Friday, May 6, 2011

Screech Release; Whip-poor-will, Tundra Swan, and Osprey Admitted; Barred Owl Update, Science Night at Lincoln High; and Why is a Harris's Hawk Black?

Hello everyone,
We are still busy here, as always, and we have some exciting news! The Eastern Screech Owl that found herself inside an Antigo woman's home after tumbling down her chimney has been released! [You can see her whole story in the Feb. 11th blog.] The little owl mistook the fire place chimney for a tree cavity, a natural living site for screech owls, and wound up inside a living room. Eastern Screech Owls generally have a range that is south of Wausau, WI, how she made it to Antigo is a mystery. Because she came in during the winter, we wanted to give her the best possible chance at survival and waited until spring to release her. We also wanted to make sure that there wasn't any underlying issues that caused this owl to become trapped inside such an unlikely abode. After monitoring and examining her, we determined she was ready to go back into the wild.

Photo above: Our Education Coordinator, Molly McKay, had the honor of releasing the little darling. Here she is preparing to open the box and welcome the owl back to the world of freedom! May she never be inside a house again!

Photo above: As soon as she was released, she went right back to being a normal owl, she straightened out her body, stuck up her feather tufts, and squinted her eyes. Many owls use this pose as a way to blend into their surroundings, and if we were just walking through the forest, we may not have noticed her clinging to that tree.

We also admitted a new patient from Wausau, WI, a Whip-poor-will who flew inside the 3M plant and couldn't find her way out. She is hungry, confused, and dusty, but has no visible injuries. Our largest concern for her is that she smells of chemicals, a very plausible scenario after being trapped inside a manufacturing facility. We are giving her frequent baths with Dawn dish soap to wash away the chemicals.
These birds are fantastically interesting and are easily confused for Nighthawks, but are smaller and lacking the white wing patches of the Nighthawk. Feeding these birds [Nighthawks, Whip-poor-wills, Nightjars, Poorwills, and even Swifts] in captivity is very difficult because they have a specialized way of hunting. It looks as if she has a tiny beak, but in reality they have a huge cavernous mouth as wide as the distance between their eyes. They open this huge net of a mouth as they are flying in the dark to capture flying insects. The force of the insect flying into their mouth pushes it down their throat meaning that they don't need or have a swallowing reflex. Trying to feed a non-flying Whip-poor-will takes a lot of patience and dedication from our wonderful rehabilitation staff, Katie Farvour and Alberta Halfmann. They do excellent work!

Photo above: This Whip-poor-will was trapped inside a local factory and is being bathed frequently to clean her feathers of the harmful chemicals she is covered in. This Whip-poor-will is a female because she is lacking the white throat patch and tail spots of a male.

Yesterday was a busy day for the rehabilitation team with many new patients admitted. They received a call about a Tundra Swan who was left alone in a pond after the other swans she was migrating with continued on their way north. She has an injured wing so she couldn't fly away, but the problem was that she was in a pond and it required a couple boats and a few fast-running feet to catch her. More about this story in an upcoming blog, but what I'll say for now is that they were able to successfully capture her and bring her to safety.

Photo above: Steve Fisher, Marge Gibson, Alberta Halfmann, and Katie Farvour are relieved after successfully capturing the injured Tundra Swan.

Photo above: Back at the REGI facility, the injured Tundra Swan was very relieved to be with swans again after her family was forced to migrate without her. You can see her left wing is injured and hanging.

An Osprey was also admitted with a broken leg. It appears that he may have been caught in some sort of jaw trap meant for mammals. His prognosis is not great as the bone is broken very near a joint, typically resulting in a calcification of the joint and a lack of mobility.

Photo above: This Osprey was admitted with a broken left leg. You can see there are abrasions to both legs, likely from a jaw trap.

Photo above: The Osprey admitted last evening was found standing this morning. A good sign, but still not a recovery.

Several blog posts ago, we wrote about a couple of Barred Owls that were admitted suffering from starvation due to unfortunate weather conditions. I am pleased to announce that these owls are now eating completely solid foods and have been moved to an outside flight enclosure. While starving, their bodies began to absorb their muscles to make up for the lack of food. Now they must exercise their muscles and rebuild them in preparation of being released. That is good news for these beautiful owls!

Photo above: These two Barred Owls have been moved to an outside flight enclosure to rebuild the muscles lost during starvation.

The education team was invited to "Science Night" at Lincoln High School in Wisconsin Rapids and Steve Fisher and I were delighted to speak with the students and their families. It is so great that schools in the area include presentations like ours into their science activities, and it is an honor to be able to teach people about our magnificent raptors.

Photo above: Education Director, Steve Fisher, and Eastern Screech Owl, Wookie, teach the attendees of "Science Night" about the strong raptor in a tiny package.

We brought our Harris's Hawk to the program to teach people about a new species. Harris's hawks are desert dwellers and have many adaptations that allow them to live in such harsh climates. After the program, one bright young woman asked me, "If Harris's Hawks live in the desert where it is so hot, why are they black instead of a lighter color?" Wow, I never really thought about it. It would make sense for a desert species to be a lighter color so they could stay cooler in the searing midday sun. I didn't have a good answer for her so I went home and did a whole bunch of research. What I found was quite surprising, so I hope this blog post finds its way to her.

Photo above: Gypsy, our educational Harris's Hawk shows off her beautiful dark plumage.

I found a journal article that covered the topic very well. Here is the citation if you want to look it up yourself. [Ward J.M., J.D. Blount, G.D. Ruxton & D.C. Houston 2002. The adaptive
significance of dark plumage for birds in desert environments. Ardea 90(2):311-323.] They found that many avian desert species have dark colored feathers and there are a number of reasons why biologists think this has developed. First of all, the pigment in dark feathers is melanin, the same pigment that determines the color of human skin. Melanin is a strong pigment and that makes the keratin the feathers are made of stronger as a result. It is likely that these stronger feathers stand up to the inhospitableness of the desert; thorny cactuses and blowing sand. Another possible function is resistance to damage from UV-rays. Similarly seen in our species early in human evolution, people living closest to the equator developed darker skin with more melanin which helped to protect them from damaging UV-rays. After thinking about it that way, it makes a lot of sense for desert dwelling birds to have darker plumage richer in melanin. A final "simpler" explanation is visibility. The coloration in the desert is usually pretty light; tan sand, green cactuses, etc. If a bird has dark colors, like the Harris's Hawk does, it is easier for other members of the species to spot them on the landscape. Harris's Hawks are social birds and live in family groups where communication is important. These explanations all make a lot of sense to me and I am grateful for that young woman who challenged me to think about these magnificent birds in another way.

Thanks everyone!

Karissa Mohr
Wildlife Educator

No comments:

Post a Comment