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- Permanent Link:
- http://dpanther.fiu.edu/dpService/dpPurlService/purl/FI14090845/00001
Notes
- Scope and Content:
- Source: Purple Martins 1
Length of Segment: 00:01:15
Hi, I'm Dr. Jerry Jackson, out with the wild things. Late summer roosts of purple martins in the southeastern U.S. are often spectacular, numbering in tens of thousands of birds with one roost estimated to have included over half a million martins. The roosts occur as young and adult martins leave nesting colonies and move to forested wetlands and other areas with high concentrations of flying insects. Roosts may be staging areas for migration but are also areas for social exchange and safety in this highly social bird. With summer heat and rains, insect populations are at seasonal highs and lucky is the community that has a martin roost. Most martin roosts are in remote areas, but in an urban area, a roost such as one in downtown Fort Myers near the Henry Street Station can offer viewers a spectacular show. Martins begin arriving about an hour before sunset, perching on buildings and wires before settling in for the night in trees. They leave before dawn to feed on insects throughout the region. The Fort Myers roost includes between 10,000 and 40,000 martins, varying in numbers as new groups arrive and others leave. Through August and September, numbers of birds in roosts decline as they head for their winter home in South America. ( English )
- Scope and Content:
- Source: Purple Martins 2
Length of Segment: 00:01:14
Hi, I'm Dr. Jerry Jackson, out with the wild things. As with many migrant birds, purple martins appear in spring in a somewhat orderly fashion. Adult males arrive first, with younger males and females arriving a week or two behind. The reason for these differences in arrival time is a tug-of-war between the incidence of late cold weather and the ability to secure the best nesting sites. Since purple martins feed on flying insects, a period of cold weather can mean starvation. Usually, this isn't a problem in South Florida, but elsewhere cold weather can mean death. The return of martins to South America for the winter is not so well documented, but lacks much of the urgency of the northward trip. When the last martin nestlings have fledged, young and old gather in loose flocks to feed near rivers, lakes, and swamps where flying insects abound. They build strength and energy reserves for their southward migration and young improve their flying, hunting, and social skills. At night in late summer, martin flocks gather to roost, usually in forested areas but some along city streets such as a roost in downtown Fort Myers. By day, they may travel tens of miles in search of food. ( English )
- Scope and Content:
- Source: Purple Martins 3
Length of Segment: 00:01:15
Hi, I'm Dr. Jerry Jackson, out with the wild things. Purple martins nest throughout the United States and into southern Canada. Their numbers decline to the north and west, and in the west, few martins nest in housing provided by humans. Instead, they depend on long-dead trees with multiple abandoned woodpecker holes for their colonies. At the end of the nesting season, however, all martins abandon their nesting site and gather in roosts close to prime feeding areas, usually in a forested wetland where flying insects abound. At first, adults and young from a single colony may roost together. They may use a roost for a week or more, then begin a gradual movement southward. Birds from other colonies join the nightly roosts along the way; there's safety in numbers and the birds are in a new territory. There may also be sharing of information about local food supplies. The farther south the birds get, the larger nightly roosts become as more and more birds converge on traditional migration routes and the prime feeding habitats of swamp lands and forested rivers of the southeast. The largest martin roosts in North America occur along the Gulf Coast from Florida to Louisiana, where martins remain to feed for a few weeks before crossing the Gulf of Mexico to their winter home. ( English )
Record Information
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- Resource Identifier:
- FI00900178
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