Sitta pygmaea
pygmy nuthatch

Pygmy Nuthatches are found along the Pacific coast from Baja up into southern British Columbia, and range as far south as central Mexico. Pygmy Nuthatches can be found as far east as central Montana and Colorado. They also live in patches throughout the mountainous regions of Mexico (Bent, 1948).

Pygmy Nuthatches prefer to make their homes in long-needle pine forests, especially in Ponderosa, Monterey, and Jeffrey pines. They are found in their highest density in old-growth forests that are undisturbed and contain numerous dead pines. Pygmy Nuthatches live in valleys, and they are also found in mountainous areas all the way up to the tree line, as long as there is an abundance of old-growth pine trees (Kingery and Ghalambor, 2001).

Male Pygmy Nuthatches have a grayish-brown crown on their heads; they also have a black stripe through their eyes, and a white line over their eyes. Their back and central tail feathers are bluish gray, and they have reddish brown underbellies. Pygmy Nuthatches have white spots on their outer tail feathers and have dark brown bills and feet. Female Pygmy Nuthatches are very similar to the males, differing in that the females have a bluish gray crown along with underbodies that are usually paler then the underbodies of males (Hoffman, 1927).

The lifespan of Pygmy Nuthatches was determined by recapturing birds that were banded. The maximum recorded lifespan was 8 years 2 months (Kingery and Ghalambor, 2001).

Pygmy Nuthatches move quickly when they walk, hop, or climb. When they climb on a tree they always move head first going up or down the tree. Pygmy Nuthatches do not fly for extended periods; most of the time they fly only for quick, short trips between trees to look for food. A breeding pair of Pygmy Nuthatches occupies a territory year round but usually only defends it during the breeding season. Pygmy Nuthatches commonly bath in pools of rain water and melted snow, they also engage in preening and allopreening while in flocks. This species of nuthatch does not migrate so it must find a place to roost for the winter. Pygmy Nuthatches usually choose an old-growth pine for their winter roost and they have been known to roost in groups of 170 individuals. Pygmy Nuthatches roost together in large groups to reduce their loss of thermal energy. They can also engage in controlled hypothermia while roosting to conserve energy, this allows them to lower their body temperature and reduce their metabolic rate while they are sleeping. Pygmy Nuthatches become very aggressive towards other Pygmy Nuthatches and other organisms in their territory during breeding season. They actively guard against other Nuthatches that are feeding in their area, and they chase off larger predators that venture too close to their nest (Kingery and Ghalambor, 2001).

During the breeding season Pygmy Nuthatches have a diet which consists of 60-85% insects, such as beetles, wasps, ants, and caterpillars. The other portion of their diet includes seeds from pine trees and other plant materials. Pygmy Nuthatches use their bills to probe the cracks of trees and peel off bark to expose the insects that are inside the tree. They also search inside the crevices of pine cones on trees and on the ground for insects. Pygmy Nuthatches feed in flocks, especially during the non-breeding season. This appears to increase the ability of the flock members to find a food source. The winter diet of this bird comprises of seeds or insects, depending on the birds location and the food available (Kingery and Ghalambor, 2001).

Pygmy Nuthatches have many adaptations to help them avoid predators. This species of nuthatch sometimes feeds in flocks, which helps it to look for predators and confuse them if they attack. If a predator attacks a flock of Pygmy Nuthatches all the birds in the flock scatter at the same time, and this sometimes confuses the predator long enough for all or most of the Pygmy Nuthatches to fly to a safe location.

When solitary Pygmy Nuthatches spot a predator they position themselves on the opposite side of a tree or branch from the predator to block the advance of the predator.

When squirrels try to invade nests that contain eggs or juveniles, female Pygmy Nuthatches perch at the entrance of their nest, spread their wings, and sway back and forth slowly in a rhythmic movement. Pygmy Nuthatches have also been seen mobbing hawks or other larger birds that may invade their area (Kingery and Ghalambor, 2001).

Pygmy Nuthatches prefer to nest in old-growth pine forests and they eat pine tree seeds and insects. So, they are responsible for some seed dispersal. Since the majority of Pygmy Nuthatches' diet is insects, they are also responsible for influencing the population of insects in their territory (Kingery and Ghalambor, 2001).

No significant negative economic aspects were attributed to Pygmy Nuthatches.

No significant economic contributions were attributed to Pygmy Nuthatches, though this species of nuthatch could be a source of insect control.

Pygmy Nuthatches need old-growth pines for nesting and collection of food, so they are excellent indicators of the health and age of the pine forests where they are found. Since Pygmy Nuthatches need a specific type of environment to live in they are especially vulnerable to deforestation, by humans and natural causes, which results in significant depletion of old-growth pine trees. Pine forests that have been logged or destroyed because of other reasons have resulted in significant drops in populations of Pygmy Nuthatches (Kingery and Ghalambor, 2001).