Northern Wheatear (Oenanthe oenanthe) Science Article 4 abstract Experiments testing predictions of optimal migration theory so far have concentrated on time and energy as the expenses that birds strive to minimize during migration. Taking advantage of the high variation in numbers of migrating raptors over the island of Helgoland, a field experiment with northern wheatears […]
Category: Passeriformes
Stopover behaviour and departure decision of northern wheatears,Oenanthe oenanthe, facing different onward non-stop flight distances
Northern Wheatear (Oenanthe oenanthe) Science Article 1 abstract On the small North Sea island Helgoland (54 deg 11??N, 07 deg 55??E) we studied the stopover ecology of two subspecies of northern wheatear, Oenanthe oenanthe, during spring migration. Birds heading for Scandinavia (O. o. oenanthe) face only short flights across an ecological barrier (50-500 km) whereas […]
Stopover behaviour and departure decision of northern wheatears,Oenanthe oenanthe, facing different onward non-stop flight distances
Northern Wheatear (Oenanthe oenanthe) Science Article 1 abstract On the small North Sea island Helgoland (54 deg 11??N, 07 deg 55??E) we studied the stopover ecology of two subspecies of northern wheatear, Oenanthe oenanthe, during spring migration. Birds heading for Scandinavia (O. o. oenanthe) face only short flights across an ecological barrier (50-500 km) whereas […]
Evolution of Leks
Ochre-bellied Flycatcher (Mionectes oleagineus) Science Article 2 abstract The most likely reason for males banding in groups known as ‘leks’) for courtship behavior is because it providesan opportunity for females to assess a wide range of males for selection of the best possible traits-and isadvantageous for males because leks increase their chance for encountering females. […]
BEHAVIOR AND SOCIAL ORGANIZATION DURING THE BREEDING SEASON IN MIONECTES OLEAGINEUS, A LEKKING FLYCATCHER
Ochre-bellied Flycatcher (Mionectes oleagineus) Science Article 3 abstract The social systems and behavior of Tyrannids are best known for the North American representatives, a small percentage of a large and diverse family. In this paper, we describe the breeding season social organization and behavior of the Ochre-bellied Flycatcher, Mionecteso leagineusa, lek-breeding Neotropical Tyrannid. We describe […]
Lek size variation and its consequences in the ochre-bellied flycatcher, Mionectes oleagineus
Ochre-bellied Flycatcher (Mionectes oleagineus) Science Article 1 abstract Several hypotheses suggest that the costs and benefits of display in aggregations of different sizes play a major role in both the evolution of leks and in the distribution of males across lekj of different sizes. We examined the consequences of variation in lek size for both […]
Lek size variation and its consequences in the ochre-bellied flycatcher, Mionectes oleagineus
Ochre-bellied Flycatcher (Mionectes oleagineus) Science Article 1 abstract Several hypotheses suggest that the costs and benefits of display in aggregations of different sizes play a major role in both the evolution of leks and in the distribution of males across lekj of different sizes. We examined the consequences of variation in lek size for both […]
Differential timing of spring migration in northern wheatears Oenanthe oenanthe: hurried males or weak females?
Northern Wheatear (Oenanthe oenanthe) Science Article 2 abstract In a field experiment on the island of Helgoland (southeast North Sea), we investigated whether migration strategy or competition between the sexes cause the differential timing of spring migration of male and female northern wheatears (Oenanthe oenanthe) (males migrating earlier). The study included two subspecies, heading towards […]
MAGNETIC ORIENTATION OF MIGRATORY WHEATEARS(OENANTHE OENANTHE) IN SWEDEN AND GREENLAND
Northern Wheatear (Oenanthe oenanthe) Science Article 5 abstract Orientation experiments were performed with wheatears (Oenanthe oenanthe) subjected to artificially manipulated magnetic fields, in Sweden and Western Greenland, during the autumn migration period. The objective was to compare responses by birds exposed to widely different geomagnetic conditions and, specifically, to clarify if birds are able to […]
MAGNETIC ORIENTATION OF MIGRATORY WHEATEARS(OENANTHE OENANTHE) IN SWEDEN AND GREENLAND
Northern Wheatear (Oenanthe oenanthe) Science Article 5 abstract Orientation experiments were performed with wheatears (Oenanthe oenanthe) subjected to artificially manipulated magnetic fields, in Sweden and Western Greenland, during the autumn migration period. The objective was to compare responses by birds exposed to widely different geomagnetic conditions and, specifically, to clarify if birds are able to […]