Table 4.

List of published articles using both direct and indirect methods for characterizing magnetic particles in various animal groups/species and the techniques applied. A list of acronyms and abbreviated terms for specific techniques is provided in table 1. SD, single domain; SPM, superparamagnetic magnetite; P-SD, pseudo-single domain; H, head; Th, thorax; Ab, abdomen.

species	reported particle characteristics	material observed	techniques	location	reference
insects
Apis mellifera	100–900 nm granules	hydrous iron oxide (ferrihydrite)	LM, PB, TEM, EDS, SAED, Möss	Ab	[84]
	100–600 nm granules with SPM inclusions, an average density of 1.25 g cm−3	hydrous iron oxide with magnetite inclusions	LM, TEM, EDS, SQUID, EPR, AFM, MFM, ESCA	Ab	[85]
Bombus terrestris	SPM	magnetite, wuesite	SEM, EDS, VSM, Möss, XRD	H, wing	[80]
Nasutitermes exitiosus	10 nm SPM	ferrimagnetic material	TEM, Cryo mag	H, Th + Ab	[82]
Amitermes meridionalis
fish
Thunnus albacares	SD, mean size 45 × 38 nm ± 5 nm SE	magnetite	TEM, XRD, EDS, SQUID	H (dermethmoid tissue)	[86,87]
Oncorhynchus tshawytscha	SD chains	magnetite	TEM, XRD, SQUID	H (dermethmoid cartilage)	[88]
Salmo salar	SD 60–100 nm and 340–380 nm	magnetite	TEM, EDS, SQUID	lateral line	[89]
Anguilla anguilla	SD, mean 90 nm ± 40 nm	magnetite	TEM, EDS, SQUID	lateral line (mandibular)	[90]
birds
Columba liva	SD	magnetite	XRD, EDS, SQUID	H	[91]
	1–5 nm SPM particles in 1–3 µm clusters that form 200 µm elongate aggregates	magnetite	LM, PB, TEM, SAED, SQUID	upper beak	[64,92]
	SPM, 1–4 µm aggregates	magnetite	LM, PB, SQUID	upper beak	[93]
Dolichonyx oryzivorus	SD, P-SD	magnetite, other iron material present	LM, PB, TEM, SEM, EDS, spinner mag	H (various)	[94]
mammals
Homo sapiens	SD in 50–100 clumps	magnetite (5 M particles per g tissue estimated)	TEM, SAED, SQUID	brain	[95]
nematode
Caenorhabditis elegans	10 s of nm	magnetite	TEM, EELS, EFTEM, EDS, SQUID	whole	[96]