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Byrd AJ, Talbott KM, Smiley TM, Verrett TB, Gross MS, Hladik ML, Ketterson ED, Becker DJ. Determinants of spring migration departure dates in a New World sparrow: Weather variables reign supreme. Ecol Evol 2024; 14:e10874. [PMID: 38390000 PMCID: PMC10883105 DOI: 10.1002/ece3.10874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 12/30/2023] [Accepted: 01/08/2024] [Indexed: 02/24/2024] Open
Abstract
Numerous factors influence the timing of spring migration in birds, yet the relative importance of intrinsic and extrinsic variables on migration initiation remains unclear. To test for interactions among weather, migration distance, parasitism, and physiology in determining spring departure date, we used the Dark-eyed Junco (Junco hyemalis) as a model migratory species known to harbor diverse and common haemosporidian parasites. Prior to spring migration departure from their wintering grounds in Indiana, USA, we quantified the intrinsic variables of fat, body condition (i.e., mass ~ tarsus residuals), physiological stress (i.e., ratio of heterophils to lymphocytes), cellular immunity (i.e., leukocyte composition and total count), migration distance (i.e., distance to the breeding grounds) using stable isotopes of hydrogen from feathers, and haemosporidian parasite intensity. We then attached nanotags to determine the timing of spring migration departure date using the Motus Wildlife Tracking System. We used additive Cox proportional hazard mixed models to test how risk of spring migratory departure was predicted by the combined intrinsic measures, along with meteorological predictors on the evening of departure (i.e., average wind speed and direction, relative humidity, and temperature). Model comparisons found that the best predictor of spring departure date was average nightly wind direction and a principal component combining relative humidity and temperature. Juncos were more likely to depart for spring migration on nights with largely southwestern winds and on warmer and drier evenings (relative to cooler and more humid evenings). Our results indicate that weather conditions at take-off are more critical to departure decisions than the measured physiological and parasitism variables.
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Affiliation(s)
- Allison J Byrd
- Environmental Resilience Institute Indiana University Bloomington Indiana USA
- Department of Biology Indiana University Bloomington Indiana USA
| | | | - Tara M Smiley
- Department of Ecology and Evolution Stony Brook University Stony Brook New York USA
| | - Taylor B Verrett
- School of Biological Sciences University of Oklahoma Norman Oklahoma USA
| | - Michael S Gross
- U.S. Geological Survey California Water Science Center Sacramento California USA
| | - Michelle L Hladik
- U.S. Geological Survey California Water Science Center Sacramento California USA
| | - Ellen D Ketterson
- Environmental Resilience Institute Indiana University Bloomington Indiana USA
- Department of Biology Indiana University Bloomington Indiana USA
| | - Daniel J Becker
- School of Biological Sciences University of Oklahoma Norman Oklahoma USA
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Kelly TR, Cannon AL, Stansberry KR, Kimball MG, Lattin CR. Changes in hypothalamic-pituitary-adrenal axis function, immunity, and glucose during acute Plasmodium relictum infection in house sparrows (Passer domesticus). Gen Comp Endocrinol 2024; 345:114388. [PMID: 37802425 DOI: 10.1016/j.ygcen.2023.114388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 10/02/2023] [Indexed: 10/10/2023]
Abstract
Hosts of the same species vary in physiological responses to the same parasite, and some groups of individuals can disproportionately affect disease dynamics; however, the underlying pathophysiology of host-parasite interactions is poorly understood in wildlife. We tested the hypothesis that the hypothalamic-pituitary-adrenal (HPA) axis mediates host resistance and tolerance to avian malaria during the acute phase of infection by evaluating whether individual variation in circulating glucocorticoids predicted resistance to avian malaria in a songbird. We experimentally inoculated wild-caught house sparrows (Passer domesticus) with naturally sourced Plasmodium relictum and quantified baseline and restraint-induced circulating corticosterone, negative feedback ability, cellular and humoral immune function, and baseline and restraint-induced glycemia, prior to and during acute malaria infection. During peak parasitemia, we also evaluated the expression of several liver cytokines that are established pathological hallmarks of malaria in mammals: two pro-inflammatory (IFN-γ and TNF-α) and two anti-inflammatory (IL-10 and TGF-β). Although most of the host metrics we evaluated were not correlated with host resistance or tolerance to avian malaria, this experiment revealed novel relationships between malarial parasites and the avian immune system that further our understanding of the pathology of malaria infection in birds. Specifically, we found that: (1) TNF-α liver expression was positively correlated with parasitemia; (2) sparrows exhibited an anti-inflammatory profile during malaria infection; and (3) IFN-γ and circulating glucose were associated with several immune parameters, but only in infected sparrows. We also found that, during the acute phase of infection, sparrows increased the strength of corticosterone negative feedback at the level of the pituitary. In the context of our results, we discuss future methodological considerations and aspects of host physiology that may confer resistance to avian malaria, which can help inform conservation and rehabilitation strategies for avifauna at risk.
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Affiliation(s)
- T R Kelly
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
| | - A L Cannon
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - K R Stansberry
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - M G Kimball
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - C R Lattin
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
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Kelly TR, Butnari AC, MacDougall-Shackleton EA, MacDougall-Shackleton SA. Rising to the Challenge: Mounting an Acute Phase Immune Response Has No Long-Term Negative Effects on Captive Sparrow Migratory Body Composition or Migratory Restlessness. Integr Comp Biol 2023; 63:1182-1196. [PMID: 37537146 DOI: 10.1093/icb/icad109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/10/2023] [Accepted: 07/15/2023] [Indexed: 08/05/2023] Open
Abstract
Migratory animals may trade-off between investing energy in immune defense versus investing in energy reserves needed for seasonal migration. However, these trade-offs are often masked by other sources of variation and may not be detected through observational field studies of free-living animals. Moreover, observational studies can rarely distinguish the costs of pathogenic infection from those of mounting an immune response. To disentangle such effects, we conducted an immune challenge experiment. We captured song sparrows (Melospiza melodia) and white-throated sparrows (Zonotrichia albicollis) in autumn migratory condition, challenged the sparrows with non-infectious antigens that induce an acute-phase immune response, then monitored body composition and migratory restlessness behavior. For both species, body mass was higher the day after exposure to keyhole limpet hemocyanin (KLH) compared to controls. White-throated sparrows, but not song sparrows, increased lean mass 1 week after exposure to lipopolysaccharide (LPS), suggesting that effects of immune upregulation on body composition may be long-lasting and specific to certain combinations of hosts and antigens. White-throated sparrows exposed to KLH increased nocturnal migratory restlessness (Zugunruhe) for the week following exposure. These findings suggest that short-term activation of the acute immune response does not constrain migratory physiology in these songbirds.
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Affiliation(s)
- T R Kelly
- Advanced Facility for Avian Research, University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada
| | - A C Butnari
- Advanced Facility for Avian Research, University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada
| | - E A MacDougall-Shackleton
- Advanced Facility for Avian Research, University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada
| | - S A MacDougall-Shackleton
- Advanced Facility for Avian Research, University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada
- Department of Psychology, University of Western Ontario, London, Ontario, N6A 5C2, Canada
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Schoepf I, Olson S, Moore IT, Bonier F. Experimental reduction of haemosporidian infection affects maternal reproductive investment, parental behaviour and offspring condition. Proc Biol Sci 2022; 289:20221978. [PMID: 36448284 PMCID: PMC9709520 DOI: 10.1098/rspb.2022.1978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/07/2022] [Indexed: 12/05/2022] Open
Abstract
When hosts have a long coevolutionary history with their parasites, fitness costs of chronic infection have often been assumed to be negligible. Yet, experimental manipulation of infections sometimes reveals effects of parasites on their hosts, particularly during reproduction. Whether these effects translate into fitness costs remains unclear. Here, we present the results of an experimental study conducted in a free-ranging population of red-winged blackbirds (Agelaius phoeniceus) naturally experiencing a high prevalence of haemosporidian infections, with more than 95% of breeding adults infected with parasites from one or more haemosporidian genus. To assess effects of infection during reproduction, we manipulated adult red-winged blackbird females' parasite burden by administering an anti-haemosporidian medication before onset of egg-laying. Experimental reduction of infection resulted in significant benefits to mothers and their offspring. Medicated females laid heavier clutches, invested more in incubation and provisioning behaviour, and produced more fledglings than control females. Nestlings of medicated females had higher haematocrit, higher blood glucose, and lower reactive oxygen metabolites than nestlings of control females. Overall, our results provide evidence that, even in a species with high prevalence of infection, parasites can lead to decreased maternal investment and offspring quality, substantially reducing fitness.
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Affiliation(s)
- Ivana Schoepf
- Biology Department, Queen's University, 116 Barrie Street, Kingston, Ontario, Canada K7L 3N6
- Department of Biological Sciences, Virginia Tech, 1405 Perry Street, Blacksburg, VA 24061, USA
- University of Alberta, Augustana Campus, 4901 46 Avenue, Camrose, Alberta, Canada T4V 2R3
| | - Sarena Olson
- Biology Department, Queen's University, 116 Barrie Street, Kingston, Ontario, Canada K7L 3N6
| | - Ignacio T. Moore
- Department of Biological Sciences, Virginia Tech, 1405 Perry Street, Blacksburg, VA 24061, USA
| | - Frances Bonier
- Biology Department, Queen's University, 116 Barrie Street, Kingston, Ontario, Canada K7L 3N6
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Bottini CLJ, Whiley RE, Branfireun BA, MacDougall-Shackleton SA. Effects of methylmercury and food stress on migratory activity in song sparrows, Melospiza melodia. Horm Behav 2022; 146:105261. [PMID: 36126358 DOI: 10.1016/j.yhbeh.2022.105261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 09/01/2022] [Accepted: 09/03/2022] [Indexed: 11/25/2022]
Abstract
Avian migration is a challenging life stage susceptible to the adverse effects of stressors, including contaminants like methylmercury (MeHg). Although birds often experience stressors and contaminants concurrently in the wild, no study to date has investigated how simultaneous exposure to MeHg and food stress affects migratory behavior. Our objectives were to determine if MeHg or food stress exposure during summer, alone or combined, has carry-over effects on autumn migratory activity, and if hormone levels (corticosterone, thyroxine) and body condition were related to these effects. We tested how exposure to dietary MeHg and/or food stress (unpredictable temporary food removal) affected migratory behavior in captive song sparrows, Melospiza melodia. Nocturnal activity was influenced by a 3-way interaction between MeHg × stress × nights of the study, indicating that activity changed over time in different ways depending on prior treatments. Thyroxine was not affected by treatment or sampling date. During the migratory season, fecal corticosterone metabolite concentrations increased in birds co-exposed to MeHg and food stress compared to controls, suggesting an additive carry-over effect. As well, during the period of behavioral recording, body condition increased with time in unstressed birds, but not in stressed birds. Fecal corticosterone metabolite concentrations were positively correlated to duration of nocturnal activity, but thyroxine levels and body condition were not. The differences in nocturnal activity between groups suggest that food stress and MeHg exposure on breeding grounds could have direct and indirect carry-over effects that have the potential to affect the fall migration journey.
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Affiliation(s)
- Claire L J Bottini
- University of Western Ontario, Department of Biology, 1151 Richmond St., London, Ontario N6A 5B7, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada.
| | - Rebecca E Whiley
- University of Western Ontario, Department of Biology, 1151 Richmond St., London, Ontario N6A 5B7, Canada; Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
| | - Brian A Branfireun
- University of Western Ontario, Department of Biology, 1151 Richmond St., London, Ontario N6A 5B7, Canada
| | - Scott A MacDougall-Shackleton
- Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada; University of Western Ontario, Department of Psychology, 1151 Richmond St., London, Ontario N6A 5C2, Canada
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Churchman E, MacDougall-Shackleton SA. Leptin administration does not influence migratory behaviour in white-throated sparrows ( Zonotrichia albicollis). PeerJ 2022; 10:e13584. [PMID: 35726262 PMCID: PMC9206435 DOI: 10.7717/peerj.13584] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 05/23/2022] [Indexed: 01/17/2023] Open
Abstract
Migratory flights by birds are among the most energetically demanding forms of animal movement, and are primarily fueled by fat as an energy source. Leptin is a critical fat-regulation hormone associated with energy balance in non-avian species but its function in birds is highly controversial. Prior research indicated the effects of leptin differed between birds in migratory condition or not, but no research has assessed the effect of leptin on migratory behaviour itself. In this study, our objective was to determine if leptin affects migratory restlessness and fat deposition in migratory songbirds. We used photoperiod manipulation to induce spring migratory condition, and measured migratory restlessness in leptin-injected and saline-injected white-throated sparrows (Zonotrichia albicollis). Leptin treatment had no effect on migratory restlessness nor fat deposition, providing evidence that leptin does not influence avian migratory motivation or behaviour. Our results also further support the idea that birds in a hyperphagic migratory condition may be insensitive to leptin.
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Affiliation(s)
- Emma Churchman
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Scott A. MacDougall-Shackleton
- Department of Biology, University of Western Ontario, London, Ontario, Canada,Department of Psychology, University of Western Ontario, London, Ontario, Canada,Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
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