ORNITHOLOGY
FIELD NOTEBOOK - SPECIES ACCOUNTS
SUMMARIESReturn to Biology 444 Home Page
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ORNITHOLOGY
FIELD NOTEBOOK - SPECIES ACCOUNTS
SUMMARIES
Return to
Biology
444 Home Page
Return to Biology
Department Home Page
Hot links to ornithology-natural resources related web
sites
Author:
Vanessa J.
Smith
| White-faced Ibis | Great Horned Owl | Wood Duck | ||
| Eastern Bluebird | Crested Wood Partridge |
Species name:
Bufflehead
Total hours of
observation time for this species: 7
Bufflehead information
links:
1
2
3
Other bird species
present: Mallard, Wood Duck, Hooded Merganser, other unidentifiable
waterfowl
Summary of observations,
including hypotheses tested and data analyses:
I observed a pair of captive buffleheads at the Minnesota Zoo for a total of 6 hours (5 different observation times from March-April) and a pair of migrating wild buffleheads for 1 hour on April 11, 1998 near the Prescott Bridge in Minnesota. The captive pair lived in the beaver exhibit, which consisted of two small ponds (each about 200 square feet ). The wild pair were feeding in a pond that is 10 acres in size. The behaviors of the two pairs were quite different from each other.
During the six hours of observation of the captive pair of buffleheads, they were active for a total of 45 minutes (in half-hour and 15 minute segments). The pair was not alone in the pond; mergansers, mallards, and wood ducks were also present. When they were active, the buffleheads moved about the pond with quick, nervous movements and swam around the pond very fast (especially the female). They were acting as if intimidated by the mallards and wood ducks and tried to stay out of their way. Although the ducks were not fed on the bottom of the ponds, they still dove and swam near the bottom picking things off the pond floor. In fact, I never saw them feed (all the ducks in the beaver pond are fed bird pellets at 7:00am and 4:00pm every day). During the 5.25 hours when they were not active, both male and female remained in the same spot and slept or simply stood and looked around.
In sharp contrast, the wild pair of buffleheads were quite active during the hour I observed them. They were not alone in the pond; mergansers and mallards were also present, but they did not act nervous. During the entire hour I watched them, they fed from the bottom of the pond. After observing them for about five minutes, I constructed four hypotheses: 1) Buffleheads almost always dive simultaneously, 2) Zoo birds (specifically buffleheads) feed far less often than wild birds because food is so much more obtainable in captivity, 3) The female bufflehead stays under water longer than the male, and 4) The male bufflehead is dominant over the famale.
sex |
total # of dives | # of dives without other sex | total # of simultaneous dives |
male |
57 |
1 |
56 |
| female | 59 |
3 |
56 |
During the 1 hour observation of the wild buffleheads, 60 dives were observed. Of those 60 dives, 56 of them were simultaneous. Three of the non-simultaneous dives were done by the female (the male remained on the surface). The pair dove within approximately three feet of each other and surfaced within six feet. The female initiated the dive as often as the male, but the male was sometimes slower to follow her (sometimes waiting for up to five seconds before diving); the female dove almost always dove within one second when the male initiated the dive. There was no noticable pattern on who stayed down the longest (I was unable to time the dives for need of a stopwatch). Most of the dives were performed near the shore, and they surfaced close to where they went down. When on the surface, the female more frequently followed the male wherever he went.
Conclusions to be
drawn from the above observations:
Three of the four hypotheses are supported by the results. The number of simultaneous dives significantly outnumbers the unsimultaneous dives (93% were simultaneous). The male does appear to be slightly dominant over the female (remained on surface during three of the four unsimultaneous dives, followed the female down more slowly than she to him, and female tended to swim wherever the male swam). Although not enough time was spent watching the wild buffleheads to adequately provide sufficient data supporting the hypothesis that they need to feed much more often and for longer periods of time than captive buffleheads, a tentative assumption can be made that it is so (based on the amount of feeding time for the captive buffleheads). The dives of the female in contrast to the male did not seem significantly longer; more accurate data could be obtained with a stopwatch.
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SUMMARY OF SPECIES ACCOUNT #2
Species name:
White-Faced Ibis
Total hours of observation
time for this species: 2
White-faced Ibis
info links:
1 2
3
4
5
Other bird species
present: American Coot, Blue-winged Teal, Northern Shoveler,
Black-Necked Stilt, Great-tailed Grackle, merganser, Sanderling, Cattle Egret
Summary of observations,
including hypotheses tested and data analyses:
I observed two White-faced Ibis in Corpus Christi, Texas. The observations were done in early morning (7:00 - 9:00 a.m.) on March 20, 1998; the ibis were feeding in a flooded field. They both appeared a speckled brown color (like the above picture), which is their characteristic non-breeding plumage.
Before reaching the field, I decided to test the hypothesis that the ibis spend more time feeding in water than out of water. The numbers were quite contrary to what I expected.
| Time Feeding in Water | Time Feeding out of Water | |
| Ibis 1 | 10 minutes |
110 minutes |
| Ibis 2 | 5 minutes |
115 minutes |
They appeared to be eating seeds or insects from the ground, rather than the almost exclusive diet of aquatic invertibrates that they are known to consume.
The ibis were not disturbed by other birds species present (see above list), nor did they show any sort of aggression to the other birds. They were the largest bird in the flooded field, and it appeared fearless. At one point, a large group of Great-tailed Grackles approached the pond, making very loud and apparently aggressive vocalizations and swooping over the other birds. Many waterfowl cleared out of the area by running or flying (then came back later when the coast was clear), but the ibis stood their ground and continued to feed.
Conclusions to be
drawn from the above observations:
My hypothesis was not correct for this situation: the two White-faced Ibis fed mostly from the ground rather than by wading in the water. However, this observation did not represent other areas that the ibis feed - in this instance, the feeding area was a flooded field where no aquatic invertibrates are found. The ibis were forced to feed on insects on the ground because that was the only available food source at that particular area. More observations in a variety of ibis' feeding areas would be necessary to get more accurate results to support my hypothesis.
Species name:
Cattle Egret
Total hours of
observation time for this species: 2.5
Other bird species
present: American Coot, Blue-winged Teal, Northern Shoveler,
Black-Necked Stilt, Great-tailed Grackle, unknown species of merganser,
Sanderling, White-faced Ibis
Summary of observations,
including hypotheses tested and data analyses:
I observed the behavior of Cattle Egrets in Corpus Christi, Texas, on March 19th and 20th, 1998. The first observation was performed in a cattle pasture during mid-morning, from about 9:00-9:30 a.m. (I was unable to stay longer than that because a bull in the pasture was getting restless). The second observation was performed at the same location (a flooded field) and at the same time (early morning - 6:30-8:30 a.m.) as the White-faced Ibis. At that time, the egrets were in their breeding plumage.
On the morning of March 19th, I rode out in the pasture on the "Green Machine," a small John Deere ATV resembling a golf cart. When I approached a herd of cows, I observed six Cattle Egrets feeding around the herd. The egrets were less disturbed by my approach than the cattle were. During the half-hour I observed them, they continued to stay close to the cows and peck at the insects disturbed by the cow's movements. The egrets stayed apart from one another; they did not pair up or form a group at any time during my observation.
The following morning, I observed the egrets while I simultaneously observed the White-faced Ibis. The egrets were behaving as all gregarious species do - about 50 of them were together in this group. They were located on the same side of the flooded field as the White-faced Ibis, but were about 50 yards away from them. Unlike the ibis, the egrets stayed well away from water. When they flew in from a different location, they landed on the ground rather than in the water. During the two hours I observed them, I never saw them feed. As time went on, more and more flew off, probably to a nearby field to feed. Like the ibis, they were unafraid of the aggressive Great-tailed Grackle and did not fly away when harassed.
Conclusions to be
drawn from the above observations:
Cattle Egrets do not appear to be shy or easily frightened birds - they showed no fear of me or the machine I was on, nor did they yield to the overbearing grackles.
My observations indicate that Cattle Egrets feed mainly in fields where cattle or horses are present. Because I did not observe any feeding for the two hours near the flooded field, I assume egrets do not feed near their "home base," the place where they gather with other egrets to rest and socialize (mate, etc.). Of course, more time observing Cattle Egrets would be necessary to more strongly support that assumption.
Species name:
Great Horned Owl
Total hours of
observation time for this species: 1
Great Horned Owl
info links:
1
2
3
4
5
Other bird species
present: none apparent
Summary of observations,
including hypotheses tested and data analyses:
On April 23, 1998, fellow classmate Sarah Hollerich and I went to Willow River State Park near Hudson, Wisconsin to observe the reactions of the Great Horned Owl to a prerecorded Great Horned Owl vocalization. The tape was about 3 minutes in length, and was comprised of four identical vocalizations (it was redundant - the same 45-second call was dubbed four times). The location in which these observations took place was on a park trail next to Willow River. The river was surrounded on both sides by a hardwood forest.
We first played the owl vocalization within the woods, not directly on the river. There was no response. We traveled down the trail, stopped by the river, and again played the vocalization. Approximately two minutes after we began the tape, an owl swooped very closely over our heads, landed on a tree directly across the river, and screeched. It then began hooting and two distant owls began hooting as well. The first owl soon stopped, but the distant owls continued for about five minutes; the female hooted first, followed immediately by the male (the vocalization of the male is higher-pitched than the female). When they were quiet, the tape was played again. The two owls hooted for two minutes, much less enthusiastically than previously. The tape was played again, and they hooted for only thirty seconds. After the tape was played another time, there was no response. The tape was played at other locations along the trail, but there were no more responses.
Conclusions to be
drawn from the above observations:
The owls eventually figured out that the tape was not another Great Horned Owl invading their territory. This statement is supported by the behavior of the first owl: after it swooped down to see what or who was making the vocalization, it screeched, vocalized for only a couple of minutes, then probably flew away (we didn't hear any sounds from it, but it may have remained in the tree and watched us). It likely realized that humans were responsible for the owl vocalization, and thus did not need to worry about defending its territory from an invading owl. After hearing the taped vocalization a couple times, the two distant owls probably realized from the repetitiveness of the taped call that a real owl was not making that vocalization.
Because no response was heard when the tape was played in other locations
along the trail, I assumed that there are only a certain number of owls within
an area (territorial birds). The three we heard could possibly have
been the only three in the area - they knew we weren't an imposter owl, so
they did not continue their vocalizations.
Species name:
Wood Duck
Total hours of
observation time for this species: 6
Wood Duck info
links:
1
2
3
4
5
Other bird species
present: Mallard, Hooded Merganser, Bufflehead, Canada Goose
Summary of observations,
including hypotheses tested and data analyses:
I observed a pair of captive Wood Ducks between March 26 and April 23 , 1998, in the beaver exhibit at the Minnesota Zoo for a total of six hours (5 separate days). I simultaneously observed the behavior of captive Buffleheads; that account is given above. After observing the ducks for about 10 minutes, the following hypothesis was constructed: During breeding season, the male Wood Duck is very possessive of the female and will not venture further than six feet away from her 99% of the time. Attempts were made to observe pairs of Wood Ducks at Afton State Park and Twin Lakes to compare behaviors between wild and captive ducks, but none were sighted. Other observations were made of the Wood Ducks' behaviors in the presence of wild Mallards and a wild male Wood Duck.
The pair of captive Wood Ducks showed mating behavior (I saw the male mount the female 8 times) during the first three days I observed them (March 26, April 2, and April 9). The male was hardly ever more than six feet from the female, and he was most frequently within three feet of her. During the four hours I observed them during their apparent breeding time, the male was the female's shadow: he ate when she ate, slept when she slept, swam where she swam, preened when she preened, etc.
| # of times more than 6 feet
away from the female |
amount of time spent more than
6 feet away from the female |
amount of time spent within 6 feet of female |
4 |
1.1 minutes |
239 minutes |
The table shows that the male Wood Duck spent only about 1 minute from the female out of the four hours I observed them. This is less than 1 % of his time spent further than six feet away from the female! However, during the last two times I observed them (April 16 and April 23), they spent much more time apart. During those two hours of observation time, the female spent most of that time in the nest box and the male was no longer constantly by her side.
The wood ducks reacted to the presence of wild Mallards in two completely different ways: aggression and submission. In most of the situations, they were clearly dominant over the Mallards; in one situation, the female approached a solitary Mallard, quacking at him, and the Mallard flew completely out of the pond. However, in one instance, they were actually harrassed by two male Mallards. The male Mallards flew in to the pond with a single female Mallard - they appeared to be "bullys" from the beginning (they even harrassed the female they were with). The two males surrounded the female Wood Duck (for no apparent reason, other than to cause trouble). The male Wood Duck attempted to get to her, but one of the Mallards chased him away. The female Wood Duck was very submissive and did not show her usual agressive behavior towards the Mallards. When the Mallards lost interest, they swam away and the two Wood Ducks immediately rejoined.
On April 16, the presence of a wild male Wood Duck was noted in the beaver pond. During this observation, the female was in her nest box. The captive male was much plumper than the wild Wood Duck. The wild Wood Duck seemed more dominant than the captive one, even though he was in the captive Wood Duck's territory. The wild male swam toward the captive male on several occasions, and the captive male would look away from him and swim in the opposite direction. After about 10 minutes of swimming away from the wild male, the captive male climbed out of the water on to the rocks near where the Buffleheads and the female Hooded Mergansers were resting. He preened, then simply stood there while the wild male swam around the entire pond, clearly dominant. He even tolerated one of the female Hooded Mergansers quacking in his ear and biting his head, when usually he was the aggressive one of the pond and would not have put up with that! During the rest of that observation (a total of 1 hour), he never went back into the water.
Conclusions to be
drawn from the above observations:
My hypothesis was correct: during their breeding time, the male Wood Duck was within 6 feet of the female more than 99% of the time. Unfortunately, I was unable to locate wild pairs of Wood Ducks to compare and contrast their breeding behavior. The male may have been spending that much time near the female because he did not have to try to find food, defend his territory, or strive in other ways to survive like wild males do. Also, there was only one female available to him; it was predetermined who his mate was and, unlike wild males, he was forced to be with that certain female.
Although on most occasions the captive pair of Wood Ducks were the dominant birds of their territory, especially towards the other captive waterfowl present, they were submissive in other instances. Again, observations of wild Wood Duck interactions with other waterfowl would have been helpful in determining if the captive pair's behavior was normal.
Species name:
Eastern Bluebird
Total hours of
observation time for this species: 6 hours
Bluebird info
Links:
1
2
3
4
5
Other bird species
present: Northern Cardinal, Field Sparrow, Brown-headed Cowbird,
Red-winged Blackbird, American Crow, Eastern Phoebe, Black-capped Chickadee,
Wild Turkey, House Wren, Blue-gray Gnatcatcher, other unidentifiable species
Summary of observations,
including hypotheses tested and data analyses:
Although formerly on the Threatened Species list throughout its range, the Eastern Bluebird population has rebounded within the last decade. Even though their population has increased dramatically, they are still somewhat difficult to locate and observe. I observed them at Afton State Park, located near Afton , Minnesota, at two different times: April 11 and May 10, 1998. I also observed them at the Minnesota Zoo, located in Apple Valley, Minnesota, at two different times: April 23 and May 7.
My first observation, performed on April 11 in the restored prairie habitat of Afton State Park, was for only one hour. This was a hard time to try to observe the Eastern Bluebird - they were looking for potential nest sites, and did not remain in one place for long. A pair of bluebirds stayed in the vicinity of a pair of bluebird houses for about a half an hour; at one point, the male stood atop their preferred house and sang beautifully for about ten minutes. The female flew towards the male, and both flew off. They did not return within the thirty minutes I remained there.
The second observation occured along a cross-country ski trail (designated a bluebird trail during the spring and summer) at the Minnesota Zoo on April 23. A covolunteer and I walked the trail to check all the bluebird houses for possible nests. Of the 12 houses located along the trail, only two had bluebird nests. Two had Tree Swallow nests. The nests of the two species were quite different from each other: the Eastern Bluebird nest is more uniform in type and size, while the Tree Swallow nest has a variety of coarser grasses and is lined with feathers. Of the 7 locations of paired bluebird nest boxes, 6 were in typical bluebird habitat - grassy, open, and prairie-like. Interestingly, one of the bluebird nest boxes that contained a bluebird nest was located near a wetland, which was surrounded on three sides by a hardwood forest and one side by a highway. This apparently was a popular nesting site; bluebirds nested there frequently in past years. At both sites, the male bluebird swooped at us when we opened his nest box (not nearly as close to our heads at the Tree Swallows!).
On May 7th, we walked the bluebird trail again. Both of the nests now contained 5 small, blue eggs. In the first nest box checked, the female was on the nest. When the nest box was tapped gently, she flew out and perched on a barbed wire to watch. Neither the male nor the female bluebird swooped at us (they were probably getting used to human presence - their nest box was checked twice a week). The female was not present in the second nest box, but the male was nearby on a tree branch, watching. Like the first pair, he did not attempt to dive at us. Four of the nest boxes now contained Tree Swallow nests (only one had an egg in it). The Tree Swallows were still very aggressive, swooping and calling when we were near their boxes. Two of the nest boxes that were being used by the Tree Swallows were paired - within 20 feet of each other. This seemed very odd: usually, Tree Swallows only occupy one of a pair of nest boxes because they are territorial birds. This is not good for the Eastern Bluebird. In this case, the Tree Swallows are monopolizing both of a pair of nest boxes and leaving none for the bluebird!
I returned to Afton State Park on May 10, 1998. By this time, the bluebirds had found their preferred nest boxes and remained in the vicinity long enough to record their behavior. Their nest box contained five eggs. While I was checking their box, they both fluttered around above a tree nearby (obviously unhappy at my presence). They did not swoop at me. During the 1.5 hours I observed them, they did not sing their beautiful song that I heard during the last observation at Afton State Park. They (especially the male) had a low-toned warble, which they put forth when they landed on their nest box. Click here for their timed species observation account.
The last observation was, again, at the Minnesota Zoo, on May 14. Two nest boxes that were empty on May 7th now contained House Wren nests (constructed of twigs). We cleared those out of the boxes - bluebirds have a definate priority over House Wrens. Suprisingly, the bluebird eggs were hatched in both nest boxes being used: all five were hatched in the first box and three in the second box. They were very newly hatched; they could barely lift their head up! One was able to...he stretched his head up high above the rest with his beak wide-open (hoping for something to eat). The young birds had patches of blue down on their otherwise-naked skin. No sounds came from them. No eggshells were present in the nest. While we were looking in the nest boxes, the male and female bluebirds sat in a nearby tree and watched us. As mentioned above, they were getting used to human presence and made no attempt to defend their nest. There were no new Tree Swallow nests, and the Tree Swallow eggs were not hatched (six eggs were observed in one of the nest boxes).
Conclusions to be
drawn from the above observations:
From the above observations, the Eastern Bluebird seems much more timid and less aggressive than the Tree Swallow under similar conditions. After a few weeks of human presence, the bluebirds got used to humans and gave up trying to defend their nest - they probably realized no harm would come to it. Based on the Afton State Park observations, the bluebird seemed to only put forth his beautiful song when staking out his territory; once his stake on his nest box was established, he did not sing.
The bluebird eggs hatched much earlier than usual. The early hatching may have occured because of the early spring and the extremely warm weather during the two weeks prior to the hatching. The bluebirds at the Minnesota Zoo will probably hatch one or two more sets this summer because of the early start.
Since only the female was observed in the nest box, an assumption can be made that she performs most, if not all, of the incubation. The male was more defensive of territory than the female, and also more brave (did not fly away as readily upon human encounters). However, the Eastern Bluebird is no competition for the larger and more aggressive Tree Swallow, who manages to use most of the houses designated for the bluebirds. Yet, the populations of Eastern Bluebirds are rebounding, and there is no need to interfere with nature by removing Tree Swallow nests any longer.
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SUMMARY OF SPECIES ACCOUNT #7
Species name:
Mute Swan
Total hours of
observation time for this species: 2.5
Other bird species
present: Canada Goose, Mallard, Great Blue Heron, Red-winged Blackbird,
Trumpeter Swan
Summary of observations,
including hypotheses tested and data analyses:
I observed a pair of breeding swans on the St. Croix River from a fire tower located in Gordon, Wisconsin. Although Nothwestern Wisconsin is not in their typical breeding range, mute swans breed on this area of the flowage annually. Trumpeter Swans also breed in this area (I observed three of them), and local citizens dislike the Mute Swans because they are extremely territorial and prevent other Trumpeter Swans from nesting in this ideal habitat. I observed the pair of Mute Swans at two different times on May 2, 1998: 8:00 - 9:00 am and 6:30-8:30 pm.
Before observing the swans, I was aware of their agressive behavior towards other waterfowl, especially when defending their territory. I decided to test the hypothesis that mute swans would defend their territory from any and all waterfowl.
During the 2.5 hours of observation, the female remained on her nest and moved very little (even when Canada Geese flew only three feet overhead and landed in a pond within thirty feet). The male, however, was most frequently gracefully swimming and eating in the portion of the river that is closest to the nest. He very rarely remained still or left the water (for only a 15 minute period, he stood on a sandbar and preened). He was not disturbed by the presence of ducks (mallards) or by a single Canada Goose (Goose 1). Goose 1 remained perched on a rock; in close vicinity of the swan during the entire observation time. All other Canada Geese that landed or swam into the swan's (assumed) territory were chased out immediately by the male swan. I found this very interesting: why would he allow one goose to remain in his territory while he attempted to attack all other geese? He virtually ignored all the ducks, even when they boldly swam within 10 feet of him. At one point, a mallard was very close to where the female and the nest were located and a goose landed far away from the nest (approximately 400 feet); the male swan immediately swam past the mallard and toward the goose with his neck extended, hissing. The Canada Geese (the five that I observed) were aware of the domineering behavior of the Mute Swan, and in very short order got out of his way when being chased.
| bird species | # in Mute Swan Territory | # Chased away |
| Canada Goose | 6 |
5 |
| Mallard | 10 |
0 |
| Great Blue Heron | 1 |
0 |
| Red Winged Blackbird | 5 |
0 |
Another interesting behavior exhibited by the swan was performed while he was chasing a pair of Canada Geese (Goose 2 and 3). The geese split into a V and swam in different directions. The swan followed Goose 2; when the goose went up on ground and stopped only three feet from the edge, the swan swam up to the shore edge and stopped. He did not attempt to attack the goose, even though it was only three feet away! Instead, he turned around and began swimming toward the Goose 3. This goose did not climb ashore; instead, it swam and then flew to avoid contact with the swan. The swan swam after it until the Goose 3 was out of his territory, landed, then swam serenely around once more. When the Goose 3 flew back to where Goose 2 was located, both flew over the female swan, landed in a small pond within thirty feet of her, and remained there for more than 45 minutes. The male swan (and the female swan) never again attempted to remove those two from their territory.
Conclusions to be
drawn from the above observations:
My hypothesis was not proven to be correct: according to my observations, Mute Swans are not defensive against all waterfowl. They are aggressive towards Canada Geese, however; the possible reason being that Canada Geese are closer to the swans' ecological niche and may compete for food and nesting sites. In contrast, the mallards and other small waterfowl occupy a different ecological niche, and therefore provide little competition to the Mute Swan. Therefore, the swan does not feel threatened by mallards and virtually ignores them. However, the aforementioned assumptions do not explain why the male swan did not attempt to remove Goose 1. Possibly, he allowed a certain number of birds to occupy his territory as long as his food source and nesting site was not threatened, but discouraged any newcomers from settling in the vicinity.
Goose 1 was perched on a rock; and out of the water during my entire observation time. The fact that the male swan stopped his chase after the Goose 2 once it climbed on land, or after the pair of geese when they were close to his nest (in an inland water pocket), is intriguing. Judging from my observations, the male swan seemed to only be defending his water territory! Even though the pair of geese were a potential threat to his mate and his nest, the male swan made no move to go inland to remove the geese from the area. He possibly is territorial of only the water within his territory because he is defensive of his food source. That he did not attempt to defend his nest or his mate could be explained by the possibility that he did not see the geese land in the pond - the river and water pocket were separated by high grasses and reeds.
Species name:
Crested Wood Partridge
Total hours of
observation time for this species: 2.5 hours
Crested Wood Partrige
info links:
1
2
Other bird species
present: Red-billed Leiothrix, Dhyal Thrush, Yellow-cheeked Tit,
Gaudy Red-throated Barbet
Summary of observations,
including hypotheses tested and data analyses:
I observed the Crested Wood Partridge at the Minnesota Zoo on two separate days (April 16th and May 7th, 1998). This partridge is not native to North America; its habitat is the evergreen forests of Southeast Asia. A pair of Crested Wood Partridge is displayed within the aviary on the tropics exhibit at the zoo. Male and female display extreme sexual dimorphism: the male is irradescently blue with a bright red crown of feathers and a partly red beak (see picture above), while the female is a duller green (which allows her to become perfectly hidden within the undergrowth) with an all-black beak. Other birds within their exhibit are listed above.
On April 16th, I observed the pair of partridge and their three newly-hatched chicks. The male appeared to be dominant; most of the time I observed them, the female and the chicks followed him wherever he went. The chicks were brown, enabling them to blend in very well with the soil and rotten logs (lower right corner of above picture). The precocial chicks were not able to obtain their own food yet (I estimated their age to be less than three days old), but they were well able to run around after their parents. Although a ground feeder filled with food was available to them, the partridge preferred to pick at the ground for nourishment. Both parents picked food off the ground and fed it to their chicks in an approximately equal number of times. However, the chicks spend more time closer to the female. When the female was apparently ready to nap, all three chicks crawled under her (perfectly hidden). Click here for their timed species observation account.
On May 7th, I returned to their exhibit to observe the changes in behavior between the young chicks and their parents. The chicks were much larger, about half the size of their parents; also, their body shape more closely resembled that of their parents. They were still brown, but they now had white speckles on their body. The chicks were much more independent - they were able to feed on their own and they spent much more time away from their parents. Click here for their timed species observation account.
Conclusions to be
drawn from the above observations:
A conflict never arose between the Crested Wood Partridge and other species present within the aviary. The partridge is the only ground-dwelling bird, however; the other species of birds spend most of there time high in the treetops.
The female apparently was in charge of the nest. During the first observation, the chicks spent more time with the female than with the male; however, the second observation revealed an equal amount of time spent with both adults. This indicates that the female predominately cares for the young during the first couple weeks, but as the chicks become more independent, both adults equally care for the young.
In only three weeks, the chicks grew very fast and became much more independent of their parents. This is evolutionarily significant: species which produce fast-growing young have a higher rate of survival because less are lost to predators. Also, the chicks become independent in such a short amount of time, the adults are able to produce more families and sustain the numbers of the population.
Species name:
Canada Goose
Total hours of
observation time for this species: 5
Canada Goose
info links:
1
2
3
4
5
Other bird species
present: Mallard, Mute Swan, Red-winged Blackbird, Wood Duck, Great
Blue Heron, other bird species
Summary of observations,
including hypotheses tested and data analyses:
The Canada Goose is very abundant in the Minnesota-Wisconsin area, and they were present in almost every location I was observing other birds. I observed geese on Lake George in River Falls, but the observations were rather uneventful. To save time and server space, I will report on three observations in other areas.
On May 2, 1998, I observed them simultaneously with the Mute Swan (see above for Mute Swan Account) from the fire tower in Gordon, Wisconsin. Although mostly dominant in other situations I observed them, they were not dominant in the presence of Mute Swans! When a pair of geese landed in the territory of the pair of Mute Swans, the male Mute Swan immediately swam at them to remove them from his area. Interestingly, the constantly honking pair swam in different directions (a V-shape), as if to divert the swan's attention. When the swan went after one goose (Goose 1), the goose swam rapidly and when he reached the shore, climbed up and remained still. It seemed to know that the swan would not attempt to climb up to get at it. When the swan went after the second goose (Goose 2), it flew away with the swan hot on its tail. Shortly after the swan chased it out of his so-called water territory, it flew back to its mate (who then went back into the water). Both remained in the territorial water of the swan for about a minute, honking to each other. Goose 2 repeatedly thrust his neck up in the air, honking (it almost seemed as if they were conversing over the past incident!). When they saw the swan approaching again, they flew off to a water pocket near the female swan and remained there. A solitary Canada goose and another pair landed in the swan's territory, and they just as quickly flew away when they saw the Mute Swan approach.
The second observation was performed on the Northern Trail at the Minnesota Zoo on May 7, 1998. This trail is outdoors, and wild Canada Geese are very abundant along the entire trail. I observed the peaceful interaction between the many Canada Geese and a pair of captive Trumpeter Swans, as well as a pair of wild Wood Ducks. They were tolerant of the both species, even with goslings present. The geese are also approachable by humans, and a pair with goslings let me approach several times to within eight feet of them without showing any sign of aggression (even when the adults were outside the fence!). This was surprising - I thought they would be more defensive of their young.
The third and most memorable observation was also performed on the Northern Trail, on May 14, 1998. Unfortunately, in this instance, the single Canada Goose was in the Siberian Tiger exhibit. The tiger exhibit contains a small pond surrounded on three sides by walls and one side by land. The pond is so small that there probably wasn't enough room to take off into flight, so the Canada Goose was trapped there. The two young tigers in the exhibit practiced their hunting skills on this goose for more than three hours - fortunately for the goose, these tigers were well fed and only two years old, with absolutely no knowledge about how to hunt (except instinct). One tiger did most of the attacking. The goose came out of the water and stood on shore, preening (it seemed as if it was teasing the tiger); the tiger crouched low and slowly crept forward. The goose got back into the water and swam towards the opposite wall, honking continuously. The tiger pounced into the water and swam after the goose (sometimes he landed directly on top of where the goose was); the goose dove deep under the water (to avoid the claws right above it) and surfaced about ten seconds later at a distance of about ten feet from the tiger. The goose was obviously very frightened; he was noticably trembling every time he surfaced. The tiger swam after the goose (the tiger is a very fast swimmer) and when it would get close, the goose dove again. Sometimes, it flapped it wings, attempting to fly. Eventually, the tiger got tired and climbed out of the water and laid by the water. After awhile, the goose climbed out of the water again, and the cycle went on. This continued for the entire hour I observed them, and I heard from other volunteers and zoo visitors that it went on for at least two more hours. When I returned four hours later, the tigers had given up (the day was very hot) and the goose was still in the pond. A pair of Mallards landed, and the goose swam over to them, honking. The Mallards were indifferent, but the goose was insistant on carrying a one-sided conversation with them (as if glad to see other waterfowl). He eventually lost interest in the Mallards. When the tigers were out of sight, the Canada Goose climbed out of the water and slowly crept along the fence, as if looking for a way out. He remained trapped until after the zoo closed and the tigers were taken back into their cages; the zookeepers then came and removed the goose from the exhibit.
Conclusions to be
drawn from the above observations:
From the observations on the St. Croix River in Gordon, Wisconsin, I can assume that Canada Geese are most frequently submissive to the aggressiveness of the Mute Swan.
More than likely, the Canada Geese at the Minnesota Zoo are very tolerant of waterfowl because they are fed well. They do not need to defend a territory from other birds because of that fact; therefore, they do not show any aggressive behavior towards them. The geese are in the constant presence of humans, and usually humans do not attempt to harm them. They do not show aggression even in the presence of their goslings - this shows a very high tolerance of humans.
For the May 2nd incident, I believe the goose flew into the tiger exhibit pond, not knowing of its dangerous occupants. I can't come to a conclusion on why he continuously climbed out of the pond and preened. Perhaps he was in shock and wasn't thinking clearly; I would assume that a rationally-thinking bird would stay in the water, as far from the tigers as possible.
SUMMARY OF SPECIES ACCOUNT #10
Species name:
Mallard Duck
Total hours of
observation time for this species: 10
Other bird species
present: Canada Goose, Wood Duck, Bufflehead, Hooded Merganser,
Mute Swan, Blue-winged Teal, many other waterfowl
Summary of observations,
including hypotheses tested and data analyses:
Like the Canada Geese, Mallards are a very common waterfowl species throughout the United States. I observed them simultaneously with the Wood Duck, the Bufflehead, the Canada Goose, and the Mute Swan.
Much of the Mallard behavior towards the captive Wood Duck at the Minnesota Zoo can be read in the Wood Duck Species Account. Frequently, the capive pair of Wood Ducks were dominant over the wild Mallards. However, in one situation, two male Mallards harrassed the female captive Wood Duck (click here to read about this instance). These same two Mallards harrassed the single female Mallard who was with them. One of the males wanted to mate with the female, but she swam away. The male hopped on her anyway, bit her head and mated, then sat on top of her and quacked. The other male swam around the two while the mating occured and quacked.
On two other occasions in the beaver exhibit at the Minnesota Zoo, I observed two male Mallards and one female. In both instances, one male was more dominant than the other, and thus kept the other male from the female. On March 26, a pair of Mallards were displaying mating behavior. The pair faced each other and bobbed their heads up and down, about one time per minute. When the other male approached (several times), the dominant male chased it away. He then mounted the female for only a few seconds. The pair lost interest in mating, got out of the water, and preened. When they returned to the water, the other male repeatedly attempted to approach the pair; the dominant male kept him away from the female by swimming towards him. At one point, the less dominant male climbed onto the rocks and quacked continuously for about a minute; the dominant male climbed up the rocks, chased him, and bit his retrices.
Conclusions to be
drawn from the above observations:
The Wood Duck is dominant over the Mallard because the beaver pond is the Wood Duck's territory. As mentioned above, I was unable to observe the Wood Duck in the wild (except in the presence of Trumpeter Swans and Canada Geese), so I am unable to compare the behaviors of the interactions between wild Wood Ducks and Mallards. Because of the aggression the captive Wood Duck displayed to all other waterfowl, I assume that Mallards are submissive to them in the wild as well.
The actions of the less dominant Mallard toward the pair of Mallards was perplexing. Mallards seem to be social birds (they preen together, swim together, feed together, etc.); he may have been simply trying to be near others of his kind. The reason for quacking on the rocks could be that he was trying to draw attention to himself. Another possible reason for his behavior could be that he was simply jealous and tried to keep the dominant male away from the female.
Hot links
to ornithology/natural resources related web sites:
Cornell Lab of
Ornithology.
http://www.ornith.cornell.edu/
Waterfowl
Identification in the Central
Flyway. http://www.npwrc.usgs.gov/resource/tools/waterfwl/waterfwl.htm
The City
Naturalist - Guide to Animals.
http://www.nysite.com/nature/fauna.htm
"IV the
Birds" - Birds of the Imperial Valley.
http://www.imperial.cc.ca.us/birds/iv-birds.htm
North American
Bluebird Society.
http://www.cobleskill.edu/nabs/
Nature Notes.
http://www.ducks.ca/naturenotes/
Birding
on the Web.
http://www-stat.wharton.upenn.edu/~siler/birding.html
The National
Audubon Society.
http://www.audubon.org/
Peterson
Online.
http://www.petersononline.com/
Yahoo!
Corporation's List of Birding Sites.
http://www.yahoo.com/Recreation/Outdoors/Birding/
Electronic
Resources on Ornithology.
http://www.chebucto.ns.ca/Environment/NHR/bird.html
The O.W.L.
- Ornithological Web Library.
http://www.bright.net/~vfazio/the-owl.htm
