Date: Wed, 2 May 2001 22:33:39 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Tim Ray Subject: April nesting observations MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1 I have long dreamed of spending most of April & May outside witnessing the miracles of spring (especially the nesting of birds). This past month, I partially realized that dream. For those who might be interested, here is a summary of my observations of the nesting habits of birds. In his great book =93On Watching Birds=94, Lawrence Kilham talks about the advantages of observing whichever birds are handy. I adopted his strategy, spending much of my free time walking around my neighborhood and watching the local birds. I live in the Longfellow area of Columbia (Maryland), where a fairly mature forest was left standing between the streets and along the stream. Some of my time was spent in other places (so as to observe habitats that are not available around my house). Dr. Kilham also writes about the joy of discovering things for himself (even if the =93discovery=94= has already been made by other people); after my experiences this past month, I agree. <<>> It=92s easy to find nests while they are being built. However, the nest- building stage may not last very long (e.g. a few days). After the nest is built, some species stay away from it for a while. I have noticed this in cardinals and chickadees. Perhaps copulation follows nest-building (it wouldn=92t make sense to produce eggs before a nest is ready). Perhaps it gives the female time to fatten up. It may make also sense for hole-nesters to complete a nest before it is needed, so that a replacement nest hole may be made/found in the event that another bird takes over the original hole. In some species, the male make frequent visits to the nest to feed the female while she incubates the eggs. This can be another easy time to find a nest. I found this particularly helpful for finding white-breasted nuthatch nests (they are typically in an old knothole). I followed many pairs of nuthatches around during March and early April without once finding a nest. When the nuthatches began incubation (second week of April), I quickly found several nests. From previous years, I know that another time when a nest is easier to find is when there are young in the nest (and the parents are making frequent visits to bring food). Interestingly, many birds make soft calls when flying to the nest. For example, female cardinals often make soft chips. The bird moves stealthily yet advertises with its chips. Nuthatches are another good example. When the male is bringing food to his mate on the nest, he usually makes a soft "ank" call as he arrives. I have found that many birds fly to the nest in stages when building their nests. Most birds fly directly from the nest to the supply of nest materials, then fly back in short hops. So, when a bird with nest material flies to a shrub, keep watching -- it may make several more short flights before it reaches the nest. However, most birds do not change direction during these hops. If I lose track of the bird, I look roughly straight out from the last place I saw it. Streambanks are popular with birds when nest-building. They collect wet brown leaves or fresh moss to use in their nests. Tent caterpillar silk is also popular as nest material (tent caterpillars live inside white silk nests that they build in the forks of cherry trees). It is especially popular with blue-gray gnatcatchers; they use it to glue their nest to the tree it is built in. Certain species usually build their nests before other species start theirs. For example, cardinals typically build their nests before the titmice. I suspect that there is a sequence to nesting that is somewhat similar to other sequences in nature (examples: the blooming times of different plant species, the arrival dates of different migratory bird species). Generally, year-round residents get a head start on migrants; many of the residents have their nests built before most migrants arrive. Nests that are clearly visible when first built often become well-hidden a short time later when the trees leaf out. A house that provides many bird feeders may attract many nesting birds. Food from the feeders is used in mate-feeding (both during courtship and when the female is on the nest). One house near my local stream has many feeders, and nearby nests of carolina wrens, titmice, nuthatches, chickadees, cardinals, and blue jays. 4-way forks near the very top of young red maples are popular nesting sites. The tree must be about 10-25' tall so that the volume at the base of the fork is the right size for a nest. Multiflora rose shrubs are popular with birds -- they like to build nests on the horizontal portion of an arching limb. Hole-nesters will look over potential nest sites long before they decide on a site. For example, titmice looked over one of my nest boxes in late February (and again during March); the first nest-building I saw was on April 20th. By watching the behavior of a species at a known nest site, I was able to clue in on behavior that helped locate other nest sites for that species. For example, while monitoring a white-breasted nuthatch nest in a box in my neighbor=92s back yard, I =93discovered=94 that the male makes frequent visi= ts to the nest to feed the female during incubation. With this clue, I quickly found some other nuthatch nests in my neighborhood. <<>> There are quite a few blue jay nests in my neighborhood, and I found the jays to be quite interesting to observe. They build a =93dummy=94 nest befo= re building the =93real=94 nest. A good clue to finding the dummy nest is to h= ear a =93wheedle-deedle=94 call followed by the snap of a small twig off a tree.= The bird will carry the twig to the dummy nest. Another good clue to nest- building activity is to see a pair of jays quietly playing =93leap frog=94 w= ith lilting flights within the forest. First one jay flies a short distance and lands; then its mate flies a short distance past it and lands; then the first bird flies a short distance past its mate=85 They do this in a stealthy manner; and it is that stealthy manner which I eventually learned to recognize. In addition, they seem to like sturdy 3-way and 4-way forks in trees. My theory is that these forks are easy places for starting a nest =96 I watched jays try to start nests in 2-way forks and most of the early twigs fell off. I have been amazed by the variety of calls that the blue jays have made this spring. In particular, they have a deep rumbling call that I found accompanied by head-bobbing (it seemed to be used during territorial disputes). Interestingly, despite all their stealth, one pair built their =93final=94 nest under a deck during a week in which workman wer= e present every day. <<>> A flicker flew directly to an active nuthatch nest-hole and perched at the entrance. It looked in (carefully) and then made soft =93wik wik=94 calls. The female nuthatch (inside the hole; presumably incubating eggs) made non- stop =93ank ank=94 calls. A minute later, the male nuthatch flew in and perched above the flicker. He =93danced=94 nervously, but was quiet and did= not attack the flicker. (when I looked back up after resting my neck for a second, the flicker was flying away). Titmice built their nest in an old metal bucket hanging from the outside wall of a shed. One bird brought all the nest material to the bucket; its mate flew with it, but neither carried material nor visited the bucket. On one visit, I saw the =93female=94 fly to the bucket but immediately fly on t= o cover =96 a hawk was flying low over the area. I think I heard its mate giv= e an alarm call just prior to it taking cover. Tim Ray Columbia MD tray160@home.com 410-715-0623 ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================