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Hagman, Mattias
Publikationer (10 of 48) Visa alla publikationer
Elmberg, J., Hagman, M., Löwenborg, K., Pettersson, G., Voisin, A. & Kärvemo, S. (2019). Movements and habitat choice of resident and translocated adult female Grass Snakes (Natrix natrix) during the egg-laying period. Herpetological Journal, 29(4), 245-251
Öppna denna publikation i ny flik eller fönster >>Movements and habitat choice of resident and translocated adult female Grass Snakes (Natrix natrix) during the egg-laying period
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2019 (Engelska)Ingår i: Herpetological Journal, ISSN 0268-0130, Vol. 29, nr 4, s. 245-251Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

We used externally applied transmitters to study movements of female grass snakes (Natrix natrix) during the egg-laying period in a near-urban landscape in Sweden. Half of the studied snakes were residents while the other half were translocated individuals with no previous experience of the area. As predicted, resident females moved more goal-oriented and shorter distances than did translocated individuals. Habitat use did not differ between resident and translocated snakes; they were typically found in bushes, reeds, and tall vegetation. Habitat preference (use in relation to availability) showed that bushy habitats, tall grassy vegetation and reedbeds were over-used in proportion to availability, whereas forest and open grass lawns were used less than expected based on availability. Our study highlights the importance of preserving and restoring linear habitat components providing shelter and connectivity in conservation of grass snakes. We suggest that externally applied transmitters are a better option than surgically implanted ones in movement studies of grass snakes, and that translocation as a conservation method for snakes has drawbacks.

Nyckelord
colubridae, external transmitters, oviposition, radio tracking, telemetry, translocation
Nationell ämneskategori
Biologiska vetenskaper
Identifikatorer
urn:nbn:se:su:diva-184005 (URN)10.33256/hj29.4.245251 (DOI)000545350800007 ()
Tillgänglig från: 2020-08-30 Skapad: 2020-08-30 Senast uppdaterad: 2022-02-25Bibliografiskt granskad
Löwenborg, K. & Hagman, M. (2017). Scale asymmetries and lateral rib duplication in snakes: correlates and effects on locomotor performance. Biological Journal of the Linnean Society, 120(1), 189-194
Öppna denna publikation i ny flik eller fönster >>Scale asymmetries and lateral rib duplication in snakes: correlates and effects on locomotor performance
2017 (Engelska)Ingår i: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 120, nr 1, s. 189-194Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Thermally-induced scale asymmetries in reptiles are often considered to be indicative of underlying osteological deformities that incur fitness costs. However, this typically rests on subjective plausibility arguments and anecdotal reports about links between deformities and fitness, as well as between superficial asymmetries and deeper deformities rather than on empirical data. To shed light on these issues, we used a combination of Xrays of museum specimens and locomotor performance trials of hatchlings grass snakes (Natrix natrix) incubated in the laboratory at either 25 degrees C or 31 degrees C. We found that 30% of the museum specimens with asymmetrical ventral scales also had a rib duplication on one side of the underlying vertebrae associated with a scale asymmetry. In some cases, there was also a second extra rib on the opposite side of the vertebrae. However, although there was a statistically significant association between asymmetric ventral scales and rib duplication, a relatively weak correlation coefficient (r(s) = 0.35) indicated that scale asymmetries are not a very strong predictor of rib duplication. In the performance trials, scale asymmetries had a significant effect on terrestrial but not aquatic locomotor ability of the hatchlings, and the magnitude of this effect depended on the temperature regimes that they experienced as embryos during incubation. Although both asymmetrical and normal snakes incubated at the higher temperature had more stamina than their respective counterparts incubated at the lower temperature, asymmetrical hatchlings overall became exhausted much sooner than normal snakes across the two treatments.

Nyckelord
abnormalities, fitness, natricine, osteological anomalies, vertebrae
Nationell ämneskategori
Biologiska vetenskaper
Identifikatorer
urn:nbn:se:su:diva-143492 (URN)10.1111/bij.12889 (DOI)000400943400014 ()
Tillgänglig från: 2017-05-30 Skapad: 2017-05-30 Senast uppdaterad: 2022-02-28Bibliografiskt granskad
Hagman, M. & Ord, T. J. (2016). Many Paths to a Common Destination: Morphological Differentiation of a Functionally Convergent Visual Signal. American Naturalist, 188(3), 306-318
Öppna denna publikation i ny flik eller fönster >>Many Paths to a Common Destination: Morphological Differentiation of a Functionally Convergent Visual Signal
2016 (Engelska)Ingår i: American Naturalist, ISSN 0003-0147, E-ISSN 1537-5323, Vol. 188, nr 3, s. 306-318Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Understanding the interacting outcomes of selection and historical contingency in shaping adaptive evolution remains a challenge in evolutionary biology. While selection can produce convergent outcomes when species occupy similar environments, the unique history of each species can also influence evolutionary trajectories and result in different phenotypic end points. The question is to what extent historical contingency places species on different adaptive pathways and, in turn, the extent to which we can predict evolutionary outcomes. Among lizards there are several distantly related genera that have independently evolved an elaborate extendible dewlap for territorial communication. We conducted a detailed morphological study and employed new phylogenetic comparative methods to investigate the evolution of the underlying hyoid that powers the extension of the dewlap. This analysis showed that there appear to have been multiple phenotypic pathways for evolving a functionally convergent dewlap. The biomechanical complexity that underlies this morphological structure implies that adaptation should have been constrained to a narrow phenotypic pathway. However, multiple adaptive solutions have been possible in apparent response to a common selection pressure. Thus, the phenotypic outcome that subsequently evolved in different genera seems to have been contingent on the history of the group in question. This blurs the distinction between convergent and historically contingent adaptation and suggests that adaptive phenotypic diversity can evolve without the need for divergent natural selection.

Nyckelord
adaptation, agamidae, convergence, iguanidae, phylogenetic, phylogenetic principal component analysis
Nationell ämneskategori
Biologiska vetenskaper
Identifikatorer
urn:nbn:se:su:diva-134230 (URN)10.1086/687560 (DOI)000381286000005 ()27501088 (PubMedID)
Tillgänglig från: 2016-10-07 Skapad: 2016-10-03 Senast uppdaterad: 2022-02-28Bibliografiskt granskad
Hagman, M., Löwenborg, K. & Shine, R. (2015). Determinants of anti-predator tactics in hatchling grass snakes (Natrix natrix). Behavioural Processes, 113, 60-65
Öppna denna publikation i ny flik eller fönster >>Determinants of anti-predator tactics in hatchling grass snakes (Natrix natrix)
2015 (Engelska)Ingår i: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 113, s. 60-65Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Many organisms exhibit diverse anti-predator tactics, influenced by genetics and prior experience. In ectothermic taxa, offspring phenotypes are often sensitive to developmental temperatures. If the effectiveness of alternative anti-predator responses depends on thermally sensitive traits, then the temperatures experienced during embryonic life should also affect how offspring respond to an approaching predator. We incubated 16 clutches of Swedish grass snakes (Natrix natrix) at a range of developmental temperatures, and scored body size, colour pattern, locomotor performance and anti-predator responses of 213 hatchlings from those clutches. A hatchling snake’s size and locomotor abilities were affected by its clutch of origin, its developmental temperature, and by an interaction between these two factors. Anti-predator tactics were strongly linked to locomotor ability, such that slower snakes tended to rely upon aggressive displays rather than flight. Incubation temperatures that generated slow (and thus aggressive) snakes also modified the colour of the snake’s nuchal spot. Temperatures in the low to medium range generated mostly cream, white and orange spots, whereas medium to high temperatures generated more yellow spots. Incubation effects, and gene X environment interactions, thus may generate complex correlations between morphology, locomotor ability, and anti-predator tactics.

Nyckelord
Developmental plasticity, Incubation effects, Maternal effects, Trait correlations
Nationell ämneskategori
Etologi
Identifikatorer
urn:nbn:se:su:diva-129137 (URN)10.1016/j.beproc.2015.01.009 (DOI)000351790800008 ()
Tillgänglig från: 2016-04-15 Skapad: 2016-04-15 Senast uppdaterad: 2023-10-23Bibliografiskt granskad
Hagman, M., Kärvemo, S., Elmberg, J. & Löwenborg, K. (2013). Life at the edge: the nesting ecology of the world’s most northerly oviparous snake and its implications for conservation. In: William I. Lutterschmidt (Ed.), Reptiles in Research: Investigations of Ecology, Physiology and Behavior from Desert to Sea (pp. 247-264). New York: Nova Science Publishers, Inc.
Öppna denna publikation i ny flik eller fönster >>Life at the edge: the nesting ecology of the world’s most northerly oviparous snake and its implications for conservation
2013 (Engelska)Ingår i: Reptiles in Research: Investigations of Ecology, Physiology and Behavior from Desert to Sea / [ed] William I. Lutterschmidt, New York: Nova Science Publishers, Inc., 2013, s. 247-264Kapitel i bok, del av antologi (Refereegranskat)
Ort, förlag, år, upplaga, sidor
New York: Nova Science Publishers, Inc., 2013
Nationell ämneskategori
Zoologi
Identifikatorer
urn:nbn:se:su:diva-100227 (URN)9781628085990 (ISBN)
Tillgänglig från: 2014-01-30 Skapad: 2014-01-30 Senast uppdaterad: 2022-02-24Bibliografiskt granskad
Elmberg, J., Hagman, M., Löwenbrog, K. & Kärvemo, S. (2013). Snokens barnkammare försvinner. Fauna och flora : populär tidskrift för biologi, 108(1), 10-16
Öppna denna publikation i ny flik eller fönster >>Snokens barnkammare försvinner
2013 (Svenska)Ingår i: Fauna och flora : populär tidskrift för biologi, ISSN 0014-8903, Vol. 108, nr 1, s. 10-16Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm)) Published
Nationell ämneskategori
Ekologi
Identifikatorer
urn:nbn:se:su:diva-124503 (URN)
Tillgänglig från: 2015-12-26 Skapad: 2015-12-26 Senast uppdaterad: 2022-02-23Bibliografiskt granskad
Löwenborg, K., Kärvemo, S., Tiwe, A. & Hagman, M. (2012). Agricultural by-products provide critical habitat components for cold-climate populations of an oviparous snake (Natrix natrix). Biodiversity and Conservation, 21(10), 2477-2488
Öppna denna publikation i ny flik eller fönster >>Agricultural by-products provide critical habitat components for cold-climate populations of an oviparous snake (Natrix natrix)
2012 (Engelska)Ingår i: Biodiversity and Conservation, ISSN 0960-3115, E-ISSN 1572-9710, Vol. 21, nr 10, s. 2477-2488Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Populations of snakes and other reptiles are declining worldwide. Habitat loss and degradation is thought to be a significant factor in these declines, so to improve management strategies it is important to increase our understanding of reptilian habitat requirements. Modern agriculture is abandoning the tradition of gathering compost and manure in large heaps. Consequently these unusually warm environments are disappearing from the landscape. This may imperil populations of grass snakes (Natrix natrix) that rely on these anthropogenic heat sources to incubate their eggs. We conducted a relocation experiment to examine if eggs can develop successfully in other more natural environments that grass snakes potentially could utilize in the absence of manure heaps and compost piles. We found that hatching success was high (71 %) when we placed eggs in manure heaps and non-existent (0 %) when we placed them in potential ‘natural’ nests. Placement in compost piles resulted in intermediate (43 %) hatching success. Eggs in manure heaps hatched earlier than eggs in compost piles and thermal data from the nests showed that temperatures were higher and more stable in manure heaps than in compost piles and potential ‘natural’ nests. Jointly these results suggest that manure heaps generally provide a better nesting habitat than compost piles, attributable to thermal differences between the environments. Our findings facilitate improvement of current management strategies and have implications for conservation of oviparous reptiles in general.

Nyckelord
Anthropogenic, Developmental plasticity, Incubation, Nesting-sites, Phenotype, Reptile
Nationell ämneskategori
Ekologi
Forskningsämne
zoologisk ekologi
Identifikatorer
urn:nbn:se:su:diva-76917 (URN)10.1007/s10531-012-0308-0 (DOI)000307533100004 ()
Tillgänglig från: 2012-05-24 Skapad: 2012-05-24 Senast uppdaterad: 2022-02-24Bibliografiskt granskad
Tegelaar, K., Hagman, M., Glinwood, R., Petterson, J. & Leimar, O. (2012). Ant-aphid mutualism: the influence of ants on the aphid summer cycle. Oikos, 121(1), 61-66
Öppna denna publikation i ny flik eller fönster >>Ant-aphid mutualism: the influence of ants on the aphid summer cycle
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2012 (Engelska)Ingår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 121, nr 1, s. 61-66Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

There are few longtime studies on the effects on aphids of being tended by ants. The aim of this study is to investigate how the presence of ants influences settling decisions by colonizing aphids and the post-settlement growth and survival of aphid colonies. We conducted a field experiment using the facultative myrmecophile Aphis fabae and the ant Lasius niger. The experiment relied on natural aphid colonization of potted plants of scentless mayweed Tripleurospermum perforatum placed outdoors. Ants occurred naturally at the field site and had access to half of the pots and were prevented from accessing the remainder. The presence of winged, dispersing aphids, the growth and survival of establishing aphid colonies, and the presence of parasitoids were measured in relation to presence or absence of ants, over a period of five weeks. The presence of ants did not significantly influence the pattern of initial host plant colonization or the initial colony growth, but ant-tended aphids were subject to higher parasitism by hymenopteran parasitoids. The net result over the experimental period was that the presence of ants decreased aphid colony productivity, measured as the number of winged summer migrants produced from the colonized host plants. This implies that aphids do not always benefit from the presence of ants, but under some conditions rather pay a cost in the form of reduced dispersal.

Nationell ämneskategori
Zoologi
Forskningsämne
etologi
Identifikatorer
urn:nbn:se:su:diva-71655 (URN)10.1111/j.1600-0706.2011.19387.x (DOI)000298484200007 ()
Tillgänglig från: 2012-01-29 Skapad: 2012-01-29 Senast uppdaterad: 2022-02-24Bibliografiskt granskad
Hagman, M., Elmberg, J., Kärvemo, S. & Löwenborg, K. (2012). Grass snakes (Natrix natrix) in Sweden decline together with their anthropogenic nesting-environments. Herpetological Journal, 22(3), 199-202
Öppna denna publikation i ny flik eller fönster >>Grass snakes (Natrix natrix) in Sweden decline together with their anthropogenic nesting-environments
2012 (Engelska)Ingår i: Herpetological Journal, ISSN 0268-0130, Vol. 22, nr 3, s. 199-202Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In this paper we show that the number of grass snake (Natrix natrix L.) specimens deposited in Swedish museum collections has declined in the last eighty years, and that this is correlated with a dramatic national decrease in the number of livestock holdings. These results support the hypothesis that Swedish grass snakes are declining and that this may be linked to a loss of important nesting-environments provided by open manure heaps in small-scale farming. Our study suggests that information obtained from museum databases potentially may be used to explore population trends for snakes and other reptiles.

Nyckelord
conservation, databases, manure heaps, museum mining, oviparity
Nationell ämneskategori
Ekologi
Forskningsämne
zoologisk ekologi
Identifikatorer
urn:nbn:se:su:diva-76915 (URN)000309893600012 ()
Tillgänglig från: 2012-05-24 Skapad: 2012-05-24 Senast uppdaterad: 2022-02-24Bibliografiskt granskad
Löwenborg, K., Gotthard, K. & Hagman, M. (2012). How a thermal dichotomy in nesting environments influences offspring of the world's most northerly oviparous snake, Natrix natrix (Colubridae). Biological Journal of the Linnean Society, 107(4), 833-844
Öppna denna publikation i ny flik eller fönster >>How a thermal dichotomy in nesting environments influences offspring of the world's most northerly oviparous snake, Natrix natrix (Colubridae)
2012 (Engelska)Ingår i: Biological Journal of the Linnean Society, ISSN 0024-4066, E-ISSN 1095-8312, Vol. 107, nr 4, s. 833-844Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Temperature has a major influence on the rate of embryonic development in ectothermic organisms. While incubation experiments unambiguously show that constant high temperature accelerates development and shortens embryonic life, studies on the effect of fluctuating temperatures have generated contradictory results. Grass snakes (Natrix natrix) occur at latitudes and altitudes that are unusually cool for an oviparous reptile. In these cool climates females typically lay their eggs in heat-generating anthropogenic microhabitats that provide either a highly fluctuating (compost piles) or a relatively constant (manure heaps) thermal nesting environment. A laboratory experiment with fluctuating and constant incubation temperatures mimicking those recorded in such nests in the field showed that this nest-site dichotomy influences the development of the embryos, and the morphology and locomotor performance of the hatchlings. The incubation period increased at fluctuating temperatures and the fact that the rate of embryonic development showed a decelerating pattern with temperature suggests that periods of low temperature had a relatively larger influence on average development than periods of high temperature. Our study demonstrates how a dichotomy in the nesting environments available to female grass snakes in cool climates can affect variation in the duration of the incubation period and offspring phenotypes in ways that may have consequences for fitness.

Nyckelord
compost, development, embryo, incubation, manure heap, phenotype, reptiles, thermal fluctuation
Nationell ämneskategori
Zoologi
Forskningsämne
zoologisk ekologi
Identifikatorer
urn:nbn:se:su:diva-84804 (URN)10.1111/j.1095-8312.2012.01972.x (DOI)000311404100009 ()
Forskningsfinansiär
A multiscale, cross‐disciplinary approach to the study of climate change effect on ecosystem services and biodiversityVetenskapsrådetForskningsrådet Formas
Anmärkning

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Tillgänglig från: 2013-01-02 Skapad: 2013-01-02 Senast uppdaterad: 2022-02-24Bibliografiskt granskad
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