Necropsy Techniques
in seabirds
The project
Brief history
In Brazil, on the northern coast of the state of Rio Grande do Norte, there is a peninsula where the municipality of Galinhos is located.
The municipality, which has vast areas of mangroves and restinga, is visited by migratory birds that use the region as a stopping point for feeding and resting.
Starting in 2010, through the Potiguar Basin Beach Monitoring Project (PMP-BP), carried out by the Costa Branca Cetacean Project (PCCB-UERN), a high frequency of injured birds began to be recorded on the beach strip.
The birds were mostly from the tern group and the injuries on the body showed signs of collision with an obstacle. The presence of a power line crossing the beach was soon found to be the source of the accidents.
Many of these birds had American bands, indicating that they were migratory birds that were part of populations that bred in the USA. When cases were reported to American institutions that study animals, a dialogue began to better understand the situation and develop a mitigation plan to reduce or eliminate collision events..
the birds
Roseate Tern
Predominantly white in color, and with a black upper region of the head, terns are charismatic birds that delight admirers from all over the world.
The speciesSterna dougallii, known as the roseate tern, gull, white swallow or roseate tern, it can weigh around 119 grams and have a wingspan of 79 cm. They are surprising for their ability to migrate great distances every year. Just before the start of the harsh winter in the Northern Hemisphere, they fly from countries like Canada and the United States, and migrate to South America in search of a milder climate, plenty of food and good resting places.
And what happens when the winter season in the Northern Hemisphere comes to an end?
They flap their wings back there and begin the breeding season, which is when these animals gather in nesting colonies and make efforts to perpetuate the species.
IMAGE OF THE MARKER AND THE MONITORING TEAM
Roseate Terns are seabirds.
But... How can birds be marine animals?
To be a marine animal, the animal must depend on resources that come from the sea and have adaptations to live in that environment (such as salt glands, in the case of seabirds). Terns feed on fish from the marine environment. For most of the day they forage at sea, and at night they rest on beaches and sandbanks. That's why they are considered seabirds.
To capture or fish fish, terns fly over the sea and observe the water in search of schools of small fish that are part of their diet. When they finally find the fish, they dive to shallow depths, capture the fish with their beaks and fly in search of more fish.
The marking of
power line
and monitoring
The mitigation measure designed to address the problem of collisions was marking the distribution line with reflective markers. The objective of installing the markers was to make the wires more visible and thus eliminate or reduce bird collisions. After signaling the line, it was then proposed to monitor it in order to evaluate effectiveness of the measure as well as the different arrangements in which the markers were placed.
Complementary activities also joined the monitoring of the Galinhos power distribution line. New risk areas were identified and, from that moment on, monitoring of a new power line was carried out on a section of the RN-402 state highway. Furthermore, observation studies of Trinta-réis were carried out in five points in the region of the Galinhos peninsula to identify how the birds use the area.
