The phrase "animals are speculated to" is correct and usable in written English.
It can be used when discussing theories or hypotheses regarding animal behavior, characteristics, or phenomena that are not definitively proven.
Example: "In recent studies, animals are speculated to possess a greater level of emotional intelligence than previously thought."
Alternatives: "It is believed that animals" or "Researchers suggest that animals".
Although the pathophysiology of migraine is not fully understood, cortical spreading depression (CSD), a depolarization wave that propagates across the brain cortex and activates the trigeminal nerve in animal models, is speculated to cause the neurological symptoms typical of migraine [7].
In animals, the process is speculated to be more complex: honeybees are able to fine tune signals directed at individuals within the hive that elicit highly specific behavioral changes in response to specific environmental cues (Wenner, 1962; Schneider and Lewis, 2004; Richard et al., 2012).
A wolf-like animal photographed in Eritrea in 2004 was speculated to be an Egyptian jackal [15].
Based on the nucleotide sequence, the virus is speculated to have evolved and been maintained in an animal host.
But the repercussions are also speculated to be vast.
But people are speculating.
Since DIO2 gene expression was increased in our study in resilient (nonanhedonic) mice or animals that received imipramine, it can be speculated that elevated synthesis of thyroid hormones in the hippocampus is associated with resilience to a depressive-like syndrome.
The reason for a few strains becoming predominant in a region or nation is not known, but it has been speculated that trade of animals can cause a certain genotype to become widespread [ 15] and that certain genotypes could also have specific traits that increase their chance of spread [ 17, 27].
In this study calves were euthanised for post mortem examination at 7 or 10 days post infection, therefore no booster antibody response could be detected but it can be speculated that the animals would have reacted with a booster response.
