Yucatan Jay Cyanocorax yucatanicus

  • Order: Passeriformes
  • Family: Corvidae
  • Polytypic: 2 subspecies
  • Authors: Abigail Duvall
Sections

Behavior

Behavior

Social foragers in loose flocks during and outside the breeding season. Sometimes will be high in the canopy, sometimes near the ground. As they move along in a slow, deliberate manner they examine leaves and branches for fruit and animal matter. Has been observed following army ant columns to capture the invertebrates flushed by the ants. (Raitt and Hardy 1976)

Have been reported as somewhat shy, but some birds in the tourist regions will scavenge tables (pers. observation).

Territoriality

Breeding flocks occupy home ranges of up to 400 m in diameter, with preference for patchy forest/field mixes. The separation of flocks suggests territoriality may be present, but Raitt and Hardy were unable to observe direct territorial behavior during their studies of these birds.

(Raitt and Hardy 1976)

Sexual Behavior

These jays breed in cooperative groups which usually consist of one breeding pair and other adults, 2-year olds and 1-year olds. (Raitt and Hardy 1976)

Social and interspecific behavior

Highly gregarious birds, Yucatan Jays are found in flocks throughout the year. Raitt and Hardy found wintering flocks of 45, 45 and 53 birds, with about 40-50% of the flock consisting of first-year birds. During the breeding season, flocks were found to average 7.7 and 12.4 members in two different years, with adults, 2-year olds and yearlings all together (Raitt and Hardy 1976).

Yucatan Jays display ritualized behavior in both breeding and nonbreeding flocks. The threat display of the jays is rarely seen, but is a sleek-feathered, rigid upright posture or a head forward posture directed toward the victim. This posturing may be followed by actual aggression aimed towards the tarsi and face of the victim.

The "up-fluffing" behavior of the jays works as a signal of appeasement and is believed to be the reason that aggressive behavior is so rare in these jays. In a captive flock observed by Hardy, up-fluffing was seen 29 times in five minutes in a flock of 6 jays, with 11 cases being mutual. In the behavior, the neck is extended and the feathers of the neck and head are erected slowly, revealing the pinkish skin of the neck. The behavior varies in intensity, with the most extreme form being to point the bill downward and away from the recipient while erecting the neck feathers. The action solicits positive feedback in the form of "peck-preening," a type of allopreening.

There is an extreme form of submissive behavior known as "appeasement gaping" where the victim crouches, fluffs all head feathers, and gapes at another bird. It is most frequently seen in first-year birds and the behavior is released when the aggressor pecks at the face or tarsi. It is not usually seen in established social groups of mature wild birds. Allofeeding by one bird to another is seen between members of different age and sex groups and is not a pair-bonding behavior, but rather a group bonding behavior.

The "Sotto-voce" song display is a soft, throaty vocalizing which occurs only very rarely in Yucatan Jays, but is much more common in other species of blue and black jays.

(Hardy 1974)

Predation

Tree squirrels have been described as significant predators of nestlings. Snakes also consume young birds. Adults will make alarm calls in response to a threat and sometimes successfully manage to ward off attackers through pecking and striking (Raitt and Hardy 1976).

Recommended Citation

Duvall, A. (2010). Yucatan Jay (Cyanocorax yucatanicus), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.yucjay1.01