Blue-crowned Motmot (Momotus momota)
SSP Manager: Kevin Graham - Disney's Animal Kingdom
Taxonomy
Characteristics shared between motmots and other members of the Coraciiformes order include small feet relative to body mass, syndactyl toes, cavity nesting (typically in cliffs, banks, rock crevices, or trees), and a primarily carnivorous nature. With a wide geographic range and differing habitat usage, the Blue-crowned Motmots have been classified into 20 distinct subspecies.
Some of these subspecies are geographically isolated and display significant morphological differences. These few subspecies may eventually be considered at a future time for individual species status. An example of this possibility would be Momotus momota bahamensis found only on the islands of Trinidad and Tobago. Due to an apparent inability of motmots to cross large waterways in flight, these two populations have been genetically isolated from each other and the remaining 19 subspecies for approximately 11,000 years. Closer examination of the DNA fingerprint of the island species may show differences from the mainland population (del Hoya; 2001).
Another example of a subspecies that may eventually qualify for species level would be Momotus momota lessonii, ranging from southern Mexico to Panama. Although the geographic range potentially overlaps with several other subspecies, M.m. lessonii varies morphologically and vocally from other forms found on the opposite side of the Andes Mountain range significant enough to classify them as a distinct species (del Hoya; 2001).
The Motmotidae appear to originate as an Old World family, primarily relating to a fossil record of Protornis glarniensis, found in Switzerland. The recovery in Florida of a yet to be named fossil motmot from the late Miocene period that is physiologically and morphologically similar to the living motmots of today changed theories on the appearance of motmots in the New World. The connection between this fossil and the current living population of motmots can be found in the proximal end of the humerus, which is distinctive in the Momotidae and differentiates them from the remainder of the Coraciiformes (Feduccia, 1996).
The study of this fossil dates the appearance of motmots in North America as significantly prior to any fossil records encountered in Central or South America. This indicates that the origin of the Momotidae in the New World was not of South or Central American origin as was once considered. Instead, it is believed that motmots spread from North America into Central America initially, and then into South America with the opening of the Central American Land Bridge. Motmots then became restricted geographically from North America due to inter-specific competition and climatic change (Feduccia, 1996).
Description
Blue-crowned Motmots are attractive birds with a similar color pattern to that found in all ten Momotidae species found over a wide geographic range. This pattern includes bright colors on the tail, face, and to a lesser extent the wings. Similar arrangement of patterns and colors exist on the heads of most species, with bright blue markings heightened by black contrasts. An apostrophe-like black marking surrounded in some subspecies by a turquoise border is found on the chest of most species. Body coloring is varying shades of olive, light blue, rust,and brown. Blue-crowned Motmots typically undergo a postnuptial molt, occurring anywhere from July through October. All subspecies are primarily monomorphic, with the males typically being slightly larger in body size and tail length. Physical characteristics cannot be reliably used to determine sex.
The legs of Blue-crowned Motmots are characterized by short tarsi and a syndactyl foot, which is distinguished by a single rear facing toe, and a middle toe almost completely joined to the inner toe. Blue-crowned Motmots, like many cavity nesters and insectivores, have well developed tactile rictal bristles which appear to originate from contour feathers. The rictal bristles have a stiff rachis (shaft) and only have barbs near the base. It is likely that the rictal bristles serve primarily as a sensory device for use in the tunnel system and nesting chamber, but they may also assist in filtering dust and dirt particles from the nares. Adult birds possess a red iris, juveniles possess a dark brown iris. All Motmots have shared characteristics including the possession of a beak that is short, down-curved slightly, and heavily serrated along the edges of the upper and lower mandible running the entire length of the beak. All representatives of the family Momotidae have short, rounded wings which are not well suited for long flights.
The most striking physical characteristic of Blue-crowned Motmots is their spatulate shaped, racqueted tail, which is formed by the loss of barbs on the two long, upper central tail feathers. The center retrices after molt are feathered throughout the length, only becoming spatulate after the natural loss of the barbs. At one time it was thought that the racqueted tail feathers were a result of the birds themselves removing the feathers, but it has been since found that the barbs are loosely attached at that region of the retrix and detach from the feather shaft on their own. Members of the genus Momotus are the only representatives of the family Momotidae that possess 12 retrices, all other members of the family possess 10. The center retrices in males tend to be slightly longer than those in the females.
The fledged young resemble the adults, but the crown is greenish-blue with indistinct borders, the mask is sooty black and smaller than that of adults. The fledglings also do not possess the distinct breast spot or tail racquets of adults and have a dark brown iris as opposed to the red iris found in adult birds.
Blue-crowned Motmots, depending on the subspecies involved, have a body length ranging from 17-20" (43-50cm), including the tail length. Depending on the subspecies involved, the normal body weight range for Blue-crowned Motmots can vary from as little as 77 grams to as much as 175 grams. The largest subspecies are those found in the tropical lowlands east of Andes, the smallest subspecies being found in the peripheral parts of the range.
Status
At this time the wild status of Blue-crowned Motmots is not listed as threatened or endangered, in fact Blue-crowned Motmots are common throughout much of their native range. Due to a wide geographic range, tolerance of intrusion by man, and numerous protected areas comprising habitat Blue-crowned Motmots as a species should continue to thrive.
Range
Ten species, forty-seven taxa, and six genera of Motmots are found in Mexico, the majority of South America (with the exception of Chile and Uruguay), andmost of Argentina. Blue-crowned Motmots inhabit a wide geographic range, including Bolivia, Paraguay, Argentina, Brazil, Colombia, Ecuador, Peru, Mexico, Trinidad, and Tobago. Throughout this range, Blue-crowned Motmots are divided into twenty currently recognized subspecies, but captive management in the population management plan will occur strictly at the species level.
Habitat
Blue-crowned motmots occupy a variety of habitats, including tropical evergreen and deciduous forests, coastal forests, mountainous forests, and secondary vegetation. They live on the edges of rainforest, secondary growth forests, and plantations. They range to altitudes up to 4,300 feet (1,300 meters), living near water for drinking and bathing.
Vocalizations
Motmots typically do not vocalize frequently, with the exception of during breeding season. They are most vocal during the hours just prior to dawn and at dusk. During this time, a variety of vocalizations can be used for territory settlement, advertisement, courtship, pair bonding, and maintenance of boundaries. The advertisement call by the male is a low frequency double note represented as "hoot-hoot". This call can occasionally be extended to a series of up to eight notes. The female generally will respond to this advertisement call with a single note response represented as "hoot".
Another commonly heard vocalization is used during feeding to assemble small family based forage groups. This call is a loud clucking sound similar to "kla-kla-kla-kla". This vocalization is variable in intensity and can last from two to five minutes in length.
During aggressive interactions or territorial defense, the vocalization may include a hoarse, dry, coughing bark. This may be repeated in a long series of chattering.
The parents, upon entering the nest tunnels to feed, will utter soft vocalizations along with feather ruffling sounds. The chicks will respond to these calls with begging vocalizations. Initially the young in the nest tunnel system are quiet, but as they grow their vocalizations increase in strength and duration. After about 10 days of age, the young birds can be heard vocalizing from a distance thirty to fifty meters from the nest entrance. (Orejuela, 1975).
Reproduction
Nest tunnels are generally dug during the rainy season when the soil is soft, which over the geographic distribution ranges from August to October. Blue-crowned Motmots generally prefer to excavate their tunnels into the sides of cliffs or into horizontal ground, but will use rock crevices on occasion if suitable nesting sites do not exist within the territory. Both the male and female share relatively equally in the digging tasks. The excavation of the nest tunnel system and the terminal nesting chamber can take as long as 2 ½ months to complete. The timing of the work is focused primarily on the late morning until the late afternoon when the soil is typically the driest. It is not unusual for the motmots to begin and abandon several nest tunnels before settling on one particular area.
With the intrusion of man-made structures into the habitat of Blue-crowned Motmots has come the introduction of new nesting opportunities in the way of roadside berms, banks, and cliffs. In some areas this intrusion has allowed the motmots to attain a higher population density then was previously possible in pristine habitat.
The excavation efforts will result in a long, winding burrow typically measuring at least 5 feet in length, but ranging up to 14 feet in length and 3-4 inches in diameter, with the unlined terminal nesting chamber measuring approximately 10 inches high, 10 inches in width, and 14 inches in length. The winding nature of the tunnel system aids in the avoidance of nest predation by shielding the nesting chamber from being viewed from the tunnel mouth. This winding tunnel system may also be the result of obstructions such as rocks or root masses being encountered and avoided during the excavation. The entrance to the nesting burrow may be concealed by root masses or overhanging vegetation.
Another method used to attempt to limit nest predation is each parent undertaking extended incubation bouts to limit the amount of activity around the entrance to the nest tunnels. Typically, the incubation shift of each parent will last at least 3 hours, with some shifts lasting more than 8 hours. There have been reports of the motmots relieving each other only twice during the course of the day, once at dawn and once at dusk. This behavior has been observed in both the wild by Alexander Skutch and in the captive population at various participating institutions.
After the tunnel system is completed, including the nest chamber, the birds abandon the area until the following March or April, the onset of the breeding season. At this point, the birds will return to the area for the onset of the nesting season. Motmots in the higher elevation regions have been observed roosting in the nest burrow during the non-breeding season. This behavior is thought to be climate dependant, since those motmots found in more tropical regions of their distribution do not roost in the nesting cavities during non-breeding seasons.
No recorded evidence of nest sanitation by motmots has been observed, which would explain the typical behavior of digging a new nest tunnel each breeding season. It has been observed that motmots do not reuse the same nest site in successive breeding seasons. Even with the absence of nest sanitation, the motmot chicks exit from the nest tunnels in immaculate feather condition.
After the courtship rituals have concluded, copulation between the pair, which lasts 5 to 10 seconds based on captive bird observations, occurs in late April to early May. The female will then lay 3 to 4 white eggs, each measuring approximately 26 mm in length and 23 mm in width. Incubation lasts approximately 21 days, during which time one bird will incubate from early afternoon until the following dawn, before being relieved by its mate for incubation during daylight hours. By only relieving each other from incubation duties twice daily, movement around the nest tunnel entrance is kept to a minimum.
Reproduction in Captivity
Both males and females in captivity have shown themselves to be capable of reproduction at one year of age, but reliable reproduction generally does not occur until both are three years of age. In captivity, the oldest recorded breeding male was 24 years old. Females in the captive records appear to become post-reproductive at 15 years old.
Although the nest chamber is unlined, courtship rituals between the pair still include the male offering leaves, twigs, grass, and flowers to the female. This courtship offering behavior has been observed regularly in both the wild population and in captive settings and appears to reinforce the pair-bonding.
Penduluming of the tail increases in speed, frequency and duration when the birds are excited, whether that is due to pair bonding and courtship behavior, feeding behavior, or territory defense.
Blue-crowned Motmots are completely altricial, and thus the parents must provide for all needs. Feather shafts will begin to emerge from the hatchlings altricial bodies at approximately 7-9 days of age, and the eyes will begin to open at approximately 14-15 days of age. After 29-31 days in the nest, the offspring will begin to make their way up the tunnels towards the entrance, by which time they will look identical to the parents, with the exception of lacking the racketed tail. After exiting the nest tunnels, the fledglings are extremely weak flyers and exhibit difficulty in perching due to their subterranean development. This quickly fades, as the fledglings develop these skills within the first day or two post-fledging. The young gain independence relatively soon after fledging, some being observed self-feeding within 3-4 days. Approximately two weeks after leaving the nest tunnels, the young are consistently self-feeding, and 3-5 weeks post fledge the offspring will have gained complete independence from the parents.
Blue-crowned Motmot Chick Development Gallery
After hatching, the parents alternate brooding, with the female being primarily responsible for the brooding and the male providing most food items. When the offspring are approximately one week old, both parents will be out of the nest occasionally hunting for food. Initially, the feeding will occur at 2-5 minute intervals, with the parents focusing almost exclusively on live food such as crickets, mealworms, waxworms, and earthworms. The frequency of feeding will decrease as the hatchlings age, with the trips into the nest dropping to 5-6 per hour within two weeks post hatching. The parents begin to offer a variety of live insects, pinky mice, and other protein-based food items almost immediately post hatching, and pelleted food items at approximately day 12-14 post hatching, although live food continues to be the overwhelming preference.
In captivity, Blue-crowned Motmots have proven to be excellent parents and hand-rearing is rarely, if ever, necessary. If this must be undertaken, care is similar to that of many soft-billed birds and an example of a hand-rearing protocol can be seen here. Blue-crowned Motmot offspring are offered a diet similar to that given to adult birds, with the overwhelming majority consisting of protein based items. This can be soaked pellets, soaked cat food, soaked dog food, bird of prey meat, mealworms, waxworms, crickets, earthworms, pinky mice, etc. Trace amounts of fruits can be added to round out the diet. Due to their altricial nature, hatchling motmots require supplemental heat and humidity until feather development allows the birds to thermoregulate.
Diet
Blue-crowned Motmots generally sit quietly hidden in shady trees searching for prey items, flycatching insects and pouncing on small land dwelling animals. Blue-crowned Motmots also use their heavy set, deeply serrated bill to brush away leaf litter and probe into the earth searching for prey items. If the prey item eludes the motmot's first capture attempt, the motmot may hop in pursuit. The prey species may include: small lizards, frogs, birds, small rodents, arthropods, centipedes, spiders, butterflies, cicadas, beetles, and mantis. Trace quantities of fruit will be consumed as a portion of the diet. Research by Orejuela in the Yucatan Peninsula found that 84.2% by volume of the diet of Blue-crowned Motmots was comprised of insects. The remainder was found to be gastropod mollusks, arachnids, and chilopods, with a small portion of fruit and plant reproductive parts. This consumption would be regionally influenced and would depend heavily on food items available within the home territory of the motmots (Orejuela, 1975). A study of the stomach contents of 52 Blue-crowned Motmots found that 61.5% contained arthropods only, 21.2% contained arthropods and fruit, 15.4% contained fruit only, and 1.9% contained unidentifiable mush.
Large food items are caught and taken to a perch where the item will be repeatedly bashed against the tree branch or rock to kill and tenderize the prey item. After the pulverizing is complete, the food item is swallowed whole.
The observation of wild motmot nests has shown that the chicks are not fed fruit until the young were at an average of approximately 13 days old, and even from that point on it was offered as a very small proportion of the overall diet.
A wide variety
of diets have been used successfully by institutions, all of which are
similar in basic components. The diets are based on a combination of proprietary
pellets, bird of prey meat, insects, pinky mice, and a small portion of
minced fruits/vegetables. Location of the diet does not appear to influence
the consumption levels as motmots routinely feed on both arboreal and
ground dwelling food items. A sample diet previously in use is listed
below:
Blue-crowned Motmot Sample Diet (Per Pair) - 140 gram Birds
Diets Fed Out Twice Daily - Each Feeding Contains:
Diced Pinky Mice, increasing in size as chicks age
1/2 tsp (2g) Variety of Diced Fruits and Vegetables
1/2 tsp (2g) Variety of Diced Fruits and Vegetables
Variety of Diced Fruits and Vegetables
Enclosure Design
Blue-crowned
Motmots can safely be housed in either mixed species free flight exhibits
or in smaller "jewel-box"enclosures. These are not particularly
active birds, and therefore can be housed in spaces as small as 8' x 8'
x 8' (or similar square footage). Larger allotted areas would be preferable
and likely would increase the instance of reproduction.
The construction
of the enclosure can be accomplished through numerous available designs.
The preference for wire mesh would be not larger than ½" x
3" x 18 gauge. Smaller mesh opening sizes are preferable to restrict
rodent and snake movement into the enclosure. Phantom mesh, Cascade Coil,
and Zoomesh are suitable for barriers, although these are more expensive
then standard galvanized after welded wire. Glass or plexiglass can also
be used, although care must be taken to lessen the likelihood of impact
when birds are introduced to the enclosure. Glass and plexiglass also
reduce airflow and could potentially lead to stagnant air and/or fungal
infestations of enclosures. Piano wire can be utilized, but it does offer
the potential for an escape route with motmots flying through the wire
if it is not small enough openings and under sufficient tension.
Motmots
have not proven to be exceptional escape artists. Only 19 out of 504 (3.77%)
specimens listed in the historical studbook have escaped to the wild at
one time or another. Of those that have escaped, 7 were recaptured. An
additional 16 birds were listed in the North American Regional Studbook
as having escaped their enclosure into and being recaptured from a secondary
containment area. The enclosure should have a double door safety cage
if it is an outdoor system due to the distinct threat of escape through
a single door system. The bottom of the enclosure should be protected
through the use of wire or concrete to keep predators from digging into
the enclosure and keep motmots from digging out. There have been multiple
cases of the escapes being linked to birds digging out of the enclosure.
If an artificial
nest box design is to be used, the construction is fairly simplistic and
straightforward. A rectangular plywood box with a 3" PVC tube connection
to simulate the tunnel can be constructed. The measurements are not critical
as long as sufficient space is provided within for the two adult birds
and the potential of 4-5 offspring. Ease of maintenance and access should
be considered due to the fairly infrequent nest maintenance procedures
undertaken by the adult birds.
For breeding
purposes, the ideal group composition would be 1.1 Blue-crowned Motmots,
as it is extremely likely that the pair will become territorial and aggressive
towards any con-specifics sharing the enclosure during breeding season.
In rare cases, large free-flight aviaries may successfully house mixed
gender groups of birds during the non-breeding season, but this is not
ideal and usually will necessitate the removal of all but the dominant
pair during breeding season. Most institutions that have attempted to
house multiple pairs in the same aviary have needed to remove all but
the dominant pair when sexual maturity and breeding season were reached.
There have been several institutions that have successfully housed single-sex
groups long term in the same enclosure long term without any significant
aggressive interactions.
Offspring
may be left in the exhibit with parents through the non-breeding season
if necessary, however they should be removed prior to the onset of the
following breeding season, beginning with the excavation of the tunnel
system in early fall. Typically the aggression from the adult pair towards
the juveniles has escalated to necessitate the removal of the offspring
when the juveniles reached approximately four to five months in age. Based
on captive breeding records, this occurs between September and November
in the majority of incidences.
Coraciiformes Taxon Advisory Group - 
The legs of Blue-crowned Motmots are characterized by short tarsi and a syndactyl foot, which is distinguished by a single rear facing toe, and a middle toe almost completely joined to the inner toe. Blue-crowned Motmots, like many cavity nesters and insectivores, have well developed tactile rictal bristles which appear to originate from contour feathers. The rictal bristles have a stiff rachis (shaft) and only have barbs near the base. It is likely that the rictal bristles serve primarily as a sensory device for use in the tunnel system and nesting chamber, but they may also assist in filtering dust and dirt particles from the nares. Adult birds possess a red iris, juveniles possess a dark brown iris. All Motmots have shared characteristics including the possession of a beak that is short, down-curved slightly, and heavily serrated along the edges of the upper and lower mandible running the entire length of the beak. All representatives of the family Momotidae have short, rounded wings which are not well suited for long flights.
Range
Penduluming of the tail increases in speed, frequency and duration when the birds are excited, whether that is due to pair bonding and courtship behavior, feeding behavior, or territory defense.