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Habitat

Ontario’s Purple Martins forage over towns, cities, parks, open fields, dunes, streams, wet meadows, beaver ponds, and other open areas.  Sometimes  dead snags offer abandoned  woodpecker holes to nest in and martins take advantage of them if there is no man made housing available. Ontario’s Purple Martin seems to be totally dependent on nest boxes and likes to live close to humans.  Purple Martins are neo-tropical and spend their winter in Bolivia, Brazil, and elsewhere in South America especially in the Amazon region. At night, wintering large flocks of martins settle into cities and towns to roost on buildings or trees or onto treed islands located on the Rio Negro in the Amazon region.

Feeding Behavior

The Purple Martin eats flying insects at altitudes higher than most swallows, often exceeding 50 meters and sometimes 150 meters or more off the ground. When they encounter prey, they will often turn suddenly, speed up, and then open their tails as they trap the insect. The Purple Martin diet may include:  beetles, flies, dragonflies, damselflies, leafhoppers, grasshoppers, crickets, butterflies, moths, wasps, bees, caddisflies, spiders, cicadas, termites, and mayflies. They usually feed during the day and often in pairs. Martins pick up small bits of gravel or egg shells to help them with digestion . In an emergency, they will often take flung crickets or even scrambled eggs.

NEST PLACEMENT

Males will often arrive early in the season to claim a particular nesting site and rigorously defend it from other males. Afterwards, both sexes will often visit various house cavities before choosing the final location. Sometimes they may claim two compartments and rigorously defend them both from other martins. The cavity  may be located in a birdhouse, gourd, dead tree, saguaro cactus, building, or cliff, but sometimes in other structures like traffic lights, street lamps, dock pilings, or oil pumps. Purple Martin birdhouses and gourds are either natural, made of wood or aluminum, and contain 8–12 rooms. Housing units can be hung from wires or sit atop poles in open areas and can  be made to raise and lower.

NEST DESCRIPTION

Ontario’s martins usually nest in birdhouses provided by humans. Seldom do they nest in woodpecker holes in trees since their numbers are severely in decline. Nests usually contain twigs, plant stems, mud, bean straw, grass or pine straw.

NESTING FACTS

Eggs and Young

Clutch Size:         3-6 eggs

Number of Broods:          Usually 1 brood

Egg Length:         0.8-1.1 in (2.1-2.7 cm)

Egg Width:          0.6-0.8 in (1.6-1.9 cm)

Incubation Period:           15-18 days

Nestling Period: 27-36 days

Egg Description:                Pure white and smooth.

Condition at Hatching:   Weak, with completely bare pink skin.

Ontario Conservation status

Ontario’s Purple Martins are fairly common birds, especially in the southeastern U.S., but their numbers declined by approximately 0.5% per year, resulting in a cumulative decline of about 25% between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 9.3 million and rates them 10 out of 20 on the Continental Concern Score, indicating a species of relatively low conservation concern. Humans have helped counteract declines somewhat by putting up nest boxes, and people now provide virtually all nest sites for Purple Martins in the eastern U.S. However, introduced species such as European Starlings and House Sparrows often take over martin houses and injure or kill eggs and nestlings. Pur­ple mar­tins com­pete with these in­va­sive house spar­rows and Eu­ro­pean star­lings for nest­ing sites  (Brown, 1997; Fraser, et al., 1997)

 Purple Martins are also sensitive to cold snaps; bad weather kills more birds than all other sources of mortality combined. When unseasonably cold temperatures last more than three or four days, the birds starve for lack of insects. In the western U.S., logging practices that remove dead trees can reduce nesting habitat for martins. Reduction of pesticide use on their South American wintering grounds and protection of large winter roosts in Brazil is also important to the conservation of this species.

Lifespan/Longevity

The longevity of purple martins ranges from 0 to 13 years and nine months. Purple martin mortality is often the result of severe weather. Three to four days of severe weather can lead to insect numbers drastically declining. If there is a lack of food, purple martins cannot survive and this often results in population decline. Another hindrance to long life expectancy is often body parasites. Purple martins host a protozoan blood parasite Haemoproteus prognei. This parasite can have disastrous effects on the surviving rate of first year birds during the winter and migration period. (Brown, 1997; Layton, 1972)