| 1. |
|
|
| 2. |
- Jonsson, B. G., et al.
(författare)
-
Skogspolitiken hotar biologiska mångfalden
- 2008
-
Ingår i: Dagens Nyheter. ; 14 april
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Ledande svenska forskare varnar för att det nationella naturarvet äventyras: Vi skäms över våra beslutsfattares likgiltighet för miljön. Den svenska skogen har förvandlats till en jättelik odlingsyta. Där förr otaliga arter levde samman i harmoni dominerar numera helt gran, tall och inplanterade främmande trädslag. Denna skogsodling utgör ett hot mot den biologiska mångfalden vilket strider mot riksdagens miljökvalitetsmål. Den svenska skogspolitiken vilar officiellt på att produktion av skogsråvara och miljö är likvärdiga mål. Men i praktiken har produktionen satts i första rummet. Bortåt 2 000 skogslevande arters överlevnad hotas på grund av den förda politiken. Vi är djupt oroade och skäms över att det rika Sverige inte arbetar effektivt för att nå nationella och internationella miljömål. Det skriver 14 ledande forskare i bland annat växtekologi, ekologisk zoologi och botanik.
|
|
| 3. |
- Lisovski, Simeon, et al.
(författare)
-
The Indo-European flyway : Opportunities and constraints reflected by Common Rosefinches breeding across Europe
- 2021
-
Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 48:6, s. 1255-1266
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: The configuration of the earth's landmasses influences global weather systems and spatiotemporal resource availability, thereby shaping biogeographical patterns and migratory routes of animals. Here, we aim to identify potential migratory barriers and corridors, as well as general migration strategies within the understudied Indo-European flyway. Location Europe, Central Asia. Major taxon studied Common rosefinches.Methods: We used a combination of theoretical optimization modelling and empirical tracking of Common Rosefinches (Carpodacus erythrinus) breeding across a large latitudinal gradient in Europe. First, we identified optimal migration routes driven by wind and resource availability along the Indo-European flyway. Second, we tracked rosefinches from five breeding populations using light-level geolocators. Finally, we compared to what extent empirical tracks overlapped with the modelled optimal routes.Results: In autumn, theoretical wind driven migration routes formed a broad-front corridor connecting Europe and the Indian Subcontinent while the theoretical resource driven routes formed a distinct north-south divide. The latter pattern also reflected the rosefinch tracks with all but the most southerly breeding birds making a northern detour towards non-breeding sites in Pakistan and India. In spring, the resource availability model predicted a similar migratory divide, however, the southern route seemed relatively more favourable and closely matched with the optimal wind driven migration routes. Spring tracking data showed larger overlap with the modelled wind driven migration routes compared to the resource driven routes.Main conclusions: Optimal wind and resource driven migration routes along the Indo-European flyway are seasonally specific and to a large extend do not overlap with one another. Under these conditions, migratory birds adopt seasonally distinct migration strategies following energy minimization strategy in autumn, driven by resource availability, and time minimizing strategy in spring, driven by wind conditions. Our optimal migration models can be applied worldwide and used to validate against empirical data to explain large-scale biogeographic pattern of migratory animals.
|
|
| 4. |
- Hedlund, Johanna, et al.
(författare)
-
Increase in protandry over time in a long-distance migratory bird
- 2022
-
Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 12:7
-
Tidskriftsartikel (refereegranskat)abstract
- Protandry is a widespread life-history phenomenon describing how males precede females at the site or state of reproduction. In migratory birds, protandry has an important influence on individual fitness, the migratory syndrome, and phenological response to climate change. Despite its significance, accurate analyses on the dynamics of protandry using data sets collected at the breeding site, are lacking. Basing our study on records collected during two time periods, 1979 to 1988 and 2006 to 2016, we aim to investigate protandry dynamics over 38 years in a breeding population of willow warblers (Phylloscopus trochilus). Change in the timing of arrival was analyzed in males and females, and protandry (number of days between male and female arrival) was investigated both at population level and within breeding pairs. Our results show advancement in the arrival time at the breeding site in both sexes, but male arrival has advanced to a greater extent, leading to an increase in protandry both at the population level and within breeding pairs. We did not observe any change in sex ratio that could explain the protandry increase, but pronounced temperature change has occurred and been reported in the breeding area and along the migratory route. Typically, natural selection opposes too early arrival in males, but given warmer springs, this counteracting force may be relaxing, enabling an increase in protandry. We discuss whether our results suggest that climate change has induced sex-specific effects, if these could be evolutionary and whether the timing of important life-history stages such as arrival at the breeding site may change at different rates in males and females following environmental shifts.
|
|
| 5. |
- Olofsson, Martin, 1980-, et al.
(författare)
-
Eyespot display in the peacock butterfly triggers antipredator behaviors in naive adult fowl
- 2013
-
Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 24:1, s. 305-310
-
Tidskriftsartikel (refereegranskat)abstract
- Large conspicuous eyespots have evolved in multiple taxa and presumably function to thwart predator attacks. Traditionally, large eyespots were thought to discourage predator attacks because they mimicked eyes of the predators' own predators. However, this idea is controversial and the intimidating properties of eyespots have recently been suggested to Amply be a consequence of their conspicuousness. Some lepidopteran species include large eyespots in their antipredation repertoire. In the peacock butterfly, Mathis io, eyespots are typically hidden during rest and suddenly exposed by the butterfly when disturbed. Previous experiments have shown that small wild passerines are intimidated by this display. Here, we test whether eyespots also intimidate a considerably larger bird, domestic fowl, Gallus gallus domesticus, by staging interactions between birds and peacock butterflies that were sham-painted or had their eyespots painted oven Our results show that birds typically fled when peacock butterflies performed their display regardless of whether eyespots were visible or painted over. However, birds confronting butterflies with visible eyespots delayed their return to the butterfly, were more vigilant, and more likely to utter alarm calls associated with detection of ground-based predators, compared with birds confronting butterflies with eyespots painted over. Because production of alarm calls and increased vigilance are antipredation behaviors in the fowl, their reaction suggests that eyespots may elicit fear rather than just an aversion to conspicuous patterns. Our results, therefore, suggest that predators perceive large lepidopteran eyespots as belonging to the eyes of a potential predator.
|
|
| 6. |
- Boström, Jannika, et al.
(författare)
-
Autumn migratory fuelling : a response to simulated magnetic displacement in juvenile wheatears, Oenathe oenathe
- 2010
-
Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 64:11, s. 1725-1732
-
Tidskriftsartikel (refereegranskat)abstract
- Recent experiments exposing migratory birds to altered magnetic fields simulating geographical displacements have shown that the geomagnetic field acts as an external cue affecting migratory fuelling behaviour. This is the first study investigating fuel deposition in relation to geomagnetic cues in long-distance migrants using the western passage of the Mediterranean region. Juvenile wheatears (Oenanthe oenanthe) were exposed to a magnetically simulated autumn migration from southern Sweden to West Africa. Birds displaced parallel to the west of their natural migration route, simulating an unnatural flight over the Atlantic Ocean, increased their fuel deposition compared to birds experiencing a simulated migration along the natural route. These birds, on the other hand, showed relatively low fuel loads in agreement with earlier data on wheatears trapped during stopover. The experimental displacement to the west, corresponding to novel sites in the Atlantic Ocean, led to a simulated longer distance to the wintering area, probably explaining the observed larger fuel loads. Our data verify previous results suggesting that migratory birds use geomagnetic cues for fuelling decisions and, for the first time, show that birds, on their first migration, can use geomagnetic cues to compensate for a displacement outside their normal migratory route, by adjusting fuel deposition.
|
|
| 7. |
- Henshaw, Ian, et al.
(författare)
-
Geomagnetic field affects spring migratory direction in a long distance migrant
- 2010
-
Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 64:8, s. 1317-1323
-
Tidskriftsartikel (refereegranskat)abstract
- Night-migrating song birds travel to and from their wintering and breeding areas often separated thousands of kilometers apart and are clearly capable of finding intended goal areas from a distant location. Displacement experiments provide a useful way to highlight orientation and navigational skills in migrants. To investigate which cues birds actually use to compensate for displacement and the exact mechanism of each cue, experiments with manipulation of single cues are required. We conducted a simulated displacement of lesser whitethroats Sylvia curruca on spring migration. Birds were displaced not geographically but in geomagnetic space only, north and south of their breeding area to test whether they incorporate information from the geomagnetic field to find their breeding area. Lesser whitethroats held in southeast Sweden but experiencing a simulated displacement north of their breeding area (Norway) failed to show a consistent direction of orientation, whereas birds displaced south of their breeding area (Czech Republic) exhibited consistent northerly orientation, close to the expected seasonally appropriate direction, after displacement toward the trapping location. The absence of a clear compensatory direction in birds displaced north might be due to unfamiliar magnetic information or lack of sufficient information such as a magnetic gradient when moving around. By isolating one orientation cue, the geomagnetic field, we have been able to show that lesser whitethroats might incorporate geomagnetic field information to determine latitude during spring migration.
|
|
| 8. |
- Hedlund, Johanna S. U., et al.
(författare)
-
Long-term phenological shifts and intra-specific differences in migratory change in the willow warbler Phylloscopus trochilus
- 2015
-
Ingår i: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 46:1, s. 97-106
-
Tidskriftsartikel (refereegranskat)abstract
- Climate change can influence many aspects of avian phenology and especially migratory shifts and changes in breeding onset receive much research interest in this context. However, changes in these different life-cycle events in birds are often investigated separately and by means of ringing records of mixed populations. In this long-term study on the willow warbler Phylloscopus trochilus, we investigated timing of spring and autumn migration in conjunction with timing of breeding. We made distinction among individuals with regard to age, sex, juvenile origin and migratory phase. The data set comprised 22-yr of ringing records and two temporally separated data sets of egg-laying dates and arrival of the breeding population close to the ringing site. The results reveal an overall advancement consistent in most, but not all, phenological events. During spring migration, early and median passage of males and females became earlier by between 4.4 to 6.3 d and median egg-laying dates became earlier by 5 d. Male arrival advanced more, which may lead to an increase in the degree of protandry in the future. Among breeding individuals, only female arrival advanced in timing. In autumn, adults and locally hatched juvenile females did not advanced median passage, but locally hatched juvenile males appeared 4.2 d earlier. Migrating juvenile males and females advanced passage both in early and median migratory phase by between 8.4 to 10.1 d. The dissimilarities in the response between birds of different age, sex and migratory phase emphasize that environmental change may elicit intra-specific selection pressures. The overall consistency of the phenological change in spring, autumn and egg-laying, coupled with the unchanged number of days between median spring and autumn migration in adults, indicate that the breeding area residence has advanced seasonally but remained temporally constant.
|
|
| 9. |
- Olofsson, Martin, et al.
(författare)
-
Winter predation on two species of hibernating butterflies: monitoring rodent attacks with infrared cameras
- 2011
-
Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 81:3, s. 529-534
-
Tidskriftsartikel (refereegranskat)abstract
- Documentation of predator attacks in nature is important for understanding how specific antipredator defences have evolved, but previous accounts have been mostly anecdotal. Therefore, we monitored predation on two closely related butterfly species, Aglais urticae and Inachis io, during winter hibernation. Butterflies were placed singly close to the floor on walls in dark, seminatural hibernation sites (e.g. unheated outhouses). We used motion-initiated infrared-sensitive cameras to record predator attacks on the butterflies. The antipredator attributes of the two species have two characteristics: during rest the butterflies reduce predators’ attention by mimicking leaves but they can suddenly change their guise by repeatedly flicking their wings. The wing flicking also produces hissing sounds and ultrasonic clicks and, furthermore, I. io, but not A. urticae, have large eyespots on the dorsal wing surface. The two butterfly species suffer from mouse predation during the winter and mice have been suggested as potential targets for the butterflies’ sound production. Results showed that (1) mice (Apodemus spp.) were important predators on butterflies, (2) I. io often survived attacks by wing-flicking behaviour, and (3) both species moved to less accessible positions after interactions with mice and other small mammalian predators, but I. io more often so. The successful predator evasion in darkness by I. io suggests a multimodal defence; in addition to the large eyespots, which intimidate birds, we suggest that the hissing and/or click sounds produced during wing flicking may have evolved as defence against rodent attacks
|
|
| 10. |
- Stach, Robert, 1971-, et al.
(författare)
-
Migration routes and timing in a bird wintering in South Asia, the Common Rosefinch Carpodacus erythrinus
- 2016
-
Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 157, s. 671-679
-
Tidskriftsartikel (refereegranskat)abstract
- Only few bird species from Western Europe migrate eastward to wintering areas in South Asia, and little is known about this migratory flyway. The Common Rosefinch has in the past century expanded its breeding range westward to include Western Europe and migrate along this flyway to wintering sites in South Asia. This is the first study describing the migration routes of Common Rosefinches between Europe and Asia in detail, revealed by light level geolocators. The rosefinches showed loop-migration with more northerly routes in autumn than in spring, possibly in order to shorten the flight over the Central Asian deserts, which are very inhospitable at this time of the year. In spring the deserts are less dry and richer in vegetation, which may have supported the more southerly routes. During autumn migration the birds used several staging sites in Central Asia for prolonged periods. Although the birds passed over mountain regions at this time, which potentially act as barriers to them, the length of the stops seem unrealistically long for only fuel deposition. Instead, this suggests that the birds temporarily suspended migration to take advantage of abundant and predictable food sources in this region. During spring migration the birds made a few longer stops while still in north India or Central Asia, before migrating at fast speeds towards the breeding grounds. The birds covered 4–5000 km with only very short stopovers and thus most of the fuel used on spring migration must have been accumulated in Asia. Our results thus indicate that Central Asia, and north India, are important staging areas for this species in both autumn and spring. During winter, birds used two sites located several hundred kilometres apart, and relocation was probably a response to local food availability.
|
|
