Eastern whip-poor-will (Antrostomus vociferous) is continuously declining due to habitat loss and unavailability of insects for food. Little is known about whip-poor-will migration because of their nocturnal quite habit during non-breeding season. At high latitude 80% avian species are migratory wherein factors affecting migration includes predators, anthropogenic threats and pathogens. Migratory strategies allows individual to track seasonal changes mostly for temperate breeding aerial insectivores. However, population declines among temperate insectivore birds due to extreme weather condition, cost of migration and reliance on sensitive prey. In addition it is important to determine the migratory routes, year round habitat requirement and temporal constraints of threatened species.
Geolocator deployment of Whip-poor will
There were 20 males and 2 females of whip-poor-will have been tracked using geolocators in four regions of Canada. The study shows that this species breed more in northern part than southern breeding population and experienced different wintering conditions. Also a high migratory cost happens such as novel threats, energy expenditure and the ability to adjust time in tracking breeding ground condition. In contrast, both eastern and western breeding individuals wintered together wherein mostly concentrated in Guatemala and some provinces of Mexico. However, male often have higher benefits of early arrival on the breeding grounds thus accept higher cost of wintering further. Additionally, early arrival on breeding grounds is more advantageous on whip-poor-will males allowing occupation on higher quality territories.
On the other hand female whip-poor-will forced to migrate further on lower latitude with less competition and more abundant resources. Most of this species travel overland through Mexico and Central America. However, only two individuals flights across portion of the Gulf of Mexico during autumn and spring. It just shows that this pattern is the response to prevailing winds and availability of resources along different route. Also more species migrating along Eastern North America, South and Central America over ocean flights during autumn. While in spring more species taking longer over land route around western side of the Gulf of Mexico.
Therefore, geolocators is helpful in identifying wintering areas, stopovers and migratory route of whip-poor-will. These migratory stopovers in the southeastern and central United States as well as in southern Mexico and Central America are both important for the whip-poor-will species. Finally, habitat protection and insect population might increase the number of these species despite pressures of long migrations and climate changes.
Source: Prepared by Joan Tura from Springer BMC Zoology
Volume 2:5, 2017
Waterbirds are very important indicators in the ecosystem particularly wetlands. Due to climate change and human activities such as pollution, over-hunting and habitat loss about 23% globally are declining. Some have been listed as threatened species by the International Union for Conservation of Nature (IUCN) for about 19% worldwide. In view of this severe condition, waterbirds diversity has been rapidly decreasing and its conservation status received attention. In China there are 53.6 million hectares of wetlands making it the first among Asia and fourth in the world. There were different wetland types in China including swamps, rivers, lakes, coastal wetlands and estuaries. Conservation of waterbirds in China has been implemented establishing nature reserves, designating key habitat and captive breeding to increase population.
Population Trends of Waterbirds in China
According to Wetlands International there were 871 waterbird species in 32 families and 8 orders in the world. In China, 260 waterbird species has been identified that belongs to 21 families. 84 species exhibited a declining trend, 35 species remained stable while 16 species showed increasing trends. Threatened species includes Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern and Data Deficient. Moreover, the migratory and residents waterbirds suffered serious threats and a total of 38 species listed as threatened species. Also there were 6 species listed as Critically Endangered, 16 species Vulnerable, 16 species Endangered and 27 species as Near Threatened.
Threats to waterbirds include both direct and indirect human activities such as illegal hunting, disturbances, pollution and habitat loss. However, habitat loss is the most common threat because of large scale reclamation in both coastal and inland wetlands. According to the national surveys a decreased of 3.4 million hectares of wetlands wherein coastal losses more than inland wetlands. In recent years, continuous development and industrialization affects the natural habitats of waterbirds. In which foraging time have been reduced, vigilance behavior increased and recurrently being flushed away. As a consequence human disturbances forced the birds to abandon habitats and nest due to breeding failure.
Therefore, waterbirds in China might be in more serious situation than we thought that is why conservation must be implemented. Like restoration of degraded wetlands, public awareness, cracking down on illegal hunting and enforcement of Wildlife Protection Law. Additionally, restoration of highly threatened species through artificial intervention is needed. As well as promoting cooperation between international and regional information on conservation.
Source: Prepared by Joan Tura from Springer Nature BMC Avian Research
Published: 28 April 2018