Magnetic orientation and magnetoreception in birds and other animals

“Triplet products are chemically different from the singlet products and thus may play a role in magnetoreception (modified from Ritz et al. 2000) Hence the radical pair model can only apply to the magnetic compass of birds, amphibians and marine turtles (see Table 1).”

“When these fields were presented parallel to the geomagnetic vector, the birds were oriented in their migratory direction, whereas they were disoriented when the same fields were presented at an angle of 24 or 48 to the geomagnetic field (Fig. 10; Ritz et al. 2004; Thalau et al. 2005).”

“This phenomenon was described in birds as ‘inclination compass’: that is based on the inclination angle and provides information about the ‘poleward’ direction by an increase up to 90° inclination, and ‘equatorward’ direction by a decrease down to 0° inclination (Wiltschko and Wiltschko 2005).”

“As the magnetic fields were suggested to impose effects on organisms in a nonlinear way within a narrow functional range (Wiltschko and Wiltschko, 2005), the deflected flight orientation of the armyworm moths in the 1.”

“…systems based on iron minerals in birds are usually discussed as providing a magnetic component of the avian navigational ‘map’ system involved in determining its position with respect to a goal (e.g., Beason et al. 1997; Munro et al. 1997; Wiltschko and Wiltschko 2005; Fleissner et al. 2007).”

“Many animals rely on the Earth’s magnetic field for spatial orientation and navigation, especially migratory species of birds [1, 2] and pigeons [3], fish [4–6], insects [7, 8], sea turtles [9, 10], lobsters [11, 12], and bats [13, 14].”

“Orientation cues that can provide directional information on an earthwide scale are called compass cues, and there are two general types (Able, 2001; Wiltschko and Wiltschko, 2009): magnetic cues, based on the earth’s magnetic field (Wiltschko and Wiltschko, 2005; Walker, 1997; Wajnberg et al., 2010); and celestial cu…”

“One course topic, quantum biology, is less familiar and deserves further explanation here.”

“To find the correct course when traveling long distances, birds use different types of information, such as the sun and star compasses, the Earth’s magnetic field and the polarization pattern of the sky (Moore 1987; Ossenkopp and Barbeito 1978; Wiltschko and Wiltschko 2005).”

“All these and several other animal species are able to use magnetic cues for orientation [4,5].”

“Indeed, the intensity of the fastest time variations of the natural signal (erratic periodicity ranging from 0.1 s to a few minutes) is always 10 nT, which is lower then the accepted discrimination threshold of MR [Wiltschko and Wiltschko, 2005].”

“Behavioural experiments on animals—amphibians and birds in particular—have shown that their compass orienta- tion according to the geomagnetic Weld depended on the spectral composition of light under which the animals were tested (reviewed by Wiltschko and Wiltschko 1995, 2005).”

“Many animals are susceptible to the geomagnetic field and utilise this ability for their navigation [18].”

“Many vertebrates, such as migratory birds and sea turtles, have the ability to perceive the earth’s magnetic field (geomagnetic field, GMF) for positional and directional information during their longdistance migrations [Shaw et al., 2002; Wiltschko and Wiltschko, 2005].”

“A number of more recent studies show that, in addition to animal behavior (Wiltschko and Wiltschko 2005), the activity of the Sun and other related changes in the geophysical environment could affect human health and functions of the human body (Cornelissen et al.”

“Kirschvink et al. 2001; Ritz et al. 2002; Johnsen and Lohmann 2005; Wiltschko and Wiltschko 2005, 2006 ).”

“sensitivity, even in the dark, as a supplementary reference system for orientation, is of great adaptive value for orientation in migrating and non-migrating animals (for discussions concerning the physics and physiology of magneto-reception in urodeles, cf. Lohmann and Johnson 2000; Wiltschko and Wiltschko 2005; Schl…”

“Two separate receptor systems provide birds with magnetic information (see Wiltschko and Wiltschko 2005, 2007a; Mouritsen and Ritz 2005): a radical pair mechanism based on spin-correlated chemical reactions possibly located in the eye (Wiltschko et al. 2002) derives directional information from the magnetic Weld (Ritz…”

“Birds, salmonids, and hymenopteran insects all have known magnetoreceptive abilities (Wiltschko and Wiltschko, 2005; Lohmann et al., 2008; Wajnberg et al., 2010), and alongside any role in long distance navigation, these animals could also switch to a magnetic compass during short distance navigation if their primary…”

“Wiltschko W, Wiltschko R. 2005.”

“The avian magnetic inclination compass is light-dependent, requiring wavelengths between UV and green light (Wiltschko and Wiltschko 2005), and it is localized in the eye (Semm et al. 1984; Semm and Demaine 1986; Wiltschko et al. 2002, 2003; Mouritsen et al. 2005; Liedvogel et al. 2007; Heyers et…”

“Such receptors have only recently been localized and described structurally (Fleissner et al. 2003; Williams and Wild 2001; see also the recent review of Wiltschko and Wiltschko 2005 ).”

“…Thoss and Bartsch 2003; Thoss et al. 2000, 2002; Tian et al. 2007; Vargas et al. 2006; Walcott et al. 1988; Wallraff and Sinsch 1988; Wiltschko et al. 1993, 1994, 2003, 2004, 2006, 2008, 2010, 2013; Wiltschko and Wiltschko 1995, 2001, 2002, 2005, 2006, 2007; Wu and Dickman 2011; Yano et al. 1996).”

“Changes in the geomagnetic activity level are related to fluctuations in solar activity and are involved in climate regulation and various animals (Wiltschko and Wiltschko, 1995, 2005) and human behaviour (Babayev and Allahverdiyeva, 2007).”

“We anticipated that removal of power from the treated perch during the time when naive birds were in the cage could bias our results by (1) affording naive individuals immediate perch space on the treated perch, and before any recognition of potential risk-avoidance behaviour from exposed birds; and (2) elimination of…”

“Another major driver of migration is wayfinding factors such as magnetic field (e.g. Cain et al., 2005 ; Diebel et al., 2000 ; Keller et al., 2021 ; Wiltschko & Wiltschko, 2005 ) and olfactory cues (e.g. Durif et al., 2021 ; Koch et al., 1969 ), which regulate the route and accuracy of migration.”

“The most informative experimental paradigms have been used to verify true navigation capability that the animals are motivated to reach the goal locations by geomagnetic cues [10],[11].”

“Use of magnetic cues for spatial orientation has been demonstrated in multiple classes of vertebrates, as well as in a variety of invertebrates (for review see Wiltschko & Wiltschko, 2005).”

“Although, both magnetoreception mechanisms differ in their functional properties (Ritz et al. 2000, 2004, 2010; Wiltschko and Wiltschko 2005; Rodgers and Hore 2009), the available evidence demonstrates that both mechanisms are not necessarily mutually exclusive since at least birds (Wiltschko et…”

“Since the geomagnetic field is omnipresent, even within animal laboratories, and underlies CME-induced changes it is mechanistically understandable how solar activity can affect experimental animals, provided adequate receptor mechanisms exist (Wiltschko and Wiltschko 2005; Winklhofer, 2010).”

“The GMF is also a source of information for many organisms (mainly animals) whose abilities include magneto-detection and magneto-navigation (Wiltschko & Wiltschko, 2005; Brothers & Lohmann, 2015; Yosef et al., 2020).”

“We do know that insects, birds, sea turtles, fishes, and amphibians rely on magnetic compass information to point them in the right direction (Wiltschko and Wiltschko 1972, 2005; Lohmann and Lohmann 1993; Bottesch et al.”

“Magnetoreception is a much more widely distributed sense (Wiltschko & Wiltschko, 2005), with different physiological mechanisms possibly involved in sensing the magnitude, direction and inclination of the geomagnetic fi eld (Johnsen & Lohman, 2008).”

“Animals The experiments were run as previously described in an arena-like test situation (Schlegel 2006; Schlegel and Renner 2006; Merkel and Wiltschko 1966; reviewed by Wiltschko and Wiltschko 1995, 2003, 2005) (Table 1).”

“Experiments on magnetic field effects have been carried out on various living organisms, from bacteria to invertebrates to lower and higher vertebrates, including fishes (Kalmijn 1982; Kirschvink 1997; Valles 1998; Kirschvink et al. 2001; Wiltschko & Wiltschko 2005; Holland et al. 2008).”

“Over time, many organisms (insects, fishes, birds, and mammals) formed the ability to perceive and use geomagnetic field for daily activities, spatial orientation, and communication (Etheredge et al., 1999; Lucas and Baras, 2001; Wiltschko and Wiltschko, 2005; Kimchi and Terkel, 2001).”

“in the weak magnetic field of the Earth (about 50 μT) presents another well established effect [5,20,21].”

“Magnetic compass orientation has been demonstrated in a wide variety of animals (Wiltschko & Wiltschko 1995; Diego-Rasilla 2004; Wiltschko & Wiltschko 2005).”

“, detecting poleward and equatorward) (Wiltschko and Wiltschko 2005).”

“Pigeons, for example, use the position of the sun to navigate during migration periods [7].”

“…to the inclination, rather than polarity of the magnetic field, 2) disrupted by low-level radio-frequency fields in the MHz range, 3) affected by light, 4) and unaffected by pulse remagnetization treatments, all properties consistent with a radical-pair mechanism (Wiltschko & Wiltschko 2005).”

“As organisms have finite cognitive and computational resources, they must therefore multitask and develop optimal schemes to dynamically allocate resources to different tasks [1–6].”

“Many animal species rely on the GMF for migration purposes (for a review: Mouritsen 2018), most famously birds (for a review: Wiltschko and Wiltschko 2005) and sea turtles (e.g. Lohmann et al.”

“Dozens of experiments have now shown that diverse animal species, including bees, salmons, sea turtles and birds, have the ability to sense and utilize the Earth's magnetic field for orientation and migration over long distances (Wiltschko and Wiltschko, 1988; Wiltschko and Wiltschko, 2005).”

“Such a set of tested magnetic conditions on the assumption of the unimodal distribution of the preferred direction of motion allows for understanding which parameter of the external magnetic field (either polarity or inclination ) may be perceived by fish (Wiltschko and Wiltschko , 2005).”

“longer wavelengths on CRY activation, a proposal based on RPM theory of magnetoreception [21,22], remains to be determined.”

“…butter fl ies, salmon and migratory birds can sense and use GMF information to navigate long distances, nesting or burrowing (Kirschvink et al., 2001; Wiltschko and Wiltschko, 2005, 2006; Guerra et al., 2014; Hore and Mouritsen, 2016; Qin et al., 2016; Mouritsen, 2018; Wan et al., 2021; Xie, 2022).”

“These have shown that avian magnetoreception has certain characteristic features: (a) photo-initiation by a certain frequency of light [7,12], (b) dependence on only the inclination of the geomagnetic field [6], (c) disruption by radio-frequency (RF) fields of certain frequencies [9,11,13,14], (d) an adaptive selectiv…”

“Magnetoreception is the ability of birds and some other animals to detect the direction and intensity of Earth's magnetic field, and use it to navigate (Wiltschko & Wiltschko, 2005; Wiltschko & Wiltschko, 2019).”

“There are evidences that these migratory species can use the magnetic field of the Earth [3] [4] [5] [6], the polarization of sunlight [7], oceanic electric fields [8], as well as visual landmarks, olfactory cues, to navigate through the migration routes.”