dense, mostly coniferous northern woods.  The unique plumage that the adult goshawk has makes it unlikely to be confused with its more common cousins.  However, the two smaller hawks are very similar in appearance.

In fact, these agile little hawks can look so frustratingly alike, especially in flight, that in making a call oftentimes the bewildered birder can only be certain that he/she has seen an accipiter.  An estimate of the bird’s size isn’t always of much help, either, because of the near overlap in the range of body lengths of Sharp-shinned and Cooper’s Hawks.  There is, of course, the difference between the species’ long tails: the Cooper’s Hawk’s is rounded; the Sharp-shinned’s is squared.  Sometimes this feature isn’t very noticeable or obvious, though, and that’s when knowing the differences in body shape between the two birds comes in handy.

Perched, a Sharp-shinned Hawk usually sits in a more upright position than the Cooper’s.  Its chest is proportionately wider and its hips narrower than its larger relatives.  It’s almost as if the little “Sharpie” has to make up for its diminutive size by adopting this straight, proud posture.  Another way you can tell the smaller species from the larger is by noting the leg thickness.  Sharp-shinned Hawks have very thin legs, a trait noticeable in even the large female birds that resemble Cooper’s Hawks.  Head patterning is a little different, too; the Sharp-shinned has a more extensive black cap than the Cooper’s, and on a brownish-colored immature bird the presence of a reddish cast to the head feathers indicates Cooper’s.

The proportionately long neck of the Cooper's Hawk is a useful feature in separating the species from the Sharp-shinned, especially when the birds are in flight.  Flight pattern can also be used as an identification tool, and the more experience you have with observing flying accipiters, the easier it becomes to distinguish the two species.  The Sharp-shinned Hawk has faster, more erratic wingbeats when compared to the Cooper’s Hawk, whose wingbeats are easier to count.

In my experience, it certainly isn’t easy to count feeding songbirds when a hawk decides to show up and check out the menu!  But then I guess we’d be ready to leave, too, if we  were those birds—or for that matter, if we were lizards, frogs, mice, rats, or insects.  All of these creatures are consumed by Sharp-shinned and Cooper’s Hawks, although to a lesser degree than birds.

Both the Sharp-shinned and Cooper’s Hawks declined perilously in numbers from DDT poisoning after World War II and were seen infrequently in Mississippi.  After the ban on DDT in 1972, their numbers steadily increased, and now they can be found commonly in the fall, winter and spring.  Cooper’s Hawks used to be fairly numerous and widespread as breeding residents in the state, but they are now scarce nesters in the summer months.

Part of the supposed scarcity could be from the fact that the hawks’ nests are tricky to find.  In mixed forest where the Cooper’s Hawk nests, it’s difficult to see through all the leaves that conceal the tree branches.  If you were to discover a Cooper’s Hawk’s nest, it would be a platform of sticks and twigs on a branch near the trunk of a deciduous tree.  The male hawk constructs the nest with some help from the female.  The brown-spotted eggs are incubated for 32-36 days, mostly by the female.  The resulting young hawks can fly after 27-34 days but are still dependent on their parents for over a month after that.

I said that the Cooper’s Hawks build their own nests, but there are always exceptions in the avian world.  Occasionally, these hawks will take the easy road and use an old crow’s nest.  Stranger still, a few nests have even been built on the ground.

I hope this article will help you appreciate the Sharp-shinned and Cooper’s Hawks even more, whether you see them darting through a dense forest, gliding high over fields or even stealthily hunting near your backyard feeders.  Just be very thankful that you’re not a little songbird!

Sources:

Birds of Mississippi.  Turcotte, William H., and Watts, David L.  University Press of Mississippi, Jackson.  Mississippi Department of Wildlife, Fisheries and Parks.  1999.

The Cornell Lab of Ornithology’s Guide to Birds of North America, version 3.  2001.

Field Guide to the Birds of North America, Third Edition.  National Geographic Society, 1145 17th Street N.W., Washington, DC.  1999.

Hawks, Owls, and Wildlife.  Craighead, John J., and Craighead, Frank C.  Wildlife Management Institute.  1956.


 

Friday, September 29, 2017

September Swimmers and Waders

Wood Stork at Bluff Lake
Don’t be fooled by the wide open mouth—the Wood Stork (Mycteria americana) perched in the cypress tree in the photo (taken early this month at Sam D. Hamilton Noxubee National Wildlife Refuge) was simply cooling off, not making noise.  But why was it here to begin with?  Wood Storks don’t nest at this wildlife refuge, but, during the summer and early fall, they disperse northward from their breeding grounds in Mexico, South Carolina, Florida, and Georgia.  Flocks are seen regularly in Mississippi during this time.  In fact, a few days after I photographed this perched stork, I saw a flock of twelve soaring over MSU’s campus.  
Wood Stork flock over MSU
It’s a little hard to see detail in this photo, but the outstretched necks of the storks are evident.  Herons and egrets usually fold their necks in when they fly.  The ungainly appearance of Wood Storks belies their grace in the air.  You really have to see a flock in action to appreciate it.  These particular individuals circled around several times, which made me think that they might have been checking out a small pond on campus.  They never landed, though. 
 
Great Egret at Bluff Lake
Storks nest very early in the year—late winter to spring.  Herons and egrets generally nest much later, so in August and September, the juveniles are busy maturing and preparing to disperse or migrate.  Some species, such as the Great Egret (Ardea alba) will usually remain in an area like Noxubee NWR year-round, but others, like the Snowy Egret (Egretta thula), Cattle Egret (Bubulcus ibis), and Little Blue Heron (Egretta caerulea), typically migrate farther south for the winter.
White Ibises at Bluff Lake (didn't get the memo to not wear white after Labor Day)
Like Wood Storks, White Ibises (Eudocimus albus) fly with their necks extended.  Their snowy plumage and decurved bills make them look somewhat similar to Wood Storks, but they are not in the same taxonomic family.  They often nest with herons and egrets in rookeries.  The ibises in the photo were also seen at Noxubee NWR, where they foraged methodically for invertebrates in the mud and weeds of Bluff Lake.  They must have been at it for a while; their necks were covered in mud. 
Common Gallinule at Loakfoma Lake

Just as a reminder that not all lakeshore or wading birds are as ectomorphic as the egrets, herons, storks, and ibises, here’s a Common Gallinule (Gallinula galeata).  It’s a stocky, chicken-like little bird, closely related to the much more secretive rails.  Its incredibly long, yellow legs and toes provide an important clue to its behavior.  Along with the flashier Purple Gallinule (Porphyrio martinicus), it spends most of its time walking over emergent vegetation (and swimming between the vegetation clusters), and the long toes help to spread the bird’s weight out over the surface area of the leaves.
 
Finally, a video showing a Purple Gallinule in action!  This was taken a couple of years ago at Noxubee NWR, but it seemed like an appropriate way to conclude this discussion.  Remember to keep your eyes peeled for interesting wildlife.