Light weight and complicated tracking devices have made it possible to study the behavior of birds in all kinds of useful ways, for example, helping keep them safe from ships or monito-ring their changing migration patterns in a warming world. For a research team in Australia, however these efforts haven't quite gone to plan, with a group of tagged magpies (喜鹊) promptly removing each other’s tracking devices.
The research was led by animal ecologists from the University of the Sunshine Coast, who were looking to studying the movement and social dynamics of Australian magpies. To do so, the team actually designed a new type of tagging solution in which a belt was used to secure the tracking device to the bird, allowing them to use one with a large enough battery and storage capacity, despite the relatively small size of the animal.
The tracking devices weighed less than a gram (0.03 oz) and were successfully fitted to five magpies, with the scientists excited to learn the answers to questions such as how far the magpies were traveling, and what their movement patterns and schedules looked like. But before long, the plans of the researchers were thwarted.
Within 10 minutes of fitting the final tracker, the team watched on as an adult female used her bill to remove the belt from a younger bird in the group. A few hours on, most of the other trackers had been removed. By day three, they were all gone. It’s unclear whether one bird was helping out all the others, or if they shared the unfastening responsibilities between the group, but this is the first instance the scientists know of where birds have cooperated to remove tracking devices, and the first example of altruism (利他主义) in magpies. It appears that the magpies see the trackers as a form of parasite (寄生虫) that needs to be removed. This very rare behavior is known as “rescuing”, and the scientists say the only similar example they have found in literature is a group of birds-Seychelles warblers-freeing one another from a pile of sticky seeds.
【小题1】Why were tracking devices often used to help birds according to the text？| A．To search the ships for food. |
| B．To warn them of the warming world. |
| C．To help them avoid being injured by other animals. |
| D．To monitor their travelling according to the season. |
| A．The process of the experiment. |
| B．The background of the experiment. |
| C．The new objects of the experiment. |
| D．The special device of the experiment. |
| A．followed | B．prevented | C．discovered | D．questioned |
| A．It’s rare for the birds. |
| B．It was first observed by researchers. |
| C．It disappointed the researchers very much. |
| D．It shows that the birds are behaving similarly. |
